rar: Move the RAR driver into the right place as its now clean

We exit staging rar! rar! rar!...

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 694 insertions, 0 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 724b2ed1a3cb..2f173bc0ff05 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -539,6 +539,28 @@ config INTEL_SCU_IPC
 	  some embedded Intel x86 platforms. This is not needed for PC-type
 	  machines.
 
+config RAR_REGISTER
+	bool "Restricted Access Region Register Driver"
+	depends on PCI && X86_MRST
+	default n
+	---help---
+	  This driver allows other kernel drivers access to the
+	  contents of the restricted access region control registers.
+
+	  The restricted access region control registers
+	  (rar_registers) are used to pass address and
+	  locking information on restricted access regions
+	  to other drivers that use restricted access regions.
+
+	  The restricted access regions are regions of memory
+	  on the Intel MID Platform that are not accessible to
+	  the x86 processor, but are accessible to dedicated
+	  processors on board peripheral devices.
+
+	  The purpose of the restricted access regions is to
+	  protect sensitive data from compromise by unauthorized
+	  programs running on the x86 processor.
+
 config INTEL_IPS
 	tristate "Intel Intelligent Power Sharing"
 	depends on ACPI
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 7318fc2c1629..ed50eca1b556 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -26,4 +26,5 @@ obj-$(CONFIG_TOPSTAR_LAPTOP)	+= topstar-laptop.o
 obj-$(CONFIG_ACPI_TOSHIBA)	+= toshiba_acpi.o
 obj-$(CONFIG_TOSHIBA_BT_RFKILL)	+= toshiba_bluetooth.o
 obj-$(CONFIG_INTEL_SCU_IPC)	+= intel_scu_ipc.o
+obj-$(CONFIG_RAR_REGISTER)	+= intel_rar_register.o
 obj-$(CONFIG_INTEL_IPS)		+= intel_ips.o
diff --git a/drivers/platform/x86/intel_rar_register.c b/drivers/platform/x86/intel_rar_register.c
new file mode 100644
index 000000000000..73f8e6d72669
--- /dev/null
+++ b/drivers/platform/x86/intel_rar_register.c
@@ -0,0 +1,671 @@
+/*
+ *  rar_register.c - An Intel Restricted Access Region register driver
+ *
+ *  Copyright(c) 2009 Intel 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; either version 2 of the
+ *  License, or (at your option) any later version.
+ *
+ *  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.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ *  02111-1307, USA.
+ *
+ * -------------------------------------------------------------------
+ *  20091204 Mark Allyn <mark.a.allyn@intel.com>
+ *	     Ossama Othman <ossama.othman@intel.com>
+ *	Cleanup per feedback from Alan Cox and Arjan Van De Ven
+ *
+ *  20090806 Ossama Othman <ossama.othman@intel.com>
+ *      Return zero high address if upper 22 bits is zero.
+ *      Cleaned up checkpatch errors.
+ *      Clarified that driver is dealing with bus addresses.
+ *
+ *  20090702 Ossama Othman <ossama.othman@intel.com>
+ *      Removed unnecessary include directives
+ *      Cleaned up spinlocks.
+ *      Cleaned up logging.
+ *      Improved invalid parameter checks.
+ *      Fixed and simplified RAR address retrieval and RAR locking
+ *      code.
+ *
+ *  20090626 Mark Allyn <mark.a.allyn@intel.com>
+ *      Initial publish
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/rar_register.h>
+
+/* === Lincroft Message Bus Interface === */
+#define LNC_MCR_OFFSET		0xD0	/* Message Control Register */
+#define LNC_MDR_OFFSET		0xD4	/* Message Data Register */
+
+/* Message Opcodes */
+#define LNC_MESSAGE_READ_OPCODE	0xD0
+#define LNC_MESSAGE_WRITE_OPCODE 0xE0
+
+/* Message Write Byte Enables */
+#define LNC_MESSAGE_BYTE_WRITE_ENABLES	0xF
+
+/* B-unit Port */
+#define LNC_BUNIT_PORT	0x3
+
+/* === Lincroft B-Unit Registers - Programmed by IA32 firmware === */
+#define LNC_BRAR0L	0x10
+#define LNC_BRAR0H	0x11
+#define LNC_BRAR1L	0x12
+#define LNC_BRAR1H	0x13
+/* Reserved for SeP */
+#define LNC_BRAR2L	0x14
+#define LNC_BRAR2H	0x15
+
+/* Moorestown supports three restricted access regions. */
+#define MRST_NUM_RAR 3
+
+/* RAR Bus Address Range */
+struct rar_addr {
+	dma_addr_t low;
+	dma_addr_t high;
+};
+
+/*
+ *	We create one of these for each RAR
+ */
+struct client {
+	int (*callback)(unsigned long data);
+	unsigned long driver_priv;
+	bool busy;
+};
+
+static DEFINE_MUTEX(rar_mutex);
+static DEFINE_MUTEX(lnc_reg_mutex);
+
+/*
+ *	One per RAR device (currently only one device)
+ */
+struct rar_device {
+	struct rar_addr rar_addr[MRST_NUM_RAR];
+	struct pci_dev *rar_dev;
+	bool registered;
+	bool allocated;
+	struct client client[MRST_NUM_RAR];
+};
+
+/* Current platforms have only one rar_device for 3 rar regions */
+static struct rar_device my_rar_device;
+
+/*
+ *	Abstract out multiple device support. Current platforms only
+ *	have a single RAR device.
