gpu: nvgpu: Return error code properly from nvgpu_vm_map_linux

The function nvgpu_vm_map_linux() used to return GPU VA on successful
map or 0 when things didn't go smoothly. However, this scheme does not
propagate the actual map error back to the userspace.

So, modify the function a bit: return error and return the GPU VA via
pointer on success.

Bug 1705731

Change-Id: I2174b5fbaf64dcb00f9567dab1c583d6ddfa5d78
Signed-off-by: Sami Kiminki <skiminki@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1590961
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

2 files changed, 23 insertions, 18 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/cde.c b/drivers/gpu/nvgpu/common/linux/cde.c
index f6020d9a..775f9657 100644
--- a/drivers/gpu/nvgpu/common/linux/cde.c
+++ b/drivers/gpu/nvgpu/common/linux/cde.c
@@ -1046,15 +1046,16 @@ __releases(&l->cde_app->mutex)
 
         /* map the destination buffer */
         get_dma_buf(compbits_scatter_buf); /* a ref for nvgpu_vm_map_linux */
-        map_vaddr = nvgpu_vm_map_linux(cde_ctx->vm, compbits_scatter_buf, 0,
+        err = nvgpu_vm_map_linux(cde_ctx->vm, compbits_scatter_buf, 0,
                                  NVGPU_AS_MAP_BUFFER_FLAGS_CACHEABLE |
                                  NVGPU_AS_MAP_BUFFER_FLAGS_DIRECT_KIND_CTRL,
                                  NV_KIND_INVALID,
                                  compbits_kind, /* incompressible kind */
                                  gk20a_mem_flag_none,
                                  map_offset, map_size,
-                                 NULL);
-        if (!map_vaddr) {
+                                 NULL,
+                                 &map_vaddr);
+        if (err) {
                 dma_buf_put(compbits_scatter_buf);
                 err = -EINVAL;
                 goto exit_idle;
diff --git a/drivers/gpu/nvgpu/common/linux/vm.c b/drivers/gpu/nvgpu/common/linux/vm.c
index d04ed5ed..123807d9 100644
--- a/drivers/gpu/nvgpu/common/linux/vm.c
+++ b/drivers/gpu/nvgpu/common/linux/vm.c
@@ -201,7 +201,7 @@ static u64 __nvgpu_vm_find_mapping(struct vm_gk20a *vm,
         return mapped_buffer->addr;
 }
 
-u64 nvgpu_vm_map_linux(struct vm_gk20a *vm,
+int nvgpu_vm_map_linux(struct vm_gk20a *vm,
                        struct dma_buf *dmabuf,
                        u64 offset_align,
                        u32 flags,
@@ -210,7 +210,8 @@ u64 nvgpu_vm_map_linux(struct vm_gk20a *vm,
                        int rw_flag,
                        u64 buffer_offset,
                        u64 mapping_size,
-                       struct vm_gk20a_mapping_batch *batch)
+                       struct vm_gk20a_mapping_batch *batch,
+                       u64 *gpu_va)
 {
         struct gk20a *g = gk20a_from_vm(vm);
         struct device *dev = dev_from_gk20a(g);
@@ -263,12 +264,14 @@ u64 nvgpu_vm_map_linux(struct vm_gk20a *vm,
                         flags, map_key_kind, rw_flag);
                 if (map_offset) {
                         nvgpu_mutex_release(&vm->update_gmmu_lock);
-                        return map_offset;
+                        *gpu_va = map_offset;
+                        return 0;
                 }
         }
 
         sgt = gk20a_mm_pin(dev, dmabuf);
         if (IS_ERR(sgt)) {
+                err = PTR_ERR(sgt);
                 nvgpu_warn(g, "oom allocating tracking buffer");
                 goto clean_up;
         }
@@ -424,7 +427,8 @@ u64 nvgpu_vm_map_linux(struct vm_gk20a *vm,
 
         nvgpu_mutex_release(&vm->update_gmmu_lock);
 
-        return map_offset;
+        *gpu_va = map_offset;
+        return 0;
 
 clean_up:
         nvgpu_kfree(g, mapped_buffer);
@@ -435,7 +439,7 @@ clean_up:
 
         nvgpu_mutex_release(&vm->update_gmmu_lock);
         nvgpu_log_info(g, "err=%d", err);
-        return 0;
+        return err;
 }
 
 int nvgpu_vm_map_buffer(struct vm_gk20a *vm,
@@ -483,18 +487,18 @@ int nvgpu_vm_map_buffer(struct vm_gk20a *vm,
                 return err;
         }
 
-        ret_va = nvgpu_vm_map_linux(vm, dmabuf, *offset_align,
-                                    flags, compr_kind, incompr_kind,
-                                    gk20a_mem_flag_none,
-                                    buffer_offset,
-                                    mapping_size,
-                                    batch);
+        err = nvgpu_vm_map_linux(vm, dmabuf, *offset_align,
+                                 flags, compr_kind, incompr_kind,
+                                 gk20a_mem_flag_none,
+                                 buffer_offset,
+                                 mapping_size,
+                                 batch,
+                                 &ret_va);
 
-        *offset_align = ret_va;
-        if (!ret_va) {
+        if (!err)
+                *offset_align = ret_va;
+        else
                 dma_buf_put(dmabuf);
-                err = -EINVAL;
-        }
 
         return err;
 }