[Intel-gfx] [PATCH 1/6] drm/i915: Allow removal of whitelist register and refactor

[Umesh Nerlige Ramappa]

- Add a helper to remove whitelisted register from the list.
- Refactor _wa_add to use _wa_index to find an existing whitelisted
  register.
- Free the old list when growing the whitelist.

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
---
 drivers/gpu/drm/i915/gt/intel_workarounds.c | 82 +++++++++++++++------
 1 file changed, 58 insertions(+), 24 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index cef1c122696f..98927f5d63ab 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -81,10 +81,49 @@ static void wa_init_finish(struct i915_wa_list *wal)
 			 wal->wa_count, wal->name, wal->engine_name);
 }
 
+static int _wa_index(struct i915_wa_list *wal, i915_reg_t reg)
+{
+	unsigned int addr = i915_mmio_reg_offset(reg);
+	int start = 0, end = wal->count;
+
+	while (start < end) {
+		int mid = start + (end - start) / 2;
+		unsigned int wal_reg = i915_mmio_reg_offset(wal->list[mid].reg);
+
+		wal_reg &= RING_FORCE_TO_NONPRIV_ADDRESS_MASK;
+
+		if (wal_reg < addr)
+			start = mid + 1;
+		else if (wal_reg > addr)
+			end = mid;
+		else
+			return mid;
+	}
+
+	return -1;
+}
+
+static void _wa_remove(struct i915_wa_list *wal, i915_reg_t reg)
+{
+	int index = _wa_index(wal, reg);
+	struct i915_wa *wa = wal->list;
+
+	if (index < 0)
+		return;
+
+	memset(wa + index, 0, sizeof(*wa));
+
+	while (index < wal->count - 1) {
+		swap(wa[index], wa[index + 1]);
+		index++;
+	}
+
+	wal->count--;
+}
+
 static void _wa_add(struct i915_wa_list *wal, const struct i915_wa *wa)
 {
-	unsigned int addr = i915_mmio_reg_offset(wa->reg);
-	unsigned int start = 0, end = wal->count;
+	int index;
 	const unsigned int grow = WA_LIST_CHUNK;
 	struct i915_wa *wa_;
 
@@ -100,36 +139,31 @@ static void _wa_add(struct i915_wa_list *wal, const struct i915_wa *wa)
 			return;
 		}
 
-		if (wal->list)
+		if (wal->list) {
 			memcpy(list, wal->list, sizeof(*wa) * wal->count);
+			kfree(wal->list);
+		}
 
 		wal->list = list;
 	}
 
-	while (start < end) {
-		unsigned int mid = start + (end - start) / 2;
+	index = _wa_index(wal, wa->reg);
+	if (index >= 0) {
+		wa_ = &wal->list[index];
 
-		if (i915_mmio_reg_offset(wal->list[mid].reg) < addr) {
-			start = mid + 1;
-		} else if (i915_mmio_reg_offset(wal->list[mid].reg) > addr) {
-			end = mid;
-		} else {
-			wa_ = &wal->list[mid];
-
-			if ((wa->clr | wa_->clr) && !(wa->clr & ~wa_->clr)) {
-				DRM_ERROR("Discarding overwritten w/a for reg %04x (clear: %08x, set: %08x)\n",
-					  i915_mmio_reg_offset(wa_->reg),
-					  wa_->clr, wa_->set);
-
-				wa_->set &= ~wa->clr;
-			}
+		if ((wa->clr | wa_->clr) && !(wa->clr & ~wa_->clr)) {
+			DRM_ERROR("Discarding overwritten w/a for reg %04x (clear: %08x, set: %08x)\n",
+				  i915_mmio_reg_offset(wa_->reg),
+				  wa_->clr, wa_->set);
 
-			wal->wa_count++;
-			wa_->set |= wa->set;
-			wa_->clr |= wa->clr;
-			wa_->read |= wa->read;
-			return;
+			wa_->set &= ~wa->clr;
 		}
+
+		wal->wa_count++;
+		wa_->set |= wa->set;
+		wa_->clr |= wa->clr;
+		wa_->read |= wa->read;
+		return;
 	}
 
 	wal->wa_count++;
-- 
2.20.1