+ */
+
+/**
+ *	alloc_rar_device	-	return a new RAR structure
+ *
+ *	Return a new (but not yet ready) RAR device object
+ */
+static struct rar_device *alloc_rar_device(void)
+{
+	if (my_rar_device.allocated)
+		return NULL;
+	my_rar_device.allocated = 1;
+	return &my_rar_device;
+}
+
+/**
+ *	free_rar_device		-	free a RAR object
+ *	@rar: the RAR device being freed
+ *
+ *	Release a RAR object and any attached resources
+ */
+static void free_rar_device(struct rar_device *rar)
+{
+	pci_dev_put(rar->rar_dev);
+	rar->allocated = 0;
+}
+
+/**
+ *	_rar_to_device		-	return the device handling this RAR
+ *	@rar: RAR number
+ *	@off: returned offset
+ *
+ *	Internal helper for looking up RAR devices. This and alloc are the
+ *	two functions that need touching to go to multiple RAR devices.
+ */
+static struct rar_device *_rar_to_device(int rar, int *off)
+{
+	if (rar >= 0 && rar <= 3) {
+		*off = rar;
+		return &my_rar_device;
+	}
+	return NULL;
+}
+
+/**
+ *	rar_to_device		-	return the device handling this RAR
+ *	@rar: RAR number
+ *	@off: returned offset
+ *
+ *	Return the device this RAR maps to if one is present, otherwise
+ *	returns NULL. Reports the offset relative to the base of this
+ *	RAR device in off.
+ */
+static struct rar_device *rar_to_device(int rar, int *off)
+{
+	struct rar_device *rar_dev = _rar_to_device(rar, off);
+	if (rar_dev == NULL || !rar_dev->registered)
+		return NULL;
+	return rar_dev;
+}
+
+/**
+ *	rar_to_client		-	return the client handling this RAR
+ *	@rar: RAR number
+ *
+ *	Return the client this RAR maps to if a mapping is known, otherwise
+ *	returns NULL.
+ */
+static struct client *rar_to_client(int rar)
+{
+	int idx;
+	struct rar_device *r = _rar_to_device(rar, &idx);
+	if (r != NULL)
+		return &r->client[idx];
+	return NULL;
+}
+
+/**
+ *	rar_read_addr		-	retrieve a RAR mapping
+ *	@pdev: PCI device for the RAR
+ *	@offset: offset for message
+ *	@addr: returned address
+ *
+ *	Reads the address of a given RAR register. Returns 0 on success
+ *	or an error code on failure.
+ */
+static int rar_read_addr(struct pci_dev *pdev, int offset, dma_addr_t *addr)
+{
+	/*
+	 * ======== The Lincroft Message Bus Interface ========
+	 * Lincroft registers may be obtained via PCI from
+	 * the host bridge using the Lincroft Message Bus
+	 * Interface.  That message bus interface is generally
+	 * comprised of two registers: a control register (MCR, 0xDO)
+	 * and a data register (MDR, 0xD4).
+	 *
+	 * The MCR (message control register) format is the following:
+	 *   1.  [31:24]: Opcode
+	 *   2.  [23:16]: Port
+	 *   3.  [15:8]: Register Offset
+	 *   4.  [7:4]: Byte Enables (use 0xF to set all of these bits
+	 *              to 1)
+	 *   5.  [3:0]: reserved
+	 *
+	 *  Read (0xD0) and write (0xE0) opcodes are written to the
+	 *  control register when reading and writing to Lincroft
+	 *  registers, respectively.
+	 *
+	 *  We're interested in registers found in the Lincroft
+	 *  B-unit.  The B-unit port is 0x3.
+	 *
+	 *  The six B-unit RAR register offsets we use are listed
+	 *  earlier in this file.
