[PATCH v6 1/5] dma-buf: system_heap: Rework system heap to use sgtables instead of pagelists
John Stultz
john.stultz at linaro.org
Sat Nov 21 04:49:51 UTC 2020
In preparation for some patches to optmize the system
heap code, rework the dmabuf exporter to utilize sgtables rather
then pageslists for tracking the associated pages.
This will allow for large order page allocations, as well as
more efficient page pooling.
In doing so, the system heap stops using the heap-helpers logic
which sadly is not quite as generic as I was hoping it to be, so
this patch adds heap specific implementations of the dma_buf_ops
function handlers.
Cc: Sumit Semwal <sumit.semwal at linaro.org>
Cc: Liam Mark <lmark at codeaurora.org>
Cc: Laura Abbott <labbott at kernel.org>
Cc: Brian Starkey <Brian.Starkey at arm.com>
Cc: Hridya Valsaraju <hridya at google.com>
Cc: Suren Baghdasaryan <surenb at google.com>
Cc: Sandeep Patil <sspatil at google.com>
Cc: Daniel Mentz <danielmentz at google.com>
Cc: Chris Goldsworthy <cgoldswo at codeaurora.org>
Cc: Ørjan Eide <orjan.eide at arm.com>
Cc: Robin Murphy <robin.murphy at arm.com>
Cc: Ezequiel Garcia <ezequiel at collabora.com>
Cc: Simon Ser <contact at emersion.fr>
Cc: James Jones <jajones at nvidia.com>
Cc: linux-media at vger.kernel.org
Cc: dri-devel at lists.freedesktop.org
Reviewed-by: Brian Starkey <brian.starkey at arm.com>
Signed-off-by: John Stultz <john.stultz at linaro.org>
---
v2:
* Fix locking issue and an unused return value Reported-by:
kernel test robot <lkp at intel.com>
Julia Lawall <julia.lawall at lip6.fr>
* Make system_heap_buf_ops static Reported-by:
kernel test robot <lkp at intel.com>
v3:
* Use the new sgtable mapping functions, as Suggested-by:
Daniel Mentz <danielmentz at google.com>
v4:
* Make sys_heap static (indirectly) Reported-by:
kernel test robot <lkp at intel.com>
* Spelling fix suggested by BrianS
v6:
* Fixups against drm-misc-next, from Sumit
---
drivers/dma-buf/heaps/system_heap.c | 346 ++++++++++++++++++++++++----
1 file changed, 300 insertions(+), 46 deletions(-)
diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
index 0bf688e3c023..e5f9f964b910 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -3,7 +3,11 @@
* DMABUF System heap exporter
*
* Copyright (C) 2011 Google, Inc.
- * Copyright (C) 2019 Linaro Ltd.
+ * Copyright (C) 2019, 2020 Linaro Ltd.
+ *
+ * Portions based off of Andrew Davis' SRAM heap:
+ * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
+ * Andrew F. Davis <afd at ti.com>
*/
#include <linux/dma-buf.h>
@@ -15,72 +19,323 @@
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
-#include <linux/sched/signal.h>
-#include <asm/page.h>
+#include <linux/vmalloc.h>
+
+static struct dma_heap *sys_heap;
-#include "heap-helpers.h"
+struct system_heap_buffer {
+ struct dma_heap *heap;
+ struct list_head attachments;
+ struct mutex lock;
+ unsigned long len;
+ struct sg_table sg_table;
+ int vmap_cnt;
+ struct dma_buf_map *map;
+};
-struct dma_heap *sys_heap;
+struct dma_heap_attachment {
+ struct device *dev;
+ struct sg_table *table;
+ struct list_head list;
+};
-static void system_heap_free(struct heap_helper_buffer *buffer)
+static struct sg_table *dup_sg_table(struct sg_table *table)
{
- pgoff_t pg;
+ struct sg_table *new_table;
+ int ret, i;
+ struct scatterlist *sg, *new_sg;
+
+ new_table = kzalloc(sizeof(*new_table), GFP_KERNEL);
+ if (!new_table)
+ return ERR_PTR(-ENOMEM);
+
+ ret = sg_alloc_table(new_table, table->orig_nents, GFP_KERNEL);
+ if (ret) {
+ kfree(new_table);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ new_sg = new_table->sgl;
+ for_each_sgtable_sg(table, sg, i) {
+ sg_set_page(new_sg, sg_page(sg), sg->length, sg->offset);
+ new_sg = sg_next(new_sg);
+ }
+
+ return new_table;
+}
+
+static int system_heap_attach(struct dma_buf *dmabuf,
+ struct dma_buf_attachment *attachment)
+{
+ struct system_heap_buffer *buffer = dmabuf->priv;
+ struct dma_heap_attachment *a;
+ struct sg_table *table;
+
+ a = kzalloc(sizeof(*a), GFP_KERNEL);
+ if (!a)
+ return -ENOMEM;
+
