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Diffstat (limited to 'arch/tile/include/gxio/mpipe.h')
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diff --git a/arch/tile/include/gxio/mpipe.h b/arch/tile/include/gxio/mpipe.h new file mode 100644 index 000000000000..78c598618c97 --- /dev/null +++ b/arch/tile/include/gxio/mpipe.h @@ -0,0 +1,1736 @@ +/* + * Copyright 2012 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +#ifndef _GXIO_MPIPE_H_ +#define _GXIO_MPIPE_H_ + +/* + * + * An API for allocating, configuring, and manipulating mPIPE hardware + * resources. + */ + +#include "common.h" +#include "dma_queue.h" + +#include <linux/time.h> + +#include <arch/mpipe_def.h> +#include <arch/mpipe_shm.h> + +#include <hv/drv_mpipe_intf.h> +#include <hv/iorpc.h> + +/* + * + * The TILE-Gx mPIPE&tm; shim provides Ethernet connectivity, packet + * classification, and packet load balancing services. The + * gxio_mpipe_ API, declared in <gxio/mpipe.h>, allows applications to + * allocate mPIPE IO channels, configure packet distribution + * parameters, and send and receive Ethernet packets. The API is + * designed to be a minimal wrapper around the mPIPE hardware, making + * system calls only where necessary to preserve inter-process + * protection guarantees. + * + * The APIs described below allow the programmer to allocate and + * configure mPIPE resources. As described below, the mPIPE is a + * single shared hardware device that provides partitionable resources + * that are shared between all applications in the system. The + * gxio_mpipe_ API allows userspace code to make resource request + * calls to the hypervisor, which in turns keeps track of the + * resources in use by all applications, maintains protection + * guarantees, and resets resources upon application shutdown. + * + * We strongly recommend reading the mPIPE section of the IO Device + * Guide (UG404) before working with this API. Most functions in the + * gxio_mpipe_ API are directly analogous to hardware interfaces and + * the documentation assumes that the reader understands those + * hardware interfaces. + * + * @section mpipe__ingress mPIPE Ingress Hardware Resources + * + * The mPIPE ingress hardware provides extensive hardware offload for + * tasks like packet header parsing, load balancing, and memory + * management. This section provides a brief introduction to the + * hardware components and the gxio_mpipe_ calls used to manage them; + * see the IO Device Guide for a much more detailed description of the + * mPIPE's capabilities. + * + * When a packet arrives at one of the mPIPE's Ethernet MACs, it is + * assigned a channel number indicating which MAC received it. It + * then proceeds through the following hardware pipeline: + * + * @subsection mpipe__classification Classification + * + * A set of classification processors run header parsing code on each + * incoming packet, extracting information including the destination + * MAC address, VLAN, Ethernet type, and five-tuple hash. Some of + * this information is then used to choose which buffer stack will be + * used to hold the packet, and which bucket will be used by the load + * balancer to determine which application will receive the packet. + * + * The rules by which the buffer stack and bucket are chosen can be + * configured via the @ref gxio_mpipe_classifier API. A given app can + * specify multiple rules, each one specifying a bucket range, and a + * set of buffer stacks, to be used for packets matching the rule. + * Each rule can optionally specify a restricted set of channels, + * VLANs, and/or dMACs, in which it is interested. By default, a + * given rule starts out matching all channels associated with the + * mPIPE context's set of open links; all VLANs; and all dMACs. + * Subsequent restrictions can then be added. + * + * @subsection mpipe__load_balancing Load Balancing + * + * The mPIPE load balancer is responsible for choosing the NotifRing + * to which the packet will be delivered. This decision is based on + * the bucket number indicated by the classification program. In + * general, the bucket number is based on some number of low bits of + * the packet's flow hash (applications that aren't interested in flow + * hashing use a single bucket). Each load balancer bucket keeps a + * record of the NotifRing to which packets directed to that bucket + * are currently being delivered. Based on the bucket's load + * balancing mode (@ref gxio_mpipe_bucket_mode_t), the load balancer + * either forwards the packet to the previously assigned NotifRing or + * decides to choose a new NotifRing. If a new NotifRing is required, + * the load balancer chooses the least loaded ring in the NotifGroup + * associated with the bucket. + * + * The load balancer is a shared resource. Each application needs to + * explicitly allocate NotifRings, NotifGroups, and buckets, using + * gxio_mpipe_alloc_notif_rings(), gxio_mpipe_alloc_notif_groups(), + * and gxio_mpipe_alloc_buckets(). Then the application needs to + * configure them using gxio_mpipe_init_notif_ring() and + * gxio_mpipe_init_notif_group_and_buckets(). + * + * @subsection mpipe__buffers Buffer Selection and Packet Delivery + * + * Once the load balancer has chosen the destination NotifRing, the + * mPIPE DMA engine pops at least one buffer off of the 'buffer stack' + * chosen by the classification program and DMAs the packet data into + * that buffer. Each buffer stack provides a hardware-accelerated + * stack of data buffers with the same size. If the packet data is + * larger than the buffers provided by the chosen buffer stack, the + * mPIPE hardware pops off multiple buffers and chains the packet data + * through a multi-buffer linked list. Once the packet data is + * delivered to the buffer(s), the mPIPE hardware writes the + * ::gxio_mpipe_idesc_t metadata object (calculated by the classifier) + * into the NotifRing and increments the number of packets delivered + * to that ring. + * + * Applications can push buffers onto a buffer stack by calling + * gxio_mpipe_push_buffer() or by egressing a packet with the + * ::gxio_mpipe_edesc_t::hwb bit set, indicating that the egressed + * buffers should be returned to the stack. + * + * Applications can allocate and initialize buffer stacks with the + * gxio_mpipe_alloc_buffer_stacks() and gxio_mpipe_init_buffer_stack() + * APIs. + * + * The application must also register the memory pages that will hold + * packets. This requires calling gxio_mpipe_register_page() for each + * memory page that will hold packets allocated by the application for + * a given buffer stack. Since each buffer stack is limited to 16 + * registered pages, it may be necessary to use huge pages, or even + * extremely huge pages, to hold all the buffers. + * + * @subsection mpipe__iqueue NotifRings + * + * Each NotifRing is a region of shared memory, allocated by the + * application, to which the mPIPE delivers packet descriptors + * (::gxio_mpipe_idesc_t). The application can allocate them via + * gxio_mpipe_alloc_notif_rings(). The application can then either + * explicitly initialize them with gxio_mpipe_init_notif_ring() and + * then read from them manually, or can make use of the convenience + * wrappers provided by @ref gxio_mpipe_wrappers. + * + * @section mpipe__egress mPIPE Egress Hardware + * + * Applications use eDMA rings to queue packets for egress. The + * application can allocate them via gxio_mpipe_alloc_edma_rings(). + * The application can then either explicitly initialize them with + * gxio_mpipe_init_edma_ring() and then write to them manually, or + * can make use of the convenience wrappers provided by + * @ref gxio_mpipe_wrappers. + * + * @section gxio__shortcomings Plans for Future API Revisions + * + * The API defined here is only an initial version of the mPIPE API. + * Future plans include: + * + * - Higher level wrapper functions to provide common initialization + * patterns. This should help users start writing mPIPE programs + * without having to learn the details of the hardware. + * + * - Support for reset and deallocation of resources, including + * cleanup upon application shutdown. + * + * - Support for calling these APIs in the BME. + * + * - Support for IO interrupts. + * + * - Clearer definitions of thread safety guarantees. + * + * @section gxio__mpipe_examples Examples + * + * See the following mPIPE example programs for more information about + * allocating mPIPE resources and using them in real applications: + * + * - @ref mpipe/ingress/app.c : Receiving packets. + * + * - @ref mpipe/forward/app.c : Forwarding packets. + * + * Note that there are several more examples. + */ + +/* Flags that can be passed to