[PATCH v2 1/5] drm/format-helper: Add struct drm_xfrm_buf to cache format conversion
Thomas Zimmermann
tzimmermann at suse.de
Wed Sep 20 14:24:27 UTC 2023
Hold temporary memory for format conversion in an instance of struct
drm_xfrm_buf. Update internal helpers of DRM's format-conversion code
accordingly. Drivers will later be able to keep this cache across
display updates.
Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
drivers/gpu/drm/drm_format_helper.c | 111 +++++++++++++++++++++++++---
include/drm/drm_format_helper.h | 46 ++++++++++++
2 files changed, 146 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index f93a4efcee909..029ca7893260a 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -17,9 +17,93 @@
#include <drm/drm_format_helper.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_fourcc.h>
+#include <drm/drm_managed.h>
#include <drm/drm_print.h>
#include <drm/drm_rect.h>
+static void drm_xfrm_buf_init_release(struct drm_device *dev, void *res)
+{
+ struct drm_xfrm_buf *buf = res;
+
+ drm_xfrm_buf_release(buf);
+}
+
+/**
+ * drmm_xfrm_buf_init - Initialize xfrm buffer with managed cleanup
+ * @dev: The DRM device
+ * @buf: The xfrm buffer to initialize
+ *
+ * Clears all fields in struct drm_xfrm_buf and installs a DRM release
+ * action for the buffer. The buffer will be empty with no preallocated
+ * resources.
+ *
+ * Returns:
+ * 0 on success, or a negative errno code otherwise.
+ */
+int drmm_xfrm_buf_init(struct drm_device *dev, struct drm_xfrm_buf *buf)
+{
+ buf->mem = NULL;
+ buf->size = 0;
+ buf->preallocated = false;
+
+ return drmm_add_action_or_reset(dev, drm_xfrm_buf_init_release, buf);
+}
+EXPORT_SYMBOL(drmm_xfrm_buf_init);
+
+/**
+ * drm_xfrm_buf_reserve - Allocates storage in an xfrm buffer
+ * @buf: The xfrm buffer
+ * @new_size: The minimum allocation size
+ * @flags: Flags for kmalloc()
+ *
+ * Allocates at least @new_size bytes and returns a pointer to the memory
+ * range. After calling this function, previously returned memory blocks
+ * are invalid. It's best to collect all memory requirements of a format
+ * conversion and call this function once to allocate the range.
+ *
+ * Returns:
+ * A pointer to the allocated memory range, or a pointer-encoded errno code otherwise.
+ */
+void *drm_xfrm_buf_reserve(struct drm_xfrm_buf *buf, size_t new_size, gfp_t flags)
+{
+ void *mem;
+
+ if (new_size <= buf->size)
+ goto out;
+ else if (buf->preallocated)
+ return NULL;
+
+ mem = krealloc(buf->mem, new_size, flags);
+ if (!mem)
+ return NULL;
+
+ buf->mem = mem;
+ buf->size = new_size;
+
+out:
+ return buf->mem;
+}
+EXPORT_SYMBOL(drm_xfrm_buf_reserve);
+
+/**
+ * drm_xfrm_buf_release - Releases an xfrm buffer's storage
+ * @buf: The xfrm buffer
+ *
+ * Releases the memory range references by the xfrm buffer. After
+ * this call, all pointers to the memory are invalid. Prefer
+ * drmm_xfrm_buffer_init() for cleaning up and unloading a driver.
+ */
+void drm_xfrm_buf_release(struct drm_xfrm_buf *buf)
+{
+ if (buf->preallocated)
+ return;
+
+ kfree(buf->mem);
+ buf->mem = NULL;
+ buf->size = 0;
+}
+EXPORT_SYMBOL(drm_xfrm_buf_release);
+
static unsigned int clip_offset(const struct drm_rect *clip, unsigned int pitch, unsigned int cpp)
{
return clip->y1 * pitch + clip->x1 * cpp;
@@ -45,6 +129,7 @@ EXPORT_SYMBOL(drm_fb_clip_offset);
static int __drm_fb_xfrm(void *dst, unsigned long dst_pitch, unsigned long dst_pixsize,
const void *vaddr, const struct drm_framebuffer *fb,
const struct drm_rect *clip, bool vaddr_cached_hint,
+ struct drm_xfrm_buf *xfrm,
void (*xfrm_line)(void *dbuf, const void *sbuf, unsigned int npixels))
{
unsigned long linepixels = drm_rect_width(clip);
@@ -60,7 +145,7 @@ static int __drm_fb_xfrm(void *dst, unsigned long dst_pitch, unsigned long dst_p
* one line at a time.
