gpu: nvgpu: Add configurable comptag_mem_deduct sysfs node per device

Adding a comptag_mem_deduct in the platform_gk20a has certain problems:
1) It's not really convenient for platform users to configure it.
2) All products using the same GPU have to share the same configuration.

So this patch moves this comptag_mem_deduct from struct platform_gk20a
to struct gr_gk20a (per device). And it adds an sysfs node for products
or platform users to easily configure from user space.

Note: The comptag memory will not be allocated until the GPU driver goes
through the final poweron routine. So the user space has a small window
to configure this sysfs node.

Bug 2327574
Bug 2284925

Change-Id: Ie7d00b082704e422645c0ea254b59e22f9fc3b7f
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1810334
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gr_gk20a.h b/drivers/gpu/nvgpu/gk20a/gr_gk20a.h
index 303e1f53..44b6de8d 100644
--- a/drivers/gpu/nvgpu/gk20a/gr_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/gr_gk20a.h
@@ -373,6 +373,12 @@ struct gr_gk20a {
         u32 gfxp_wfi_timeout_count;
         u32 gfxp_wfi_timeout_unit;
 
+        /*
+         * The deductible memory size for max_comptag_mem (in MBytes)
+         * Usually close to memory size that running system is taking
+         */
+        u32 comptag_mem_deduct;
+
         struct gr_ctx_buffer_desc global_ctx_buffer[NR_GLOBAL_CTX_BUF];
 
         struct nvgpu_mem mmu_wr_mem;