Introduce NPU2 support

NVLink2 is a new feature introduced on POWER9 systems. It is an
evolution of of the NVLink1 feature included in POWER8+ systems but
adds several new features including support for GPU address
translation using the Nest MMU and cache coherence.

Similar to NVLink1 the functionality is exposed to the OS as a series
of virtual PCIe devices. However the actual hardware interfaces are
significantly different which limits the amount of common code that
can be shared between implementations in the firmware.

This patch adds basic hardware initialisation and exposure of the
virtual NVLink2 PCIe devices to the running OS.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

3 files changed, 154 insertions, 0 deletions

diff --git a/include/npu2.h b/include/npu2.h
new file mode 100644
index 00000000..ec62ad21
--- /dev/null
+++ b/include/npu2.h
@@ -0,0 +1,152 @@
+/* Copyright 2013-2016 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __NPU2_H
+#define __NPU2_H
+
+/* Debugging options */
+#define NPU2DBG(p, fmt, a...)	prlog(PR_DEBUG, "NPU%d: " fmt, \
+				      (p)->phb.opal_id, ##a)
+#define NPU2INF(p, fmt, a...)	prlog(PR_INFO,  "NPU%d: " fmt, \
+				      (p)->phb.opal_id, ##a)
+#define NPU2ERR(p, fmt, a...)	prlog(PR_ERR,   "NPU%d: " fmt, \
+				      (p)->phb.opal_id, ##a)
+
+/* Number of PEs supported */
+#define NPU2_MAX_PE_NUM		16
+#define NPU2_RESERVED_PE_NUM	15
+
+/* Return the stack (0-2) of a device */
+#define NPU2DEV_STACK(ndev) ((ndev)->index / 2)
+
+/* Return the brick number (0-1) within a stack */
+#define NPU2DEV_BRICK(ndev) ((ndev)->index % 2)
+
+/* This represents the state of the actual hardware BARs not the
+ * emulated PCIe BARs. The is a subtle difference between the two as
+ * not all BARs are exposed outside of skiboot. */
+struct npu2_bar {
+#define NPU2_BAR_FLAG_ENABLED	0x0010
+
+/* Generation ID's are a single space in the hardware but we split
+ * them in two for the emulated PCIe devices so we need to keep track
+ * of which one has been enabled/disabled. */
+#define NPU2_BAR_FLAG_ENABLED0	0x0080
+#define NPU2_BAR_FLAG_ENABLED1  0x0100
+	uint32_t		flags;
+
+#define NPU2_BAR_TYPE_GLOBAL	0
+#define NPU2_BAR_TYPE_PHY	1
+#define NPU2_BAR_TYPE_NTL	2
+#define NPU2_BAR_TYPE_GENID	3
+#define NPU2_BAR_TYPE_MAX	4
+	uint32_t		type;
+	uint64_t		reg;
+	uint64_t		stack;
+	uint64_t		base;
+	uint64_t		size;
+};
+
+/* Rpresents a BAR that is exposed via the PCIe emulated
+ * devices */
+struct npu2_pcie_bar {
+#define NPU2_PCIE_BAR_FLAG_SIZE_HI	0x0020
+#define NPU2_PCIE_BAR_FLAG_TRAPPED	0x0040
+	uint32_t		flags;
+	struct npu2_bar		*npu2_bar;
+	uint64_t		base;
+	uint64_t		size;
+};
+
+struct npu2;
+struct npu2_dev {
+	uint32_t		index;
+	uint32_t                flags;
+	uint64_t                xscom;
+	void			*regs;
+	struct dt_node		*dt_node;
+	struct npu2_pcie_bar	bars[2];
+	struct npu2		*npu;
+
+	/* Device and function numbers are allocated based on GPU
+	 * association. Links to connected to the same GPU will be
+	 * exposed as different functions of the same bus/device. */
+	uint32_t		bdfn;
+	uint32_t		gpu_bdfn;
+
+	/* PCI virtual device and the associated GPU device */
+	struct pci_virt_device	*pvd;
+	struct phb		*phb;
+	struct pci_device	*pd;
+
+	/* Vendor specific capability */
+	uint32_t		vendor_cap;
+
+	/* Which PHY lanes this device is associated with */
+	uint16_t		lane_mask;
+
+	/* Track currently running procedure and step number */
+	uint16_t		procedure_number;
+	uint16_t		procedure_step;
+	uint64_t		procedure_data;
+	unsigned long		procedure_tb;
+	uint32_t		procedure_status;
+
+	/* Used to associate the NPU device with GPU PCI devices */
+	const char		*slot_label;
+};
+
+struct npu2 {
+	uint32_t	index;
+	uint32_t	flags;
+	uint32_t	chip_id;
+	uint64_t	xscom_base;
+	uint64_t	at_xscom;
+	void		*regs;
+	uint64_t	mm_base;
+	uint64_t	mm_size;
+	uint32_t	base_lsi;
+	uint32_t	total_devices;
+	struct npu2_dev	*devices;
+
+	/* IODA cache */
+	uint64_t	lxive_cache[8];
+	uint64_t	bdf2pe_cache[36];
+	uint64_t	tve_cache[16];
+	bool		tx_zcal_complete[2];
+
+	/* Used to protect global MMIO space, in particular the XTS
+	 * tables. */
+	struct lock	lock;
+
+	struct phb	phb;
+};
+
+static inline struct npu2 *phb_to_npu2(struct phb *phb)
+{
+	return container_of(phb, struct npu2, phb);
+}
+
+void npu2_write_4b(struct npu2 *p, uint64_t reg, uint64_t val);
+uint64_t npu2_read_4b(struct npu2 *p, uint64_t reg);
+void npu2_write(struct npu2 *p, uint64_t reg, uint64_t val);
+uint64_t npu2_read(struct npu2 *p, uint64_t reg);
+void npu2_write_mask(struct npu2 *p, uint64_t reg, uint64_t val, uint64_t mask);
+int64_t npu2_dev_procedure(void *dev, struct pci_cfg_reg_filter *pcrf,
+			   uint32_t offset, uint32_t len, uint32_t *data,
+			   bool write);
+
+#endif /* __NPU2_H */
diff --git a/include/pci.h b/include/pci.h
index 44bedf6f..732c1a36 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -328,6 +328,7 @@ enum phb_type {
 	phb_type_pcie_v2,
 	phb_type_pcie_v3,
 	phb_type_pcie_v4,
+	phb_type_npu_v2,
 };
 
 struct phb {
diff --git a/include/skiboot.h b/include/skiboot.h
index c55995b7..8bc767a4 100644
--- a/include/skiboot.h
+++ b/include/skiboot.h
@@ -217,6 +217,7 @@ extern void phb3_preload_vpd(void);
 extern int phb4_preload_capp_ucode(void);
 extern void phb4_preload_vpd(void);
 extern void probe_npu(void);
+extern void probe_npu2(void);
 extern void uart_init(void);
 extern void mbox_init(void);
 extern void early_uart_init(void);