The utility uses kmap_atomic() instead of vmapping the whole buffer
object. As a result there will be more book-keeping but on some
architectures this will help avoid exhausting vmalloc space and also
avoid expensive TLB flushes.
The blit utility also adds a provision to compute a bounding box of
changed content, which is very useful to optimize presentation speed
of ill-behaved applications that don't supply proper damage regions, and
for page-flips. The cost of computing the bounding box is not that
expensive when done in a cpu-blit utility like this.
Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
Reviewed-by: Brian Paul <brianp@xxxxxxxxxx>
---
drivers/gpu/drm/vmwgfx/Makefile | 2 +-
drivers/gpu/drm/vmwgfx/vmwgfx_blit.c | 506 +++++++++++++++++++++++++++++++++++
drivers/gpu/drm/vmwgfx/vmwgfx_drv.h | 48 ++++
3 files changed, 555 insertions(+), 1 deletion(-)
create mode 100644 drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
diff --git a/drivers/gpu/drm/vmwgfx/Makefile b/drivers/gpu/drm/vmwgfx/Makefile
index ad80211..794cc9d 100644
--- a/drivers/gpu/drm/vmwgfx/Makefile
+++ b/drivers/gpu/drm/vmwgfx/Makefile
@@ -7,6 +7,6 @@ vmwgfx-y := vmwgfx_execbuf.o vmwgfx_gmr.o vmwgfx_kms.o vmwgfx_drv.o \
vmwgfx_surface.o vmwgfx_prime.o vmwgfx_mob.o vmwgfx_shader.o \
vmwgfx_cmdbuf_res.o vmwgfx_cmdbuf.o vmwgfx_stdu.o \
vmwgfx_cotable.o vmwgfx_so.o vmwgfx_binding.o vmwgfx_msg.o \
- vmwgfx_simple_resource.o vmwgfx_va.o
+ vmwgfx_simple_resource.o vmwgfx_va.o vmwgfx_blit.o
obj-$(CONFIG_DRM_VMWGFX) := vmwgfx.o
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c b/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
new file mode 100644
index 0000000..2730403
--- /dev/null
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
@@ -0,0 +1,506 @@
+/**************************************************************************
+ *
+ * Copyright © 2017 VMware, Inc., Palo Alto, CA., USA
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+#include "vmwgfx_drv.h"
+
+/*
+ * Template that implements find_first_diff() for a generic
+ * unsigned integer type. @size and return value are in bytes.
+ */
+#define VMW_FIND_FIRST_DIFF(_type) \
+static size_t vmw_find_first_diff_ ## _type \
+ (const _type * dst, const _type * src, size_t size)\
+{ \
+ size_t i; \
+ \
+ for (i = 0; i < size; i += sizeof(_type)) { \
+ if (*dst++ != *src++) \
+ break; \
+ } \
+ \
+ return i; \
+}
+
+
+/*
+ * Template that implements find_last_diff() for a generic
+ * unsigned integer type. Pointers point to the item following the
+ * *end* of the area to be examined. @size and return value are in
+ * bytes.
+ */
+#define VMW_FIND_LAST_DIFF(_type) \
+static ssize_t vmw_find_last_diff_ ## _type( \
+ const _type * dst, const _type * src, size_t size) \
+{ \
+ while (size) { \
+ if (*--dst != *--src) \
+ break; \
+ \
+ size -= sizeof(_type); \
+ } \
+ return size; \
+}
+
+
+/*
+ * Instantiate find diff functions for relevant unsigned integer sizes,
+ * assuming that wider integers are faster (including aligning) up to the
+ * architecture native width, which is assumed to be 32 bit unless
+ * CONFIG_64BIT is defined.
+ */
+VMW_FIND_FIRST_DIFF(u8);
+VMW_FIND_LAST_DIFF(u8);
+
+VMW_FIND_FIRST_DIFF(u16);
+VMW_FIND_LAST_DIFF(u16);
+
+VMW_FIND_FIRST_DIFF(u32);
+VMW_FIND_LAST_DIFF(u32);
+
+#ifdef CONFIG_64BIT
+VMW_FIND_FIRST_DIFF(u64);
+VMW_FIND_LAST_DIFF(u64);
+#endif
+
+
+/* We use size aligned copies. This computes (addr - align(addr)) */
+#define SPILL(_var, _type) ((unsigned long) _var & (sizeof(_type) - 1))
+
+
+/*
+ * Template to compute find_first_diff() for a certain integer type
+ * including a head copy for alignment, and adjustment of parameters
+ * for tail find or increased resolution find using an unsigned integer find
+ * of smaller width. If finding is complete, and resolution is sufficient,
+ * the macro executes a return statement. Otherwise it falls through.
