Merge branch 'pci/controller/vmd'

- Support device ID 0x28C1 and assume that BIOS has already enumerated the
  hierarchy below VMD and stored bus range info for OS to use (Nirmal
  Patel)

- Add support for VMCONFIG BUS_RESTRICT_CFG=3, which makes it possible to
  enumerate downstream devices on Intel Arrow Lake-HX systems and probably
  others (Ali Alaei)

- Observe _OSC negotiation for VMD hierarchy only when running on bare
  metal, not when running in a VM (Nirmal Patel)

- Add Nova Lake (NVL) and Dunlow (DNL) Device IDs (Szymon Durawa)

* pci/controller/vmd:
  PCI: vmd: Add Nova Lake (NVL) and Dunlow (DNL) Device IDs
  PCI: vmd: Only copy root bridge _OSC control flags in bare metal OS
  PCI: vmd: Handle BUS_RESTRICT_CFG value 3 for Arrow Lake-HX
  PCI: vmd: Add feature to scan BIOS-enumerated devices

1 files changed, 168 insertions, 35 deletions

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index d4ae250d4bc6..241023ecf677 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -37,6 +37,12 @@
 #define MB2_SHADOW_OFFSET	0x2000
 #define MB2_SHADOW_SIZE		16
 
+/* DMR BAR4 register offsets */
+#define SHADOW_MEMBAR1_28C1		0x2818 /* MEMBAR1 physical address */
+#define SHADOW_MEMBAR2_28C1		0x2820 /* MEMBAR2 physical address */
+#define BASE_ID_REG_28C1		0x2840
+#define MEMBAR2_OFFSET_28C1		0x30d0
+
 enum vmd_features {
 	/*
 	 * Device may contain registers which hint the physical location of the
@@ -77,6 +83,15 @@ enum vmd_features {
 	 * proper power management of the SoC.
 	 */
 	VMD_FEAT_BIOS_PM_QUIRK		= (1 << 5),
+
+	/*
+	 * Newer VMD with device ID 0x28C1 has unique settings compared to its
+	 * predecessor where BIOS enumerates the entire VMD device tree and
+	 * stores respective configurations including bus start range and
+	 * shadow registers in VMD MMIO space in VMD BAR4/BAR5, otherwise
+	 * referred to as MEMBAR2 or MSI-X BAR.
+	 */
+	VMD_FEAT_USE_BIOS_INFO		= (1 << 6),
 };
 
 #define VMD_BIOS_PM_QUIRK_LTR	0x1003	/* 3145728 ns */
@@ -142,6 +157,7 @@ struct vmd_dev {
 	u8			first_vec;
 	char			*name;
 	int			instance;
+	unsigned long		features;
 };
 
 static inline struct vmd_dev *vmd_from_bus(struct pci_bus *bus)
@@ -366,6 +382,9 @@ static void vmd_set_msi_remapping(struct vmd_dev *vmd, bool enable)
 {
 	u16 reg;
 
+	if (!!(vmd->features & VMD_FEAT_USE_BIOS_INFO))
+		return;
+
 	pci_read_config_word(vmd->dev, PCI_REG_VMCONFIG, &reg);
 	reg = enable ? (reg & ~VMCONFIG_MSI_REMAP) :
 		       (reg | VMCONFIG_MSI_REMAP);
@@ -389,11 +408,22 @@ static void vmd_remove_irq_domain(struct vmd_dev *vmd)
 	}
 }
 
+static unsigned int vmd_bus_to_ecam(struct vmd_dev *vmd, unsigned int busnr)
+{
+	if (!!(vmd->features & VMD_FEAT_USE_BIOS_INFO))
+		return busnr;
+
+	return busnr - vmd->busn_start;
+}
+
 static void __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
 				  unsigned int devfn, int reg, int len)
 {
-	unsigned int busnr_ecam = bus->number - vmd->busn_start;
-	u32 offset = PCIE_ECAM_OFFSET(busnr_ecam, devfn, reg);
+	unsigned int busnr_ecam;
+	u32 offset;
+
+	busnr_ecam = vmd_bus_to_ecam(vmd, bus->number);
+	offset = PCIE_ECAM_OFFSET(busnr_ecam, devfn, reg);
 
 	if (offset + len >= resource_size(&vmd->dev->resource[VMD_CFGBAR]))
 		return NULL;
@@ -518,22 +548,37 @@ static inline void vmd_acpi_begin(void) { }
 static inline void vmd_acpi_end(void) { }
 #endif /* CONFIG_ACPI */
 
