drm/i915: Fix unsigned overflow when calculating total data rate, v2.
On gen11, we can definitely smash the 32-bits barrier with just a
when we enable all planes in the next patch.
Changes since v1:
- Use div64_u64 (ickle).
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181022102000.30255-1-maarten.lankhorst@linux.intel.com
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 67a4d07..f42b8c3 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3784,7 +3784,7 @@ bool intel_can_enable_sagv(struct drm_atomic_state *state)
static u16 intel_get_ddb_size(struct drm_i915_private *dev_priv,
const struct intel_crtc_state *cstate,
- const unsigned int total_data_rate,
+ const u64 total_data_rate,
const int num_active,
struct skl_ddb_allocation *ddb)
{
@@ -3798,12 +3798,12 @@ static u16 intel_get_ddb_size(struct drm_i915_private *dev_priv,
return ddb_size - 4; /* 4 blocks for bypass path allocation */
adjusted_mode = &cstate->base.adjusted_mode;
- total_data_bw = (u64)total_data_rate * drm_mode_vrefresh(adjusted_mode);
+ total_data_bw = total_data_rate * drm_mode_vrefresh(adjusted_mode);
/*
* 12GB/s is maximum BW supported by single DBuf slice.
*/
- if (total_data_bw >= GBps(12) || num_active > 1) {
+ if (num_active > 1 || total_data_bw >= GBps(12)) {
ddb->enabled_slices = 2;
} else {
ddb->enabled_slices = 1;
@@ -3816,7 +3816,7 @@ static u16 intel_get_ddb_size(struct drm_i915_private *dev_priv,
static void
skl_ddb_get_pipe_allocation_limits(struct drm_device *dev,
const struct intel_crtc_state *cstate,
- const unsigned int total_data_rate,
+ const u64 total_data_rate,
struct skl_ddb_allocation *ddb,
struct skl_ddb_entry *alloc, /* out */
int *num_active /* out */)
@@ -4139,7 +4139,7 @@ int skl_check_pipe_max_pixel_rate(struct intel_crtc *intel_crtc,
return 0;
}
-static unsigned int
+static u64
skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,
const struct drm_plane_state *pstate,
const int plane)
@@ -4151,6 +4151,7 @@ skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,
struct drm_framebuffer *fb;
u32 format;
uint_fixed_16_16_t down_scale_amount;
+ u64 rate;
if (!intel_pstate->base.visible)
return 0;
@@ -4177,28 +4178,26 @@ skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,
height /= 2;
}
- data_rate = width * height * fb->format->cpp[plane];
+ data_rate = width * height;
down_scale_amount = skl_plane_downscale_amount(cstate, intel_pstate);
- return mul_round_up_u32_fixed16(data_rate, down_scale_amount);
+ rate = mul_round_up_u32_fixed16(data_rate, down_scale_amount);
+
+ rate *= fb->format->cpp[plane];
+ return rate;
}
-/*
- * We don't overflow 32 bits. Worst case is 3 planes enabled, each fetching
- * a 8192x4096@32bpp framebuffer:
- * 3 * 4096 * 8192 * 4 < 2^32
- */
-static unsigned int
+static u64
skl_get_total_relative_data_rate(struct intel_crtc_state *intel_cstate,
- unsigned int *plane_data_rate,
- unsigned int *uv_plane_data_rate)
+ u64 *plane_data_rate,
+ u64 *uv_plane_data_rate)
{
struct drm_crtc_state *cstate = &intel_cstate->base;
struct drm_atomic_state *state = cstate->state;
struct drm_plane *plane;
const struct drm_plane_state *pstate;
- unsigned int total_data_rate = 0;
+ u64 total_data_rate = 0;
if (WARN_ON(!state))
return 0;
@@ -4206,7 +4205,7 @@ skl_get_total_relative_data_rate(struct intel_crtc_state *intel_cstate,
/* Calculate and cache data rate for each plane */
drm_atomic_crtc_state_for_each_plane_state(plane, pstate, cstate) {
enum plane_id plane_id = to_intel_plane(plane)->id;
- unsigned int rate;
+ u64 rate;
/* packed/y */
rate = skl_plane_relative_data_rate(intel_cstate,
@@ -4325,11 +4324,11 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
uint16_t alloc_size, start;
uint16_t minimum[I915_MAX_PLANES] = {};
uint16_t uv_minimum[I915_MAX_PLANES] = {};
- unsigned int total_data_rate;
+ u64 total_data_rate;
enum plane_id plane_id;
int num_active;
- unsigned int plane_data_rate[I915_MAX_PLANES] = {};
- unsigned int uv_plane_data_rate[I915_MAX_PLANES] = {};
+ u64 plane_data_rate[I915_MAX_PLANES] = {};
+ u64 uv_plane_data_rate[I915_MAX_PLANES] = {};
uint16_t total_min_blocks = 0;
/* Clear the partitioning for disabled planes. */
@@ -4388,7 +4387,7 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
start = alloc->start;
for_each_plane_id_on_crtc(intel_crtc, plane_id) {
- unsigned int data_rate, uv_data_rate;
+ u64 data_rate, uv_data_rate;
uint16_t plane_blocks, uv_plane_blocks;
if (plane_id == PLANE_CURSOR)
@@ -4402,8 +4401,7 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
* result is < available as data_rate / total_data_rate < 1
*/
plane_blocks = minimum[plane_id];
- plane_blocks += div_u64((uint64_t)alloc_size * data_rate,
- total_data_rate);
+ plane_blocks += div64_u64(alloc_size * data_rate, total_data_rate);
/* Leave disabled planes at (0,0) */
if (data_rate) {
@@ -4417,8 +4415,7 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
uv_data_rate = uv_plane_data_rate[plane_id];
uv_plane_blocks = uv_minimum[plane_id];
- uv_plane_blocks += div_u64((uint64_t)alloc_size * uv_data_rate,
- total_data_rate);
+ uv_plane_blocks += div64_u64(alloc_size * uv_data_rate, total_data_rate);
if (uv_data_rate) {
ddb->uv_plane[pipe][plane_id].start = start;