gpu: nvgpu: cde: CDE optimizations

-Change cde_buf to use writecombined cpu mapping.
-Since reading writecombined cpu data is still slow, avoid reads in
  gk20a_replace_data by checking whether a patch overwrites a whole
  word.
-Remove unused distinction between src and dst buffers in cde_convert.
-Remove cde debug dump code as it causes a perf hit.

Bug 1546619

Change-Id: Ibd45d9c3a3dd3936184c2a2a0ba29e919569b328
Signed-off-by: Jussi Rasanen <jrasanen@nvidia.com>
Reviewed-on: http://git-master/r/553233
Reviewed-by: Arto Merilainen <amerilainen@nvidia.com>
Tested-by: Arto Merilainen <amerilainen@nvidia.com>

2 files changed, 22 insertions, 54 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/cde_gk20a.c b/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
index 4c33ea8d..b7264206 100644
--- a/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
@@ -34,23 +34,6 @@
 #include "hw_ccsr_gk20a.h"
 #include "hw_pbdma_gk20a.h"
 
-void gk20a_cde_dump(struct gk20a_cde_ctx *cde_ctx)
-{
-        int i;
-        for (i = 0; i < cde_ctx->num_bufs; i++) {
-                struct gk20a_cde_mem_desc *target_mem = cde_ctx->mem + i;
-                u32 *target_mem_ptr = target_mem->cpuva;
-                int j = 0;
-
-                gk20a_dbg(gpu_dbg_cde, "cde: buffer=%d, size=%zu, gpuva=%llx\n",
-                          i, target_mem->num_bytes, target_mem->gpu_va);
-
-                for (j = 0; j < target_mem->num_bytes / sizeof(u32); j++)
-                        gk20a_dbg(gpu_dbg_cde, "0x%08x ", target_mem_ptr[j]);
-                gk20a_dbg(gpu_dbg_cde, "\n\n");
-        }
-}
-
 static void gk20a_deinit_cde_img(struct gk20a_cde_ctx *cde_ctx)
 {
         struct device *dev = &cde_ctx->pdev->dev;
@@ -60,7 +43,8 @@ static void gk20a_deinit_cde_img(struct gk20a_cde_ctx *cde_ctx)
                 struct gk20a_cde_mem_desc *mem = cde_ctx->mem + i;
                 gk20a_gmmu_unmap(cde_ctx->vm, mem->gpu_va, mem->num_bytes, 1);
                 gk20a_free_sgtable(&mem->sgt);
-                dma_free_coherent(dev, mem->num_bytes, mem->cpuva, mem->iova);
+                dma_free_writecombine(dev, mem->num_bytes, mem->cpuva,
+                                                          mem->iova);
         }
 
         for (i = 0; i < cde_ctx->num_obj_ids; i++)
@@ -140,7 +124,7 @@ static int gk20a_init_cde_buf(struct gk20a_cde_ctx *cde_ctx,
         /* allocate buf */
         mem = cde_ctx->mem + cde_ctx->num_bufs;
         mem->num_bytes = buf->num_bytes;
-        mem->cpuva = dma_alloc_coherent(dev, mem->num_bytes, &mem->iova,
+        mem->cpuva = dma_alloc_writecombine(dev, mem->num_bytes, &mem->iova,
                                         GFP_KERNEL);
         if (!mem->cpuva) {
                 gk20a_warn(&cde_ctx->pdev->dev, "cde: could not allocate device memory. buffer idx = %d",
@@ -157,8 +141,9 @@ static int gk20a_init_cde_buf(struct gk20a_cde_ctx *cde_ctx,
                 goto err_get_sgtable;
         }
 
-        mem->gpu_va = gk20a_gmmu_map(cde_ctx->vm, &mem->sgt, mem->num_bytes, 0,
-                                     gk20a_mem_flag_none);
+        mem->gpu_va = gk20a_gmmu_map(cde_ctx->vm, &mem->sgt, mem->num_bytes,
+                                        0,
+                                        gk20a_mem_flag_none);
         if (!mem->gpu_va) {
                 gk20a_warn(&cde_ctx->pdev->dev, "cde: could not map buffer to gpuva. buffer idx = %d",
                            cde_ctx->num_bufs);
@@ -179,7 +164,7 @@ err_map_buffer:
         gk20a_free_sgtable(&mem->sgt);
         kfree(mem->sgt);
 err_get_sgtable:
-        dma_free_coherent(dev, mem->num_bytes, &mem->cpuva, mem->iova);
+        dma_free_writecombine(dev, mem->num_bytes, &mem->cpuva, mem->iova);
         return err;
 }
 
@@ -194,11 +179,14 @@ static int gk20a_replace_data(struct gk20a_cde_ctx *cde_ctx, void *target,
         value &= mask;
 
         /* read current data from the location */
-        if (type == TYPE_PARAM_TYPE_U32)
-                current_value = *target_mem_ptr;
-        else if (type == TYPE_PARAM_TYPE_U64_LITTLE)
-                current_value = *target_mem_ptr_u64;
-        else if (type == TYPE_PARAM_TYPE_U64_BIG) {
+        current_value = 0;
+        if (type == TYPE_PARAM_TYPE_U32) {
+                if (mask != 0xfffffffful)
+                        current_value = *target_mem_ptr;
+        } else if (type == TYPE_PARAM_TYPE_U64_LITTLE) {
+                if (mask != ~0ul)
+                        current_value = *target_mem_ptr_u64;
+        } else if (type == TYPE_PARAM_TYPE_U64_BIG) {
                 current_value = *target_mem_ptr_u64;
                 current_value = (u64)(current_value >> 32) |
                         (u64)(current_value << 32);
@@ -601,7 +589,7 @@ static int gk20a_cde_execute_buffer(struct gk20a_cde_ctx *cde_ctx,
                                            num_entries, flags, fence, fence_out);
 }
 
