gpu: nvgpu: Separate kernel and user GPU VA regions

Separate the kernel and userspace regions in the GPU virtual address
space. Do this by reserving the last part of the GPU VA aperture for
the kernel, and extend GPU VA aperture accordingly for regular address
spaces. This prevents the kernel polluting the userspace-visible GPU
VA regions, and thus, makes the success of fixed-address mapping more
predictable.

Bug 200077571

Change-Id: I63f0e73d4c815a4a9fa4a9ce568709974690ef0f
Signed-off-by: Sami Kiminki <skiminki@nvidia.com>
Reviewed-on: http://git-master/r/747191
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/gpu/nvgpu/vgpu/mm_vgpu.c b/drivers/gpu/nvgpu/vgpu/mm_vgpu.c
index c73037b6..2b23c4e6 100644
--- a/drivers/gpu/nvgpu/vgpu/mm_vgpu.c
+++ b/drivers/gpu/nvgpu/vgpu/mm_vgpu.c
@@ -34,9 +34,12 @@ static int vgpu_init_mm_setup_sw(struct gk20a *g)
         mm->g = g;
 
         /*TBD: make channel vm size configurable */
-        mm->channel.size = 1ULL << NV_GMMU_VA_RANGE;
+        mm->channel.user_size = NV_MM_DEFAULT_USER_SIZE;
+        mm->channel.kernel_size = NV_MM_DEFAULT_KERNEL_SIZE;
 
-        gk20a_dbg_info("channel vm size: %dMB", (int)(mm->channel.size >> 20));
+        gk20a_dbg_info("channel vm size: user %dMB  kernel %dMB",
+                       (int)(mm->channel.user_size >> 20),
+                       (int)(mm->channel.kernel_size >> 20));
 
         /* gk20a_init_gpu_characteristics expects this to be populated */
         vm->big_page_size = big_page_size;
@@ -276,8 +279,8 @@ static int vgpu_vm_alloc_share(struct gk20a_as_share *as_share,
         vm->big_page_size = big_page_size;
 
         vm->va_start  = big_page_size << 10;   /* create a one pde hole */
-        vm->va_limit  = mm->channel.size; /* note this means channel.size is
-                                             really just the max */
+        vm->va_limit  = mm->channel.user_size; /* note this means channel.size
+                                                  is really just the max */
 
         msg.cmd = TEGRA_VGPU_CMD_AS_ALLOC_SHARE;
         msg.handle = platform->virt_handle;