instmem for GK20A is allocated using dma_alloc_coherent(), which
provides us with a coherent CPU mapping that we never use because
instmem objects are accessed through PRAMIN. Switch to
dma_alloc_attrs() which gives us the option to dismiss that CPU mapping
and free up some CPU virtual space.
Signed-off-by: Alexandre Courbot <acour...@nvidia.com>
---
drm/nouveau/nvkm/subdev/instmem/gk20a.c | 24 ++++++++++++++++++++----
lib/include/nvif/os.h | 31 +++++++++++++++++++++++++++++++
2 files changed, 51 insertions(+), 4 deletions(-)
diff --git a/drm/nouveau/nvkm/subdev/instmem/gk20a.c
b/drm/nouveau/nvkm/subdev/instmem/gk20a.c
index 6176f50..4c8af6e 100644
--- a/drm/nouveau/nvkm/subdev/instmem/gk20a.c
+++ b/drm/nouveau/nvkm/subdev/instmem/gk20a.c
@@ -24,6 +24,10 @@
#include <core/mm.h>
#include <core/device.h>
+#ifdef __KERNEL__
+#include <linux/dma-attrs.h>
+#endif
+
#include "priv.h"
struct gk20a_instobj_priv {
@@ -34,6 +38,7 @@ struct gk20a_instobj_priv {
struct nvkm_mem _mem;
void *cpuaddr;
dma_addr_t handle;
+ struct dma_attrs attrs;
struct nvkm_mm_node r;
};
@@ -91,8 +96,8 @@ gk20a_instobj_dtor(struct nvkm_object *object)
if (unlikely(!node->handle))
return;
- dma_free_coherent(dev, node->mem->size << PAGE_SHIFT, node->cpuaddr,
- node->handle);
+ dma_free_attrs(dev, node->mem->size << PAGE_SHIFT, node->cpuaddr,
+ node->handle, &node->attrs);
nvkm_instobj_destroy(&node->base);
}
@@ -126,8 +131,19 @@ gk20a_instobj_ctor(struct nvkm_object *parent, struct
nvkm_object *engine,
node->mem = &node->_mem;
- node->cpuaddr = dma_alloc_coherent(dev, npages << PAGE_SHIFT,
- &node->handle, GFP_KERNEL);
+ init_dma_attrs(&node->attrs);
+ /*
+ * We will access this memory through PRAMIN and thus do not need a
+ * consistent CPU pointer
+ */
+ dma_set_attr(DMA_ATTR_NON_CONSISTENT, &node->attrs);
+ dma_set_attr(DMA_ATTR_WEAK_ORDERING, &node->attrs);
+ dma_set_attr(DMA_ATTR_WRITE_COMBINE, &node->attrs);
+ dma_set_attr(DMA_ATTR_NO_KERNEL_MAPPING, &node->attrs);
+
+ node->cpuaddr = dma_alloc_attrs(dev, npages << PAGE_SHIFT,
+ &node->handle, GFP_KERNEL,
+ &node->attrs);
if (!node->cpuaddr) {
nv_error(priv, "cannot allocate DMA memory\n");
return -ENOMEM;
diff --git a/lib/include/nvif/os.h b/lib/include/nvif/os.h
index f6391a5..b4d307e 100644
--- a/lib/include/nvif/os.h
+++ b/lib/include/nvif/os.h
@@ -683,6 +683,37 @@ dma_free_coherent(struct device *dev, size_t sz, void
*vaddr, dma_addr_t bus)
{
}
+enum dma_attr {
+ DMA_ATTR_WRITE_BARRIER,
+ DMA_ATTR_WEAK_ORDERING,
+ DMA_ATTR_WRITE_COMBINE,
+ DMA_ATTR_NON_CONSISTENT,
+ DMA_ATTR_NO_KERNEL_MAPPING,
+ DMA_ATTR_SKIP_CPU_SYNC,
+ DMA_ATTR_FORCE_CONTIGUOUS,
+ DMA_ATTR_MAX,
+};
+
+struct dma_attrs {
+};
+
+static inline void init_dma_attrs(struct dma_attrs *attrs) {}
+static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs) {}
+
+static inline void *
+dma_alloc_attrs(struct device *dev, size_t sz, dma_addr_t *hdl, gfp_t gfp,
+ struct dma_attrs *attrs)
+{
+ return NULL;
+}
+
+static inline void
+dma_free_attrs(struct device *dev, size_t sz, void *vaddr, dma_addr_t bus,
+ struct dma_attrs *attrs)
+{
+}
+
+
/******************************************************************************
* PCI
*****************************************************************************/
--
2.2.2
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