+ */
+#define VMW_TRY_FIND_FIRST_DIFF(_type) \
+do { \
+ unsigned int spill = SPILL(dst, _type); \
+ size_t diff_offs; \
+ \
+ if (spill && spill == SPILL(src, _type) && \
+ sizeof(_type) - spill <= size) { \
+ spill = sizeof(_type) - spill; \
+ diff_offs = vmw_find_first_diff_u8(dst, src, spill); \
+ if (diff_offs < spill) \
+ return round_down(offset + diff_offs, granularity); \
+ \
+ dst += spill; \
+ src += spill; \
+ size -= spill; \
+ offset += spill; \
+ spill = 0; \
+ } \
+ if (!spill && !SPILL(src, _type)) { \
+ size_t to_copy = size & ~(sizeof(_type) - 1); \
+ \
+ diff_offs = vmw_find_first_diff_ ## _type \
+ ((_type *) dst, (_type *) src, to_copy); \
+ if (diff_offs >= size || granularity == sizeof(_type)) \
+ return (offset + diff_offs); \
+ \
+ dst += diff_offs; \
+ src += diff_offs; \
+ size -= diff_offs; \
+ offset += diff_offs; \
+ } \
+} while (0) \
+
+
+/**
+ * vmw_find_first_diff - find the first difference between dst and src
+ *
+ * @dst: The destination address
+ * @src: The source address
+ * @size: Number of bytes to compare
+ * @granularity: The granularity needed for the return value in bytes.
+ * return: The offset from find start where the first difference was
+ * encountered in bytes. If no difference was found, the function returns
+ * a value >= @size.
+ */
+static size_t vmw_find_first_diff(const u8 *dst, const u8 *src, size_t size,
+ size_t granularity)
+{
+ size_t offset = 0;
+
+ /*
+ * Try finding with large integers if alignment allows, or we can
+ * fix it. Fall through if we need better resolution or alignment
+ * was bad.
+ */
+#ifdef CONFIG_64BIT
+ VMW_TRY_FIND_FIRST_DIFF(u64);
+#endif
+ VMW_TRY_FIND_FIRST_DIFF(u32);
+ VMW_TRY_FIND_FIRST_DIFF(u16);
+
+ return round_down(offset + vmw_find_first_diff_u8(dst, src, size),
+ granularity);
+}
+
+
+/*
+ * Template to compute find_last_diff() for a certain integer type
+ * including a tail copy for alignment, and adjustment of parameters
+ * for head find or increased resolution find using an unsigned integer find
+ * of smaller width. If finding is complete, and resolution is sufficient,
+ * the macro executes a return statement. Otherwise it falls through.
+ */
+#define VMW_TRY_FIND_LAST_DIFF(_type) \
+do { \
+ unsigned int spill = SPILL(dst, _type); \
+ ssize_t location; \
+ ssize_t diff_offs; \
+ \
+ if (spill && spill <= size && spill == SPILL(src, _type)) { \
+ diff_offs = vmw_find_last_diff_u8(dst, src, spill); \
+ if (diff_offs) { \
+ location = size - spill + diff_offs - 1; \
+ return round_down(location, granularity); \
+ } \
+ \
+ dst -= spill; \
+ src -= spill; \
+ size -= spill; \
+ spill = 0; \
+ } \
+ if (!spill && !SPILL(src, _type)) { \
+ size_t to_copy = round_down(size, sizeof(_type)); \
+ \
+ diff_offs = vmw_find_last_diff_ ## _type \
+ ((_type *) dst, (_type *) src, to_copy); \
+ location = size - to_copy + diff_offs - sizeof(_type); \
+ if (location < 0 || granularity == sizeof(_type)) \
+ return location; \
+ \
+ dst -= to_copy - diff_offs; \
+ src -= to_copy - diff_offs; \
+ size -= to_copy - diff_offs; \
+ } \
+} while (0)
+
+
+/**
+ * vmw_find_last_diff - find the last difference between dst and src
+ *
+ * @dst: The destination address
+ * @src: The source address
+ * @size: Number of bytes to compare
+ * @granularity: The granularity needed for the return value in bytes.
+ * return: The offset from find start where the last difference was
+ * encountered in bytes, or a negative value if no difference was found.