+static resource_size_t vmd_cfgbar_ecam_space(struct vmd_dev *vmd)
+{
+	resource_size_t cfgbar_buses;
+	unsigned int ecam_start;
+
+	cfgbar_buses = resource_size(&vmd->dev->resource[VMD_CFGBAR]) >> 20;
+	ecam_start = vmd_bus_to_ecam(vmd, vmd->resources[0].start);
+	if (ecam_start >= cfgbar_buses)
+		return 0;
+
+	return cfgbar_buses - ecam_start;
+}
 static void vmd_domain_reset(struct vmd_dev *vmd)
 {
 	u16 bus, max_buses = resource_size(&vmd->resources[0]);
 	u8 dev, functions, fn, hdr_type;
+	unsigned int ecam_bus;
 	char __iomem *base;
 
+	max_buses = min_t(u16, max_buses, vmd_cfgbar_ecam_space(vmd));
 	for (bus = 0; bus < max_buses; bus++) {
+		ecam_bus = vmd_bus_to_ecam(vmd, vmd->resources[0].start + bus);
 		for (dev = 0; dev < 32; dev++) {
-			base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
+			base = vmd->cfgbar + PCIE_ECAM_OFFSET(ecam_bus,
 						PCI_DEVFN(dev, 0), 0);
 
 			hdr_type = readb(base + PCI_HEADER_TYPE);
 
 			functions = (hdr_type & PCI_HEADER_TYPE_MFD) ? 8 : 1;
 			for (fn = 0; fn < functions; fn++) {
-				base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
+				base = vmd->cfgbar + PCIE_ECAM_OFFSET(ecam_bus,
 						PCI_DEVFN(dev, fn), 0);
 
 				hdr_type = readb(base + PCI_HEADER_TYPE) &
@@ -640,6 +685,8 @@ static int vmd_get_bus_number_start(struct vmd_dev *vmd)
 	pci_read_config_word(dev, PCI_REG_VMCAP, &reg);
 	if (BUS_RESTRICT_CAP(reg)) {
 		pci_read_config_word(dev, PCI_REG_VMCONFIG, &reg);
+		if (PCI_POSSIBLE_ERROR(reg))
+			return -ENODEV;
 
 		switch (BUS_RESTRICT_CFG(reg)) {
 		case 0:
@@ -648,6 +695,7 @@ static int vmd_get_bus_number_start(struct vmd_dev *vmd)
 		case 1:
 			vmd->busn_start = 128;
 			break;
+		case 3:
 		case 2:
 			vmd->busn_start = 224;
 			break;
@@ -661,6 +709,46 @@ static int vmd_get_bus_number_start(struct vmd_dev *vmd)
 	return 0;
 }
 
