[Intel-gfx] [PATCH v8 06/15] drm/ttm: Add a generic TTM memcpy move for page-based iomem

Thomas Hellström
2021-05-31T17:23:04Z

The internal ttm_bo_util memcpy uses ioremap functionality, and while it
probably might be possible to use it for copying in- and out of
sglist represented io memory, using io_mem_reserve() / io_mem_free()
callbacks, that would cause problems with fault().
Instead, implement a method mapping page-by-page using kmap_local()
semantics. As an additional benefit we then avoid the occasional global
TLB flushes of ioremap() and consuming ioremap space, elimination of a
critical point of failure and with a slight change of semantics we could
also push the memcpy out async for testing and async driver development
purposes.

A special linear iomem iterator is introduced internally to mimic the
old ioremap behaviour for code-paths that can't immediately be ported
over. This adds to the code size and should be considered a temporary
solution.

Looking at the code we have a lot of checks for iomap tagged pointers.
Ideally we should extend the core memremap functions to also accept
uncached memory and kmap_local functionality. Then we could strip a
lot of code.

Cc: Christian König <christian.koenig@amd.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
---
v3:
- Split up in various TTM files and addressed review comments by
Christian König. Tested and fixed legacy iomap memcpy path on i915.
v4:
- Fix an uninitialized variable
Reported by: kernel test robot <lkp@intel.com>
Reported by: Dan Carpenter <dan.carpenter@oracle.com>
- Minor change to the ttm_move_memcpy() interface.
- Gracefully handle lack of memremap() support on memcpy
(Reported by Matthew Auld)
- Minor style fix (Reported by Matthew Auld)
v8:
- Change num_pages from pgoff_t to uint32_t (Suggested by Christian König)
---
drivers/gpu/drm/ttm/ttm_bo_util.c | 280 ++++++++++-------------------
drivers/gpu/drm/ttm/ttm_module.c | 35 ++++
drivers/gpu/drm/ttm/ttm_resource.c | 193 ++++++++++++++++++++
drivers/gpu/drm/ttm/ttm_tt.c | 42 +++++
include/drm/ttm/ttm_bo_driver.h | 28 +++
include/drm/ttm/ttm_caching.h | 2 +
include/drm/ttm/ttm_kmap_iter.h | 61 +++++++
include/drm/ttm/ttm_resource.h | 61 +++++++
include/drm/ttm/ttm_tt.h | 16 ++
9 files changed, 536 insertions(+), 182 deletions(-)
create mode 100644 include/drm/ttm/ttm_kmap_iter.h

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index ae8b61460724..a800998a12b0 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -72,190 +72,126 @@ void ttm_mem_io_free(struct ttm_device *bdev,
mem->bus.addr = NULL;
}

-static int ttm_resource_ioremap(struct ttm_device *bdev,
- struct ttm_resource *mem,
- void **virtual)
+/**
+ * ttm_move_memcpy - Helper to perform a memcpy ttm move operation.
+ * @bo: The struct ttm_buffer_object.
+ * @new_mem: The struct ttm_resource we're moving to (copy destination).
+ * @new_iter: A struct ttm_kmap_iter representing the destination resource.
+ * @src_iter: A struct ttm_kmap_iter representing the source resource.
+ *
+ * This function is intended to be able to move out async under a
+ * dma-fence if desired.
+ */
+void ttm_move_memcpy(struct ttm_buffer_object *bo,
+ u32 num_pages,
+ struct ttm_kmap_iter *dst_iter,
+ struct ttm_kmap_iter *src_iter)
{
- int ret;
- void *addr;
-
- *virtual = NULL;
- ret = ttm_mem_io_reserve(bdev, mem);
- if (ret || !mem->bus.is_iomem)
- return ret;
+ const struct ttm_kmap_iter_ops *dst_ops = dst_iter->ops;
+ const struct ttm_kmap_iter_ops *src_ops = src_iter->ops;
+ struct ttm_tt *ttm = bo->ttm;
+ struct dma_buf_map src_map, dst_map;
+ pgoff_t i;

- if (mem->bus.addr) {
- addr = mem->bus.addr;
- } else {
- size_t bus_size = (size_t)mem->num_pages << PAGE_SHIFT;
+ /* Single TTM move. NOP */
+ if (dst_ops->maps_tt && src_ops->maps_tt)
+ return;