resource allocation functions. */ +enum gxio_mpipe_alloc_flags_e { + /* Require an allocation to start at a specified resource index. */ + GXIO_MPIPE_ALLOC_FIXED = HV_MPIPE_ALLOC_FIXED, +}; + +/* Flags that can be passed to memory registration functions. */ +enum gxio_mpipe_mem_flags_e { + /* Do not fill L3 when writing, and invalidate lines upon egress. */ + GXIO_MPIPE_MEM_FLAG_NT_HINT = IORPC_MEM_BUFFER_FLAG_NT_HINT, + + /* L3 cache fills should only populate IO cache ways. */ + GXIO_MPIPE_MEM_FLAG_IO_PIN = IORPC_MEM_BUFFER_FLAG_IO_PIN, +}; + +/* An ingress packet descriptor. When a packet arrives, the mPIPE + * hardware generates this structure and writes it into a NotifRing. + */ +typedef MPIPE_PDESC_t gxio_mpipe_idesc_t; + +/* An egress command descriptor. Applications write this structure + * into eDMA rings and the hardware performs the indicated operation + * (normally involving egressing some bytes). Note that egressing a + * single packet may involve multiple egress command descriptors. + */ +typedef MPIPE_EDMA_DESC_t gxio_mpipe_edesc_t; + +/* Get the "va" field from an "idesc". + * + * This is the address at which the ingress hardware copied the first + * byte of the packet. + * + * If the classifier detected a custom header, then this will point to + * the custom header, and gxio_mpipe_idesc_get_l2_start() will point + * to the actual L2 header. + * + * Note that this value may be misleading if "idesc->be" is set. + * + * @param idesc An ingress packet descriptor. + */ +static inline unsigned char *gxio_mpipe_idesc_get_va(gxio_mpipe_idesc_t *idesc) +{ + return (unsigned char *)(long)idesc->va; +} + +/* Get the "xfer_size" from an "idesc". + * + * This is the actual number of packet bytes transferred into memory + * by the hardware. + * + * Note that this value may be misleading if "idesc->be" is set. + * + * @param idesc An ingress packet descriptor. + * + * ISSUE: Is this the best name for this? + * FIXME: Add more docs about chaining, clipping, etc. + */ +static inline unsigned int gxio_mpipe_idesc_get_xfer_size(gxio_mpipe_idesc_t + *idesc) +{ + return idesc->l2_size; +} + +/* Get the "l2_offset" from an "idesc". + * + * Extremely customized classifiers might not support this function. + * + * This is the number of bytes between the "va" and the L2 header. + * + * The L2 header consists of a destination mac address, a source mac + * address, and an initial ethertype. Various initial ethertypes + * allow encoding extra information in the L2 header, often including + * a vlan, and/or a new ethertype. + * + * Note that the "l2_offset" will be non-zero if (and only if) the + * classifier processed a custom header for the packet. + * + * @param idesc An ingress packet descriptor. + */ +static inline uint8_t gxio_mpipe_idesc_get_l2_offset(gxio_mpipe_idesc_t *idesc) +{ + return (idesc->custom1 >> 32) & 0xFF; +} + +/* Get the "l2_start" from an "idesc". + * + * This is simply gxio_mpipe_idesc_get_va() plus + * gxio_mpipe_idesc_get_l2_offset(). + * + * @param idesc An ingress packet descriptor. + */ +static inline unsigned char *gxio_mpipe_idesc_get_l2_start(gxio_mpipe_idesc_t + *idesc) +{ + unsigned char *va = gxio_mpipe_idesc_get_va(idesc); + return va + gxio_mpipe_idesc_get_l2_offset(idesc); +} + +/* Get the "l2_length" from an "idesc". + * + * This is simply gxio_mpipe_idesc_get_xfer_size() minus + * gxio_mpipe_idesc_get_l2_offset(). + * + * @param idesc An ingress packet descriptor. + */ +static inline unsigned int gxio_mpipe_idesc_get_l2_length(gxio_mpipe_idesc_t + *idesc) +{ + unsigned int xfer_size = idesc->l2_size; + return xfer_size - gxio_mpipe_idesc_get_l2_offset(idesc); +} + +/* A context object used to manage mPIPE hardware resources. */ +typedef struct { + + /* File descriptor for calling up to Linux (and thus the HV). */ + int fd; + + /* The VA at which configuration registers are mapped. */ + char *mmio_cfg_base; + + /* The VA at which IDMA, EDMA, and buffer manager are mapped. */ + char *mmio_fast_base; + + /* The "initialized" buffer stacks. */ + gxio_mpipe_rules_stacks_t __stacks; + +} gxio_mpipe_context_t; + +/* This is only used internally, but it's most easily made visible here. */ +typedef gxio_mpipe_context_t gxio_mpipe_info_context_t; + +/* Initialize an mPIPE context. + * + * This function allocates an mPIPE "service domain" and maps the MMIO + * registers into the caller's VA space. + * + * @param context Context object to be initialized. + * @param mpipe_instance Instance number of mPIPE shim to be controlled via + * context. + */ +extern int gxio_mpipe_init(gxio_mpipe_context_t *context, + unsigned int mpipe_instance); + +/* Destroy an mPIPE context. + * + * This function frees the mPIPE "service domain" and unmaps the MMIO + * registers from the caller's VA space. + * + * If a user process exits without calling this routine, the kernel + * will destroy the mPIPE context as part of process teardown. + * + * @param context Context object to be destroyed. + */ +extern int gxio_mpipe_destroy(gxio_mpipe_context_t *context); + +/***************************************************************** + * Buffer Stacks * + ******************************************************************/ + +/* Allocate a set of buffer stacks. + * + * The return value is NOT interesting if count is zero. + * + * @param context An initialized mPIPE context. + * @param count Number of stacks required. + * @param first Index of first stack if ::GXIO_MPIPE_ALLOC_FIXED flag is set, + * otherwise ignored. + * @param flags Flag bits from ::gxio_mpipe_alloc_flags_e. + * @return Index of first allocated buffer stack, or + * ::GXIO_MPIPE_ERR_NO_BUFFER_STACK if allocation failed. + */ +extern int gxio_mpipe_alloc_buffer_stacks(gxio_mpipe_context_t *context, + unsigned int count, + unsigned int first, + unsigned int flags); + +/* Enum codes for buffer sizes supported by mPIPE. */ +typedef enum { + /* 128 byte packet data buffer. */ + GXIO_MPIPE_BUFFER_SIZE_128 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_128, + /* 256 byte packet data buffer. */ + GXIO_MPIPE_BUFFER_SIZE_256 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_256, + /* 512 byte packet data buffer. */ + GXIO_MPIPE_BUFFER_SIZE_512 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_512, + /* 1024 byte packet data buffer. */ + GXIO_MPIPE_BUFFER_SIZE_1024 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_1024, + /* 1664 byte packet data buffer. */ + GXIO_MPIPE_BUFFER_SIZE_1664 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_1664, + /* 4096 byte packet data buffer. */ + GXIO_MPIPE_BUFFER_SIZE_4096 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_4096, + /* 10368 byte packet data buffer. */ + GXIO_MPIPE_BUFFER_SIZE_10368 = + MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_10368, + /* 16384 byte packet data buffer. */ + GXIO_MPIPE_BUFFER_SIZE_16384 = MPIPE_BSM_INIT_DAT_1__SIZE_VAL_BSZ_16384 +} gxio_mpipe_buffer_size_enum_t; + +/* Convert a buffer size in bytes into a buffer size enum. */ +extern gxio_mpipe_buffer_size_enum_t +gxio_mpipe_buffer_size_to_buffer_size_enum(size_t size); + +/* Convert a buffer size enum into a buffer size in bytes. */ +extern size_t +gxio_mpipe_buffer_size_enum_to_buffer_size(gxio_mpipe_buffer_size_enum_t + buffer_size_enum); + +/* Calculate the number of bytes required to store a given number of + * buffers in the memory registered with a buffer stack via + * gxio_mpipe_init_buffer_stack(). + */ +extern size_t gxio_mpipe_calc_buffer_stack_bytes(unsigned long buffers); + +/* Initialize a buffer stack. This function binds a region of memory + * to be used by the hardware for storing buffer addresses pushed via + * gxio_mpipe_push_buffer() or as the result of sending a buffer out + * the egress with the 'push to stack when done' bit set. Once this + * function returns, the memory region's contents may be arbitrarily + * modified by the hardware at any time and software should not access + * the memory region again. + * + * @param context An initialized mPIPE context. + * @param stack The buffer stack index. + * @param buffer_size_enum The size of each buffer in the buffer stack, + * as an enum. + * @param mem The address of the buffer stack. This memory must be + * physically contiguous and aligned to a 64kB boundary. + * @param mem_size The size of the buffer stack, in bytes. + * @param mem_flags ::gxio_mpipe_mem_flags_e memory flags. + * @return Zero on success, ::GXIO_MPIPE_ERR_INVAL_BUFFER_SIZE if + * buffer_size_enum is invalid, ::GXIO_MPIPE_ERR_BAD_BUFFER_STACK if + * stack has not been allocated. + */ +extern int gxio_mpipe_init_buffer_stack(gxio_mpipe_context_t *context, + unsigned int stack, + gxio_mpipe_buffer_size_enum_t + buffer_size_enum, void *mem, + size_t mem_size, + unsigned int mem_flags); + +/* Push a buffer onto a previously initialized buffer stack. + * + * The size of the buffer being pushed must match the size that was + * registered with gxio_mpipe_init_buffer_stack(). All packet buffer + * addresses are 128-byte aligned; the low 7 bits of the specified + * buffer address will be ignored. + * + * @param context An initialized mPIPE context. + * @param stack The buffer stack index. + * @param buffer The buffer (the low seven bits are ignored). + */ +static inline void gxio_mpipe_push_buffer(gxio_mpipe_context_t *context, + unsigned int stack, void *buffer) +{ + MPIPE_BSM_REGION_ADDR_t offset = { {0} }; + MPIPE_BSM_REGION_VAL_t val = { {0} }; + + /* + * The mmio_fast_base region starts at the IDMA region, so subtract + * off that initial offset. + */ + offset.region = + MPIPE_MMIO_ADDR__REGION_VAL_BSM - + MPIPE_MMIO_ADDR__REGION_VAL_IDMA; + offset.stack = stack; + +#if __SIZEOF_POINTER__ == 4 + val.va = ((ulong) buffer) >> MPIPE_BSM_REGION_VAL__VA_SHIFT; +#else + val.va = ((long)buffer) >> MPIPE_BSM_REGION_VAL__VA_SHIFT; +#endif + + __gxio_mmio_write(context->mmio_fast_base + offset.word, val.word); +} + +/* Pop a buffer off of a previously initialized buffer stack. + * + * @param context An initialized mPIPE context. + * @param stack The buffer stack index. + * @return The buffer, or NULL if the stack is empty. + */ +static inline void *gxio_mpipe_pop_buffer(gxio_mpipe_context_t *context, + unsigned int stack) +{ + MPIPE_BSM_REGION_ADDR_t offset = { {0} }; + + /* + * The mmio_fast_base region starts at the IDMA region, so subtract + * off that initial offset. + */ + offset.region = + MPIPE_MMIO_ADDR__REGION_VAL_BSM - + MPIPE_MMIO_ADDR__REGION_VAL_IDMA; + offset.stack = stack; + + while (1) { + /* + * Case 1: val.c == ..._UNCHAINED, va is non-zero. + * Case 2: val.c == ..._INVALID, va is zero. + * Case 3: val.c == ..._NOT_RDY, va is zero. + */ + MPIPE_BSM_REGION_VAL_t val; + val.word = + __gxio_mmio_read(context->mmio_fast_base + + offset.word); + + /* + * Handle case 1 and 2 by returning the buffer (or NULL). + * Handle case 3 by waiting for the prefetch buffer to refill. + */ + if (val.c != MPIPE_EDMA_DESC_WORD1__C_VAL_NOT_RDY) + return (void *)((unsigned long)val. + va << MPIPE_BSM_REGION_VAL__VA_SHIFT); + } +} + +/***************************************************************** + * NotifRings * + ******************************************************************/ + +/* Allocate a set of NotifRings. + * + * The return value is NOT interesting if count is zero. + * + * Note that NotifRings are allocated in chunks, so allocating one at + * a time is much less efficient than allocating several at once. + * + * @param context An initialized mPIPE context. + * @param count Number of NotifRings required. + * @param first Index of first NotifRing if ::GXIO_MPIPE_ALLOC_FIXED flag + * is set, otherwise ignored. + * @param flags Flag bits from ::gxio_mpipe_alloc_flags_e. + * @return Index of first allocated buffer NotifRing, or + * ::GXIO_MPIPE_ERR_NO_NOTIF_RING if allocation failed. + */ +extern int gxio_mpipe_alloc_notif_rings(gxio_mpipe_context_t *context, + unsigned int count, unsigned int first, + unsigned int flags); + +/* Initialize a NotifRing, using the given memory and size. + * + * @param context An initialized mPIPE context. + * @param ring The NotifRing index. + * @param mem A physically contiguous region of memory to be filled + * with a ring of ::gxio_mpipe_idesc_t structures. + * @param mem_size Number of bytes in the ring. Must be 128, 512, + * 2048, or 65536 * sizeof(gxio_mpipe_idesc_t). + * @param mem_flags ::gxio_mpipe_mem_flags_e memory flags. + * + * @return 0 on success, ::GXIO_MPIPE_ERR_BAD_NOTIF_RING or + * ::GXIO_ERR_INVAL_MEMORY_SIZE on failure. + */ +extern int gxio_mpipe_init_notif_ring(gxio_mpipe_context_t *context, + unsigned int ring, + void *mem, size_t mem_size, + unsigned int mem_flags); + +/* Configure an interrupt to be sent to a tile on incoming NotifRing + * traffic. Once an interrupt is sent for a particular ring, no more + * will be sent until gxio_mica_enable_notif_ring_interrupt() is called. + * + * @param context An initialized mPIPE context. + * @param x X coordinate of interrupt target tile. + * @param y Y coordinate of interrupt target tile. + * @param i Index of the IPI register which will receive the interrupt. + * @param e Specific event which will be set in the target IPI register when + * the interrupt occurs. + * @param ring The NotifRing index. + * @return Zero on success, GXIO_ERR_INVAL if params are out of range. + */ +extern int gxio_mpipe_request_notif_ring_interrupt(gxio_mpipe_context_t + *context, int x, int y, + int i, int e, + unsigned int ring); + +/* Enable an interrupt on incoming NotifRing traffic. + * + * @param context An initialized mPIPE context. + * @param ring The NotifRing index. + * @return Zero on success, GXIO_ERR_INVAL if params are out of range. + */ +extern int gxio_mpipe_enable_notif_ring_interrupt(gxio_mpipe_context_t + *context, unsigned int ring); + +/* Map all of a client's memory via the given IOTLB. + * @param context An initialized mPIPE context. + * @param iotlb IOTLB index. + * @param pte Page table entry. + * @param flags Flags. + * @return Zero on success, or a negative error code. + */ +extern int gxio_mpipe_register_client_memory(gxio_mpipe_context_t *context, + unsigned int iotlb, HV_PTE pte, + unsigned int flags); + +/***************************************************************** + * Notif Groups * + ******************************************************************/ + +/* Allocate a set of NotifGroups. + * + * The return value is NOT interesting if count is zero. + * + * @param context An initialized mPIPE context. + * @param count Number of NotifGroups required. + * @param first Index of first NotifGroup if ::GXIO_MPIPE_ALLOC_FIXED flag + * is set, otherwise ignored. + * @param flags Flag bits from ::gxio_mpipe_alloc_flags_e. + * @return Index of first allocated buffer NotifGroup, or + * ::GXIO_MPIPE_ERR_NO_NOTIF_GROUP if allocation failed. + */ +extern int gxio_mpipe_alloc_notif_groups(gxio_mpipe_context_t *context, + unsigned int count, + unsigned int first, + unsigned int flags); + +/* Add a NotifRing to a NotifGroup. This only sets a bit in the + * application's 'group' object; the hardware NotifGroup can be + * initialized by passing 'group' to gxio_mpipe_init_notif_group() or + * gxio_mpipe_init_notif_group_and_buckets(). + */ +static inline void +gxio_mpipe_notif_group_add_ring(gxio_mpipe_notif_group_bits_t *bits, int ring) +{ + bits->ring_mask[ring / 64] |= (1ull << (ring % 64)); +} + +/* Set a particular NotifGroup bitmask. Since the load balancer + * makes decisions based on both bucket and NotifGroup state, most + * applications should use gxio_mpipe_init_notif_group_and_buckets() + * rather than using this function to configure just a NotifGroup. + */ +extern int gxio_mpipe_init_notif_group(gxio_mpipe_context_t *context, + unsigned int group, + gxio_mpipe_notif_group_bits_t bits); + +/***************************************************************** + * Load Balancer * + ******************************************************************/ + +/* Allocate a set of load balancer buckets. + * + * The return value is NOT interesting if count is zero. + * + * Note that buckets are allocated in chunks, so allocating one at + * a time is much less efficient than allocating several at once. + * + * Note that the buckets are actually divided into two sub-ranges, of + * different sizes, and different chunk sizes, and the range you get + * by default is determined by the size of the request. Allocations + * cannot span the two sub-ranges. + * + * @param context An initialized mPIPE context. + * @param count Number of buckets required. + * @param first Index of first bucket if ::GXIO_MPIPE_ALLOC_FIXED flag is set, + * otherwise ignored. + * @param flags Flag bits from ::gxio_mpipe_alloc_flags_e. + * @return Index of first allocated buffer bucket, or + * ::GXIO_MPIPE_ERR_NO_BUCKET if allocation failed. + */ +extern int gxio_mpipe_alloc_buckets(gxio_mpipe_context_t *context, + unsigned int count, unsigned int first, + unsigned int flags); + +/* The legal modes for gxio_mpipe_bucket_info_t and + * gxio_mpipe_init_notif_group_and_buckets(). + * + * All modes except ::GXIO_MPIPE_BUCKET_ROUND_ROBIN expect that the user + * will allocate a power-of-two number of buckets and initialize them + * to the same mode. The classifier program then uses the appropriate + * number of low bits from the incoming packet's flow hash to choose a + * load balancer bucket. Based on that bucket's