+ */
+static ssize_t vmw_find_last_diff(const u8 *dst, const u8 *src, size_t size,
+ size_t granularity)
+{
+ dst += size;
+ src += size;
+
+#ifdef CONFIG_64BIT
+ VMW_TRY_FIND_LAST_DIFF(u64);
+#endif
+ VMW_TRY_FIND_LAST_DIFF(u32);
+ VMW_TRY_FIND_LAST_DIFF(u16);
+
+ return round_down(vmw_find_last_diff_u8(dst, src, size) - 1,
+ granularity);
+}
+
+
+/**
+ * vmw_memcpy - A wrapper around kernel memcpy with allowing to plug it into a
+ * struct vmw_diff_cpy.
+ *
+ * @diff: The struct vmw_diff_cpy closure argument (unused).
+ * @dest: The copy destination.
+ * @src: The copy source.
+ * @n: Number of bytes to copy.
+ */
+void vmw_memcpy(struct vmw_diff_cpy *diff, u8 *dest, const u8 *src, size_t n)
+{
+ memcpy(dest, src, n);
+}
+
+
+/**
+ * vmw_adjust_rect - Adjust rectangle coordinates for newly found difference
+ *
+ * @diff: The struct vmw_diff_cpy used to track the modified bounding box.
+ * @diff_offs: The offset from @diff->line_offset where the difference was
+ * found.
+ */
+static void vmw_adjust_rect(struct vmw_diff_cpy *diff, size_t diff_offs)
+{
+ size_t offs = (diff_offs + diff->line_offset) / diff->cpp;
+ struct drm_rect *rect = &diff->rect;
+
+ rect->x1 = min_t(int, rect->x1, offs);
+ rect->x2 = max_t(int, rect->x2, offs + 1);
+ rect->y1 = min_t(int, rect->y1, diff->line);
+ rect->y2 = max_t(int, rect->y2, diff->line + 1);
+}
+
+/**
+ * vmw_diff_memcpy - memcpy that creates a bounding box of modified content.
+ *
+ * @diff: The struct vmw_diff_cpy used to track the modified bounding box.
+ * @dest: The copy destination.
+ * @src: The copy source.
+ * @n: Number of bytes to copy.
+ *
+ * In order to correctly track the modified content, the field @diff->line must
+ * be pre-loaded with the current line number, the field @diff->line_offset must
+ * be pre-loaded with the line offset in bytes where the copy starts, and
+ * finally the field @diff->cpp need to be preloaded with the number of bytes
+ * per unit in the horizontal direction of the area we're examining.
+ * Typically bytes per pixel.
+ * This is needed to know the needed granularity of the difference computing
+ * operations. A higher cpp generally leads to faster execution at the cost of
+ * bounding box width precision.
+ */
+void vmw_diff_memcpy(struct vmw_diff_cpy *diff, u8 *dest, const u8 *src,
+ size_t n)
+{
+ ssize_t csize, byte_len;
+
+ if (WARN_ON_ONCE(round_down(n, diff->cpp) != n))
+ return;
+
+ /* TODO: Possibly use a single vmw_find_first_diff per line? */
+ csize = vmw_find_first_diff(dest, src, n, diff->cpp);
+ if (csize < n) {
+ vmw_adjust_rect(diff, csize);
+ byte_len = diff->cpp;
+
+ /*
+ * Starting from where first difference was found, find
+ * location of last difference, and then copy.
+ */
+ diff->line_offset += csize;
+ dest += csize;
+ src += csize;
+ n -= csize;
+ csize = vmw_find_last_diff(dest, src, n, diff->cpp);
+ if (csize >= 0) {
+ byte_len += csize;
+ vmw_adjust_rect(diff, csize);
+ }
+ memcpy(dest, src, byte_len);
+ }
+ diff->line_offset += n;
+}
+
+/**
+ * struct vmw_bo_blit_line_data - Convenience argument to vmw_bo_cpu_blit_line
+ *
+ * @mapped_dst: Already mapped destination page index in @dst_pages.
+ * @dst_addr: Kernel virtual address of mapped destination page.
+ * @dst_pages: Array of destination bo pages.
+ * @dst_num_pages: Number of destination bo pages.
+ * @dst_prot: Destination bo page protection.
+ * @mapped_src: Already mapped source page index in @dst_pages.
+ * @src_addr: Kernel virtual address of mapped source page.
+ * @src_pages: Array of source bo pages.
+ * @src_num_pages: Number of source bo pages.
+ * @src_prot: Source bo page protection.
+ * @diff: Struct vmw_diff_cpy, in the end forwarded to the memcpy routine.
