drm/i915/gvt: decouple check_vgpu() from uncore_init()

With multiple uncore to initialize (GT vs Display), it makes little
sense to have the vgpu_check inside uncore_init(). We also have
a catch-22 scenario where the uncore is required to read the vgpu
capabilities while the vgpu capabilities are required to decide if
we need to initialize forcewake support. To remove this circular
dependency, we can perform the required MMIO access by mmapping just
the vgtif shared page in mmio space and use raw accessors.

v2: rename check_vgpu to detect_vgpu (Chris)

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190620010021.20637-7-daniele.ceraolospurio@intel.com

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 00b6512cdee612ca173de7ae146afe5d198b8693..8f84ed26e972106a0e276d4153499fd3ad2605c1 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1899,6 +1899,8 @@ int i915_driver_load(struct pci_dev *pdev, const struct pci_device_id *ent)
 
        disable_rpm_wakeref_asserts(&dev_priv->runtime_pm);
 
+       i915_detect_vgpu(dev_priv);
+
        ret = i915_driver_init_mmio(dev_priv);
        if (ret < 0)
                goto out_runtime_pm_put;

diff --git a/drivers/gpu/drm/i915/i915_pvinfo.h b/drivers/gpu/drm/i915/i915_pvinfo.h
index 969e514916abec2b5a272e459550e6cd120a0558..ca4661e98f79246bab7fd28dd79f75cd8d46dba1 100644 (file)
--- a/drivers/gpu/drm/i915/i915_pvinfo.h
+++ b/drivers/gpu/drm/i915/i915_pvinfo.h
@@ -110,8 +110,9 @@ struct vgt_if {
        u32  rsv7[0x200 - 24];    /* pad to one page */
 } __packed;
 
-#define vgtif_reg(x) \
-       _MMIO((VGT_PVINFO_PAGE + offsetof(struct vgt_if, x)))
+#define vgtif_offset(x) (offsetof(struct vgt_if, x))
+
+#define vgtif_reg(x) _MMIO(VGT_PVINFO_PAGE + vgtif_offset(x))
 
 /* vGPU display status to be used by the host side */
 #define VGT_DRV_DISPLAY_NOT_READY 0

diff --git a/drivers/gpu/drm/i915/i915_vgpu.c b/drivers/gpu/drm/i915/i915_vgpu.c
index 94d3992b599d24a88c473839e831ab81f903427b..1a8f7c731126373e13d45675b2feda356736e2a7 100644 (file)
--- a/drivers/gpu/drm/i915/i915_vgpu.c
+++ b/drivers/gpu/drm/i915/i915_vgpu.c
@@ -52,34 +52,53 @@
  */
 
 /**
- * i915_check_vgpu - detect virtual GPU
+ * i915_detect_vgpu - detect virtual GPU
  * @dev_priv: i915 device private
  *
  * This function is called at the initialization stage, to detect whether
  * running on a vGPU.
  */
-void i915_check_vgpu(struct drm_i915_private *dev_priv)
+void i915_detect_vgpu(struct drm_i915_private *dev_priv)
 {
-       struct intel_uncore *uncore = &dev_priv->uncore;
+       struct pci_dev *pdev = dev_priv->drm.pdev;
        u64 magic;
        u16 version_major;
+       void __iomem *shared_area;
 
        BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE);
 
-       magic = __raw_uncore_read64(uncore, vgtif_reg(magic));
-       if (magic != VGT_MAGIC)
+       /*
+        * This is called before we setup the main MMIO BAR mappings used via
+        * the uncore structure, so we need to access the BAR directly. Since
+        * we do not support VGT on older gens, return early so we don't have
+        * to consider differently numbered or sized MMIO bars
+        */
+       if (INTEL_GEN(dev_priv) < 6)
+               return;
+
+       shared_area = pci_iomap_range(pdev, 0, VGT_PVINFO_PAGE, VGT_PVINFO_SIZE);
+       if (!shared_area) {
+               DRM_ERROR("failed to map MMIO bar to check for VGT\n");
                return;
+       }
+
+       magic = readq(shared_area + vgtif_offset(magic));
+       if (magic != VGT_MAGIC)
+               goto out;
 
-       version_major = __raw_uncore_read16(uncore, vgtif_reg(version_major));
+       version_major = readw(shared_area + vgtif_offset(version_major));
        if (version_major < VGT_VERSION_MAJOR) {
                DRM_INFO("VGT interface version mismatch!\n");
-               return;
+               goto out;
        }
 
-       dev_priv->vgpu.caps = __raw_uncore_read32(uncore, vgtif_reg(vgt_caps));
+       dev_priv->vgpu.caps = readl(shared_area + vgtif_offset(vgt_caps));
 
        dev_priv->vgpu.active = true;
        DRM_INFO("Virtual GPU for Intel GVT-g detected.\n");
+
+out:
+       pci_iounmap(pdev, shared_area);
 }
 
 bool intel_vgpu_has_full_ppgtt(struct drm_i915_private *dev_priv)

diff --git a/drivers/gpu/drm/i915/i915_vgpu.h b/drivers/gpu/drm/i915/i915_vgpu.h
index ebe1b7bced980707040b74eee88e2c9693f8f38f..a919735fb6ce491c2ee3b9d78b703ecfea8af669 100644 (file)
--- a/drivers/gpu/drm/i915/i915_vgpu.h
+++ b/drivers/gpu/drm/i915/i915_vgpu.h
@@ -26,7 +26,7 @@
 
 #include "i915_pvinfo.h"
 
-void i915_check_vgpu(struct drm_i915_private *dev_priv);
+void i915_detect_vgpu(struct drm_i915_private *dev_priv);
 
 bool intel_vgpu_has_full_ppgtt(struct drm_i915_private *dev_priv);
 

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 2bd602a41bb744630ce50f35456de136999af1b5..68d54e126d79aa2bdc6335d05e2904dd63b5ed0c 100644 (file)
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1650,8 +1650,6 @@ int intel_uncore_init_mmio(struct intel_uncore *uncore)
        if (ret)
                return ret;
 
-       i915_check_vgpu(i915);
-
        if (INTEL_GEN(i915) > 5 && !intel_vgpu_active(i915))
                uncore->flags |= UNCORE_HAS_FORCEWAKE;