-int gk20a_cde_convert(struct gk20a *g, struct dma_buf *src,
+int gk20a_cde_convert(struct gk20a *g,
                       struct dma_buf *dst,
                       s32 dst_kind, u64 dst_byte_offset,
                       u32 dst_size, struct nvgpu_fence *fence,
@@ -611,7 +599,7 @@ int gk20a_cde_convert(struct gk20a *g, struct dma_buf *src,
         struct gk20a_cde_app *cde_app = &g->cde_app;
         struct gk20a_comptags comptags;
         struct gk20a_cde_ctx *cde_ctx;
-        u64 dst_vaddr = 0, src_vaddr = 0;
+        u64 dst_vaddr = 0;
         u32 flags;
         int err, i;
 
@@ -647,30 +635,13 @@ int gk20a_cde_convert(struct gk20a *g, struct dma_buf *src,
                 goto exit_unlock;
         }
 
-        /* ensure that the src buffer has drvdata */
-        err = gk20a_dmabuf_alloc_drvdata(src, &g->dev->dev);
-        if (err)
-                goto exit_unlock;
-
-        /* map the source buffer to prevent premature release */
-        get_dma_buf(src); /* a ref for gk20a_vm_map */
-        src_vaddr = gk20a_vm_map(g->cde_app.vm, src, 0,
-                                 NVGPU_MAP_BUFFER_FLAGS_CACHEABLE_TRUE,
-                                 dst_kind, NULL, true,
-                                 gk20a_mem_flag_none,
-                                 0, 0);
-        if (!src_vaddr) {
-                dma_buf_put(src);
-                err = -EINVAL;
-                goto exit_unlock;
-        }
-
         if (!dst_size)
                 dst_size = dst->size - dst_byte_offset;
 
         /* reload buffer converter if it has failed */
         if (cde_ctx->ch->has_timedout) {
                 mutex_unlock(&cde_app->mutex);
+                gk20a_warn(&cde_ctx->pdev->dev, "cde: had timed out, reloading");
                 err = gk20a_cde_reload(g);
                 if (err)
                         return err;
@@ -685,8 +656,8 @@ int gk20a_cde_convert(struct gk20a *g, struct dma_buf *src,
         }
 
         /* store source buffer compression tags */
-        gk20a_get_comptags(&g->dev->dev, src, &comptags);
-        cde_ctx->src_vaddr = src_vaddr;
+        gk20a_get_comptags(&g->dev->dev, dst, &comptags);
+        cde_ctx->src_vaddr = dst_vaddr;
         cde_ctx->src_param_offset = comptags.offset;
         cde_ctx->src_param_lines = comptags.lines;
 
@@ -722,7 +693,6 @@ int gk20a_cde_convert(struct gk20a *g, struct dma_buf *src,
                  g->gr.compbit_store.size, cde_ctx->backing_store_vaddr);
         gk20a_dbg(gpu_dbg_cde, "cde: buffer=dst, size=%llu, gpuva=%llx\n",
                  cde_ctx->dest_size, cde_ctx->dest_vaddr);
-        gk20a_cde_dump(cde_ctx);
 
         /* execute the init push buffer */
         if (!cde_ctx->init_cmd_executed) {
@@ -747,8 +717,6 @@ exit_unlock:
         /* unmap the buffers - channel holds references to them now */
         if (dst_vaddr)
                 gk20a_vm_unmap(g->cde_app.vm, dst_vaddr);
-        if (src_vaddr)
-                gk20a_vm_unmap(g->cde_app.vm, src_vaddr);
 
         mutex_unlock(&cde_app->mutex);
 
@@ -1054,7 +1022,7 @@ static int gk20a_buffer_convert_gpu_to_cde(
         err = gk20a_init_cde_support(g);
         if (err)
                 goto out;
-        err = gk20a_cde_convert(g, dmabuf, dmabuf,
+        err = gk20a_cde_convert(g, dmabuf,
                                 0, /* dst kind */
                                 compbits_offset,
                                 0, /* dst_size, 0 = auto */
diff --git a/drivers/gpu/nvgpu/gk20a/cde_gk20a.h b/drivers/gpu/nvgpu/gk20a/cde_gk20a.h
index c427d4db..b93e56c8 100644
--- a/drivers/gpu/nvgpu/gk20a/cde_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/cde_gk20a.h
@@ -258,7 +258,7 @@ struct gk20a_cde_app {
 int gk20a_cde_destroy(struct gk20a *g);
 int gk20a_init_cde_support(struct gk20a *g);
 int gk20a_cde_reload(struct gk20a *g);
-int gk20a_cde_convert(struct gk20a *g, struct dma_buf *src, struct dma_buf *dst,
+int gk20a_cde_convert(struct gk20a *g, struct dma_buf *dst,
                       s32 dst_kind, u64 dst_word_offset,
                       u32 dst_size, struct nvgpu_fence *fence,
                       u32 __flags, struct gk20a_cde_param *params,