*/
if (!vaddr_cached_hint) {
- stmp = kmalloc(sbuf_len, GFP_KERNEL);
+ stmp = drm_xfrm_buf_reserve(xfrm, sbuf_len, GFP_KERNEL);
if (!stmp)
return -ENOMEM;
}
@@ -79,8 +164,6 @@ static int __drm_fb_xfrm(void *dst, unsigned long dst_pitch, unsigned long dst_p
dst += dst_pitch;
}
- kfree(stmp);
-
return 0;
}
@@ -88,6 +171,7 @@ static int __drm_fb_xfrm(void *dst, unsigned long dst_pitch, unsigned long dst_p
static int __drm_fb_xfrm_toio(void __iomem *dst, unsigned long dst_pitch, unsigned long dst_pixsize,
const void *vaddr, const struct drm_framebuffer *fb,
const struct drm_rect *clip, bool vaddr_cached_hint,
+ struct drm_xfrm_buf *xfrm,
void (*xfrm_line)(void *dbuf, const void *sbuf, unsigned int npixels))
{
unsigned long linepixels = drm_rect_width(clip);
@@ -101,9 +185,9 @@ static int __drm_fb_xfrm_toio(void __iomem *dst, unsigned long dst_pitch, unsign
void *dbuf;
if (vaddr_cached_hint) {
- dbuf = kmalloc(dbuf_len, GFP_KERNEL);
+ dbuf = drm_xfrm_buf_reserve(xfrm, dbuf_len, GFP_KERNEL);
} else {
- dbuf = kmalloc(stmp_off + sbuf_len, GFP_KERNEL);
+ dbuf = drm_xfrm_buf_reserve(xfrm, stmp_off + sbuf_len, GFP_KERNEL);
stmp = dbuf + stmp_off;
}
if (!dbuf)
@@ -124,8 +208,6 @@ static int __drm_fb_xfrm_toio(void __iomem *dst, unsigned long dst_pitch, unsign
dst += dst_pitch;
}
- kfree(dbuf);
-
return 0;
}
@@ -139,17 +221,24 @@ static int drm_fb_xfrm(struct iosys_map *dst,
static const unsigned int default_dst_pitch[DRM_FORMAT_MAX_PLANES] = {
0, 0, 0, 0
};
+ struct drm_xfrm_buf tmp = DRM_XFRM_BUF_INIT;
+ int ret;
if (!dst_pitch)
dst_pitch = default_dst_pitch;
/* TODO: handle src in I/O memory here */
if (dst[0].is_iomem)
- return __drm_fb_xfrm_toio(dst[0].vaddr_iomem, dst_pitch[0], dst_pixsize[0],
- src[0].vaddr, fb, clip, vaddr_cached_hint, xfrm_line);
+ ret = __drm_fb_xfrm_toio(dst[0].vaddr_iomem, dst_pitch[0], dst_pixsize[0],
+ src[0].vaddr, fb, clip, vaddr_cached_hint, &tmp,
+ xfrm_line);
else
- return __drm_fb_xfrm(dst[0].vaddr, dst_pitch[0], dst_pixsize[0],
- src[0].vaddr, fb, clip, vaddr_cached_hint, xfrm_line);
+ ret = __drm_fb_xfrm(dst[0].vaddr, dst_pitch[0], dst_pixsize[0],
+ src[0].vaddr, fb, clip, vaddr_cached_hint, &tmp,
+ xfrm_line);
+ drm_xfrm_buf_release(&tmp);
+
+ return ret;
}
/**
diff --git a/include/drm/drm_format_helper.h b/include/drm/drm_format_helper.h
index 291deb09475bb..245a5edc4735a 100644
--- a/include/drm/drm_format_helper.h
+++ b/include/drm/drm_format_helper.h
@@ -15,6 +15,52 @@ struct drm_rect;
struct iosys_map;
+/**
+ * struct drm_xfrm_buf - Stores transformation and conversion state
+ *
+ * DRM helpers for format conversion store temporary state in
+ * struct drm_xfrm_buf. The buffer's resources can be reused
+ * among multiple conversion operations.
+ *
+ * All fields are considered private.
+ */
+struct drm_xfrm_buf {
+ void *mem;
+ size_t size;
+ bool preallocated;
+};
+
+/**
+ * DRM_XFRM_BUF_INIT - Initializer for struct drm_xfrm_buf
+ *
+ * Initializes an instance of struct drm_xfrm_buf to default
+ * values.
+ */
+#define DRM_XFRM_BUF_INIT { \
+ .mem = NULL, \
+ .size = 0, \
+ .preallocated = false, \
+ }
+
+/**
+ * DRM_XFRM_BUF_INIT_PREALLOCATED - Initializer for struct drm_xfrm_buf
+ * @_mem: The preallocated memory area
+ * @_size: The number of bytes in _mem
+ *
+ * Initializes an instance of struct drm_xfrm_buf to preallocated
+ * storage. The caller is responsible for a releases the provided
+ * memory range.
+ */
+#define DRM_XFRM_BUF_INIT_PREALLOCATED(_mem, _size) { \
+ .mem = (_mem), \
+ .size = (_size), \
+ .preallocated = true, \
+ }
+
+int drmm_xfrm_buf_init(struct drm_device *dev, struct drm_xfrm_buf *buf);
+void *drm_xfrm_buf_reserve(struct drm_xfrm_buf *buf, size_t new_size, gfp_t flags);
+void drm_xfrm_buf_release(struct drm_xfrm_buf *buf);
+
unsigned int drm_fb_clip_offset(unsigned int pitch, const struct drm_format_info *format,
const struct drm_rect *clip);
--
2.42.0
More information about the dri-devel
mailing list