+ table = dup_sg_table(&buffer->sg_table);
+ if (IS_ERR(table)) {
+ kfree(a);
+ return -ENOMEM;
+ }
+
+ a->table = table;
+ a->dev = attachment->dev;
+ INIT_LIST_HEAD(&a->list);
+
+ attachment->priv = a;
+
+ mutex_lock(&buffer->lock);
+ list_add(&a->list, &buffer->attachments);
+ mutex_unlock(&buffer->lock);
+
+ return 0;
+}
+
+static void system_heap_detach(struct dma_buf *dmabuf,
+ struct dma_buf_attachment *attachment)
+{
+ struct system_heap_buffer *buffer = dmabuf->priv;
+ struct dma_heap_attachment *a = attachment->priv;
+
+ mutex_lock(&buffer->lock);
+ list_del(&a->list);
+ mutex_unlock(&buffer->lock);
+
+ sg_free_table(a->table);
+ kfree(a->table);
+ kfree(a);
+}
+
+static struct sg_table *system_heap_map_dma_buf(struct dma_buf_attachment *attachment,
+ enum dma_data_direction direction)
+{
+ struct dma_heap_attachment *a = attachment->priv;
+ struct sg_table *table = a->table;
+ int ret;
+
+ ret = dma_map_sgtable(attachment->dev, table, direction, 0);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return table;
+}
+
+static void system_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
+ struct sg_table *table,
+ enum dma_data_direction direction)
+{
+ dma_unmap_sgtable(attachment->dev, table, direction, 0);
+}
+
+static int system_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
+ enum dma_data_direction direction)
+{
+ struct system_heap_buffer *buffer = dmabuf->priv;
+ struct dma_heap_attachment *a;
+
+ mutex_lock(&buffer->lock);
+
+ if (buffer->vmap_cnt)
+ invalidate_kernel_vmap_range(buffer->map->vaddr, buffer->len);
+
+ list_for_each_entry(a, &buffer->attachments, list) {
+ dma_sync_sgtable_for_cpu(a->dev, a->table, direction);
+ }
+ mutex_unlock(&buffer->lock);
+
+ return 0;
+}
+
+static int system_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
+ enum dma_data_direction direction)
+{
+ struct system_heap_buffer *buffer = dmabuf->priv;
+ struct dma_heap_attachment *a;
+
+ mutex_lock(&buffer->lock);
+
+ if (buffer->vmap_cnt)
+ flush_kernel_vmap_range(buffer->map->vaddr, buffer->len);
- for (pg = 0; pg < buffer->pagecount; pg++)
- __free_page(buffer->pages[pg]);
- kfree(buffer->pages);
+ list_for_each_entry(a, &buffer->attachments, list) {
+ dma_sync_sgtable_for_device(a->dev, a->table, direction);
+ }
+ mutex_unlock(&buffer->lock);
+
+ return 0;
+}
+
+static int system_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+ struct system_heap_buffer *buffer = dmabuf->priv;
+ struct sg_table *table = &buffer->sg_table;
+ unsigned long addr = vma->vm_start;
+ struct sg_page_iter piter;
+ int ret;
+
+ for_each_sgtable_page(table, &piter, vma->vm_pgoff) {
+ struct page *page = sg_page_iter_page(&piter);
+
+ ret = remap_pfn_range(vma, addr, page_to_pfn(page), PAGE_SIZE,
+ vma->vm_page_prot);
+ if (ret)
+ return ret;
+ addr += PAGE_SIZE;
+ if (addr >= vma->vm_end)
+ return 0;
+ }
+ return 0;
+}
+
+static int system_heap_do_vmap(struct system_heap_buffer *buffer, struct dma_buf_map *map)
+{
+ struct sg_table *table = &buffer->sg_table;
+ int npages = PAGE_ALIGN(buffer->len) / PAGE_SIZE;
+ struct page **pages = vmalloc(sizeof(struct page *) * npages);
+ struct page **tmp = pages;
+ struct sg_page_iter piter;
+ void *vaddr;
+
+ if (!pages)
+ return -ENOMEM;
+
+ for_each_sgtable_page(table, &piter, 0) {
+ WARN_ON(tmp - pages >= npages);
+ *tmp++ = sg_page_iter_page(&piter);
+ }
+
+ vaddr = vmap(pages, npages, VM_MAP, PAGE_KERNEL);
+ vfree(pages);
+
+ if (!vaddr)
+ return -ENOMEM;
+
+ dma_buf_map_set_vaddr(map, vaddr);
+ buffer->map = map;
+
+ return 0;
+}
+
+static int system_heap_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
+{
+ struct system_heap_buffer *buffer = dmabuf->priv;
+ int ret = 0;
+
+ mutex_lock(&buffer->lock);
+ if (buffer->vmap_cnt) {
+ buffer->vmap_cnt++;
+ map = buffer->map;
+ goto out;
+ }
+
+ ret = system_heap_do_vmap(buffer, map);
+ if (ret)
+ goto out;
+
+ buffer->vmap_cnt++;
+out:
+ mutex_unlock(&buffer->lock);
+
+ return ret;
+}
+
+static void system_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
+{
+ struct system_heap_buffer *buffer = dmabuf->priv;
