This workaround is primarily implemented by the BIOS. However if the
BIOS applies the workaround it will reserve a small piece of our DSM
(which should be at the top, right below the WOPCM); we just need to
keep that region reserved so that nothing else attempts to re-use it.
Signed-off-by: Dnyaneshwar Bhadane <dnyaneshwar.bhadane@xxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_stolen.c | 18 ++++++++++++++++++
drivers/gpu/drm/i915/i915_reg.h | 2 ++
2 files changed, 20 insertions(+)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
index 1a766d8e7cce..b2bc5aab88d3 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
@@ -409,6 +409,24 @@ static void icl_get_stolen_reserved(struct drm_i915_private *i915,
*base -= *size;
else
*base = reg_val & GEN11_STOLEN_RESERVED_ADDR_MASK;
+
+ /* Wa_14019821291*/
+ if (IS_MEDIA_GT_IP_STEP(i915->media_gt, IP_VER(13, 0), STEP_A0, STEP_C0)) {
+ /*
+ * This workaround is primarily implemented by the BIOS. We
+ * just need to figure out whether the BIOS has applied the
+ * workaround (meaning the programmed address falls within
+ * the DSM) and, if so, reserve that part of the DSM to
+ * prevent accidental reuse. The DSM location should be just
+ * below the WOPCM.
+ */
+
+ u64 gscpsmi_base = intel_uncore_read64_2x32(uncore,
+ MTL_GSCPSMI_BASEADDR_LSB,
+ MTL_GSCPSMI_BASEADDR_MSB);
+ if (gscpsmi_base >= *base && gscpsmi_base < *base + *size)
+ *size = gscpsmi_base - *base;
+ }
}
/*
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 135e8d8dbdf0..31d0692a5620 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6399,5 +6399,7 @@ enum skl_power_gate {
#define MTL_TRDPRE_MASK REG_GENMASK(7, 0)
#define MTL_MEDIA_GSI_BASE 0x380000
+#define MTL_GSCPSMI_BASEADDR_LSB _MMIO(MTL_MEDIA_GSI_BASE + 0x880c)
+#define MTL_GSCPSMI_BASEADDR_MSB _MMIO(MTL_MEDIA_GSI_BASE + 0x8810)
#endif /* _I915_REG_H_ */
--
2.34.1
