drm/i915/tgl: Implement Wa_1604555607

Implement Wa_1604555607 (set the DS pairing timer to 128 cycles).
FF_MODE2 is part of the register state context, that's why it is
implemented here.

At TGL A0 stepping, FF_MODE2 register read back is broken, hence
disabling the WA verification.

v2: Rebased on top of the WA refactoring (Oscar)
v3: Correctly add to ctx_workarounds_init (Michel)
v4:
  uncore read is used [Tvrtko]
  Macros as used for MASK definition [Chris]
v5:
  Skip the Wa_1604555607 verification [Ram]
  i915 ptr retrieved from engine. [Tvrtko]
v6:
  Added wa_add as a wrapper for __wa_add [Chris]
  wa_add is directly called instead of new wrapper [tvrtko]

BSpec: 19363
HSDES: 1604555607
Signed-off-by: Michel Thierry <michel.thierry@intel.com>
Signed-off-by: Ramalingam C <ramlingam.c@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> [v5]
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191128021005.3350-1-ramalingam.c@intel.com

diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index 0c6d398..195ccf7 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -147,21 +147,27 @@ static void _wa_add(struct i915_wa_list *wal, const struct i915_wa *wa)
        }
 }
 
-static void
-wa_write_masked_or(struct i915_wa_list *wal, i915_reg_t reg, u32 mask,
-                  u32 val)
+static void wa_add(struct i915_wa_list *wal, i915_reg_t reg, u32 mask,
+                  u32 val, u32 read_mask)
 {
        struct i915_wa wa = {
                .reg  = reg,
                .mask = mask,
                .val  = val,
-               .read = mask,
+               .read = read_mask,
        };
 
        _wa_add(wal, &wa);
 }
 
 static void
+wa_write_masked_or(struct i915_wa_list *wal, i915_reg_t reg, u32 mask,
+                  u32 val)
+{
+       wa_add(wal, reg, mask, val, mask);
+}
+
+static void
 wa_masked_en(struct i915_wa_list *wal, i915_reg_t reg, u32 val)
 {
        wa_write_masked_or(wal, reg, val, _MASKED_BIT_ENABLE(val));
@@ -569,9 +575,24 @@ static void icl_ctx_workarounds_init(struct intel_engine_cs *engine,
 static void tgl_ctx_workarounds_init(struct intel_engine_cs *engine,
                                     struct i915_wa_list *wal)
 {
+       u32 val;
+
        /* Wa_1409142259:tgl */
        WA_SET_BIT_MASKED(GEN11_COMMON_SLICE_CHICKEN3,
                          GEN12_DISABLE_CPS_AWARE_COLOR_PIPE);
+
+       /* Wa_1604555607:tgl */
+       val = intel_uncore_read(engine->uncore, FF_MODE2);
+       val &= ~FF_MODE2_TDS_TIMER_MASK;
+       val |= FF_MODE2_TDS_TIMER_128;
+       /*
+        * FIXME: FF_MODE2 register is not readable till TGL B0. We can
+        * enable verification of WA from the later steppings, which enables
+        * the read of FF_MODE2.
+        */
+       wa_add(wal, FF_MODE2, FF_MODE2_TDS_TIMER_MASK, val,
+              IS_TGL_REVID(engine->i915, TGL_REVID_A0, TGL_REVID_A0) ? 0 :
+                           FF_MODE2_TDS_TIMER_MASK);
 }
 
 static void

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 94d0f59..a99fdf8 100644 (file)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7922,6 +7922,10 @@ enum {
 #define   PIXEL_ROUNDING_TRUNC_FB_PASSTHRU     (1 << 15)
 #define   PER_PIXEL_ALPHA_BYPASS_EN            (1 << 7)
 
+#define FF_MODE2                       _MMIO(0x6604)
+#define   FF_MODE2_TDS_TIMER_MASK      REG_GENMASK(23, 16)
+#define   FF_MODE2_TDS_TIMER_128       REG_FIELD_PREP(FF_MODE2_TDS_TIMER_MASK, 4)
+
 /* PCH */
 
 #define PCH_DISPLAY_BASE       0xc0000u