- if (mem->bus.caching == ttm_write_combined)
- addr = ioremap_wc(mem->bus.offset, bus_size);
-#ifdef CONFIG_X86
- else if (mem->bus.caching == ttm_cached)
- addr = ioremap_cache(mem->bus.offset, bus_size);
-#endif
- else
- addr = ioremap(mem->bus.offset, bus_size);
- if (!addr) {
- ttm_mem_io_free(bdev, mem);
- return -ENOMEM;
+ /* Don't move nonexistent data. Clear destination instead. */
+ if (src_ops->maps_tt && (!ttm || !ttm_tt_is_populated(ttm))) {
+ if (ttm && !(ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC))
+ return;
+
+ for (i = 0; i < num_pages; ++i) {
+ dst_ops->map_local(dst_iter, &dst_map, i);
+ if (dst_map.is_iomem)
+ memset_io(dst_map.vaddr_iomem, 0, PAGE_SIZE);
+ else
+ memset(dst_map.vaddr, 0, PAGE_SIZE);
+ if (dst_ops->unmap_local)
+ dst_ops->unmap_local(dst_iter, &dst_map);
}
+ return;
}
- *virtual = addr;
- return 0;
-}
-
-static void ttm_resource_iounmap(struct ttm_device *bdev,
- struct ttm_resource *mem,
- void *virtual)
-{
- if (virtual && mem->bus.addr == NULL)
- iounmap(virtual);
- ttm_mem_io_free(bdev, mem);
-}
-
-static int ttm_copy_io_page(void *dst, void *src, unsigned long page)
-{
- uint32_t *dstP =
- (uint32_t *) ((unsigned long)dst + (page << PAGE_SHIFT));
- uint32_t *srcP =
- (uint32_t *) ((unsigned long)src + (page << PAGE_SHIFT));
-
- int i;
- for (i = 0; i < PAGE_SIZE / sizeof(uint32_t); ++i)
- iowrite32(ioread32(srcP++), dstP++);
- return 0;
-}
-
-static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
- unsigned long page,
- pgprot_t prot)
-{
- struct page *d = ttm->pages[page];
- void *dst;
-
- if (!d)
- return -ENOMEM;
-
- src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
- dst = kmap_atomic_prot(d, prot);
- if (!dst)
- return -ENOMEM;
-
- memcpy_fromio(dst, src, PAGE_SIZE);
-
- kunmap_atomic(dst);
-
- return 0;
-}
-
-static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
- unsigned long page,
- pgprot_t prot)
-{
- struct page *s = ttm->pages[page];
- void *src;

- if (!s)
- return -ENOMEM;
-
- dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
- src = kmap_atomic_prot(s, prot);
- if (!src)
- return -ENOMEM;
-
- memcpy_toio(dst, src, PAGE_SIZE);
-
- kunmap_atomic(src);
+ for (i = 0; i < num_pages; ++i) {
+ dst_ops->map_local(dst_iter, &dst_map, i);
+ src_ops->map_local(src_iter, &src_map, i);
+
+ if (!src_map.is_iomem && !dst_map.is_iomem) {
+ memcpy(dst_map.vaddr, src_map.vaddr, PAGE_SIZE);
+ } else if (!src_map.is_iomem) {
+ dma_buf_map_memcpy_to(&dst_map, src_map.vaddr,
+ PAGE_SIZE);
+ } else if (!dst_map.is_iomem) {
+ memcpy_fromio(dst_map.vaddr, src_map.vaddr_iomem,
+ PAGE_SIZE);
+ } else {
+ int j;
+ u32 __iomem *src = src_map.vaddr_iomem;
+ u32 __iomem *dst = dst_map.vaddr_iomem;

- return 0;
+ for (j = 0; j < (PAGE_SIZE / sizeof(u32)); ++j)
+ iowrite32(ioread32(src++), dst++);
+ }
+ if (src_ops->unmap_local)
+ src_ops->unmap_local(src_iter, &src_map);
+ if (dst_ops->unmap_local)
+ dst_ops->unmap_local(dst_iter, &dst_map);
+ }
}
+EXPORT_SYMBOL(ttm_move_memcpy);