+	 *
+	 *  Lastly writing to the MCR register requires the "Byte
+	 *  enables" bits to be set to 1.  This may be achieved by
+	 *  writing 0xF at bit 4.
+	 *
+	 * The MDR (message data register) format is the following:
+	 *   1. [31:0]: Read/Write Data
+	 *
+	 *  Data being read from this register is only available after
+	 *  writing the appropriate control message to the MCR
+	 *  register.
+	 *
+	 *  Data being written to this register must be written before
+	 *  writing the appropriate control message to the MCR
+	 *  register.
+	*/
+
+	int result;
+	u32 addr32;
+
+	/* Construct control message */
+	u32 const message =
+		 (LNC_MESSAGE_READ_OPCODE << 24)
+		 | (LNC_BUNIT_PORT << 16)
+		 | (offset << 8)
+		 | (LNC_MESSAGE_BYTE_WRITE_ENABLES << 4);
+
+	dev_dbg(&pdev->dev, "Offset for 'get' LNC MSG is %x\n", offset);
+
+	/*
+	* We synchronize access to the Lincroft MCR and MDR registers
+	* until BOTH the command is issued through the MCR register
+	* and the corresponding data is read from the MDR register.
+	* Otherwise a race condition would exist between accesses to
+	* both registers.
+	*/
+
+	mutex_lock(&lnc_reg_mutex);
+
+	/* Send the control message */
+	result = pci_write_config_dword(pdev, LNC_MCR_OFFSET, message);
+	if (!result) {
+		/* Read back the address as a 32bit value */
+		result = pci_read_config_dword(pdev, LNC_MDR_OFFSET, &addr32);
+		*addr = (dma_addr_t)addr32;
+	}
+	mutex_unlock(&lnc_reg_mutex);
+	return result;
+}
+
+/**
+ *	rar_set_addr		-	Set a RAR mapping
+ *	@pdev: PCI device for the RAR
+ *	@offset: offset for message
+ *	@addr: address to set
+ *
+ *	Sets the address of a given RAR register. Returns 0 on success
+ *	or an error code on failure.
+ */
+static int rar_set_addr(struct pci_dev *pdev,
+	int offset,
+	dma_addr_t addr)
+{
+	/*
+	* Data being written to this register must be written before
+	* writing the appropriate control message to the MCR
+	* register.
+	* See rar_get_addrs() for a description of the
+	* message bus interface being used here.
+	*/
+
+	int result;
+
+	/* Construct control message */
+	u32 const message = (LNC_MESSAGE_WRITE_OPCODE << 24)
+		| (LNC_BUNIT_PORT << 16)
+		| (offset << 8)
+		| (LNC_MESSAGE_BYTE_WRITE_ENABLES << 4);
+
+	/*
+	* We synchronize access to the Lincroft MCR and MDR registers
+	* until BOTH the command is issued through the MCR register
+	* and the corresponding data is read from the MDR register.
+	* Otherwise a race condition would exist between accesses to
+	* both registers.
+	*/
+
+	mutex_lock(&lnc_reg_mutex);
+
+	/* Send the control message */
+	result = pci_write_config_dword(pdev, LNC_MDR_OFFSET, addr);
+	if (!result)
+		/* And address */
+		result = pci_write_config_dword(pdev, LNC_MCR_OFFSET, message);
+
+	mutex_unlock(&lnc_reg_mutex);
+	return result;
+}
+
+/*
+ *	rar_init_params		-	Initialize RAR parameters
+ *	@rar: RAR device to initialise
+ *
+ *	Initialize RAR parameters, such as bus addresses, etc. Returns 0
+ *	on success, or an error code on failure.
+ */
+static int init_rar_params(struct rar_device *rar)
+{
+	struct pci_dev *pdev = rar->rar_dev;
+	unsigned int i;
+	int result = 0;
+	int offset = 0x10;	/* RAR 0 to 2 in order low/high/low/high/... */
+
+	/* Retrieve RAR start and end bus addresses.
+	* Access the RAR registers through the Lincroft Message Bus
+	* Interface on PCI device: 00:00.0 Host bridge.
+	*/
+
+	for (i = 0; i < MRST_NUM_RAR; ++i) {
+		struct rar_addr *addr = &rar->rar_addr[i];
+
+		result = rar_read_addr(pdev, offset++, &addr->low);
+		if (result != 0)
+			return result;
+
+		result = rar_read_addr(pdev, offset++, &addr->high);
+		if (result != 0)
+			return result;
+
+
+		/*
+		* Only the upper 22 bits of the RAR addresses are
+		* stored in their corresponding RAR registers so we
+		* must set the lower 10 bits accordingly.
