[PATCH v2] drm/amdgpu: Default disable GDS for compute VMIDs

[Greathouse, Joseph]

The GDS and GWS blocks default to allowing all VMIDs to
access all entries. Graphics VMIDs can handle setting
these limits when the driver launches work. However,
compute workloads under HWS control don't go through the
kernel driver. Instead, HWS firmware should set these
limits when a process is put into a VMID slot.

Disable access to these devices by default by turning off
all mask bits (for OA) and setting BASE=SIZE=0 (for GDS
and GWS) for all compute VMIDs. If a process wants to use
these resources, they can request this from the HWS
firmware (when such capabilities are enabled). HWS will
then handle setting the base and limit for the process when
it is assigned to a VMID.

This will also prevent user kernels from getting 'stuck' in
GWS by accident if they write GWS-using code but HWS
firmware is not set up to handle GWS reset. Until HWS is
enabled to handle GWS properly, all GWS accesses will
MEM_VIOL fault the kernel.

v2: Move initialization outside of SRBM mutex

Change-Id: I8edcea9d0b14d16a7444bcf9fbf9451aef8b707d
Signed-off-by: Joseph Greathouse <Joseph.Greathouse at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c | 9 +++++++++
 drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c  | 9 +++++++++
 drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c  | 9 +++++++++
 drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c  | 9 +++++++++
 4 files changed, 36 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
index 618291df659b..73dcb632a3ce 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
@@ -1516,6 +1516,15 @@ static void gfx_v10_0_init_compute_vmid(struct amdgpu_device *adev)
 	}
 	nv_grbm_select(adev, 0, 0, 0, 0);
 	mutex_unlock(&adev->srbm_mutex);
+
+	/* Initialize all compute VMIDs to have no GDS, GWS, or OA
+	   acccess. These should be enabled by FW for target VMIDs. */
+	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_BASE, 2 * i, 0);
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_SIZE, 2 * i, 0);
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_GWS_VMID0, i, 0);
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_OA_VMID0, i, 0);
+	}
 }
 
 static void gfx_v10_0_tcp_harvest(struct amdgpu_device *adev)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
index e1e2a44ee13c..3f98624772a4 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
@@ -1877,6 +1877,15 @@ static void gfx_v7_0_init_compute_vmid(struct amdgpu_device *adev)
 	}
 	cik_srbm_select(adev, 0, 0, 0, 0);
 	mutex_unlock(&adev->srbm_mutex);
+
+	/* Initialize all compute VMIDs to have no GDS, GWS, or OA
+	   acccess. These should be enabled by FW for target VMIDs. */
+	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {
+		WREG32(amdgpu_gds_reg_offset[i].mem_base, 0);
+		WREG32(amdgpu_gds_reg_offset[i].mem_size, 0);
+		WREG32(amdgpu_gds_reg_offset[i].gws, 0);
+		WREG32(amdgpu_gds_reg_offset[i].oa, 0);
+	}
 }
 
 static void gfx_v7_0_config_init(struct amdgpu_device *adev)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
index 8c590a554675..e4028d54f8f7 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
@@ -3702,6 +3702,15 @@ static void gfx_v8_0_init_compute_vmid(struct amdgpu_device *adev)
 	}
 	vi_srbm_select(adev, 0, 0, 0, 0);
 	mutex_unlock(&adev->srbm_mutex);
+
+	/* Initialize all compute VMIDs to have no GDS, GWS, or OA
+	   acccess. These should be enabled by FW for target VMIDs. */
+	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {
+		WREG32(amdgpu_gds_reg_offset[i].mem_base, 0);
+		WREG32(amdgpu_gds_reg_offset[i].mem_size, 0);
+		WREG32(amdgpu_gds_reg_offset[i].gws, 0);
+		WREG32(amdgpu_gds_reg_offset[i].oa, 0);
+	}
 }
 
 static void gfx_v8_0_config_init(struct amdgpu_device *adev)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index 5af60e1c735a..259a35395fec 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -2025,6 +2025,15 @@ static void gfx_v9_0_init_compute_vmid(struct amdgpu_device *adev)
 	}
 	soc15_grbm_select(adev, 0, 0, 0, 0);
 	mutex_unlock(&adev->srbm_mutex);
+
+	/* Initialize all compute VMIDs to have no GDS, GWS, or OA
+	   acccess. These should be enabled by FW for target VMIDs. */
+	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_BASE, 2 * i, 0);
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_SIZE, 2 * i, 0);
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_GWS_VMID0, i, 0);
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_OA_VMID0, i, 0);
+	}
 }
 
 static void gfx_v9_0_constants_init(struct amdgpu_device *adev)
-- 
2.19.1