int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
struct ttm_operation_ctx *ctx,
- struct ttm_resource *new_mem)
+ struct ttm_resource *dst_mem)
{
struct ttm_device *bdev = bo->bdev;
- struct ttm_resource_manager *man = ttm_manager_type(bdev, new_mem->mem_type);
+ struct ttm_resource_manager *dst_man =
+ ttm_manager_type(bo->bdev, dst_mem->mem_type);
struct ttm_tt *ttm = bo->ttm;
- struct ttm_resource *old_mem = &bo->mem;
- struct ttm_resource old_copy = *old_mem;
- void *old_iomap;
- void *new_iomap;
- int ret;
- unsigned long i;
-
- ret = ttm_bo_wait_ctx(bo, ctx);
- if (ret)
- return ret;
-
- ret = ttm_resource_ioremap(bdev, old_mem, &old_iomap);
- if (ret)
- return ret;
- ret = ttm_resource_ioremap(bdev, new_mem, &new_iomap);
- if (ret)
- goto out;
-
- /*
- * Single TTM move. NOP.
- */
- if (old_iomap == NULL && new_iomap == NULL)
- goto out2;
-
- /*
- * Don't move nonexistent data. Clear destination instead.
- */
- if (old_iomap == NULL &&
- (ttm == NULL || (!ttm_tt_is_populated(ttm) &&
- !(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)))) {
- memset_io(new_iomap, 0, new_mem->num_pages*PAGE_SIZE);
- goto out2;
- }
+ struct ttm_resource *src_mem = &bo->mem;
+ struct ttm_resource_manager *src_man =
+ ttm_manager_type(bdev, src_mem->mem_type);
+ struct ttm_resource src_copy = *src_mem;
+ union {
+ struct ttm_kmap_iter_tt tt;
+ struct ttm_kmap_iter_linear_io io;
+ } _dst_iter, _src_iter;
+ struct ttm_kmap_iter *dst_iter, *src_iter;
+ int ret = 0;

- /*
- * TTM might be null for moves within the same region.
- */
- if (ttm) {
+ if (ttm && ((ttm->page_flags & TTM_PAGE_FLAG_SWAPPED) ||
+ dst_man->use_tt)) {
ret = ttm_tt_populate(bdev, ttm, ctx);
if (ret)
- goto out1;
+ return ret;
}

- for (i = 0; i < new_mem->num_pages; ++i) {
- if (old_iomap == NULL) {
- pgprot_t prot = ttm_io_prot(bo, old_mem, PAGE_KERNEL);
- ret = ttm_copy_ttm_io_page(ttm, new_iomap, i,
- prot);
- } else if (new_iomap == NULL) {
- pgprot_t prot = ttm_io_prot(bo, new_mem, PAGE_KERNEL);
- ret = ttm_copy_io_ttm_page(ttm, old_iomap, i,
- prot);
- } else {
- ret = ttm_copy_io_page(new_iomap, old_iomap, i);
- }
- if (ret)
- goto out1;
+ dst_iter = ttm_kmap_iter_linear_io_init(&_dst_iter.io, bdev, dst_mem);
+ if (PTR_ERR(dst_iter) == -EINVAL && dst_man->use_tt)
+ dst_iter = ttm_kmap_iter_tt_init(&_dst_iter.tt, bo->ttm);
+ if (IS_ERR(dst_iter))
+ return PTR_ERR(dst_iter);
+
+ src_iter = ttm_kmap_iter_linear_io_init(&_src_iter.io, bdev, src_mem);
+ if (PTR_ERR(src_iter) == -EINVAL && src_man->use_tt)
+ src_iter = ttm_kmap_iter_tt_init(&_src_iter.tt, bo->ttm);
+ if (IS_ERR(src_iter)) {
+ ret = PTR_ERR(src_iter);
+ goto out_src_iter;
}
- mb();
-out2:
- old_copy = *old_mem;

- ttm_bo_assign_mem(bo, new_mem);
-
- if (!man->use_tt)
- ttm_bo_tt_destroy(bo);
+ ttm_move_memcpy(bo, dst_mem->num_pages, dst_iter, src_iter);
+ src_copy = *src_mem;
+ ttm_bo_move_sync_cleanup(bo, dst_mem);

-out1:
- ttm_resource_iounmap(bdev, old_mem, new_iomap);
-out:
- ttm_resource_iounmap(bdev, &old_copy, old_iomap);
+ if (!src_iter->ops->maps_tt)
+ ttm_kmap_iter_linear_io_fini(&_src_iter.io, bdev, &src_copy);
+out_src_iter:
+ if (!dst_iter->ops->maps_tt)
+ ttm_kmap_iter_linear_io_fini(&_dst_iter.io, bdev, dst_mem);

- /*
- * On error, keep the mm node!
- */
- if (!ret)
- ttm_resource_free(bo, &old_copy);
return ret;
}
EXPORT_SYMBOL(ttm_bo_move_memcpy);
@@ -336,27 +272,7 @@ pgprot_t ttm_io_prot(struct ttm_buffer_object *bo, struct ttm_resource *res,
man = ttm_manager_type(bo->bdev, res->mem_type);
caching = man->use_tt ? bo->ttm->caching : res->bus.caching;

