pci: pci-uclass: Add support for Single-Root I/O Virtualization

SR-IOV - Single Root I/O Virtualization
PF - Physical Function VF - Virtual Function

If SR-IOV capability is present, use it to initialize Virtual Function
PCI device instances. pci_sriov_init function will read SR-IOV
registers to create VF devices under the PF PCI device and also bind
driver if available. This function needs to be invoked from Physical
function device driver which expects VF device support, creating
minimal impact on existing framework.

Signed-off-by: Suneel Garapati <sgarapati@marvell.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Bin Meng <bmeng.cn@gmail.com>

3 files changed, 162 insertions, 0 deletions

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 1c47a21101d..4635752a95c 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -53,6 +53,16 @@ config PCI_REGION_MULTI_ENTRY
 	  region type. This helps to add support for SoC's like OcteonTX/TX2
 	  where every peripheral is on the PCI bus.
 
+config PCI_SRIOV
+	bool "Enable Single Root I/O Virtualization support for PCI"
+	depends on PCI || DM_PCI
+	default n
+	help
+	  Say Y here if you want to enable PCI Single Root I/O Virtualization
+	  capability support. This helps to enumerate Virtual Function devices
+	  if available on a PCI Physical Function device and probe for
+	  applicable drivers.
+
 config PCIE_ECAM_GENERIC
 	bool "Generic ECAM-based PCI host controller support"
 	default n
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index fa6115a105e..51871bfe624 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -1586,6 +1586,120 @@ int dm_pci_flr(struct udevice *dev)
 	return 0;
 }
 
+#if defined(CONFIG_PCI_SRIOV)
+int pci_sriov_init(struct udevice *pdev, int vf_en)
+{
+	u16 vendor, device;
+	struct udevice *bus;
+	struct udevice *dev;
+	pci_dev_t bdf;
+	u16 ctrl;
+	u16 num_vfs;
+	u16 total_vf;
+	u16 vf_offset;
+	u16 vf_stride;
+	int vf, ret;
+	int pos;
+
+	pos = dm_pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_SRIOV);
+	if (!pos) {
+		debug("Error: SRIOV capability not found\n");
+		return -ENOENT;
+	}
+
+	dm_pci_read_config16(pdev, pos + PCI_SRIOV_CTRL, &ctrl);
+
+	dm_pci_read_config16(pdev, pos + PCI_SRIOV_TOTAL_VF, &total_vf);
+	if (vf_en > total_vf)
+		vf_en = total_vf;
+	dm_pci_write_config16(pdev, pos + PCI_SRIOV_NUM_VF, vf_en);
+
+	ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
+	dm_pci_write_config16(pdev, pos + PCI_SRIOV_CTRL, ctrl);
+
+	dm_pci_read_config16(pdev, pos + PCI_SRIOV_NUM_VF, &num_vfs);
+	if (num_vfs > vf_en)
+		num_vfs = vf_en;
+
+	dm_pci_read_config16(pdev, pos + PCI_SRIOV_VF_OFFSET, &vf_offset);
+	dm_pci_read_config16(pdev, pos + PCI_SRIOV_VF_STRIDE, &vf_stride);
+
+	dm_pci_read_config16(pdev, PCI_VENDOR_ID, &vendor);
+	dm_pci_read_config16(pdev, pos + PCI_SRIOV_VF_DID, &device);
+
+	bdf = dm_pci_get_bdf(pdev);
+
+	pci_get_bus(PCI_BUS(bdf), &bus);
+
+	if (!bus)
+		return -ENODEV;
+
+	bdf += PCI_BDF(0, 0, vf_offset);
+
+	for (vf = 0; vf < num_vfs; vf++) {
+		struct pci_child_platdata *pplat;
+		ulong class;
+
+		pci_bus_read_config(bus, bdf, PCI_CLASS_DEVICE,
+				    &class, PCI_SIZE_16);
+
+		debug("%s: bus %d/%s: found VF %x:%x\n", __func__,
+		      bus->seq, bus->name, PCI_DEV(bdf), PCI_FUNC(bdf));
+
+		/* Find this device in the device tree */
+		ret = pci_bus_find_devfn(bus, PCI_MASK_BUS(bdf), &dev);
+
+		if (ret == -ENODEV) {
+			struct pci_device_id find_id;
+
+			memset(&find_id, '\0', sizeof(find_id));
+			find_id.vendor = vendor;
+			find_id.device = device;
+			find_id.class = class;
+
+			ret = pci_find_and_bind_driver(bus, &find_id,
+						       bdf, &dev);
+
+			if (ret)
+				return ret;
+		}
+
+		/* Update the platform data */
+		pplat = dev_get_parent_platdata(dev);
+		pplat->devfn = PCI_MASK_BUS(bdf);
+		pplat->vendor = vendor;
+		pplat->device = device;
+		pplat->class = class;
+		pplat->is_virtfn = true;
+		pplat->pfdev = pdev;
+		pplat->virtid = vf * vf_stride + vf_offset;
+
+		debug("%s: bus %d/%s: found VF %x:%x %x:%x class %lx id %x\n",
+		      __func__, dev->seq, dev->name, PCI_DEV(bdf),
+		      PCI_FUNC(bdf), vendor, device, class, pplat->virtid);
+		bdf += PCI_BDF(0, 0, vf_stride);
+	}
+
+	return 0;
+}
+
+int pci_sriov_get_totalvfs(struct udevice *pdev)
+{
+	u16 total_vf;
+	int pos;
+
+	pos = dm_pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_SRIOV);
+	if (!pos) {
+		debug("Error: SRIOV capability not found\n");
+		return -ENOENT;
+	}
+
+	dm_pci_read_config16(pdev, pos + PCI_SRIOV_TOTAL_VF, &total_vf);
+
+	return total_vf;
+}
+#endif /* SRIOV */
+
 UCLASS_DRIVER(pci) = {
 	.id		= UCLASS_PCI,
 	.name		= "pci",
diff --git a/include/pci.h b/include/pci.h
index da755af852c..115d3312a4a 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -493,6 +493,17 @@
 #define PCI_EXP_SLTCAP		20	/* Slot Capabilities */
 #define  PCI_EXP_SLTCAP_PSN	0xfff80000 /* Physical Slot Number */
 #define PCI_EXP_LNKCTL2		48	/* Link Control 2 */
+/* Single Root I/O Virtualization Registers */
+#define PCI_SRIOV_CAP		0x04	/* SR-IOV Capabilities */
+#define PCI_SRIOV_CTRL		0x08	/* SR-IOV Control */
+#define  PCI_SRIOV_CTRL_VFE	0x01	/* VF Enable */
+#define  PCI_SRIOV_CTRL_MSE	0x08	/* VF Memory Space Enable */
+#define PCI_SRIOV_INITIAL_VF	0x0c	/* Initial VFs */
+#define PCI_SRIOV_TOTAL_VF	0x0e	/* Total VFs */
+#define PCI_SRIOV_NUM_VF	0x10	/* Number of VFs */
+#define PCI_SRIOV_VF_OFFSET	0x14	/* First VF Offset */
+#define PCI_SRIOV_VF_STRIDE	0x16	/* Following VF Stride */
+#define PCI_SRIOV_VF_DID	0x1a	/* VF Device ID */
 