+static int vmd_get_bus_info_from_bar4(struct vmd_dev *vmd,
+				       resource_size_t *offset1,
+				       resource_size_t *offset2)
+{
+	u64 phys1, phys2, bar4_2840;
+	void __iomem *bar4;
+	u32 base_id;
+	u8 base_bus;
+
+	bar4 = pci_ioremap_bar(vmd->dev, 4);
+	if (!bar4)
+		return -ENOMEM;
+
+	/* Read shadow registers for MEMBAR1 and MEMBAR2 physical addresses */
+	phys1 = readq(bar4 + SHADOW_MEMBAR1_28C1);
+	phys2 = readq(bar4 + SHADOW_MEMBAR2_28C1);
+
+	/*
+	 * Read and set bus start number from Base ID register. 24-bit Base ID
+	 * register is part of 64-bit shadowed reqid hide range register and
+	 * holds segment, bus, device and function.
+	 */
+	bar4_2840 = readq(bar4 + BASE_ID_REG_28C1);
+	base_id = bar4_2840 & 0xFFFFFF;
+	base_bus = base_id >> 8;
+	vmd->busn_start = base_bus;
+
+	/* Calculate offsets like vmd_get_phys_offsets() does */
+	if (phys1)
+		*offset1 = vmd->dev->resource[VMD_MEMBAR1].start -
+			(phys1 & PCI_BASE_ADDRESS_MEM_MASK);
+	if (phys2)
+		*offset2 = vmd->dev->resource[VMD_MEMBAR2].start -
+			(phys2 & PCI_BASE_ADDRESS_MEM_MASK);
+
+	pci_iounmap(vmd->dev, bar4);
+
+	return 0;
+}
+
 static irqreturn_t vmd_irq(int irq, void *data)
 {
 	struct vmd_irq_list *irqs = data;
@@ -711,6 +799,52 @@ static int vmd_alloc_irqs(struct vmd_dev *vmd)
 	return 0;
 }
 
+static int vmd_prepare_offsets_and_bus(struct vmd_dev *vmd,
+					unsigned long features,
+					resource_size_t *membar2_offset,
+					resource_size_t *offset1,
+					resource_size_t *offset2)
+{
+	int ret;
+
+	/*
+	 * Shadow registers may exist in certain VMD device IDs which allow
+	 * guests to correctly assign host physical addresses to the root ports
+	 * and child devices. These registers will either return the host value
+	 * or 0, depending on an enable bit in the VMD device.
+	 *
+	 * For certain VMD devices (i.e. 0x28C1), BIOS places device info
+	 * in BAR4 shadow registers to determine the base bus number and memory
+	 * offsets.
+	 */
+	if (features & VMD_FEAT_USE_BIOS_INFO) {
+		*membar2_offset = MEMBAR2_OFFSET_28C1;
+		ret = vmd_get_bus_info_from_bar4(vmd, offset1, offset2);
+		if (ret)
+			return ret;
+	} else if (features & VMD_FEAT_HAS_MEMBAR_SHADOW) {
+		*membar2_offset = MB2_SHADOW_OFFSET + MB2_SHADOW_SIZE;
+		ret = vmd_get_phys_offsets(vmd, true, offset1, offset2);
+		if (ret)
+			return ret;
+	} else if (features & VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP) {
+		ret = vmd_get_phys_offsets(vmd, false, offset1, offset2);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * Certain VMD devices may have a root port configuration option which
+	 * limits the bus range to between 0-127, 128-255, or 224-255.
+	 */
+	if (features & VMD_FEAT_HAS_BUS_RESTRICTIONS) {
+		ret = vmd_get_bus_number_start(vmd);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
 /*
  * Since VMD is an aperture to regular PCIe root ports, only allow it to
  * control features that the OS is allowed to control on the physical PCI bus.
@@ -780,42 +914,25 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 	LIST_HEAD(resources);
 	resource_size_t offset[2] = {0};
 	resource_size_t membar2_offset = 0x2000;
+	resource_size_t busn_end;
 	struct pci_bus *child;
 	struct pci_dev *dev;
+	bool vmd_in_guest;
 	int ret;
 
-	/*
-	 * Shadow registers may exist in certain VMD device ids which allow
-	 * guests to correctly assign host physical addresses to the root ports
-	 * and child devices. These registers will either return the host value
-	 * or 0, depending on an enable bit in the VMD device.
-	 */
-	if (features & VMD_FEAT_HAS_MEMBAR_SHADOW) {
-		membar2_offset = MB2_SHADOW_OFFSET + MB2_SHADOW_SIZE;
-		ret = vmd_get_phys_offsets(vmd, true, &offset[0], &offset[1]);
-		if (ret)
-			return ret;
-	} else if (features & VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP) {
-		ret = vmd_get_phys_offsets(vmd, false, &offset[0], &offset[1]);
-		if (ret)
-			return ret;
-	}
-
-	/*
-	 * Certain VMD devices may have a root port configuration option which
-	 * limits the bus range to between 0-127, 128-255, or 224-255
-	 */
-	if (features & VMD_FEAT_HAS_BUS_RESTRICTIONS) {
-		ret = vmd_get_bus_number_start(vmd);
-		if (ret)
-			return ret;
-	}
+	ret = vmd_prepare_offsets_and_bus(vmd, features, &membar2_offset,
+					  &offset[0], &offset[1]);
+	if (ret)
+		return ret;
 