+
+		* The low address has its lower 10 bits cleared, and
+		* the high address has all its lower 10 bits set,
+		* e.g.:
+		* low = 0x2ffffc00
+		*/
+
+		addr->low &= (dma_addr_t)0xfffffc00u;
+
+		/*
+		* Set bits 9:0 on uppser address if bits 31:10 are non
+		* zero; otherwize clear all bits
+		*/
+
+		if ((addr->high & 0xfffffc00u) == 0)
+			addr->high = 0;
+		else
+			addr->high |= 0x3ffu;
+	}
+	/* Done accessing the device. */
+
+	if (result == 0) {
+		for (i = 0; i != MRST_NUM_RAR; ++i) {
+			/*
+			* "BRAR" refers to the RAR registers in the
+			* Lincroft B-unit.
+			*/
+			dev_info(&pdev->dev, "BRAR[%u] bus address range = "
+			  "[%lx, %lx]\n", i,
+			  (unsigned long)rar->rar_addr[i].low,
+			  (unsigned long)rar->rar_addr[i].high);
+		}
+	}
+	return result;
+}
+
+/**
+ *	rar_get_address		-	get the bus address in a RAR
+ *	@start: return value of start address of block
+ *	@end: return value of end address of block
+ *
+ *	The rar_get_address function is used by other device drivers
+ *	to obtain RAR address information on a RAR. It takes three
+ *	parameters:
+ *
+ *	The function returns a 0 upon success or an error if there is no RAR
+ *	facility on this system.
+ */
+int rar_get_address(int rar_index, dma_addr_t *start, dma_addr_t *end)
+{
+	int idx;
+	struct rar_device *rar = rar_to_device(rar_index, &idx);
+
+	if (rar == NULL) {
+		WARN_ON(1);
+		return -ENODEV;
+	}
+
+	*start = rar->rar_addr[idx].low;
+	*end = rar->rar_addr[idx].high;
+	return 0;
+}
+EXPORT_SYMBOL(rar_get_address);
+
+/**
+ *	rar_lock	-	lock a RAR register
+ *	@rar_index: RAR to lock (0-2)
+ *
+ *	The rar_lock function is ued by other device drivers to lock an RAR.
+ *	once a RAR is locked, it stays locked until the next system reboot.
+ *
+ *	The function returns a 0 upon success or an error if there is no RAR
+ *	facility on this system, or the locking fails
+ */
+int rar_lock(int rar_index)
+{
+	struct rar_device *rar;
+	int result;
+	int idx;
+	dma_addr_t low, high;
+
+	rar = rar_to_device(rar_index, &idx);
+
+	if (rar == NULL) {
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	low = rar->rar_addr[idx].low & 0xfffffc00u;
+	high = rar->rar_addr[idx].high & 0xfffffc00u;
+
+	/*
+	* Only allow I/O from the graphics and Langwell;
+	* not from the x86 processor
+	*/
+
+	if (rar_index == RAR_TYPE_VIDEO) {
+		low |= 0x00000009;
+		high |= 0x00000015;
+	} else if (rar_index == RAR_TYPE_AUDIO) {
+		/* Only allow I/O from Langwell; nothing from x86 */
+		low |= 0x00000008;
+		high |= 0x00000018;
+	} else
+		/* Read-only from all agents */
+		high |= 0x00000018;
+
+	/*
+	* Now program the register using the Lincroft message
+	* bus interface.
+	*/
+	result = rar_set_addr(rar->rar_dev,
+				2 * idx, low);
+
+	if (result == 0)
+		result = rar_set_addr(rar->rar_dev,
+				2 * idx + 1, high);
+
+	return result;
+}
+EXPORT_SYMBOL(rar_lock);
+
+/**
+ *	register_rar		-	register a RAR handler
+ *	@num: RAR we wish to register for
+ *	@callback: function to call when RAR support is available
+ *	@data: data to pass to this function
+ *
+ *	The register_rar function is to used by other device drivers
+ *	to ensure that this driver is ready. As we cannot be sure of
+ *	the compile/execute order of drivers in ther kernel, it is
+ *	best to give this driver a callback function to call when
+ *	it is ready to give out addresses. The callback function
+ *	would have those steps that continue the initialization of
+ *	a driver that do require a valid RAR address. One of those
+ *	steps would be to call rar_get_address()
+ *
+ *	This function return 0 on success or an error code on failure.