 /* Include the ID list */
 
@@ -890,12 +901,20 @@ struct udevice;
  * @vendor:	PCI vendor ID (see pci_ids.h)
  * @device:	PCI device ID (see pci_ids.h)
  * @class:	PCI class, 3 bytes: (base, sub, prog-if)
+ * @is_virtfn:	True for Virtual Function device
+ * @pfdev:	Handle to Physical Function device
+ * @virtid:	Virtual Function Index
  */
 struct pci_child_platdata {
 	int devfn;
 	unsigned short vendor;
 	unsigned short device;
 	unsigned int class;
+
+	/* Variables for CONFIG_PCI_SRIOV */
+	bool is_virtfn;
+	struct udevice *pfdev;
+	int virtid;
 };
 
 /* PCI bus operations */
@@ -1208,6 +1227,25 @@ int pci_generic_mmap_read_config(
 	ulong *valuep,
 	enum pci_size_t size);
 
+#if defined(CONFIG_PCI_SRIOV)
+/**
+ * pci_sriov_init() - Scan Virtual Function devices
+ *
+ * @pdev:	Physical Function udevice handle
+ * @vf_en:	Number of Virtual Function devices to enable
+ * @return 0 on success, -ve on error
+ */
+int pci_sriov_init(struct udevice *pdev, int vf_en);
+
+/**
+ * pci_sriov_get_totalvfs() - Get total available Virtual Function devices
+ *
+ * @pdev:	Physical Function udevice handle
+ * @return count on success, -ve on error
+ */
+int pci_sriov_get_totalvfs(struct udevice *pdev);
+#endif
+
 #ifdef CONFIG_DM_PCI_COMPAT
 /* Compatibility with old naming */
 static inline int pci_write_config_dword(pci_dev_t pcidev, int offset,