+ */
+struct vmw_bo_blit_line_data {
+ u32 mapped_dst;
+ u8 *dst_addr;
+ struct page **dst_pages;
+ u32 dst_num_pages;
+ pgprot_t dst_prot;
+ u32 mapped_src;
+ u8 *src_addr;
+ struct page **src_pages;
+ u32 src_num_pages;
+ pgprot_t src_prot;
+ struct vmw_diff_cpy *diff;
+};
+
+/**
+ * vmw_bo_cpu_blit_line - Blit part of a line from one bo to another.
+ *
+ * @d: Blit data as described above.
+ * @dst_offset: Destination copy start offset from start of bo.
+ * @src_offset: Source copy start offset from start of bo.
+ * @bytes_to_copy: Number of bytes to copy in this line.
+ */
+static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
+ u32 dst_offset,
+ u32 src_offset,
+ u32 bytes_to_copy)
+{
+ struct vmw_diff_cpy *diff = d->diff;
+
+ while (bytes_to_copy) {
+ u32 copy_size = bytes_to_copy;
+ u32 dst_page = dst_offset >> PAGE_SHIFT;
+ u32 src_page = src_offset >> PAGE_SHIFT;
+ u32 dst_page_offset = dst_offset & ~PAGE_MASK;
+ u32 src_page_offset = src_offset & ~PAGE_MASK;
+ bool unmap_dst = d->dst_addr && dst_page != d->mapped_dst;
+ bool unmap_src = d->src_addr && (src_page != d->mapped_src ||
+ unmap_dst);
+
+ copy_size = min_t(u32, copy_size, PAGE_SIZE - dst_page_offset);
+ copy_size = min_t(u32, copy_size, PAGE_SIZE - src_page_offset);
+
+ if (unmap_src) {
+ ttm_kunmap_atomic_prot(d->src_addr, d->src_prot);
+ d->src_addr = NULL;
+ }
+
+ if (unmap_dst) {
+ ttm_kunmap_atomic_prot(d->dst_addr, d->dst_prot);
+ d->dst_addr = NULL;
+ }
+
+ if (!d->dst_addr) {
+ if (WARN_ON_ONCE(dst_page >= d->dst_num_pages))
+ return -EINVAL;
+
+ d->dst_addr =
+ ttm_kmap_atomic_prot(d->dst_pages[dst_page],
+ d->dst_prot);
+ if (!d->dst_addr)
+ return -ENOMEM;
+
+ d->mapped_dst = dst_page;
+ }
+
+ if (!d->src_addr) {
+ if (WARN_ON_ONCE(src_page >= d->src_num_pages))
+ return -EINVAL;
+
+ d->src_addr =
+ ttm_kmap_atomic_prot(d->src_pages[src_page],
+ d->src_prot);
+ if (!d->src_addr)
+ return -ENOMEM;
+
+ d->mapped_src = src_page;
+ }
+ diff->memcpy(diff, d->dst_addr + dst_page_offset,
+ d->src_addr + src_page_offset, copy_size);
+
+ bytes_to_copy -= copy_size;
+ dst_offset += copy_size;
+ src_offset += copy_size;
+ }
+
+ return 0;
+}
+
+/**
+ * ttm_bo_cpu_blit - in-kernel cpu blit.
+ *
+ * @dst: Destination buffer object.
+ * @dst_offset: Destination offset of blit start in bytes.
+ * @dst_stride: Destination stride in bytes.
+ * @src: Source buffer object.
+ * @src_offset: Source offset of blit start in bytes.
+ * @src_stride: Source stride in bytes.
+ * @w: Width of blit.
+ * @h: Height of blit.
+ * return: Zero on success. Negative error value on failure. Will print out
+ * kernel warnings on caller bugs.
+ *
+ * Performs a CPU blit from one buffer object to another avoiding a full
+ * bo vmap which may exhaust- or fragment vmalloc space.
+ * On supported architectures (x86), we're using kmap_atomic which avoids
+ * cross-processor TLB- and cache flushes and may, on non-HIGHMEM systems
+ * reference already set-up mappings.
+ *
+ * Neither of the buffer objects may be placed in PCI memory
+ * (Fixed memory in TTM terminology) when using this function.
