[PATCH 2/4] drm/i915/bxt: Determine BXT slice/subslice/EU info

jeff.mcgee
2015-04-04T01:12:50Z

Modify the Gen9 SSEU info initialization logic to support
Broxton. Broxton reuses the SKL fuse registers but has at most
1 slice and 6 EU per subslice.

Signed-off-by: Jeff McGee <jeff.mcgee@intel.com>
---
drivers/gpu/drm/i915/i915_dma.c | 47 ++++++++++++++++++++++++++---------------
drivers/gpu/drm/i915/i915_reg.h | 4 +---
2 files changed, 31 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 9691f0f..a9b7770 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -611,9 +611,21 @@ static void gen9_sseu_info_init(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_device_info *info;
- const int s_max = 3, ss_max = 4, eu_max = 8;
+ int s_max = 3, ss_max = 4, eu_max = 8;
int s, ss;
- u32 fuse2, eu_disable[s_max], s_enable, ss_disable;
+ u32 fuse2, s_enable, ss_disable, eu_disable;
+ u8 eu_mask = 0xff;
+
+ /*
+ * BXT has a single slice. BXT also has at most 6 EU per subslice,
+ * and therefore only the lowest 6 bits of the 8-bit EU disable
+ * fields are valid.
+ */
+ if (IS_BROXTON(dev)) {
+ s_max = 1;
+ eu_max = 6;
+ eu_mask = 0x3f;
+ }

info = (struct intel_device_info *)&dev_priv->info;
fuse2 = I915_READ(GEN8_FUSE2);
@@ -622,10 +634,6 @@ static void gen9_sseu_info_init(struct drm_device *dev)
ss_disable = (fuse2 & GEN9_F2_SS_DIS_MASK) >>
GEN9_F2_SS_DIS_SHIFT;

- eu_disable[0] = I915_READ(GEN8_EU_DISABLE0);
- eu_disable[1] = I915_READ(GEN8_EU_DISABLE1);
- eu_disable[2] = I915_READ(GEN8_EU_DISABLE2);
-
info->slice_total = hweight32(s_enable);
/*
* The subslice disable field is global, i.e. it applies
@@ -644,25 +652,26 @@ static void gen9_sseu_info_init(struct drm_device *dev)
/* skip disabled slice */
continue;

+ eu_disable = I915_READ(GEN9_EU_DISABLE(s));
for (ss = 0; ss < ss_max; ss++) {
- u32 n_disabled;
+ int eu_per_ss;

if (ss_disable & (0x1 << ss))
/* skip disabled subslice */
continue;

- n_disabled = hweight8(eu_disable[s] >>
- (ss * eu_max));
+ eu_per_ss = eu_max - hweight8((eu_disable >> (ss*8)) &
+ eu_mask);

/*
* Record which subslice(s) has(have) 7 EUs. we
* can tune the hash used to spread work among
* subslices if they are unbalanced.
*/
- if (eu_max - n_disabled == 7)
+ if (eu_per_ss == 7)
info->subslice_7eu[s] |= 1 << ss;

- info->eu_total += eu_max - n_disabled;
+ info->eu_total += eu_per_ss;
}
}

@@ -670,7 +679,8 @@ static void gen9_sseu_info_init(struct drm_device *dev)
* SKL is expected to always have a uniform distribution
* of EU across subslices with the exception that any one
* EU in any one subslice may be fused off for die
- * recovery.
+ * recovery. BXT is expected to be perfectly uniform in EU
+ * distribution.
*/
info->eu_per_subslice = info->subslice_total ?
DIV_ROUND_UP(info->eu_total,
@@ -678,11 +688,14 @@ static void gen9_sseu_info_init(struct drm_device *dev)
/*
* SKL supports slice power gating on devices with more than
* one slice, and supports EU power gating on devices with
- * more than one EU pair per subslice.
+ * more than one EU pair per subslice. BXT supports subslice
+ * power gating on devices with more than one subslice, and
+ * supports EU power gating on devices with more than one EU
+ * pair per subslice.
*/
- info->has_slice_pg = (info->slice_total > 1) ? 1 : 0;
- info->has_subslice_pg = 0;
- info->has_eu_pg = (info->eu_per_subslice > 2) ? 1 : 0;
+ info->has_slice_pg = (IS_SKYLAKE(dev) && (info->slice_total > 1));
+ info->has_subslice_pg = (IS_BROXTON(dev) && (info->subslice_total > 1));
+ info->has_eu_pg = (info->eu_per_subslice > 2);
}

/*
@@ -747,7 +760,7 @@ static void intel_device_info_runtime_init(struct drm_device *dev)
/* Initialize slice/subslice/EU info */
if (IS_CHERRYVIEW(dev))
cherryview_sseu_info_init(dev);
- else if (IS_SKYLAKE(dev))
+ else if (INTEL_INFO(dev)->gen >= 9)
gen9_sseu_info_init(dev);

DRM_DEBUG_DRIVER("slice total: %u\n", info->slice_total);
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index b134fa3..69d3689 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1554,9 +1554,7 @@ enum skl_disp_power_wells {
#define GEN9_F2_SS_DIS_SHIFT 20
#define GEN9_F2_SS_DIS_MASK (0xf << GEN9_F2_SS_DIS_SHIFT)

-#define GEN8_EU_DISABLE0 0x9134
-#define GEN8_EU_DISABLE1 0x9138
-#define GEN8_EU_DISABLE2 0x913c
+#define GEN9_EU_DISABLE(slice) (0x9134 + (slice)*0x4)

#define GEN6_BSD_SLEEP_PSMI_CONTROL 0x12050
#define GEN6_BSD_SLEEP_MSG_DISABLE (1 << 0)