drm/i915/gvt: Save/restore HW status to support GVT suspend/resume

This patch save/restore necessary GVT info during i915 suspend/resume so
that GVT enabled QEMU VM can continue running.

Only GGTT and fence regs are saved/restored now. GVT will save GGTT
entries on each host_entry update, restore the saved dirty entries
and re-init fence regs in resume routine.

V2:
- Change kzalloc/kfree to vzalloc/vfree since the space allocated
from kmalloc may not enough for all saved GGTT entries.
- Keep gvt suspend/resume wrapper in intel_gvt.h/intel_gvt.c and
move the actual implementation to gvt.h/gvt.c. (zhenyu)
- Check gvt config on and active with intel_gvt_active(). (zhenyu)

V3: (zhenyu)
- Incorrect copy length. Should be num entries * entry size.
- Use memcpy_toio()/memcpy_fromio() instead of memcpy for iomem.
- Add F_PM_SAVE flags to indicate which MMIOs to save/restore for PM.

V4:
Rebase.

V5:
Fail intel_gvt_save_ggtt as -ENOMEM if fail to alloc memory to save
ggtt. Free allocated ggtt_entries on failure.

V6:
Save host entry to per-vGPU gtt.ggtt_mm on each host_entry update.

V7:
Restore GGTT entry based on present bit.
Split fence restore and mmio restore in different functions.

Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Hang Yuan <hang.yuan@linux.intel.com>
Signed-off-by: Colin Xu <colin.xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20201027045308.158955-1-colin.xu@intel.com

1 files changed, 41 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
index c7cf15fe9ef6..62b49c72a7d0 100644
--- a/drivers/gpu/drm/i915/gvt/handlers.c
+++ b/drivers/gpu/drm/i915/gvt/handlers.c
@@ -3091,9 +3091,10 @@ static int init_skl_mmio_info(struct intel_gvt *gvt)
 	MMIO_DFH(TRVATTL3PTRDW(2), D_SKL_PLUS, F_CMD_ACCESS, NULL, NULL);
 	MMIO_DFH(TRVATTL3PTRDW(3), D_SKL_PLUS, F_CMD_ACCESS, NULL, NULL);
 	MMIO_DFH(TRVADR, D_SKL_PLUS, F_CMD_ACCESS, NULL, NULL);
-	MMIO_DFH(TRTTE, D_SKL_PLUS, F_CMD_ACCESS,
-		NULL, gen9_trtte_write);
-	MMIO_DH(_MMIO(0x4dfc), D_SKL_PLUS, NULL, gen9_trtt_chicken_write);
+	MMIO_DFH(TRTTE, D_SKL_PLUS, F_CMD_ACCESS | F_PM_SAVE,
+		 NULL, gen9_trtte_write);
+	MMIO_DFH(_MMIO(0x4dfc), D_SKL_PLUS, F_PM_SAVE,
+		 NULL, gen9_trtt_chicken_write);
 
 	MMIO_D(_MMIO(0x46430), D_SKL_PLUS);
 
@@ -3630,3 +3631,40 @@ default_rw:
 		intel_vgpu_default_mmio_read(vgpu, offset, pdata, bytes) :
 		intel_vgpu_default_mmio_write(vgpu, offset, pdata, bytes);
 }
+
+void intel_gvt_restore_fence(struct intel_gvt *gvt)
+{
+	struct intel_vgpu *vgpu;
+	int i, id;
+
+	idr_for_each_entry(&(gvt)->vgpu_idr, vgpu, id) {
+		mmio_hw_access_pre(gvt->gt);
+		for (i = 0; i < vgpu_fence_sz(vgpu); i++)
+			intel_vgpu_write_fence(vgpu, i, vgpu_vreg64(vgpu, fence_num_to_offset(i)));
+		mmio_hw_access_post(gvt->gt);
+	}
+}
+
+static inline int mmio_pm_restore_handler(struct intel_gvt *gvt,
+					  u32 offset, void *data)
+{
+	struct intel_vgpu *vgpu = data;
+	struct drm_i915_private *dev_priv = gvt->gt->i915;
+
+	if (gvt->mmio.mmio_attribute[offset >> 2] & F_PM_SAVE)
+		I915_WRITE(_MMIO(offset), vgpu_vreg(vgpu, offset));
+
+	return 0;
+}
+
+void intel_gvt_restore_mmio(struct intel_gvt *gvt)
+{
+	struct intel_vgpu *vgpu;
+	int id;
+
+	idr_for_each_entry(&(gvt)->vgpu_idr, vgpu, id) {
+		mmio_hw_access_pre(gvt->gt);
+		intel_gvt_for_each_tracked_mmio(gvt, mmio_pm_restore_handler, vgpu);
+		mmio_hw_access_post(gvt->gt);
+	}
+}