gpu: nvgpu: implement PCIe Gen2 frequency swap

Implement the ability to swap between different PCIe bus speeds. This
code is called during init in case the GPU is not running at the max
supported PCIe bus speed.

JIRA DNVGPU-89

Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/1218178
(cherry picked from commit 8dcd3e10f46f524c9bac9fd5dae0f0a899123c23)
Change-Id: I21f96110578a68d5c5e30ae21776cff69aefba5d
Reviewed-on: http://git-master/r/1227922
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gm206/bios_gm206.h b/drivers/gpu/nvgpu/gm206/bios_gm206.h
index 5aa20364..1ee4e14c 100644
--- a/drivers/gpu/nvgpu/gm206/bios_gm206.h
+++ b/drivers/gpu/nvgpu/gm206/bios_gm206.h
@@ -17,6 +17,8 @@
 #define PERF_PTRS_WIDTH 0x4
 #define PERF_PTRS_WIDTH_16 0x2
 
+#define NV_PCFG 0x88000
+
 enum {
         CLOCKS_TABLE = 2,
         CLOCK_PROGRAMMING_TABLE,