- /* Cached mappings need no adjustment */
- if (caching == ttm_cached)
- return tmp;
-
-#if defined(__i386__) || defined(__x86_64__)
- if (caching == ttm_write_combined)
- tmp = pgprot_writecombine(tmp);
- else if (boot_cpu_data.x86 > 3)
- tmp = pgprot_noncached(tmp);
-#endif
-#if defined(__ia64__) || defined(__arm__) || defined(__aarch64__) || \
- defined(__powerpc__) || defined(__mips__)
- if (caching == ttm_write_combined)
- tmp = pgprot_writecombine(tmp);
- else
- tmp = pgprot_noncached(tmp);
-#endif
-#if defined(__sparc__)
- tmp = pgprot_noncached(tmp);
-#endif
- return tmp;
+ return ttm_prot_from_caching(caching, tmp);
}
EXPORT_SYMBOL(ttm_io_prot);

diff --git a/drivers/gpu/drm/ttm/ttm_module.c b/drivers/gpu/drm/ttm/ttm_module.c
index 56b0efdba1a9..997c458f68a9 100644
--- a/drivers/gpu/drm/ttm/ttm_module.c
+++ b/drivers/gpu/drm/ttm/ttm_module.c
@@ -31,12 +31,47 @@
*/
#include <linux/module.h>
#include <linux/device.h>
+#include <linux/pgtable.h>
#include <linux/sched.h>
#include <linux/debugfs.h>
#include <drm/drm_sysfs.h>
+#include <drm/ttm/ttm_caching.h>

#include "ttm_module.h"

+/**
+ * ttm_prot_from_caching - Modify the page protection according to the
+ * ttm cacing mode
+ * @caching: The ttm caching mode
+ * @tmp: The original page protection
+ *
+ * Return: The modified page protection
+ */
+pgprot_t ttm_prot_from_caching(enum ttm_caching caching, pgprot_t tmp)
+{
+ /* Cached mappings need no adjustment */
+ if (caching == ttm_cached)
+ return tmp;
+
+#if defined(__i386__) || defined(__x86_64__)
+ if (caching == ttm_write_combined)
+ tmp = pgprot_writecombine(tmp);
+ else if (boot_cpu_data.x86 > 3)
+ tmp = pgprot_noncached(tmp);
+#endif
+#if defined(__ia64__) || defined(__arm__) || defined(__aarch64__) || \
+ defined(__powerpc__) || defined(__mips__)
+ if (caching == ttm_write_combined)
+ tmp = pgprot_writecombine(tmp);
+ else
+ tmp = pgprot_noncached(tmp);
+#endif
+#if defined(__sparc__)
+ tmp = pgprot_noncached(tmp);
+#endif
+ return tmp;
+}
+
struct dentry *ttm_debugfs_root;

static int __init ttm_init(void)
diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
index 59e2b7157e41..931bcd1a9b9b 100644
--- a/drivers/gpu/drm/ttm/ttm_resource.c
+++ b/drivers/gpu/drm/ttm/ttm_resource.c
@@ -22,6 +22,10 @@
* Authors: Christian König
*/

+#include <linux/dma-buf-map.h>
+#include <linux/io-mapping.h>
+#include <linux/scatterlist.h>
+
#include <drm/ttm/ttm_resource.h>
#include <drm/ttm/ttm_bo_driver.h>