load balancing mode, + * reference count, and currently active NotifRing, the load balancer + * chooses the NotifRing to which the packet will be delivered. + */ +typedef enum { + /* All packets for a bucket go to the same NotifRing unless the + * NotifRing gets full, in which case packets will be dropped. If + * the bucket reference count ever reaches zero, a new NotifRing may + * be chosen. + */ + GXIO_MPIPE_BUCKET_DYNAMIC_FLOW_AFFINITY = + MPIPE_LBL_INIT_DAT_BSTS_TBL__MODE_VAL_DFA, + + /* All packets for a bucket always go to the same NotifRing. + */ + GXIO_MPIPE_BUCKET_STATIC_FLOW_AFFINITY = + MPIPE_LBL_INIT_DAT_BSTS_TBL__MODE_VAL_FIXED, + + /* All packets for a bucket go to the least full NotifRing in the + * group, providing load balancing round robin behavior. + */ + GXIO_MPIPE_BUCKET_ROUND_ROBIN = + MPIPE_LBL_INIT_DAT_BSTS_TBL__MODE_VAL_ALWAYS_PICK, + + /* All packets for a bucket go to the same NotifRing unless the + * NotifRing gets full, at which point the bucket starts using the + * least full NotifRing in the group. If all NotifRings in the + * group are full, packets will be dropped. + */ + GXIO_MPIPE_BUCKET_STICKY_FLOW_LOCALITY = + MPIPE_LBL_INIT_DAT_BSTS_TBL__MODE_VAL_STICKY, + + /* All packets for a bucket go to the same NotifRing unless the + * NotifRing gets full, or a random timer fires, at which point the + * bucket starts using the least full NotifRing in the group. If + * all NotifRings in the group are full, packets will be dropped. + * WARNING: This mode is BROKEN on chips with fewer than 64 tiles. + */ + GXIO_MPIPE_BUCKET_PREFER_FLOW_LOCALITY = + MPIPE_LBL_INIT_DAT_BSTS_TBL__MODE_VAL_STICKY_RAND, + +} gxio_mpipe_bucket_mode_t; + +/* Copy a set of bucket initialization values into the mPIPE + * hardware. Since the load balancer makes decisions based on both + * bucket and NotifGroup state, most applications should use + * gxio_mpipe_init_notif_group_and_buckets() rather than using this + * function to configure a single bucket. + * + * @param context An initialized mPIPE context. + * @param bucket Bucket index to be initialized. + * @param bucket_info Initial reference count, NotifRing index, and mode. + * @return 0 on success, ::GXIO_MPIPE_ERR_BAD_BUCKET on failure. + */ +extern int gxio_mpipe_init_bucket(gxio_mpipe_context_t *context, + unsigned int bucket, + gxio_mpipe_bucket_info_t bucket_info); + +/* Initializes a group and range of buckets and range of rings such + * that the load balancer runs a particular load balancing function. + * + * First, the group is initialized with the given rings. + * + * Second, each bucket is initialized with the mode and group, and a + * ring chosen round-robin from the given rings. + * + * Normally, the classifier picks a bucket, and then the load balancer + * picks a ring, based on the bucket's mode, group, and current ring, + * possibly updating the bucket's ring. + * + * @param context An initialized mPIPE context. + * @param group The group. + * @param ring The first ring. + * @param num_rings The number of rings. + * @param bucket The first bucket. + * @param num_buckets The number of buckets. + * @param mode The load balancing mode. + * + * @return 0 on success, ::GXIO_MPIPE_ERR_BAD_BUCKET, + * ::GXIO_MPIPE_ERR_BAD_NOTIF_GROUP, or + * ::GXIO_MPIPE_ERR_BAD_NOTIF_RING on failure. + */ +extern int gxio_mpipe_init_notif_group_and_buckets(gxio_mpipe_context_t + *context, + unsigned int group, + unsigned int ring, + unsigned int num_rings, + unsigned int bucket, + unsigned int num_buckets, + gxio_mpipe_bucket_mode_t + mode); + +/* Return credits to a NotifRing and/or bucket. + * + * @param context An initialized mPIPE context. + * @param ring The NotifRing index, or -1. + * @param bucket The bucket, or -1. + * @param count The number of credits to return. + */ +static inline void gxio_mpipe_credit(gxio_mpipe_context_t *context, + int ring, int bucket, unsigned int count) +{ + /* NOTE: Fancy struct initialization would break "C89" header test. */ + + MPIPE_IDMA_RELEASE_REGION_ADDR_t offset = { {0} }; + MPIPE_IDMA_RELEASE_REGION_VAL_t val = { {0} }; + + /* + * The mmio_fast_base region starts at the IDMA region, so subtract + * off that initial offset. + */ + offset.region = + MPIPE_MMIO_ADDR__REGION_VAL_IDMA - + MPIPE_MMIO_ADDR__REGION_VAL_IDMA; + offset.ring = ring; + offset.bucket = bucket; + offset.ring_enable = (ring >= 0); + offset.bucket_enable = (bucket >= 0); + val.count = count; + + __gxio_mmio_write(context->mmio_fast_base + offset.word, val.word); +} + +/***************************************************************** + * Egress Rings * + ******************************************************************/ + +/* Allocate a set of eDMA rings. + * + * The return value is NOT interesting if count is zero. + * + * @param context An initialized mPIPE context. + * @param count Number of eDMA rings required. + * @param first Index of first eDMA ring if ::GXIO_MPIPE_ALLOC_FIXED flag + * is set, otherwise ignored. + * @param flags Flag bits from ::gxio_mpipe_alloc_flags_e. + * @return Index of first allocated buffer eDMA ring, or + * ::GXIO_MPIPE_ERR_NO_EDMA_RING if allocation failed. + */ +extern int gxio_mpipe_alloc_edma_rings(gxio_mpipe_context_t *context, + unsigned int count, unsigned int first, + unsigned int flags); + +/* Initialize an eDMA ring, using the given memory and size. + * + * @param context An initialized mPIPE context. + * @param ring The eDMA ring index. + * @param channel The channel to use. This must be one of the channels + * associated with the context's set of open links. + * @param mem A physically contiguous region of memory to be filled + * with a ring of ::gxio_mpipe_edesc_t structures. + * @param mem_size Number of bytes in the ring. Must be 512, 2048, + * 8192 or 65536, times 16 (i.e. sizeof(gxio_mpipe_edesc_t)). + * @param mem_flags ::gxio_mpipe_mem_flags_e memory flags. + * + * @return 0 on success, ::GXIO_MPIPE_ERR_BAD_EDMA_RING or + * ::GXIO_ERR_INVAL_MEMORY_SIZE on failure. + */ +extern int gxio_mpipe_init_edma_ring(gxio_mpipe_context_t *context, + unsigned int ring, unsigned int channel, + void *mem, size_t mem_size, + unsigned int mem_flags); + +/***************************************************************** + * Classifier Program * + ******************************************************************/ + +/* + * + * Functions for loading or configuring the mPIPE classifier program. + * + * The mPIPE classification processors all run a special "classifier" + * program which, for each incoming packet, parses the packet headers, + * encodes some packet metadata in the "idesc", and either drops the + * packet, or picks a notif ring to handle the packet, and a buffer + * stack to contain the packet, usually based on the channel, VLAN, + * dMAC, flow hash, and packet size, under the guidance of the "rules" + * API described below. + * + * @section gxio_mpipe_classifier_default Default Classifier + * + * The MDE provides a simple "default" classifier program. It is + * shipped as source in "$TILERA_ROOT/src/sys/mpipe/classifier.c", + * which serves as its official documentation. It is shipped as a + * binary program in "$TILERA_ROOT/tile/boot/classifier", which is + * automatically included in bootroms created by "tile-monitor", and + * is automatically loaded by the hypervisor at boot time. + * + * The L2 analysis handles LLC packets, SNAP packets, and "VLAN + * wrappers" (keeping the outer VLAN). + * + * The L3 analysis handles IPv4 and IPv6, dropping packets with bad + * IPv4 header checksums, requesting computation of a TCP/UDP checksum + * if appropriate, and hashing the dest and src IP addresses, plus the + * ports for TCP/UDP packets, into the flow hash. No special analysis + * is done for "fragmented" packets or "tunneling" protocols. Thus, + * the first fragment of a fragmented TCP/UDP packet is hashed using + * src/dest IP address and ports and all subsequent fragments are only + * hashed according to src/dest IP address. + * + * The L3 analysis handles other packets too, hashing the dMAC + * smac into a flow hash. + * + * The channel, VLAN, and dMAC used to pick a "rule" (see the + * "rules" APIs below), which in turn is used to pick a buffer stack + * (based on the packet size) and a bucket (based on the flow hash). + * + * To receive traffic matching a particular (channel/VLAN/dMAC + * pattern, an application should allocate its own buffer stacks and + * load balancer buckets, and map traffic to those stacks and buckets, + * as decribed by the "rules" API below. + * + * Various packet metadata is encoded in the idesc. The flow hash is + * four bytes at 0x0C. The VLAN is two bytes at 0x10. The ethtype is + * two bytes at 0x12. The l3 start