drm/i915/dsb: DSB code refactoring

Refactor DSB implementation to be compatible with Xe driver.

v1: RFC version.
v2: Make intel_dsb structure opaque from external usage. [Jani]
v3: Rebased on latest.
v4:
- Add boundary check in dsb_buffer_memset(). [Luca]
- Use size_t instead of u32. [Luca]
v5: WARN_ON() added for out of boudary case with some optimization. [Luca]
v6: Rebased on latest and fix a rebase-miss.

Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231110032518.3564279-1-animesh.manna@intel.com

1 files changed, 82 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_dsb_buffer.c b/drivers/gpu/drm/i915/display/intel_dsb_buffer.c
new file mode 100644
index 000000000000..c77d48bda26a
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_dsb_buffer.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright 2023, Intel Corporation.
+ */
+
+#include "gem/i915_gem_internal.h"
+#include "gem/i915_gem_lmem.h"
+#include "i915_drv.h"
+#include "i915_vma.h"
+#include "intel_display_types.h"
+#include "intel_dsb_buffer.h"
+
+u32 intel_dsb_buffer_ggtt_offset(struct intel_dsb_buffer *dsb_buf)
+{
+	return i915_ggtt_offset(dsb_buf->vma);
+}
+
+void intel_dsb_buffer_write(struct intel_dsb_buffer *dsb_buf, u32 idx, u32 val)
+{
+	dsb_buf->cmd_buf[idx] = val;
+}
+
+u32 intel_dsb_buffer_read(struct intel_dsb_buffer *dsb_buf, u32 idx)
+{
+	return dsb_buf->cmd_buf[idx];
+}
+
+void intel_dsb_buffer_memset(struct intel_dsb_buffer *dsb_buf, u32 idx, u32 val, size_t size)
+{
+	WARN_ON(idx > (dsb_buf->buf_size - size) / sizeof(*dsb_buf->cmd_buf));
+
+	memset(&dsb_buf->cmd_buf[idx], val, size);
+}
+
+bool intel_dsb_buffer_create(struct intel_crtc *crtc, struct intel_dsb_buffer *dsb_buf, size_t size)
+{
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
+	struct drm_i915_gem_object *obj;
+	struct i915_vma *vma;
+	u32 *buf;
+
+	if (HAS_LMEM(i915)) {
+		obj = i915_gem_object_create_lmem(i915, PAGE_ALIGN(size),
+						  I915_BO_ALLOC_CONTIGUOUS);
+		if (IS_ERR(obj))
+			return false;
+	} else {
+		obj = i915_gem_object_create_internal(i915, PAGE_ALIGN(size));
+		if (IS_ERR(obj))
+			return false;
+
+		i915_gem_object_set_cache_coherency(obj, I915_CACHE_NONE);
+	}
+
+	vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, 0);
+	if (IS_ERR(vma)) {
+		i915_gem_object_put(obj);
+		return false;
+	}
+
+	buf = i915_gem_object_pin_map_unlocked(vma->obj, I915_MAP_WC);
+	if (IS_ERR(buf)) {
+		i915_vma_unpin_and_release(&vma, I915_VMA_RELEASE_MAP);
+		return false;
+	}
+
+	dsb_buf->vma = vma;
+	dsb_buf->cmd_buf = buf;
+	dsb_buf->buf_size = size;
+
+	return true;
+}
+
+void intel_dsb_buffer_cleanup(struct intel_dsb_buffer *dsb_buf)
+{
+	i915_vma_unpin_and_release(&dsb_buf->vma, I915_VMA_RELEASE_MAP);
+}
+
+void intel_dsb_buffer_flush_map(struct intel_dsb_buffer *dsb_buf)
+{
+	i915_gem_object_flush_map(dsb_buf->vma->obj);
+}