@@ -147,3 +151,192 @@ void ttm_resource_manager_debug(struct ttm_resource_manager *man,
man->func->debug(man, p);
}
EXPORT_SYMBOL(ttm_resource_manager_debug);
+
+static void ttm_kmap_iter_iomap_map_local(struct ttm_kmap_iter *iter,
+ struct dma_buf_map *dmap,
+ pgoff_t i)
+{
+ struct ttm_kmap_iter_iomap *iter_io =
+ container_of(iter, typeof(*iter_io), base);
+ void __iomem *addr;
+
+retry:
+ while (i >= iter_io->cache.end) {
+ iter_io->cache.sg = iter_io->cache.sg ?
+ sg_next(iter_io->cache.sg) : iter_io->st->sgl;
+ iter_io->cache.i = iter_io->cache.end;
+ iter_io->cache.end += sg_dma_len(iter_io->cache.sg) >>
+ PAGE_SHIFT;
+ iter_io->cache.offs = sg_dma_address(iter_io->cache.sg) -
+ iter_io->start;
+ }
+
+ if (i < iter_io->cache.i) {
+ iter_io->cache.end = 0;
+ iter_io->cache.sg = NULL;
+ goto retry;
+ }
+
+ addr = io_mapping_map_local_wc(iter_io->iomap, iter_io->cache.offs +
+ (((resource_size_t)i - iter_io->cache.i)
+ << PAGE_SHIFT));
+ dma_buf_map_set_vaddr_iomem(dmap, addr);
+}
+
+static void ttm_kmap_iter_iomap_unmap_local(struct ttm_kmap_iter *iter,
+ struct dma_buf_map *map)
+{
+ io_mapping_unmap_local(map->vaddr_iomem);
+}
+
+static const struct ttm_kmap_iter_ops ttm_kmap_iter_io_ops = {
+ .map_local = ttm_kmap_iter_iomap_map_local,
+ .unmap_local = ttm_kmap_iter_iomap_unmap_local,
+ .maps_tt = false,
+};
+
+/**
+ * ttm_kmap_iter_iomap_init - Initialize a struct ttm_kmap_iter_iomap
+ * @iter_io: The struct ttm_kmap_iter_iomap to initialize.
+ * @iomap: The struct io_mapping representing the underlying linear io_memory.
+ * @st: sg_table into @iomap, representing the memory of the struct
+ * ttm_resource.
+ * @start: Offset that needs to be subtracted from @st to make
+ * sg_dma_address(st->sgl) - @start == 0 for @iomap start.
+ *
+ * Return: Pointer to the embedded struct ttm_kmap_iter.
+ */
+struct ttm_kmap_iter *
+ttm_kmap_iter_iomap_init(struct ttm_kmap_iter_iomap *iter_io,
+ struct io_mapping *iomap,
+ struct sg_table *st,
+ resource_size_t start)
+{
+ iter_io->base.ops = &ttm_kmap_iter_io_ops;
+ iter_io->iomap = iomap;
+ iter_io->st = st;
+ iter_io->start = start;
+ memset(&iter_io->cache, 0, sizeof(iter_io->cache));
+
+ return &iter_io->base;
+}
+EXPORT_SYMBOL(ttm_kmap_iter_iomap_init);
+
+/**
+ * DOC: Linear io iterator
+ *
+ * This code should die in the not too near future. Best would be if we could
+ * make io-mapping use memremap for all io memory, and have memremap
+ * implement a kmap_local functionality. We could then strip a huge amount of
+ * code. These linear io iterators are implemented to mimic old functionality,
+ * and they don't use kmap_local semantics at all internally. Rather ioremap or
+ * friends, and at least on 32-bit they add global TLB flushes and points
+ * of failure.
+ */
+
+static void ttm_kmap_iter_linear_io_map_local(struct ttm_kmap_iter *iter,
+ struct dma_buf_map *dmap,
+ pgoff_t i)
+{
+ struct ttm_kmap_iter_linear_io *iter_io =
+ container_of(iter, typeof(*iter_io), base);
+
+ *dmap = iter_io->dmap;
+ dma_buf_map_incr(dmap, i * PAGE_SIZE);
+}
+
+static const struct ttm_kmap_iter_ops ttm_kmap_iter_linear_io_ops = {
+ .map_local = ttm_kmap_iter_linear_io_map_local,
+ .maps_tt = false,
+};
+
+/**
+ * ttm_kmap_iter_linear_io_init - Initialize an iterator for linear io memory
+ * @iter_io: The iterator to initialize
+ * @bdev: The TTM device
+ * @mem: The ttm resource representing the iomap.
+ *
+ * This function is for internal TTM use only. It sets up a memcpy kmap iterator
+ * pointing at a linear chunk of io memory.
+ *
+ * Return: A pointer to the embedded struct ttm_kmap_iter or error pointer on
+ * failure.
+ */
+struct ttm_kmap_iter *