is one byte at 0x14. The l4 start + * is one byte at 0x15 for IPv4 and IPv6 packets, and otherwise zero. + * The protocol is one byte at 0x16 for IPv4 and IPv6 packets, and + * otherwise zero. + * + * @section gxio_mpipe_classifier_custom Custom Classifiers. + * + * A custom classifier may be created using "tile-mpipe-cc" with a + * customized version of the default classifier sources. + * + * The custom classifier may be included in bootroms using the + * "--classifier" option to "tile-monitor", or loaded dynamically + * using gxio_mpipe_classifier_load_from_file(). + * + * Be aware that "extreme" customizations may break the assumptions of + * the "rules" APIs described below, but simple customizations, such + * as adding new packet metadata, should be fine. + */ + +/* A set of classifier rules, plus a context. */ +typedef struct { + + /* The context. */ + gxio_mpipe_context_t *context; + + /* The actual rules. */ + gxio_mpipe_rules_list_t list; + +} gxio_mpipe_rules_t; + +/* Initialize a classifier program rules list. + * + * This function can be called on a previously initialized rules list + * to discard any previously added rules. + * + * @param rules Rules list to initialize. + * @param context An initialized mPIPE context. + */ +extern void gxio_mpipe_rules_init(gxio_mpipe_rules_t *rules, + gxio_mpipe_context_t *context); + +/* Begin a new rule on the indicated rules list. + * + * Note that an empty rule matches all packets, but an empty rule list + * matches no packets. + * + * @param rules Rules list to which new rule is appended. + * @param bucket First load balancer bucket to which packets will be + * delivered. + * @param num_buckets Number of buckets (must be a power of two) across + * which packets will be distributed based on the "flow hash". + * @param stacks Either NULL, to assign each packet to the smallest + * initialized buffer stack which does not induce chaining (and to + * drop packets which exceed the largest initialized buffer stack + * buffer size), or an array, with each entry indicating which buffer + * stack should be used for packets up to that size (with 255 + * indicating that those packets should be dropped). + * @return 0 on success, or a negative error code on failure. + */ +extern int gxio_mpipe_rules_begin(gxio_mpipe_rules_t *rules, + unsigned int bucket, + unsigned int num_buckets, + gxio_mpipe_rules_stacks_t *stacks); + +/* Set the headroom of the current rule. + * + * @param rules Rules list whose current rule will be modified. + * @param headroom The headroom. + * @return 0 on success, or a negative error code on failure. + */ +extern int gxio_mpipe_rules_set_headroom(gxio_mpipe_rules_t *rules, + uint8_t headroom); + +/* Indicate that packets from a particular channel can be delivered + * to the buckets and buffer stacks associated with the current rule. + * + * Channels added must be associated with links opened by the mPIPE context + * used in gxio_mpipe_rules_init(). A rule with no channels is equivalent + * to a rule naming all such associated channels. + * + * @param rules Rules list whose current rule will be modified. + * @param channel The channel to add. + * @return 0 on success, or a negative error code on failure. + */ +extern int gxio_mpipe_rules_add_channel(gxio_mpipe_rules_t *rules, + unsigned int channel); + +/* Commit rules. + * + * The rules are sent to the hypervisor, where they are combined with + * the rules from other apps, and used to program the hardware classifier. + * + * Note that if this function returns an error, then the rules will NOT + * have been committed, even if the error is due to interactions with + * rules from another app. + * + * @param rules Rules list to commit. + * @return 0 on success, or a negative error code on failure. + */ +extern int gxio_mpipe_rules_commit(gxio_mpipe_rules_t *rules); + +/***************************************************************** + * Ingress Queue Wrapper * + ******************************************************************/ + +/* + * + * Convenience functions for receiving packets from a NotifRing and + * sending packets via an eDMA ring. + * + * The mpipe ingress and egress hardware uses shared memory packet + * descriptors to describe packets that have arrived on ingress or + * are destined for egress. These descriptors are stored in shared + * memory ring buffers and written or read by hardware as necessary. + * The gxio library provides wrapper functions that manage the head and + * tail pointers for these rings, allowing the user to easily read or + * write packet descriptors. + * + * The initialization interface for ingress and egress rings is quite + * similar. For example, to create an ingress queue, the user passes + * a ::gxio_mpipe_iqueue_t state object, a ring number from + * gxio_mpipe_alloc_notif_rings(), and the address of memory to hold a + * ring buffer to the gxio_mpipe_iqueue_init() function. The function + * returns success when the state object has been initialized and the + * hardware configured to deliver packets to the specified ring + * buffer. Similarly, gxio_mpipe_equeue_init() takes a + * ::gxio_mpipe_equeue_t state object, a ring number from + * gxio_mpipe_alloc_edma_rings(), and a shared memory buffer. + * + * @section gxio_mpipe_iqueue Working with Ingress Queues + * + * Once initialized, the gxio_mpipe_iqueue_t API provides two flows + * for getting the ::gxio_mpipe_idesc_t packet descriptor associated + * with incoming packets. The simplest is to call + * gxio_mpipe_iqueue_get() or gxio_mpipe_iqueue_try_get(). These + * functions copy the oldest packet descriptor out of the NotifRing and + * into a descriptor provided by the caller. They also immediately + * inform the hardware that a descriptor has been processed. + * + * For applications with stringent performance requirements, higher + * efficiency can be achieved by avoiding the packet descriptor copy + * and processing multiple descriptors at once. The + * gxio_mpipe_iqueue_peek() and gxio_mpipe_iqueue_try_peek() functions + * allow such optimizations. These functions provide a pointer to the + * next valid ingress descriptor in the NotifRing's shared memory ring + * buffer, and a count of how many contiguous descriptors are ready to + * be processed. The application can then process any number of those + * descriptors in place, calling gxio_mpipe_iqueue_consume() to inform + * the hardware after each one has been processed. + * + * @section gxio_mpipe_equeue Working with Egress Queues + * + * Similarly, the egress queue API provides a high-performance + * interface plus a simple wrapper for use in posting + * ::gxio_mpipe_edesc_t egress packet descriptors. The simple + * version, gxio_mpipe_equeue_put(), allows the programmer to wait for + * an eDMA ring slot to become available and write a single descriptor + * into the ring. + * + * Alternatively, you can reserve slots in the eDMA ring using + * gxio_mpipe_equeue_reserve() or gxio_mpipe_equeue_try_reserve(), and + * then fill in each slot using gxio_mpipe_equeue_put_at(). This + * capability can be used to amortize the cost of reserving slots + * across several packets. It also allows gather operations to be + * performed on a shared equeue, by ensuring that the edescs for all + * the fragments are all contiguous in the eDMA ring. + * + * The gxio_mpipe_equeue_reserve() and gxio_mpipe_equeue_try_reserve() + * functions return a 63-bit "completion slot", which is actually a + * sequence number, the low bits of which indicate the ring buffer + * index and the high bits the number of times the application has + * gone around the egress ring buffer. The extra bits allow an + * application to check for egress completion by calling + * gxio_mpipe_equeue_is_complete() to see whether a particular 'slot' + * number has finished. Given the maximum packet rates of the Gx + * processor, the 63-bit slot number will never wrap. + * + * In practice, most applications use the ::gxio_mpipe_edesc_t::hwb + * bit to indicate that the buffers containing egress packet data + * should be pushed onto a buffer stack when egress is complete. Such + * applications generally do not need to know when an egress operation + * completes (since there is no need to free a buffer post-egress), + * and thus can use the optimized gxio_mpipe_equeue_reserve_fast() or + * gxio_mpipe_equeue_try_reserve_fast() functions, which return a 24 + * bit "slot", instead of a 63-bit "completion slot". + * + * Once a slot has been "reserved", it MUST be filled. If the + * application reserves a slot and then decides that it does not + * actually need it, it can set the ::gxio_mpipe_edesc_t::ns (no send) + * bit on the descriptor passed to