+ */
+int vmw_bo_cpu_blit(struct ttm_buffer_object *dst,
+ u32 dst_offset, u32 dst_stride,
+ struct ttm_buffer_object *src,
+ u32 src_offset, u32 src_stride,
+ u32 w, u32 h,
+ struct vmw_diff_cpy *diff)
+{
+ struct ttm_operation_ctx ctx = {
+ .interruptible = false,
+ .no_wait_gpu = false
+ };
+ u32 j, initial_line = dst_offset / dst_stride;
+ struct vmw_bo_blit_line_data d;
+ int ret = 0;
+
+ /* Buffer objects need to be either pinned or reserved: */
+ if (!(dst->mem.placement & TTM_PL_FLAG_NO_EVICT))
+ lockdep_assert_held(&dst->resv->lock.base);
+ if (!(src->mem.placement & TTM_PL_FLAG_NO_EVICT))
+ lockdep_assert_held(&src->resv->lock.base);
+
+ if (dst->ttm->state == tt_unpopulated) {
+ ret = dst->ttm->bdev->driver->ttm_tt_populate(dst->ttm, &ctx);
+ if (ret)
+ return ret;
+ }
+
+ if (src->ttm->state == tt_unpopulated) {
+ ret = src->ttm->bdev->driver->ttm_tt_populate(src->ttm, &ctx);
+ if (ret)
+ return ret;
+ }
+
+ d.mapped_dst = 0;
+ d.mapped_src = 0;
+ d.dst_addr = NULL;
+ d.src_addr = NULL;
+ d.dst_pages = dst->ttm->pages;
+ d.src_pages = src->ttm->pages;
+ d.dst_num_pages = dst->num_pages;
+ d.src_num_pages = src->num_pages;
+ d.dst_prot = ttm_io_prot(dst->mem.placement, PAGE_KERNEL);
+ d.src_prot = ttm_io_prot(src->mem.placement, PAGE_KERNEL);
+ d.diff = diff;
+
+ for (j = 0; j < h; ++j) {
+ diff->line = j + initial_line;
+ diff->line_offset = dst_offset % dst_stride;
+ ret = vmw_bo_cpu_blit_line(&d, dst_offset, src_offset, w);
+ if (ret)
+ goto out;
+
+ dst_offset += dst_stride;
+ src_offset += src_stride;
+ }
+out:
+ if (d.src_addr)
+ ttm_kunmap_atomic_prot(d.src_addr, d.src_prot);
+ if (d.dst_addr)
+ ttm_kunmap_atomic_prot(d.dst_addr, d.dst_prot);
+
+ return ret;
+}
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index 7e5f30e..99e7e426 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -678,6 +678,7 @@ extern void vmw_fence_single_bo(struct ttm_buffer_object *bo,
struct vmw_fence_obj *fence);
extern void vmw_resource_evict_all(struct vmw_private *dev_priv);
+
/**
* DMA buffer helper routines - vmwgfx_dmabuf.c
*/
@@ -1165,6 +1166,53 @@ extern int vmw_cmdbuf_cur_flush(struct vmw_cmdbuf_man *man,
bool interruptible);
extern void vmw_cmdbuf_irqthread(struct vmw_cmdbuf_man *man);
+/* CPU blit utilities - vmwgfx_blit.c */
+
+/**
+ * struct vmw_diff_cpy - CPU blit information structure
+ *
+ * @rect: The output bounding box rectangle.
+ * @line: The current line of the blit.
+ * @line_offset: Offset of the current line segment.
+ * @cpp: Bytes per pixel (granularity information).
+ * @memcpy: Which memcpy function to use.
+ */
+struct vmw_diff_cpy {
+ struct drm_rect rect;
+ size_t line;
+ size_t line_offset;
+ int cpp;
+ void (*memcpy)(struct vmw_diff_cpy *diff, u8 *dest, const u8 *src,
+ size_t n);
+};
+
+#define VMW_CPU_BLIT_INITIALIZER { \
+ .memcpy = vmw_memcpy, \
+}
+
+#define VMW_CPU_BLIT_DIFF_INITIALIZER(_cpp) { \
+ .line = 0, \
+ .line_offset = 0, \
+ .rect = { .x1 = INT_MAX/2, \
+ .y1 = INT_MAX/2, \
+ .x2 = INT_MIN/2, \
+ .y2 = INT_MIN/2 \
+ }, \
+ .cpp = _cpp, \
+ .memcpy = vmw_diff_memcpy, \
+}
+
+void vmw_diff_memcpy(struct vmw_diff_cpy *diff, u8 *dest, const u8 *src,
+ size_t n);
+
+void vmw_memcpy(struct vmw_diff_cpy *diff, u8 *dest, const u8 *src, size_t n);
+
+int vmw_bo_cpu_blit(struct ttm_buffer_object *dst,
+ u32 dst_offset, u32 dst_stride,
+ struct ttm_buffer_object *src,
+ u32 src_offset, u32 src_stride,
+ u32 w, u32 h,
+ struct vmw_diff_cpy *diff);
/**
* Inline helper functions
--
2.7.4
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