+ttm_kmap_iter_linear_io_init(struct ttm_kmap_iter_linear_io *iter_io,
+ struct ttm_device *bdev,
+ struct ttm_resource *mem)
+{
+ int ret;
+
+ ret = ttm_mem_io_reserve(bdev, mem);
+ if (ret)
+ goto out_err;
+ if (!mem->bus.is_iomem) {
+ ret = -EINVAL;
+ goto out_io_free;
+ }
+
+ if (mem->bus.addr) {
+ dma_buf_map_set_vaddr(&iter_io->dmap, mem->bus.addr);
+ iter_io->needs_unmap = false;
+ } else {
+ size_t bus_size = (size_t)mem->num_pages << PAGE_SHIFT;
+
+ iter_io->needs_unmap = true;
+ memset(&iter_io->dmap, 0, sizeof(iter_io->dmap));
+ if (mem->bus.caching == ttm_write_combined)
+ dma_buf_map_set_vaddr_iomem(&iter_io->dmap,
+ ioremap_wc(mem->bus.offset,
+ bus_size));
+ else if (mem->bus.caching == ttm_cached)
+ dma_buf_map_set_vaddr(&iter_io->dmap,
+ memremap(mem->bus.offset, bus_size,
+ MEMREMAP_WB |
+ MEMREMAP_WT |
+ MEMREMAP_WC));
+
+ /* If uncached requested or if mapping cached or wc failed */
+ if (dma_buf_map_is_null(&iter_io->dmap))
+ dma_buf_map_set_vaddr_iomem(&iter_io->dmap,
+ ioremap(mem->bus.offset,
+ bus_size));
+
+ if (dma_buf_map_is_null(&iter_io->dmap)) {
+ ret = -ENOMEM;
+ goto out_io_free;
+ }
+ }
+
+ iter_io->base.ops = &ttm_kmap_iter_linear_io_ops;
+ return &iter_io->base;
+
+out_io_free:
+ ttm_mem_io_free(bdev, mem);
+out_err:
+ return ERR_PTR(ret);
+}
+
+/**
+ * ttm_kmap_iter_linear_io_fini - Clean up an iterator for linear io memory
+ * @iter_io: The iterator to initialize
+ * @bdev: The TTM device
+ * @mem: The ttm resource representing the iomap.
+ *
+ * This function is for internal TTM use only. It cleans up a memcpy kmap
+ * iterator initialized by ttm_kmap_iter_linear_io_init.
+ */
+void
+ttm_kmap_iter_linear_io_fini(struct ttm_kmap_iter_linear_io *iter_io,
+ struct ttm_device *bdev,
+ struct ttm_resource *mem)
+{
+ if (iter_io->needs_unmap && dma_buf_map_is_set(&iter_io->dmap)) {
+ if (iter_io->dmap.is_iomem)
+ iounmap(iter_io->dmap.vaddr_iomem);
+ else
+ memunmap(iter_io->dmap.vaddr);
+ }
+
+ ttm_mem_io_free(bdev, mem);
+}
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 539e0232cb3b..0e41227116b1 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -433,3 +433,45 @@ void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages)
if (!ttm_dma32_pages_limit)
ttm_dma32_pages_limit = num_dma32_pages;
}
+
+static void ttm_kmap_iter_tt_map_local(struct ttm_kmap_iter *iter,
+ struct dma_buf_map *dmap,
+ pgoff_t i)
+{
+ struct ttm_kmap_iter_tt *iter_tt =
+ container_of(iter, typeof(*iter_tt), base);
+
+ dma_buf_map_set_vaddr(dmap, kmap_local_page_prot(iter_tt->tt->pages[i],
+ iter_tt->prot));
+}
+
+static void ttm_kmap_iter_tt_unmap_local(struct ttm_kmap_iter *iter,
+ struct dma_buf_map *map)
+{
+ kunmap_local(map->vaddr);
+}
+
+static const struct ttm_kmap_iter_ops ttm_kmap_iter_tt_ops = {
+ .map_local = ttm_kmap_iter_tt_map_local,
+ .unmap_local = ttm_kmap_iter_tt_unmap_local,
+ .maps_tt = true,
+};
+
+/**
+ * ttm_kmap_iter_tt_init - Initialize a struct ttm_kmap_iter_tt
+ * @iter_tt: The struct ttm_kmap_iter_tt to initialize.
+ * @tt: Struct ttm_tt holding page pointers of the struct ttm_resource.
+ *
+ * Return: Pointer to the embedded struct ttm_kmap_iter.
+ */
+struct ttm_kmap_iter *
+ttm_kmap_iter_tt_init(struct ttm_kmap_iter_tt *iter_tt,
+ struct ttm_tt *tt)
+{
+ iter_tt->base.ops = &ttm_kmap_iter_tt_ops;
+ iter_tt->tt = tt;
+ iter_tt->prot = ttm_prot_from_caching(tt->caching, PAGE_KERNEL);
+
+ return &iter_tt->base;
+}
+EXPORT_SYMBOL(ttm_kmap_iter_tt_init);
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index dbccac957f8f..72511992261a 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -40,6 +40,7 @@
#include <drm/ttm/ttm_device.h>