+
+ mutex_lock(&buffer->lock);
+ if (!--buffer->vmap_cnt) {
+ vunmap(buffer->map->vaddr);
+ dma_buf_map_clear(buffer->map);
+ }
+ mutex_unlock(&buffer->lock);
+}
+
+static void system_heap_dma_buf_release(struct dma_buf *dmabuf)
+{
+ struct system_heap_buffer *buffer = dmabuf->priv;
+ struct sg_table *table;
+ struct scatterlist *sg;
+ int i;
+
+ table = &buffer->sg_table;
+ for_each_sgtable_sg(table, sg, i)
+ __free_page(sg_page(sg));
+ sg_free_table(table);
kfree(buffer);
}
+static const struct dma_buf_ops system_heap_buf_ops = {
+ .attach = system_heap_attach,
+ .detach = system_heap_detach,
+ .map_dma_buf = system_heap_map_dma_buf,
+ .unmap_dma_buf = system_heap_unmap_dma_buf,
+ .begin_cpu_access = system_heap_dma_buf_begin_cpu_access,
+ .end_cpu_access = system_heap_dma_buf_end_cpu_access,
+ .mmap = system_heap_mmap,
+ .vmap = system_heap_vmap,
+ .vunmap = system_heap_vunmap,
+ .release = system_heap_dma_buf_release,
+};
+
static int system_heap_allocate(struct dma_heap *heap,
unsigned long len,
unsigned long fd_flags,
unsigned long heap_flags)
{
- struct heap_helper_buffer *helper_buffer;
+ struct system_heap_buffer *buffer;
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
struct dma_buf *dmabuf;
- int ret = -ENOMEM;
+ struct sg_table *table;
+ struct scatterlist *sg;
+ pgoff_t pagecount;
pgoff_t pg;
+ int i, ret = -ENOMEM;
- helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
- if (!helper_buffer)
+ buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
+ if (!buffer)
return -ENOMEM;
- init_heap_helper_buffer(helper_buffer, system_heap_free);
- helper_buffer->heap = heap;
- helper_buffer->size = len;
-
- helper_buffer->pagecount = len / PAGE_SIZE;
- helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
- sizeof(*helper_buffer->pages),
- GFP_KERNEL);
- if (!helper_buffer->pages) {
- ret = -ENOMEM;
- goto err0;
- }
+ INIT_LIST_HEAD(&buffer->attachments);
+ mutex_init(&buffer->lock);
+ buffer->heap = heap;
+ buffer->len = len;
- for (pg = 0; pg < helper_buffer->pagecount; pg++) {
+ table = &buffer->sg_table;
+ pagecount = len / PAGE_SIZE;
+ if (sg_alloc_table(table, pagecount, GFP_KERNEL))
+ goto free_buffer;
+
+ sg = table->sgl;
+ for (pg = 0; pg < pagecount; pg++) {
+ struct page *page;
/*
* Avoid trying to allocate memory if the process
- * has been killed by by SIGKILL
+ * has been killed by SIGKILL
*/
if (fatal_signal_pending(current))
- goto err1;
-
- helper_buffer->pages[pg] = alloc_page(GFP_KERNEL | __GFP_ZERO);
- if (!helper_buffer->pages[pg])
- goto err1;
+ goto free_pages;
+ page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!page)
+ goto free_pages;
+ sg_set_page(sg, page, page_size(page), 0);
+ sg = sg_next(sg);
}
/* create the dmabuf */
- dmabuf = heap_helper_export_dmabuf(helper_buffer, fd_flags);
+ exp_info.ops = &system_heap_buf_ops;
+ exp_info.size = buffer->len;
+ exp_info.flags = fd_flags;
+ exp_info.priv = buffer;
+ dmabuf = dma_buf_export(&exp_info);
if (IS_ERR(dmabuf)) {
ret = PTR_ERR(dmabuf);
- goto err1;
+ goto free_pages;
}
- helper_buffer->dmabuf = dmabuf;
-
ret = dma_buf_fd(dmabuf, fd_flags);
if (ret < 0) {
dma_buf_put(dmabuf);
@@ -90,12 +345,12 @@ static int system_heap_allocate(struct dma_heap *heap,
return ret;
-err1:
- while (pg > 0)
- __free_page(helper_buffer->pages[--pg]);
- kfree(helper_buffer->pages);
-err0:
- kfree(helper_buffer);
+free_pages:
+ for_each_sgtable_sg(table, sg, i)
+ __free_page(sg_page(sg));
+ sg_free_table(table);
+free_buffer:
+ kfree(buffer);
return ret;
}
@@ -107,7 +362,6 @@ static const struct dma_heap_ops system_heap_ops = {
static int system_heap_create(void)
{
struct dma_heap_export_info exp_info;
- int ret = 0;
exp_info.name = "system";
exp_info.ops = &system_heap_ops;
@@ -115,9 +369,9 @@ static int system_heap_create(void)
sys_heap = dma_heap_add(&exp_info);
if (IS_ERR(sys_heap))
- ret = PTR_ERR(sys_heap);
+ return PTR_ERR(sys_heap);
- return ret;
+ return 0;
}
module_init(system_heap_create);
MODULE_LICENSE("GPL v2");
--
2.17.1
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