From: Alex Deucher <alexander.deucher@amd.com>
Date: Thu, 30 Jul 2026 16:00:06 +0000 (-0400)
Subject: drm/amdgpu/gmc12.1: implement tlb inv semaphore
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=cda6ab11c1a25a572857b9ea2ded4b7cb13c2895;p=thirdparty%2Fkernel%2Flinux.git

drm/amdgpu/gmc12.1: implement tlb inv semaphore

Needed to properly lock the interface before using it.

Cc: Sonny Jiang <sonny.jiang@amd.com>
Reviewed-by: Sonny Jiang <sonny.jiang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 8e37aa0bd56ba75801a6a21bed45f96372cd9fdc)
Cc: stable@vger.kernel.org
---

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v12_1.c b/drivers/gpu/drm/amd/amdgpu/gmc_v12_1.c
index 855cd29cbffa..bdf6788b85b5 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v12_1.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v12_1.c
@@ -267,9 +267,24 @@ static bool gmc_v12_1_get_vmid_pasid_mapping_info(struct amdgpu_device *adev,
  * by the amdgpu vm/hsa code.
  */
 
+/**
+ * gmc_v12_1_use_invalidate_semaphore - judge whether to use semaphore
+ *
+ * @adev: amdgpu_device pointer
+ * @vmhub: vmhub type
+ *
+ */
+static bool gmc_v12_1_use_invalidate_semaphore(struct amdgpu_device *adev,
+				       uint32_t vmhub)
+{
+	return ((!AMDGPU_IS_GFXHUB(vmhub)) &&
+		(!amdgpu_sriov_vf(adev)));
+}
+
 static void gmc_v12_1_flush_vm_hub(struct amdgpu_device *adev, uint32_t vmid,
 				   unsigned int vmhub, uint32_t flush_type)
 {
+	bool use_semaphore = gmc_v12_1_use_invalidate_semaphore(adev, vmhub);
 	struct amdgpu_vmhub *hub = &adev->vmhub[vmhub];
 	u32 inv_req = hub->vmhub_funcs->get_invalidate_req(vmid, flush_type);
 	u32 tmp;
@@ -283,6 +298,19 @@ static void gmc_v12_1_flush_vm_hub(struct amdgpu_device *adev, uint32_t vmid,
 
 	spin_lock(&adev->gmc.invalidate_lock);
 
+	if (use_semaphore) {
+		for (i = 0; i < adev->usec_timeout; i++) {
+			/* a read return value of 1 means semaphore acuqire */
+			tmp = RREG32_RLC_NO_KIQ(hub->vm_inv_eng0_sem + hub->eng_distance * eng, hub_ip);
+			if (tmp & 0x1)
+				break;
+			udelay(1);
+		}
+
+		if (i >= adev->usec_timeout)
+			DRM_ERROR("Timeout waiting for sem acquire in VM flush!\n");
+	}
+
 	WREG32_RLC_NO_KIQ(hub->vm_inv_eng0_req + hub->eng_distance * eng, inv_req, hub_ip);
 
 	/* Wait for ACK with a delay.*/
@@ -296,6 +324,9 @@ static void gmc_v12_1_flush_vm_hub(struct amdgpu_device *adev, uint32_t vmid,
 		udelay(1);
 	}
 
+	if (use_semaphore)
+		WREG32_RLC_NO_KIQ(hub->vm_inv_eng0_sem + hub->eng_distance * eng, 0, hub_ip);
+
 	/* Issue additional private vm invalidation to MMHUB */
 	if (!AMDGPU_IS_GFXHUB(vmhub) &&
 	    (hub->vm_l2_bank_select_reserved_cid2) &&
@@ -431,10 +462,17 @@ static void gmc_v12_1_flush_gpu_tlb_pasid(struct amdgpu_device *adev,
 static uint64_t gmc_v12_1_emit_flush_gpu_tlb(struct amdgpu_ring *ring,
 					     unsigned vmid, uint64_t pd_addr)
 {
+	bool use_semaphore = gmc_v12_1_use_invalidate_semaphore(ring->adev, ring->vm_hub);
 	struct amdgpu_vmhub *hub = &ring->adev->vmhub[ring->vm_hub];
 	uint32_t req = hub->vmhub_funcs->get_invalidate_req(vmid, 0);
 	unsigned eng = ring->vm_inv_eng;
 
+	if (use_semaphore)
+		/* a read return value of 1 means semaphore acuqire */
+		amdgpu_ring_emit_reg_wait(ring,
+					  hub->vm_inv_eng0_sem +
+					  hub->eng_distance * eng, 0x1, 0x1);
+
 	amdgpu_ring_emit_wreg(ring, hub->ctx0_ptb_addr_lo32 +
 			      (hub->ctx_addr_distance * vmid),
 			      lower_32_bits(pd_addr));
@@ -449,6 +487,14 @@ static uint64_t gmc_v12_1_emit_flush_gpu_tlb(struct amdgpu_ring *ring,
 					    hub->eng_distance * eng,
 					    req, 1 << vmid);
 
+	if (use_semaphore)
+		/*
+		 * add semaphore release after invalidation,
+		 * write with 0 means semaphore release
+		 */
+		amdgpu_ring_emit_wreg(ring, hub->vm_inv_eng0_sem +
+				      hub->eng_distance * eng, 0);
+
 	return pd_addr;
 }