gxio_mpipe_equeue_put_at() to + * indicate that no data should be sent. This technique can also be + * used to drop an incoming packet, instead of forwarding it, since + * any buffer will still be pushed onto the buffer stack when the + * egress descriptor is processed. + */ + +/* A convenient interface to a NotifRing, for use by a single thread. + */ +typedef struct { + + /* The context. */ + gxio_mpipe_context_t *context; + + /* The actual NotifRing. */ + gxio_mpipe_idesc_t *idescs; + + /* The number of entries. */ + unsigned long num_entries; + + /* The number of entries minus one. */ + unsigned long mask_num_entries; + + /* The log2() of the number of entries. */ + unsigned long log2_num_entries; + + /* The next entry. */ + unsigned int head; + + /* The NotifRing id. */ + unsigned int ring; + +#ifdef __BIG_ENDIAN__ + /* The number of byteswapped entries. */ + unsigned int swapped; +#endif + +} gxio_mpipe_iqueue_t; + +/* Initialize an "iqueue". + * + * Takes the iqueue plus the same args as gxio_mpipe_init_notif_ring(). + */ +extern int gxio_mpipe_iqueue_init(gxio_mpipe_iqueue_t *iqueue, + gxio_mpipe_context_t *context, + unsigned int ring, + void *mem, size_t mem_size, + unsigned int mem_flags); + +/* Advance over some old entries in an iqueue. + * + * Please see the documentation for gxio_mpipe_iqueue_consume(). + * + * @param iqueue An ingress queue initialized via gxio_mpipe_iqueue_init(). + * @param count The number of entries to advance over. + */ +static inline void gxio_mpipe_iqueue_advance(gxio_mpipe_iqueue_t *iqueue, + int count) +{ + /* Advance with proper wrap. */ + int head = iqueue->head + count; + iqueue->head = + (head & iqueue->mask_num_entries) + + (head >> iqueue->log2_num_entries); + +#ifdef __BIG_ENDIAN__ + /* HACK: Track swapped entries. */ + iqueue->swapped -= count; +#endif +} + +/* Release the ring and bucket for an old entry in an iqueue. + * + * Releasing the ring allows more packets to be delivered to the ring. + * + * Releasing the bucket allows flows using the bucket to be moved to a + * new ring when using GXIO_MPIPE_BUCKET_DYNAMIC_FLOW_AFFINITY. + * + * This function is shorthand for "gxio_mpipe_credit(iqueue->context, + * iqueue->ring, idesc->bucket_id, 1)", and it may be more convenient + * to make that underlying call, using those values, instead of + * tracking the entire "idesc". + * + * If packet processing is deferred, optimal performance requires that + * the releasing be deferred as well. + * + * Please see the documentation for gxio_mpipe_iqueue_consume(). + * + * @param iqueue An ingress queue initialized via gxio_mpipe_iqueue_init(). + * @param idesc The descriptor which was processed. + */ +static inline void gxio_mpipe_iqueue_release(gxio_mpipe_iqueue_t *iqueue, + gxio_mpipe_idesc_t *idesc) +{ + gxio_mpipe_credit(iqueue->context, iqueue->ring, idesc->bucket_id, 1); +} + +/* Consume a packet from an "iqueue". + * + * After processing packets peeked at via gxio_mpipe_iqueue_peek() + * or gxio_mpipe_iqueue_try_peek(), you must call this function, or + * gxio_mpipe_iqueue_advance() plus gxio_mpipe_iqueue_release(), to + * advance over those entries, and release their rings and buckets. + * + * You may call this function as each packet is processed, or you can + * wait until several packets have been processed. + * + * Note that if you are using a single bucket, and you are handling + * batches of N packets, then you can replace several calls to this + * function with calls to "gxio_mpipe_iqueue_advance(iqueue, N)" and + * "gxio_mpipe_credit(iqueue->context, iqueue->ring, bucket, N)". + * + * Note that if your classifier sets "idesc->nr", then you should + * explicitly call "gxio_mpipe_iqueue_advance(iqueue, idesc)" plus + * "gxio_mpipe_credit(iqueue->context, iqueue->ring, -1, 1)", to + * avoid incorrectly crediting the (unused) bucket. + * + * @param iqueue An ingress queue initialized via gxio_mpipe_iqueue_init(). + * @param idesc The descriptor which was processed. + */ +static inline void gxio_mpipe_iqueue_consume(gxio_mpipe_iqueue_t *iqueue, + gxio_mpipe_idesc_t *idesc) +{ + gxio_mpipe_iqueue_advance(iqueue, 1); + gxio_mpipe_iqueue_release(iqueue, idesc); +} + +/* Peek at the next packet(s) in an "iqueue", without waiting. + * + * If no packets are available, fills idesc_ref with NULL, and then + * returns ::GXIO_MPIPE_ERR_IQUEUE_EMPTY. Otherwise, fills idesc_ref + * with the address of the next valid packet descriptor, and returns + * the maximum number of valid descriptors which can be processed. + * You may process fewer descriptors if desired. + * + * Call gxio_mpipe_iqueue_consume() on each packet once it has been + * processed (or dropped), to allow more packets to be delivered. + * + * @param iqueue An ingress queue initialized via gxio_mpipe_iqueue_init(). + * @param idesc_ref A pointer to a packet descriptor pointer. + * @return The (positive) number of packets which can be processed, + * or ::GXIO_MPIPE_ERR_IQUEUE_EMPTY if no packets are available. + */ +static inline int gxio_mpipe_iqueue_try_peek(gxio_mpipe_iqueue_t *iqueue, + gxio_mpipe_idesc_t **idesc_ref) +{ + gxio_mpipe_idesc_t *next; + + uint64_t head = iqueue->head; + uint64_t tail = __gxio_mmio_read(iqueue->idescs); + + /* Available entries. */ + uint64_t avail = + (tail >= head) ? (tail - head) : (iqueue->num_entries - head); + + if (avail == 0) { + *idesc_ref = NULL; + return GXIO_MPIPE_ERR_IQUEUE_EMPTY; + } + + next = &iqueue->idescs[head]; + + /* ISSUE: Is this helpful? */ + __insn_prefetch(next); + +#ifdef __BIG_ENDIAN__ + /* HACK: Swap new entries directly in memory. */ + { + int i, j; + for (i = iqueue->swapped; i < avail; i++) { + for (j = 0; j < 8; j++) + next[i].words[j] = + __builtin_bswap64(next[i].words[j]); + } + iqueue->swapped = avail; + } +#endif + + *idesc_ref = next; + + return avail; +} + +/* Drop a packet by pushing its buffer (if appropriate). + * + * NOTE: The caller must still call gxio_mpipe_iqueue_consume() if idesc + * came from gxio_mpipe_iqueue_try_peek() or gxio_mpipe_iqueue_peek(). + * + * @param iqueue An ingress queue initialized via gxio_mpipe_iqueue_init(). + * @param idesc A packet descriptor. + */ +static inline void gxio_mpipe_iqueue_drop(gxio_mpipe_iqueue_t *iqueue, + gxio_mpipe_idesc_t *idesc) +{ + /* FIXME: Handle "chaining" properly. */ + + if (!idesc->be) { + unsigned char *va = gxio_mpipe_idesc_get_va(idesc); + gxio_mpipe_push_buffer(iqueue->context, idesc->stack_idx, va); + } +} + +/***************************************************************** + * Egress Queue Wrapper * + ******************************************************************/ + +/* A convenient, thread-safe interface to an eDMA ring. */ +typedef struct { + + /* State object for tracking head and tail pointers. */ + __gxio_dma_queue_t dma_queue; + + /* The ring entries. */ + gxio_mpipe_edesc_t *edescs; + + /* The number of entries minus one. */ + unsigned long mask_num_entries; + + /* The log2() of the number of entries. */ + unsigned long log2_num_entries; + +} gxio_mpipe_equeue_t; + +/* Initialize an "equeue". + * + * Takes the equeue plus the same args as gxio_mpipe_init_edma_ring(). + */ +extern int gxio_mpipe_equeue_init(gxio_mpipe_equeue_t *equeue, + gxio_mpipe_context_t *context, + unsigned int edma_ring_id, + unsigned int channel, + void *mem, unsigned int mem_size, + unsigned int mem_flags); + +/* Reserve completion slots for edescs. + * + * Use gxio_mpipe_equeue_put_at() to actually populate the slots. + * + * This function is slower than gxio_mpipe_equeue_reserve_fast(), but + * returns a full 64 bit completion slot, which can be used with + * gxio_mpipe_equeue_is_complete(). + * + * @param equeue An egress queue initialized via gxio_mpipe_equeue_init(). + * @param num Number of slots to reserve (must be non-zero). + * @return The first reserved completion slot, or a negative error code. + */ +static inline int64_t gxio_mpipe_equeue_reserve(gxio_mpipe_equeue_t *equeue, + unsigned int num) +{ + return __gxio_dma_queue_reserve_aux(&equeue->dma_queue, num, true); +} + +/* Reserve completion slots for edescs, if possible. + * + * Use gxio_mpipe_equeue_put_at() to actually populate the slots. + * + * This function is slower than gxio_mpipe_equeue_try_reserve_fast(), + * but returns a full 64 bit completion slot, which can be used with + * gxio_mpipe_equeue_is_complete(). + * + * @param equeue An egress queue initialized via gxio_mpipe_equeue_init(). + * @param num Number of slots to reserve (must be non-zero). + * @return The first reserved completion slot, or a negative error code. + */ +static inline int64_t gxio_mpipe_equeue_try_reserve(gxio_mpipe_equeue_t + *equeue, unsigned int num) +{ + return __gxio_dma_queue_reserve_aux(&equeue->dma_queue, num, false); +} + +/* Reserve slots for edescs. + * + * Use gxio_mpipe_equeue_put_at() to actually populate the slots. + * + * This function is faster than gxio_mpipe_equeue_reserve(), but + * returns a 24 bit slot (instead of a 64 bit completion slot), which + * thus cannot be used with gxio_mpipe_equeue_is_complete(). + * + * @param equeue An egress queue initialized via gxio_mpipe_equeue_init(). + * @param num Number of slots to reserve (should be non-zero). + * @return The first reserved slot, or a negative error code. + */ +static inline int64_t gxio_mpipe_equeue_reserve_fast(gxio_mpipe_equeue_t + *equeue, unsigned int num) +{ + return __gxio_dma_queue_reserve(&equeue->dma_queue, num, true, false); +} + +/* Reserve slots for edescs, if possible. + * + * Use gxio_mpipe_equeue_put_at() to actually populate the slots. + * + * This function is faster than gxio_mpipe_equeue_try_reserve(), but + * returns a 24 bit slot (instead of a 64 bit completion slot), which + * thus cannot be used with gxio_mpipe_equeue_is_complete(). + * + * @param equeue An egress queue initialized via gxio_mpipe_equeue_init(). + * @param num Number of slots to reserve (should be non-zero). + * @return The first reserved slot, or a negative error code. + */ +static inline int64_t gxio_mpipe_equeue_try_reserve_fast(gxio_mpipe_equeue_t + *equeue, + unsigned int num) +{ + return __gxio_dma_queue_reserve(&equeue->dma_queue, num, false, false); +} + +/* + * HACK: This helper function tricks gcc 4.6 into avoiding saving + * a copy of "edesc->words[0]" on the stack for no obvious reason. + */ + +static inline void gxio_mpipe_equeue_put_at_aux(gxio_mpipe_equeue_t *equeue, + uint_reg_t ew[2], + unsigned long slot) +{ + unsigned long edma_slot = slot & equeue->mask_num_entries; + gxio_mpipe_edesc_t *edesc_p = &equeue->edescs[edma_slot]; + + /* + * ISSUE: Could set eDMA ring to be on generation 1 at start, which + * would avoid the negation here, perhaps allowing "__insn_bfins()". + */ + ew[0] |= !((slot >> equeue->log2_num_entries) & 1); + + /* + * NOTE: We use "__gxio_mpipe_write()", plus the fact that the eDMA + * queue alignment restrictions ensure that these two words are on + * the same cacheline, to force proper ordering between the stores. + */ + __gxio_mmio_write64(&edesc_p->words[1], ew[1]); + __gxio_mmio_write64(&edesc_p->words[0], ew[0]); +} + +/* Post an edesc to a given slot in an equeue. + * + * This function copies the supplied edesc into entry "slot mod N" in + * the underlying ring, setting the "gen" bit to the appropriate value + * based on "(slot mod N*2)", where "N" is the size of the ring. Note + * that the higher bits of slot are unused, and thus, this function + * can handle "slots" as well as "completion slots". + * + * Normally this function is used to fill in slots reserved by + * gxio_mpipe_equeue_try_reserve(), gxio_mpipe_equeue_reserve(), + * gxio_mpipe_equeue_try_reserve_fast(), or + * gxio_mpipe_equeue_reserve_fast(), + * + * This function can also be used without "reserving" slots, if the + * application KNOWS that the ring can never overflow, for example, by + * pushing fewer buffers into the buffer stacks than there are total + * slots in the equeue, but this is NOT recommended. + * + * @param equeue An egress queue initialized via gxio_mpipe_equeue_init(). + * @param edesc The egress descriptor to be posted. + * @param slot An egress slot (only the low bits are actually used). + */ +static inline void gxio_mpipe_equeue_put_at(gxio_mpipe_equeue_t *equeue, + gxio_mpipe_edesc_t edesc, + unsigned long slot) +{ + gxio_mpipe_equeue_put_at_aux(equeue, edesc.words, slot); +} + +/* Post an edesc to the next slot in an equeue. + * + * This is a convenience wrapper around + * gxio_mpipe_equeue_reserve_fast() and gxio_mpipe_equeue_put_at(). + * + * @param equeue An egress queue initialized via gxio_mpipe_equeue_init(). + * @param edesc The egress descriptor to be posted. + * @return 0 on success. + */ +static inline int gxio_mpipe_equeue_put(gxio_mpipe_equeue_t *equeue, + gxio_mpipe_edesc_t edesc) +{ + int64_t slot = gxio_mpipe_equeue_reserve_fast(equeue, 1); + if (slot < 0) + return (int)slot; + + gxio_mpipe_equeue_put_at(equeue, edesc, slot); + + return 0; +} + +/* Ask the mPIPE hardware to egress outstanding packets immediately. + * + * This call is not necessary, but may slightly reduce overall latency. + * + * Technically, you should flush all gxio_mpipe_equeue_put_at() writes + * to memory before calling this function, to ensure the descriptors + * are visible in memory before the mPIPE hardware actually looks for + * them. But this should be very rare, and the only side effect would + * be increased latency, so it is up to the caller to decide whether + * or not to flush memory. + * + * @param equeue An egress queue initialized via gxio_mpipe_equeue_init(). + */ +static inline void gxio_mpipe_equeue_flush(gxio_mpipe_equeue_t *equeue) +{ + /* Use "ring_idx = 0" and "count = 0" to "wake up" the eDMA ring. */ + MPIPE_EDMA_POST_REGION_VAL_t val = { {0} }; + /* Flush the write buffers. */ + __insn_flushwb(); + __gxio_mmio_write(equeue->dma_queue.post_region_addr, val.word); +} + +/* Determine if a given edesc has been completed. + * + * Note that this function requires a "completion slot", and thus may + * NOT be used with a "slot" from gxio_mpipe_equeue_reserve_fast() or + * gxio_mpipe_equeue_try_reserve_fast(). + * + * @param equeue An egress queue initialized via gxio_mpipe_equeue_init(). + * @param completion_slot The completion slot used by the edesc. + * @param update If true, and the desc does not appear to have completed + * yet, then update any software cache of the hardware completion counter, + * and check again. This should normally be true. + * @return True iff the given edesc has been completed. + */ +static inline int gxio_mpipe_equeue_is_complete(gxio_mpipe_equeue_t *equeue, + int64_t completion_slot, + int update) +{ + return __gxio_dma_queue_is_complete(&equeue->dma_queue, + completion_slot, update); +} + +/***************************************************************** + * Link Management * + ******************************************************************/ + +/* + * + * Functions for manipulating and sensing the state and configuration + * of physical network links. + * + * @section gxio_mpipe_link_perm Link Permissions + * + * Opening a link (with gxio_mpipe_link_open()) requests a set of link + * permissions, which control what may be done with the link, and potentially + * what permissions may be granted to other processes. + * + * Data permission allows the process to receive packets from the link by + * specifying the link's channel number in mPIPE packet distribution rules, + * and to send packets to the link by using the link's channel number as + * the target for an eDMA ring. + * + * Stats permission allows the process to retrieve link attributes (such as + * the speeds it is capable of running at, or whether it is currently up), and + * to read and write certain statistics-related registers in the link's MAC. + * + * Control permission allows the process to retrieve and modify link attributes + * (so that it may, for example, bring the link up and take it down), and + * read and write many registers in the link's MAC and PHY. + * + * Any permission may be requested as shared, which allows other processes + * to also request shared permission, or exclusive, which prevents other + * processes from requesting it. In keeping with GXIO's typical usage in + * an embedded environment, the defaults for all permissions are shared. + * + * Permissions are granted on a first-come, first-served basis, so if two + * applications request an exclusive permission on the same link, the one + * to run first will win. Note, however, that some system components, like + * the kernel Ethernet driver, may get an opportunity to open links before + * any applications run. + * + * @section gxio_mpipe_link_names Link Names + * + * Link names are of the form gbe<em>number</em> (for Gigabit Ethernet), + * xgbe<em>number</em> (for 10 Gigabit Ethernet), loop<em>number</em> (for + * internal mPIPE loopback), or ilk<em>number</em>/<em>channel</em> + * (for Interlaken links); for instance, gbe0, xgbe1, loop3, and + * ilk0/12 are all possible link names. The correspondence between + * the link name and an mPIPE instance number or mPIPE channel number is + * system-dependent; all links will not exist on all systems, and the set + * of numbers used for a particular link type may not start at zero and may + * not be contiguous. Use gxio_mpipe_link_enumerate() to retrieve the set of + * links which exist on a system, and always use