From 2a5a9c9a20f919c33bb315dab2867992ec96dfa4 Mon Sep 17 00:00:00 2001 From: Jon Derrick Date: Fri, 18 May 2018 13:28:00 -0600 Subject: [PATCH] PCI: vmd: Add offset to bus numbers if necessary Depending on platform configuration, certain VMD devices may have an additional configuration option which specifies the range of bus numbers allowed in a VMD PCIe domain. We determine this requirement by checking the value of two vendor specific config registers in the VMD endpoint: VMCAP[0] | VMCONFIG[9:8] | Bus Numbers ---------------------------------------- 0 | * | 0-255 1 | 00 | 0-127 1 | 01 | 128-255 1 | 10 | 0-255 This feature is also added as a bit in driver_data, to allow future conforming device ids which support these features to be enabled through sysfs new_id. Signed-off-by: Jon Derrick [lorenzo.pieralisi@arm.com: updated commit subject] Signed-off-by: Lorenzo Pieralisi --- drivers/pci/host/vmd.c | 34 +++++++++++++++++++++++++++++----- 1 file changed, 29 insertions(+), 5 deletions(-) diff --git a/drivers/pci/host/vmd.c b/drivers/pci/host/vmd.c index 1544121b74f3..34fa6cf0b0ee 100644 --- a/drivers/pci/host/vmd.c +++ b/drivers/pci/host/vmd.c @@ -24,6 +24,10 @@ #define VMD_MEMBAR1 2 #define VMD_MEMBAR2 4 +#define PCI_REG_VMCAP 0x40 +#define BUS_RESTRICT_CAP(vmcap) (vmcap & 0x1) +#define PCI_REG_VMCONFIG 0x44 +#define BUS_RESTRICT_CFG(vmcfg) ((vmcfg >> 8) & 0x3) #define PCI_REG_VMLOCK 0x70 #define MB2_SHADOW_EN(vmlock) (vmlock & 0x2) @@ -34,6 +38,12 @@ enum vmd_features { * resource assignment to enable guest virtualization */ VMD_FEAT_HAS_MEMBAR_SHADOW = (1 << 0), + + /* + * Device may provide root port configuration information which limits + * bus numbering + */ + VMD_FEAT_HAS_BUS_RESTRICTIONS = (1 << 1), }; /* @@ -567,7 +577,7 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) unsigned long flags; LIST_HEAD(resources); resource_size_t offset[2] = {0}; - resource_size_t membar2_offset = 0x2000; + resource_size_t membar2_offset = 0x2000, busn_start = 0; /* * Shadow registers may exist in certain VMD device ids which allow @@ -598,11 +608,25 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) } } + /* + * Certain VMD devices may have a root port configuration option which + * limits the bus range to between 0-127 or 128-255 + */ + if (features & VMD_FEAT_HAS_BUS_RESTRICTIONS) { + u32 vmcap, vmconfig; + + pci_read_config_dword(vmd->dev, PCI_REG_VMCAP, &vmcap); + pci_read_config_dword(vmd->dev, PCI_REG_VMCONFIG, &vmconfig); + if (BUS_RESTRICT_CAP(vmcap) && + (BUS_RESTRICT_CFG(vmconfig) == 0x1)) + busn_start = 128; + } + res = &vmd->dev->resource[VMD_CFGBAR]; vmd->resources[0] = (struct resource) { .name = "VMD CFGBAR", - .start = 0, - .end = (resource_size(res) >> 20) - 1, + .start = busn_start, + .end = busn_start + (resource_size(res) >> 20) - 1, .flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED, }; @@ -670,8 +694,8 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]); pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]); - vmd->bus = pci_create_root_bus(&vmd->dev->dev, 0, &vmd_ops, sd, - &resources); + vmd->bus = pci_create_root_bus(&vmd->dev->dev, busn_start, &vmd_ops, + sd, &resources); if (!vmd->bus) { pci_free_resource_list(&resources); irq_domain_remove(vmd->irq_domain);