+	/* Do not let resource[0] end go out of bounds */
 	res = &vmd->dev->resource[VMD_CFGBAR];
+	busn_end = vmd->busn_start + (resource_size(res) >> 20) - 1;
+	busn_end = min_t(resource_size_t, busn_end, 0xff);
 	vmd->resources[0] = (struct resource) {
 		.name  = "VMD CFGBAR",
 		.start = vmd->busn_start,
-		.end   = vmd->busn_start + (resource_size(res) >> 20) - 1,
+		.end   = busn_end,
 		.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
 	};
 
@@ -862,14 +979,16 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 		.parent = res,
 	};
 
+	/* Non-zero offset means guest/direct assign view. */
+	vmd_in_guest = offset[0] || offset[1];
+
 	/*
 	 * Currently MSI remapping must be enabled in guest passthrough mode
 	 * due to some missing interrupt remapping plumbing. This is probably
 	 * acceptable because the guest is usually CPU-limited and MSI
 	 * remapping doesn't become a performance bottleneck.
 	 */
-	if (!(features & VMD_FEAT_CAN_BYPASS_MSI_REMAP) ||
-	    offset[0] || offset[1]) {
+	if (!(features & VMD_FEAT_CAN_BYPASS_MSI_REMAP) || vmd_in_guest) {
 		ret = vmd_alloc_irqs(vmd);
 		if (ret)
 			return ret;
@@ -910,8 +1029,13 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 		return -ENODEV;
 	}
 
-	vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus),
-				   to_pci_host_bridge(vmd->bus->bridge));
+	/*
+	 * Don't copy _OSC control flags from root bridge if running in a VM, as
+	 * they don't reflect the physical root bridge capabilities.
+	 */
+	if (!vmd_in_guest)
+		vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus),
+					 to_pci_host_bridge(vmd->bus->bridge));
 
 	vmd_attach_resources(vmd);
 	if (vmd->irq_domain)
@@ -998,6 +1122,7 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
 
 	vmd->dev = dev;
 	vmd->sysdata.domain = PCI_DOMAIN_NR_NOT_SET;
+	vmd->features = features;
 	vmd->instance = ida_alloc(&vmd_instance_ida, GFP_KERNEL);
 	if (vmd->instance < 0)
 		return vmd->instance;
@@ -1114,6 +1239,10 @@ static const struct pci_device_id vmd_ids[] = {
 		.driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW |
 				VMD_FEAT_HAS_BUS_RESTRICTIONS |
 				VMD_FEAT_CAN_BYPASS_MSI_REMAP,},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_28C1),
+		.driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW |
+				VMD_FEAT_CAN_BYPASS_MSI_REMAP |
+				VMD_FEAT_USE_BIOS_INFO,},
 	{PCI_VDEVICE(INTEL, 0x467f),
 		.driver_data = VMD_FEATS_CLIENT,},
 	{PCI_VDEVICE(INTEL, 0x4c3d),
@@ -1132,6 +1261,10 @@ static const struct pci_device_id vmd_ids[] = {
                 .driver_data = VMD_FEATS_CLIENT,},
 	{PCI_VDEVICE(INTEL, 0xb07f),
                 .driver_data = VMD_FEATS_CLIENT,},
+	{PCI_VDEVICE(INTEL, 0xd70b),
+		.driver_data = VMD_FEATS_CLIENT,},
+	{PCI_VDEVICE(INTEL, 0xd73b),
+		.driver_data = VMD_FEATS_CLIENT,},
 	{0,}
 };
 MODULE_DEVICE_TABLE(pci, vmd_ids);