gxio_mpipe_link_instance() + * to determine which mPIPE controls a particular link. + * + * Note that in some cases, links may share hardware, such as PHYs, or + * internal mPIPE buffers; in these cases, only one of the links may be + * opened at a time. This is especially common with xgbe and gbe ports, + * since each xgbe port uses 4 SERDES lanes, each of which may also be + * configured as one gbe port. + * + * @section gxio_mpipe_link_states Link States + * + * The mPIPE link management model revolves around three different states, + * which are maintained for each link: + * + * 1. The <em>current</em> link state: is the link up now, and if so, at + * what speed? + * + * 2. The <em>desired</em> link state: what do we want the link state to be? + * The system is always working to make this state the current state; + * thus, if the desired state is up, and the link is down, we'll be + * constantly trying to bring it up, automatically. + * + * 3. The <em>possible</em> link state: what speeds are valid for this + * particular link? Or, in other words, what are the capabilities of + * the link hardware? + * + * These link states are not, strictly speaking, related to application + * state; they may be manipulated at any time, whether or not the link + * is currently being used for data transfer. However, for convenience, + * gxio_mpipe_link_open() and gxio_mpipe_link_close() (or application exit) + * can affect the link state. These implicit link management operations + * may be modified or disabled by the use of link open flags. + * + * From an application, you can use gxio_mpipe_link_get_attr() + * and gxio_mpipe_link_set_attr() to manipulate the link states. + * gxio_mpipe_link_get_attr() with ::GXIO_MPIPE_LINK_POSSIBLE_STATE + * gets you the possible link state. gxio_mpipe_link_get_attr() with + * ::GXIO_MPIPE_LINK_CURRENT_STATE gets you the current link state. + * Finally, gxio_mpipe_link_set_attr() and gxio_mpipe_link_get_attr() + * with ::GXIO_MPIPE_LINK_DESIRED_STATE allow you to modify or retrieve + * the desired link state. + * + * If you want to manage a link from a part of your application which isn't + * involved in packet processing, you can use the ::GXIO_MPIPE_LINK_NO_DATA + * flags on a gxio_mpipe_link_open() call. This opens the link, but does + * not request data permission, so it does not conflict with any exclusive + * permissions which may be held by other processes. You can then can use + * gxio_mpipe_link_get_attr() and gxio_mpipe_link_set_attr() on this link + * object to bring up or take down the link. + * + * Some links support link state bits which support various loopback + * modes. ::GXIO_MPIPE_LINK_LOOP_MAC tests datapaths within the Tile + * Processor itself; ::GXIO_MPIPE_LINK_LOOP_PHY tests the datapath between + * the Tile Processor and the external physical layer interface chip; and + * ::GXIO_MPIPE_LINK_LOOP_EXT tests the entire network datapath with the + * aid of an external loopback connector. In addition to enabling hardware + * testing, such configuration can be useful for software testing, as well. + * + * When LOOP_MAC or LOOP_PHY is enabled, packets transmitted on a channel + * will be received by that channel, instead of being emitted on the + * physical link, and packets received on the physical link will be ignored. + * Other than that, all standard GXIO operations work as you might expect. + * Note that loopback operation requires that the link be brought up using + * one or more of the GXIO_MPIPE_LINK_SPEED_xxx link state bits. + * + * Those familiar with previous versions of the MDE on TILEPro hardware + * will notice significant similarities between the NetIO link management + * model and the mPIPE link management model. However, the NetIO model + * was developed in stages, and some of its features -- for instance, + * the default setting of certain flags -- were shaped by the need to be + * compatible with previous versions of NetIO. Since the features provided + * by the mPIPE hardware and the mPIPE GXIO library are significantly + * different than those provided by NetIO, in some cases, we have made + * different choices in the mPIPE link management API. Thus, please read + * this documentation carefully before assuming that mPIPE link management + * operations are exactly equivalent to their NetIO counterparts. + */ + +/* An object used to manage mPIPE link state and resources. */ +typedef struct { + /* The overall mPIPE context. */ + gxio_mpipe_context_t *context; + + /* The channel number used by this link. */ + uint8_t channel; + + /* The MAC index used by this link. */ + uint8_t mac; +} gxio_mpipe_link_t; + +/* Retrieve one of this system's legal link names, and its MAC address. + * + * @param index Link name index. If a system supports N legal link names, + * then indices between 0 and N - 1, inclusive, each correspond to one of + * those names. Thus, to retrieve all of a system's legal link names, + * call this function in a loop, starting with an index of zero, and + * incrementing it once per iteration until -1 is returned. + * @param link_name Pointer to the buffer which will receive the retrieved + * link name. The buffer should contain space for at least + * ::GXIO_MPIPE_LINK_NAME_LEN bytes; the returned name, including the + * terminating null byte, will be no longer than that. + * @param link_name Pointer to the buffer which will receive the retrieved + * MAC address. The buffer should contain space for at least 6 bytes. + * @return Zero if a link name was successfully retrieved; -1 if one was + * not. + */ +extern int gxio_mpipe_link_enumerate_mac(int index, char *link_name, + uint8_t *mac_addr); + +/* Open an mPIPE link. + * + * A link must be opened before it may be used to send or receive packets, + * and before its state may be examined or changed. Depending up on the + * link's intended use, one or more link permissions may be requested via + * the flags parameter; see @ref gxio_mpipe_link_perm. In addition, flags + * may request that the link's state be modified at open time. See @ref + * gxio_mpipe_link_states and @ref gxio_mpipe_link_open_flags for more detail. + * + * @param link A link state object, which will be initialized if this + * function completes successfully. + * @param context An initialized mPIPE context. + * @param link_name Name of the link. + * @param flags Zero or more @ref gxio_mpipe_link_open_flags, ORed together. + * @return 0 if the link was successfully opened, or a negative error code. + * + */ +extern int gxio_mpipe_link_open(gxio_mpipe_link_t *link, + gxio_mpipe_context_t *context, + const char *link_name, unsigned int flags); + +/* Close an mPIPE link. + * + * Closing a link makes it available for use by other processes. Once + * a link has been closed, packets may no longer be sent on or received + * from the link, and its state may not be examined or changed. + * + * @param link A link state object, which will no longer be initialized + * if this function completes successfully. + * @return 0 if the link was successfully closed, or a negative error code. + * + */ +extern int gxio_mpipe_link_close(gxio_mpipe_link_t *link); + +/* Return a link's channel number. + * + * @param link A properly initialized link state object. + * @return The channel number for the link. + */ +static inline int gxio_mpipe_link_channel(gxio_mpipe_link_t *link) +{ + return link->channel; +} + +/////////////////////////////////////////////////////////////////// +// Timestamp // +/////////////////////////////////////////////////////////////////// + +/* Get the timestamp of mPIPE when this routine is called. + * + * @param context An initialized mPIPE context. + * @param ts A timespec structure to store the current clock. + * @return If the call was successful, zero; otherwise, a negative error + * code. + */ +extern int gxio_mpipe_get_timestamp(gxio_mpipe_context_t *context, + struct timespec *ts); + +/* Set the timestamp of mPIPE. + * + * @param context An initialized mPIPE context. + * @param ts A timespec structure to store the requested clock. + * @return If the call was successful, zero; otherwise, a negative error + * code. + */ +extern int gxio_mpipe_set_timestamp(gxio_mpipe_context_t *context, + const struct timespec *ts); + +/* Adjust the timestamp of mPIPE. + * + * @param context An initialized mPIPE context. + * @param delta A signed time offset to adjust, in nanoseconds. + * The absolute value of this parameter must be less than or + * equal to 1000000000. + * @return If the call was successful, zero; otherwise, a negative error + * code. + */ +extern int gxio_mpipe_adjust_timestamp(gxio_mpipe_context_t *context, + int64_t delta); + +#endif /* !_GXIO_MPIPE_H_ */ |
