gpu: nvgpu: Allow enabling PC sampling

Allow enabling of PC sampling hardware workaround. It is only
applicable to gm20b.

Bug 1517458
Bug 1573150

Change-Id: Iad6a3ae556489fb7ab9628637d291849d2cd98ea
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/710421

1 files changed, 33 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gm20b/gr_gm20b.c b/drivers/gpu/nvgpu/gm20b/gr_gm20b.c
index da1c1ab0..19340643 100644
--- a/drivers/gpu/nvgpu/gm20b/gr_gm20b.c
+++ b/drivers/gpu/nvgpu/gm20b/gr_gm20b.c
@@ -17,6 +17,7 @@
 #include <linux/delay.h>        /* for mdelay */
 #include <linux/io.h>
 #include <linux/tegra-fuse.h>
+#include <linux/vmalloc.h>
 
 #include "gk20a/gk20a.h"
 #include "gk20a/gr_gk20a.h"
@@ -946,6 +947,37 @@ static int gr_gm20b_dump_gr_status_regs(struct gk20a *g,
                 gk20a_readl(g, gr_pri_gpc0_tpc0_tpccs_tpc_exception_r()));
         gk20a_debug_output(o, "NV_PGRAPH_PRI_GPC0_TPC0_TPCCS_TPC_EXCEPTION_EN: 0x%x\n",
                 gk20a_readl(g, gr_pri_gpc0_tpc0_tpccs_tpc_exception_en_r()));
+
+        return 0;
+}
+
+static int gr_gm20b_update_pc_sampling(struct channel_gk20a *c,
+                                       bool enable)
+{
+        struct channel_ctx_gk20a *ch_ctx = &c->ch_ctx;
+        void *ctx_ptr = NULL;
+        u32 v;
+
+        gk20a_dbg_fn("");
+
+        if (!ch_ctx || !ch_ctx->gr_ctx || c->vpr)
+                return -EINVAL;
+
+        ctx_ptr = vmap(ch_ctx->gr_ctx->pages,
+                        PAGE_ALIGN(ch_ctx->gr_ctx->size) >> PAGE_SHIFT,
+                        0, pgprot_writecombine(PAGE_KERNEL));
+        if (!ctx_ptr)
+                return -ENOMEM;
+
+        v = gk20a_mem_rd32(ctx_ptr, ctxsw_prog_main_image_pm_o());
+        v &= ~ctxsw_prog_main_image_pm_pc_sampling_m();
+        v |= ctxsw_prog_main_image_pm_pc_sampling_f(enable);
+        gk20a_mem_wr32(ctx_ptr + ctxsw_prog_main_image_pm_o(), 0, v);
+
+        vunmap(ctx_ptr);
+
+        gk20a_dbg_fn("done");
+
         return 0;
 }
 
@@ -993,4 +1025,5 @@ void gm20b_init_gr(struct gpu_ops *gops)
         gops->gr.update_ctxsw_preemption_mode =
                 gr_gm20b_update_ctxsw_preemption_mode;
         gops->gr.dump_gr_regs = gr_gm20b_dump_gr_status_regs;
+        gops->gr.update_pc_sampling = gr_gm20b_update_pc_sampling;
 }