#include "ttm_bo_api.h"
+#include "ttm_kmap_iter.h"
#include "ttm_placement.h"
#include "ttm_tt.h"
#include "ttm_pool.h"
@@ -272,6 +273,23 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
bool pipeline,
struct ttm_resource *new_mem);

+/**
+ * ttm_bo_move_accel_cleanup.
+ *
+ * @bo: A pointer to a struct ttm_buffer_object.
+ * @new_mem: struct ttm_resource indicating where to move.
+ *
+ * Special case of ttm_bo_move_accel_cleanup where the bo is guaranteed
+ * by the caller to be idle. Typically used after memcpy buffer moves.
+ */
+static inline void ttm_bo_move_sync_cleanup(struct ttm_buffer_object *bo,
+ struct ttm_resource *new_mem)
+{
+ int ret = ttm_bo_move_accel_cleanup(bo, NULL, true, false, new_mem);
+
+ WARN_ON(ret);
+}
+
/**
* ttm_bo_pipeline_gutting.
*
@@ -332,4 +350,14 @@ int ttm_range_man_init(struct ttm_device *bdev,
int ttm_range_man_fini(struct ttm_device *bdev,
unsigned type);

+void ttm_move_memcpy(struct ttm_buffer_object *bo,
+ u32 num_pages,
+ struct ttm_kmap_iter *dst_iter,
+ struct ttm_kmap_iter *src_iter);
+
+struct ttm_kmap_iter *
+ttm_kmap_iter_iomap_init(struct ttm_kmap_iter_iomap *iter_io,
+ struct io_mapping *iomap,
+ struct sg_table *st,
+ resource_size_t start);
#endif
diff --git a/include/drm/ttm/ttm_caching.h b/include/drm/ttm/ttm_caching.h
index a0b4a49fa432..3c9dd65f5aaf 100644
--- a/include/drm/ttm/ttm_caching.h
+++ b/include/drm/ttm/ttm_caching.h
@@ -33,4 +33,6 @@ enum ttm_caching {
ttm_cached
};

+pgprot_t ttm_prot_from_caching(enum ttm_caching caching, pgprot_t tmp);
+
#endif
diff --git a/include/drm/ttm/ttm_kmap_iter.h b/include/drm/ttm/ttm_kmap_iter.h
new file mode 100644
index 000000000000..8bb00fd39d6c
--- /dev/null
+++ b/include/drm/ttm/ttm_kmap_iter.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+#ifndef __TTM_KMAP_ITER_H__
+#define __TTM_KMAP_ITER_H__
+
+#include <linux/types.h>
+
+struct ttm_kmap_iter;
+struct dma_buf_map;
+
+/**
+ * struct ttm_kmap_iter_ops - Ops structure for a struct
+ * ttm_kmap_iter.
+ * @maps_tt: Whether the iterator maps TT memory directly, as opposed
+ * mapping a TT through an aperture. Both these modes have
+ * struct ttm_resource_manager::use_tt set, but the latter typically
+ * returns is_iomem == true from ttm_mem_io_reserve.
+ */
+struct ttm_kmap_iter_ops {
+ /**
+ * kmap_local() - Map a PAGE_SIZE part of the resource using
+ * kmap_local semantics.
+ * @res_iter: Pointer to the struct ttm_kmap_iter representing
+ * the resource.
+ * @dmap: The struct dma_buf_map holding the virtual address after
+ * the operation.
+ * @i: The location within the resource to map. PAGE_SIZE granularity.
+ */
+ void (*map_local)(struct ttm_kmap_iter *res_iter,
+ struct dma_buf_map *dmap, pgoff_t i);
+ /**
+ * unmap_local() - Unmap a PAGE_SIZE part of the resource previously
+ * mapped using kmap_local.
+ * @res_iter: Pointer to the struct ttm_kmap_iter representing
+ * the resource.
+ * @dmap: The struct dma_buf_map holding the virtual address after
+ * the operation.
+ */
+ void (*unmap_local)(struct ttm_kmap_iter *res_iter,
+ struct dma_buf_map *dmap);
+ bool maps_tt;
+};
+
+/**
+ * struct ttm_kmap_iter - Iterator for kmap_local type operations on a
+ * resource.
+ * @ops: Pointer to the operations struct.
+ *
+ * This struct is intended to be embedded in a resource-specific specialization
+ * implementing operations for the resource.
+ *
+ * Nothing stops us from extending the operations to vmap, vmap_pfn etc,
+ * replacing some or parts of the ttm_bo_util. cpu-map functionality.
+ */
+struct ttm_kmap_iter {
+ const struct ttm_kmap_iter_ops *ops;
+};
+
+#endif /* __TTM_KMAP_ITER_H__ */
diff --git a/include/drm/ttm/ttm_resource.h b/include/drm/ttm/ttm_resource.h
index 890b9d369519..b8dc0bdb0da5 100644
--- a/include/drm/ttm/ttm_resource.h
+++ b/include/drm/ttm/ttm_resource.h
@@ -27,9 +27,11 @@

#include <linux/types.h>
#include <linux/mutex.h>
+#include <linux/dma-buf-map.h>
#include <linux/dma-fence.h>
#include <drm/drm_print.h>
#include <drm/ttm/ttm_caching.h>
+#include <drm/ttm/ttm_kmap_iter.h>