+ */
+int register_rar(int num, int (*callback)(unsigned long data),
+							unsigned long data)
+{
+	/* For now we hardcode a single RAR device */
+	struct rar_device *rar;
+	struct client *c;
+	int idx;
+	int retval = 0;
+
+	mutex_lock(&rar_mutex);
+
+	/* Do we have a client mapping for this RAR number ? */
+	c = rar_to_client(num);
+	if (c == NULL) {
+		retval = -ERANGE;
+		goto done;
+	}
+	/* Is it claimed ? */
+	if (c->busy) {
+		retval = -EBUSY;
+		goto done;
+	}
+	c->busy = 1;
+
+	/* See if we have a handler for this RAR yet, if we do then fire it */
+	rar = rar_to_device(num, &idx);
+
+	if (rar) {
+		/*
+		* if the driver already registered, then we can simply
+		* call the callback right now
+		*/
+		(*callback)(data);
+		goto done;
+	}
+
+	/* Arrange to be called back when the hardware is found */
+	c->callback = callback;
+	c->driver_priv = data;
+done:
+	mutex_unlock(&rar_mutex);
+	return retval;
+}
+EXPORT_SYMBOL(register_rar);
+
+/**
+ *	unregister_rar	-	release a RAR allocation
+ *	@num: RAR number
+ *
+ *	Releases a RAR allocation, or pending allocation. If a callback is
+ *	pending then this function will either complete before the unregister
+ *	returns or not at all.
+ */
+
+void unregister_rar(int num)
+{
+	struct client *c;
+
+	mutex_lock(&rar_mutex);
+	c = rar_to_client(num);
+	if (c == NULL || !c->busy)
+		WARN_ON(1);
+	else
+		c->busy = 0;
+	mutex_unlock(&rar_mutex);
+}
+EXPORT_SYMBOL(unregister_rar);
+
+/**
+ *	rar_callback		-	Process callbacks
+ *	@rar: new RAR device
+ *
+ *	Process the callbacks for a newly found RAR device.
+ */
+
+static void rar_callback(struct rar_device *rar)
+{
+	struct client *c = &rar->client[0];
+	int i;
+
+	mutex_lock(&rar_mutex);
+
+	rar->registered = 1;	/* Ensure no more callbacks queue */
+
+	for (i = 0; i < MRST_NUM_RAR; i++) {
+		if (c->callback && c->busy) {
+			c->callback(c->driver_priv);
+			c->callback = NULL;
+		}
+		c++;
+	}
+	mutex_unlock(&rar_mutex);
+}
+
+/**
+ *	rar_probe		-	PCI probe callback
+ *	@dev: PCI device
+ *	@id: matching entry in the match table
+ *
+ *	A RAR device has been discovered. Initialise it and if successful
+ *	process any pending callbacks that can now be completed.
+ */
+static int rar_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+	int error;
+	struct rar_device *rar;
+
+	dev_dbg(&dev->dev, "PCI probe starting\n");
+
+	rar = alloc_rar_device();
+	if (rar == NULL)
+		return -EBUSY;
+
+	/* Enable the device */
+	error = pci_enable_device(dev);
+	if (error) {
+		dev_err(&dev->dev,
+			"Error enabling RAR register PCI device\n");
+		goto end_function;
+	}
+
+	/* Fill in the rar_device structure */
+	rar->rar_dev = pci_dev_get(dev);
+	pci_set_drvdata(dev, rar);
+
+	/*
+	 * Initialize the RAR parameters, which have to be retrieved
+	 * via the message bus interface.
+	 */
+	error = init_rar_params(rar);
+	if (error) {
+		pci_disable_device(dev);
+		dev_err(&dev->dev, "Error retrieving RAR addresses\n");
+		goto end_function;
+	}
+	/* now call anyone who has registered (using callbacks) */
+	rar_callback(rar);
+	return 0;
+end_function:
+	free_rar_device(rar);
+	return error;
+}
+
+const struct pci_device_id rar_pci_id_tbl[] = {
+	{ PCI_VDEVICE(INTEL, 0x4110) },
+	{ 0 }
+};
+
+MODULE_DEVICE_TABLE(pci, rar_pci_id_tbl);
+
+const struct pci_device_id *my_id_table = rar_pci_id_tbl;
+
+/* field for registering driver to PCI device */
+static struct pci_driver rar_pci_driver = {
+	.name = "rar_register_driver",
+	.id_table = rar_pci_id_tbl,
+	.probe = rar_probe,
+	/* Cannot be unplugged - no remove */
+};
+
+static int __init rar_init_handler(void)
+{
+	return pci_register_driver(&rar_pci_driver);
+}
+
+static void __exit rar_exit_handler(void)
+{
+	pci_unregister_driver(&rar_pci_driver);
+}
+
+module_init(rar_init_handler);
+module_exit(rar_exit_handler);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Intel Restricted Access Region Register Driver");