drm/amdgpu: Fix pci platform speed and width

The new Vega series GPU cards have in-built bridges. To get the pcie
speed and width supported by the platform walk the hierarchy and get the
slowest link.

Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 46 insertions, 12 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index d7dddb936f84..fcab1fe9bb68 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3618,6 +3618,38 @@ retry:	/* Rest of adevs pre asic reset from XGMI hive. */
         return r;
 }
 
+static void amdgpu_device_get_min_pci_speed_width(struct amdgpu_device *adev,
+                                                  enum pci_bus_speed *speed,
+                                                  enum pcie_link_width *width)
+{
+        struct pci_dev *pdev = adev->pdev;
+        enum pci_bus_speed cur_speed;
+        enum pcie_link_width cur_width;
+
+        *speed = PCI_SPEED_UNKNOWN;
+        *width = PCIE_LNK_WIDTH_UNKNOWN;
+
+        while (pdev) {
+                cur_speed = pcie_get_speed_cap(pdev);
+                cur_width = pcie_get_width_cap(pdev);
+
+                if (cur_speed != PCI_SPEED_UNKNOWN) {
+                        if (*speed == PCI_SPEED_UNKNOWN)
+                                *speed = cur_speed;
+                        else if (cur_speed < *speed)
+                                *speed = cur_speed;
+                }
+
+                if (cur_width != PCIE_LNK_WIDTH_UNKNOWN) {
+                        if (*width == PCIE_LNK_WIDTH_UNKNOWN)
+                                *width = cur_width;
+                        else if (cur_width < *width)
+                                *width = cur_width;
+                }
+                pdev = pci_upstream_bridge(pdev);
+        }
+}
+
 /**
  * amdgpu_device_get_pcie_info - fence pcie info about the PCIE slot
  *
@@ -3630,8 +3662,8 @@ retry:	/* Rest of adevs pre asic reset from XGMI hive. */
 static void amdgpu_device_get_pcie_info(struct amdgpu_device *adev)
 {
         struct pci_dev *pdev;
-        enum pci_bus_speed speed_cap;
-        enum pcie_link_width link_width;
+        enum pci_bus_speed speed_cap, platform_speed_cap;
+        enum pcie_link_width platform_link_width;
 
         if (amdgpu_pcie_gen_cap)
                 adev->pm.pcie_gen_mask = amdgpu_pcie_gen_cap;
@@ -3648,6 +3680,12 @@ static void amdgpu_device_get_pcie_info(struct amdgpu_device *adev)
                 return;
         }
 
+        if (adev->pm.pcie_gen_mask && adev->pm.pcie_mlw_mask)
+                return;
+
+        amdgpu_device_get_min_pci_speed_width(adev, &platform_speed_cap,
+                                              &platform_link_width);
+
         if (adev->pm.pcie_gen_mask == 0) {
                 /* asic caps */
                 pdev = adev->pdev;
@@ -3673,22 +3711,20 @@ static void amdgpu_device_get_pcie_info(struct amdgpu_device *adev)
                                 adev->pm.pcie_gen_mask |= CAIL_ASIC_PCIE_LINK_SPEED_SUPPORT_GEN1;
                 }
                 /* platform caps */
-                pdev = adev->ddev->pdev->bus->self;
-                speed_cap = pcie_get_speed_cap(pdev);
-                if (speed_cap == PCI_SPEED_UNKNOWN) {
+                if (platform_speed_cap == PCI_SPEED_UNKNOWN) {
                         adev->pm.pcie_gen_mask |= (CAIL_PCIE_LINK_SPEED_SUPPORT_GEN1 |
                                                    CAIL_PCIE_LINK_SPEED_SUPPORT_GEN2);
                 } else {
-                        if (speed_cap == PCIE_SPEED_16_0GT)
+                        if (platform_speed_cap == PCIE_SPEED_16_0GT)
                                 adev->pm.pcie_gen_mask |= (CAIL_PCIE_LINK_SPEED_SUPPORT_GEN1 |
                                                            CAIL_PCIE_LINK_SPEED_SUPPORT_GEN2 |
                                                            CAIL_PCIE_LINK_SPEED_SUPPORT_GEN3 |
                                                            CAIL_PCIE_LINK_SPEED_SUPPORT_GEN4);
-                        else if (speed_cap == PCIE_SPEED_8_0GT)
+                        else if (platform_speed_cap == PCIE_SPEED_8_0GT)
                                 adev->pm.pcie_gen_mask |= (CAIL_PCIE_LINK_SPEED_SUPPORT_GEN1 |
                                                            CAIL_PCIE_LINK_SPEED_SUPPORT_GEN2 |
                                                            CAIL_PCIE_LINK_SPEED_SUPPORT_GEN3);
-                        else if (speed_cap == PCIE_SPEED_5_0GT)
+                        else if (platform_speed_cap == PCIE_SPEED_5_0GT)
                                 adev->pm.pcie_gen_mask |= (CAIL_PCIE_LINK_SPEED_SUPPORT_GEN1 |
                                                            CAIL_PCIE_LINK_SPEED_SUPPORT_GEN2);
                         else
@@ -3697,12 +3733,10 @@ static void amdgpu_device_get_pcie_info(struct amdgpu_device *adev)
                 }
         }
         if (adev->pm.pcie_mlw_mask == 0) {
-                pdev = adev->ddev->pdev->bus->self;
-                link_width = pcie_get_width_cap(pdev);
-                if (link_width == PCIE_LNK_WIDTH_UNKNOWN) {
+                if (platform_link_width == PCIE_LNK_WIDTH_UNKNOWN) {
                         adev->pm.pcie_mlw_mask |= AMDGPU_DEFAULT_PCIE_MLW_MASK;
                 } else {
-                        switch (link_width) {
+                        switch (platform_link_width) {
                         case PCIE_LNK_X32:
                                 adev->pm.pcie_mlw_mask = (CAIL_PCIE_LINK_WIDTH_SUPPORT_X32 |
                                                           CAIL_PCIE_LINK_WIDTH_SUPPORT_X16 |