drm/amdgpu/psp: don't free PSP buffers on suspend

We can reuse the same buffers on resume.

v2: squash in S4 fix from Shikai

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2213Reviewed-by: Christian König <christian.koenig@amd.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c

@@ -172,6 +172,7 @@ void psp_ta_free_shared_buf(struct ta_mem_context *mem_ctx)
 {
 	amdgpu_bo_free_kernel(&mem_ctx->shared_bo, &mem_ctx->shared_mc_addr,
 			      &mem_ctx->shared_buf);
+	mem_ctx->shared_bo = NULL;
 }
 
 static void psp_free_shared_bufs(struct psp_context *psp)
@@ -182,6 +183,7 @@ static void psp_free_shared_bufs(struct psp_context *psp)
 	/* free TMR memory buffer */
 	pptr = amdgpu_sriov_vf(psp->adev) ? &tmr_buf : NULL;
 	amdgpu_bo_free_kernel(&psp->tmr_bo, &psp->tmr_mc_addr, pptr);
+	psp->tmr_bo = NULL;
 
 	/* free xgmi shared memory */
 	psp_ta_free_shared_buf(&psp->xgmi_context.context.mem_context);
@@ -743,7 +745,7 @@ static int psp_load_toc(struct psp_context *psp,
 /* Set up Trusted Memory Region */
 static int psp_tmr_init(struct psp_context *psp)
 {
-	int ret;
+	int ret = 0;
 	int tmr_size;
 	void *tmr_buf;
 	void **pptr;
@@ -770,10 +772,12 @@ static int psp_tmr_init(struct psp_context *psp)
 		}
 	}
 
-	pptr = amdgpu_sriov_vf(psp->adev) ? &tmr_buf : NULL;
-	ret = amdgpu_bo_create_kernel(psp->adev, tmr_size, PSP_TMR_ALIGNMENT,
-				      AMDGPU_GEM_DOMAIN_VRAM,
-				      &psp->tmr_bo, &psp->tmr_mc_addr, pptr);
+	if (!psp->tmr_bo) {
+		pptr = amdgpu_sriov_vf(psp->adev) ? &tmr_buf : NULL;
+		ret = amdgpu_bo_create_kernel(psp->adev, tmr_size, PSP_TMR_ALIGNMENT,
+					      AMDGPU_GEM_DOMAIN_VRAM,
+					      &psp->tmr_bo, &psp->tmr_mc_addr, pptr);
+	}
 
 	return ret;
 }
@@ -2732,8 +2736,6 @@ static int psp_suspend(void *handle)
 	}
 
 out:
-	psp_free_shared_bufs(psp);
-
 	return ret;
 }