drm/msm: Add param for the highest bank bit

This parameter is programmed by the kernel and influences the tiling
layout of images. Exposing it to userspace will allow it to tile/untile
images correctly without guessing what value the kernel programmed, and
allow us to change it in the future without breaking userspace.
Signed-off-by: Connor Abbott <cwabbott0@gmail.com>
Patchwork: https://patchwork.freedesktop.org/patch/571181/Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/adreno/adreno_gpu.c

@@ -373,6 +373,9 @@ int adreno_get_param(struct msm_gpu *gpu, struct msm_file_private *ctx,
 			return -EINVAL;
 		*value = ctx->aspace->va_size;
 		return 0;
+	case MSM_PARAM_HIGHEST_BANK_BIT:
+		*value = adreno_gpu->ubwc_config.highest_bank_bit;
+		return 0;
 	default:
 		DBG("%s: invalid param: %u", gpu->name, param);
 		return -EINVAL;

include/uapi/drm/msm_drm.h

@@ -86,6 +86,7 @@ struct drm_msm_timespec {
 #define MSM_PARAM_CMDLINE    0x0d  /* WO: override for task cmdline */
 #define MSM_PARAM_VA_START   0x0e  /* RO: start of valid GPU iova range */
 #define MSM_PARAM_VA_SIZE    0x0f  /* RO: size of valid GPU iova range (bytes) */
+#define MSM_PARAM_HIGHEST_BANK_BIT 0x10 /* RO */
 
 /* For backwards compat.  The original support for preemption was based on
  * a single ring per priority level so # of priority levels equals the #