gpu: nvgpu: Add gk20a_gmmu_fixed_map() function

Add a function to allow the kernel to do fixed mappings. Necessary
for the semaphore functionality since there needs to be a common
address in each VM for the semaphores.

Bug 1732449
JIRA DNVGPU-12

Change-Id: I2b451db2d3cb3c003d951f7b0ffc87f6c91db7dc
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/1133789
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

2 files changed, 44 insertions, 7 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
index 452d3e9c..31fad8ae 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
@@ -1990,18 +1990,24 @@ int gk20a_vm_map_compbits(struct vm_gk20a *vm,
         return 0;
 }
 
-u64 gk20a_gmmu_map(struct vm_gk20a *vm,
-                struct sg_table **sgt,
-                u64 size,
-                u32 flags,
-                int rw_flag,
-                bool priv)
+/*
+ * Core GMMU map function for the kernel to use. If @addr is 0 then the GPU
+ * VA will be allocated for you. If addr is non-zero then the buffer will be
+ * mapped at @addr.
+ */
+static u64 __gk20a_gmmu_map(struct vm_gk20a *vm,
+                            struct sg_table **sgt,
+                            u64 addr,
+                            u64 size,
+                            u32 flags,
+                            int rw_flag,
+                            bool priv)
 {
         struct gk20a *g = gk20a_from_vm(vm);
         u64 vaddr;
 
         mutex_lock(&vm->update_gmmu_lock);
-        vaddr = g->ops.mm.gmmu_map(vm, 0, /* already mapped? - No */
+        vaddr = g->ops.mm.gmmu_map(vm, addr,
                                 *sgt, /* sg table */
                                 0, /* sg offset */
                                 size,
@@ -2022,6 +2028,30 @@ u64 gk20a_gmmu_map(struct vm_gk20a *vm,
         return vaddr;
 }
 
+u64 gk20a_gmmu_map(struct vm_gk20a *vm,
+                   struct sg_table **sgt,
+                   u64 size,
+                   u32 flags,
+                   int rw_flag,
+                   bool priv)
+{
+        return __gk20a_gmmu_map(vm, sgt, 0, size, flags, rw_flag, priv);
+}
+
+/*
+ * Like gk20a_gmmu_map() except it works on a fixed address instead.
+ */
+u64 gk20a_gmmu_fixed_map(struct vm_gk20a *vm,
+                         struct sg_table **sgt,
+                         u64 addr,
+                         u64 size,
+                         u32 flags,
+                         int rw_flag,
+                         bool priv)
+{
+        return __gk20a_gmmu_map(vm, sgt, addr, size, flags, rw_flag, priv);
+}
+
 int gk20a_gmmu_alloc(struct gk20a *g, size_t size, struct mem_desc *mem)
 {
         return gk20a_gmmu_alloc_attr(g, 0, size, mem);
diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.h b/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
index 2c2df1a9..e7154c84 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
@@ -471,6 +471,13 @@ u64 gk20a_gmmu_map(struct vm_gk20a *vm,
                 u32 flags,
                 int rw_flag,
                 bool priv);
+u64 gk20a_gmmu_fixed_map(struct vm_gk20a *vm,
+                struct sg_table **sgt,
+                u64 addr,
+                u64 size,
+                u32 flags,
+                int rw_flag,
+                bool priv);
 
 int gk20a_gmmu_alloc_map(struct vm_gk20a *vm,
                 size_t size,