#define TTM_MAX_BO_PRIORITY 4U

@@ -38,6 +40,10 @@ struct ttm_resource_manager;
struct ttm_resource;
struct ttm_place;
struct ttm_buffer_object;
+struct dma_buf_map;
+struct io_mapping;
+struct sg_table;
+struct scatterlist;

struct ttm_resource_manager_func {
/**
@@ -176,6 +182,45 @@ struct ttm_resource {
struct ttm_bus_placement bus;
};

+/**
+ * struct ttm_kmap_iter_iomap - Specialization for a struct io_mapping +
+ * struct sg_table backed struct ttm_resource.
+ * @base: Embedded struct ttm_kmap_iter providing the usage interface.
+ * @iomap: struct io_mapping representing the underlying linear io_memory.
+ * @st: sg_table into @iomap, representing the memory of the struct ttm_resource.
+ * @start: Offset that needs to be subtracted from @st to make
+ * sg_dma_address(st->sgl) - @start == 0 for @iomap start.
+ * @cache: Scatterlist traversal cache for fast lookups.
+ * @cache.sg: Pointer to the currently cached scatterlist segment.
+ * @cache.i: First index of @sg. PAGE_SIZE granularity.
+ * @cache.end: Last index + 1 of @sg. PAGE_SIZE granularity.
+ * @cache.offs: First offset into @iomap of @sg. PAGE_SIZE granularity.
+ */
+struct ttm_kmap_iter_iomap {
+ struct ttm_kmap_iter base;
+ struct io_mapping *iomap;
+ struct sg_table *st;
+ resource_size_t start;
+ struct {
+ struct scatterlist *sg;
+ pgoff_t i;
+ pgoff_t end;
+ pgoff_t offs;
+ } cache;
+};
+
+/**
+ * struct ttm_kmap_iter_linear_io - Iterator specialization for linear io
+ * @base: The base iterator
+ * @dmap: Points to the starting address of the region
+ * @needs_unmap: Whether we need to unmap on fini
+ */
+struct ttm_kmap_iter_linear_io {
+ struct ttm_kmap_iter base;
+ struct dma_buf_map dmap;
+ bool needs_unmap;
+};
+
/**
* ttm_resource_manager_set_used
*
@@ -237,4 +282,20 @@ int ttm_resource_manager_evict_all(struct ttm_device *bdev,
void ttm_resource_manager_debug(struct ttm_resource_manager *man,
struct drm_printer *p);

+struct ttm_kmap_iter *
+ttm_kmap_iter_iomap_init(struct ttm_kmap_iter_iomap *iter_io,
+ struct io_mapping *iomap,
+ struct sg_table *st,
+ resource_size_t start);
+
+struct ttm_kmap_iter_linear_io;
+
+struct ttm_kmap_iter *
+ttm_kmap_iter_linear_io_init(struct ttm_kmap_iter_linear_io *iter_io,
+ struct ttm_device *bdev,
+ struct ttm_resource *mem);
+
+void ttm_kmap_iter_linear_io_fini(struct ttm_kmap_iter_linear_io *iter_io,
+ struct ttm_device *bdev,
+ struct ttm_resource *mem);
#endif
diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h
index 134d09ef7766..3102059db726 100644
--- a/include/drm/ttm/ttm_tt.h
+++ b/include/drm/ttm/ttm_tt.h
@@ -29,6 +29,7 @@

#include <linux/types.h>
#include <drm/ttm/ttm_caching.h>
+#include <drm/ttm/ttm_kmap_iter.h>

struct ttm_bo_device;
struct ttm_tt;
@@ -69,6 +70,18 @@ struct ttm_tt {
enum ttm_caching caching;
};

+/**
+ * struct ttm_kmap_iter_tt - Specialization of a mappig iterator for a tt.
+ * @base: Embedded struct ttm_kmap_iter providing the usage interface
+ * @tt: Cached struct ttm_tt.
+ * @prot: Cached page protection for mapping.
+ */
+struct ttm_kmap_iter_tt {
+ struct ttm_kmap_iter base;
+ struct ttm_tt *tt;
+ pgprot_t prot;
+};
+
static inline bool ttm_tt_is_populated(struct ttm_tt *tt)
{
return tt->page_flags & TTM_PAGE_FLAG_PRIV_POPULATED;
@@ -159,6 +172,9 @@ void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm);

void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages);

+struct ttm_kmap_iter *ttm_kmap_iter_tt_init(struct ttm_kmap_iter_tt *iter_tt,
+ struct ttm_tt *tt);
+
#if IS_ENABLED(CONFIG_AGP)
#include <linux/agp_backend.h>