[igt-dev] [PATCH i-g-t v2 4/4] lib/igt_fb: Generalize the slow read from gtt mmap handling

Ville Syrjala
2018-11-02T19:37:38Z

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Make the handling of slow gtt mmap reads generic, and extend it to
the pixman converter. Makes the pixman path a bit faster.

With testing just XRGB8888 and XBGR8888 on KBL:
$ time kms_plane --r pixel-format-pipe-A-planes
- real 0m18,757s
+ real 0m2,635s

v2: Use the original src buffer if the malloc fails (Chris)
Drop the duplicated comment about things being slow

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
lib/igt_fb.c | 61 +++++++++++++++++++++++++++++++++++++---------------
1 file changed, 44 insertions(+), 17 deletions(-)

diff --git a/lib/igt_fb.c b/lib/igt_fb.c
index 97310f70b635..01efd269714b 100644
--- a/lib/igt_fb.c
+++ b/lib/igt_fb.c
@@ -1506,6 +1506,7 @@ static void write_rgb(uint8_t *rgb24, const struct igt_vec4 *rgb)
struct fb_convert_buf {
void *ptr;
struct igt_fb *fb;
+ bool slow_reads;
};

struct fb_convert {
@@ -1513,6 +1514,34 @@ struct fb_convert {
struct fb_convert_buf src;
};

+static void *convert_src_get(const struct fb_convert *cvt)
+{
+ void *buf;
+
+ if (!cvt->src.slow_reads)
+ return cvt->src.ptr;
+
+ /*
+ * Reading from the BO is awfully slow because of lack of read caching,
+ * it's faster to copy the whole BO to a temporary buffer and convert
+ * from there.
+ */
+ buf = malloc(cvt->src.fb->size);
+ if (!buf)
+ return cvt->src.ptr;
+
+ igt_memcpy_from_wc(buf, cvt->src.ptr, cvt->src.fb->size);
+
+ return buf;
+}
+
+static void convert_src_put(const struct fb_convert *cvt,
+ void *src_buf)
+{
+ if (src_buf != cvt->src.ptr)
+ free(src_buf);
+}
+
static void convert_nv12_to_rgb24(struct fb_convert *cvt)
{
int i, j;
@@ -1520,19 +1549,14 @@ static void convert_nv12_to_rgb24(struct fb_convert *cvt)
uint8_t *rgb24 = cvt->dst.ptr;
unsigned int rgb24_stride = cvt->dst.fb->strides[0];
unsigned int planar_stride = cvt->src.fb->strides[0];
- uint8_t *buf = malloc(cvt->src.fb->size);
struct igt_mat4 m = igt_ycbcr_to_rgb_matrix(cvt->src.fb->color_encoding,
cvt->src.fb->color_range);
+ uint8_t *buf;

igt_assert(cvt->src.fb->drm_format == DRM_FORMAT_NV12 &&
cvt->dst.fb->drm_format == DRM_FORMAT_XRGB8888);

- /*
- * Reading from the BO is awfully slow because of lack of read caching,
- * it's faster to copy the whole BO to a temporary buffer and convert
- * from there.
- */
- igt_memcpy_from_wc(buf, cvt->src.ptr, cvt->src.fb->size);
+ buf = convert_src_get(cvt);
y = buf + cvt->src.fb->offsets[0];
uv = buf + cvt->src.fb->offsets[1];

@@ -1622,7 +1646,7 @@ static void convert_nv12_to_rgb24(struct fb_convert *cvt)
}
}

- free(buf);
+ convert_src_put(cvt, buf);
}

static void convert_rgb24_to_nv12(struct fb_convert *cvt)
@@ -1760,10 +1784,10 @@ static void convert_yuyv_to_rgb24(struct fb_convert *cvt)
uint8_t *rgb24 = cvt->dst.ptr;
unsigned int rgb24_stride = cvt->dst.fb->strides[0];
unsigned int yuyv_stride = cvt->src.fb->strides[0];
- uint8_t *buf = malloc(cvt->src.fb->size);
struct igt_mat4 m = igt_ycbcr_to_rgb_matrix(cvt->src.fb->color_encoding,
cvt->src.fb->color_range);
const unsigned char *swz = yuyv_swizzle(cvt->src.fb->drm_format);
+ uint8_t *buf;

igt_assert((cvt->src.fb->drm_format == DRM_FORMAT_YUYV ||
cvt->src.fb->drm_format == DRM_FORMAT_UYVY ||
@@ -1771,12 +1795,7 @@ static void convert_yuyv_to_rgb24(struct fb_convert *cvt)
cvt->src.fb->drm_format == DRM_FORMAT_VYUY) &&
cvt->dst.fb->drm_format == DRM_FORMAT_XRGB8888);

- /*
- * Reading from the BO is awfully slow because of lack of read caching,
- * it's faster to copy the whole BO to a temporary buffer and convert
- * from there.
- */
- igt_memcpy_from_wc(buf, cvt->src.ptr, cvt->src.fb->size);
+ buf = convert_src_get(cvt);
yuyv = buf;

for (i = 0; i < cvt->dst.fb->height; i++) {
@@ -1816,7 +1835,7 @@ static void convert_yuyv_to_rgb24(struct fb_convert *cvt)
yuyv += yuyv_stride;
}

- free(buf);
+ convert_src_put(cvt, buf);
}

static void convert_rgb24_to_yuyv(struct fb_convert *cvt)
@@ -1877,14 +1896,17 @@ static void convert_pixman(struct fb_convert *cvt)
pixman_format_code_t src_pixman = drm_format_to_pixman(cvt->src.fb->drm_format);
pixman_format_code_t dst_pixman = drm_format_to_pixman(cvt->dst.fb->drm_format);
pixman_image_t *dst_image, *src_image;
+ void *src_ptr;

igt_assert((src_pixman != PIXMAN_invalid) &&
(dst_pixman != PIXMAN_invalid));

+ src_ptr = convert_src_get(cvt);
+
src_image = pixman_image_create_bits(src_pixman,
cvt->src.fb->width,
cvt->src.fb->height,
- cvt->src.ptr,
+ src_ptr,
cvt->src.fb->strides[0]);
igt_assert(src_image);

@@ -1900,6 +1922,8 @@ static void convert_pixman(struct fb_convert *cvt)
cvt->dst.fb->width, cvt->dst.fb->height);
pixman_image_unref(dst_image);
pixman_image_unref(src_image);
+
+ convert_src_put(cvt, src_ptr);
}

static void fb_convert(struct fb_convert *cvt)
@@ -1991,6 +2015,9 @@ static void create_cairo_surface__convert(int fd, struct igt_fb *fb)
blit->base.linear.fb.gem_handle = 0;
blit->base.linear.map = map_bo(fd, fb);
igt_assert(blit->base.linear.map);
+
+ /* reading via gtt mmap is slow */
+ cvt.src.slow_reads = is_i915_device(fd);
}

cvt.dst.ptr = blit->shadow_ptr;
--
2.18.1