The patch titled
Subject: dmapool: move debug code to own functions
has been added to the -mm mm-unstable branch. Its filename is
dmapool-move-debug-code-to-own-functions.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/dmapool-move-debug-code-to-own-functions.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Keith Busch <kbusch@xxxxxxxxxx>
Subject: dmapool: move debug code to own functions
Date: Thu, 26 Jan 2023 13:51:19 -0800
Clean up the normal path by moving the debug code outside it.
Link: https://lkml.kernel.org/r/20230126215125.4069751-7-kbusch@xxxxxxxx
Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Tony Battersby <tonyb@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/dmapool.c | 128 +++++++++++++++++++++++++++++--------------------
1 file changed, 77 insertions(+), 51 deletions(-)
--- a/mm/dmapool.c~dmapool-move-debug-code-to-own-functions
+++ a/mm/dmapool.c
@@ -96,6 +96,78 @@ static ssize_t pools_show(struct device
static DEVICE_ATTR_RO(pools);
+#ifdef DMAPOOL_DEBUG
+static void pool_check_block(struct dma_pool *pool, void *retval,
+ unsigned int offset, gfp_t mem_flags)
+{
+ int i;
+ u8 *data = retval;
+ /* page->offset is stored in first 4 bytes */
+ for (i = sizeof(offset); i < pool->size; i++) {
+ if (data[i] == POOL_POISON_FREED)
+ continue;
+ dev_err(pool->dev, "%s %s, %p (corrupted)\n",
+ __func__, pool->name, retval);
+
+ /*
+ * Dump the first 4 bytes even if they are not
+ * POOL_POISON_FREED
+ */
+ print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1,
+ data, pool->size, 1);
+ break;
+ }
+ if (!want_init_on_alloc(mem_flags))
+ memset(retval, POOL_POISON_ALLOCATED, pool->size);
+}
+
+static bool pool_page_err(struct dma_pool *pool, struct dma_page *page,
+ void *vaddr, dma_addr_t dma)
+{
+ unsigned int offset = vaddr - page->vaddr;
+ unsigned int chain = page->offset;
+
+ if ((dma - page->dma) != offset) {
+ dev_err(pool->dev, "%s %s, %p (bad vaddr)/%pad\n",
+ __func__, pool->name, vaddr, &dma);
+ return true;
+ }
+
+ while (chain < pool->allocation) {
+ if (chain != offset) {
+ chain = *(int *)(page->vaddr + chain);
+ continue;
+ }
+ dev_err(pool->dev, "%s %s, dma %pad already free\n",
+ __func__, pool->name, &dma);
+ return true;
+ }
+ memset(vaddr, POOL_POISON_FREED, pool->size);
+ return false;
+}
+
+static void pool_init_page(struct dma_pool *pool, struct dma_page *page)
+{
+ memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
+}
+#else
+static void pool_check_block(struct dma_pool *pool, void *retval,
+ unsigned int offset, gfp_t mem_flags)
+
+{
+}
+
+static bool pool_page_err(struct dma_pool *pool, struct dma_page *page,
+ void *vaddr, dma_addr_t dma)
+{
+ return false;
+}
+
+static void pool_init_page(struct dma_pool *pool, struct dma_page *page)
+{
+}
+#endif
+
/**
* dma_pool_create - Creates a pool of consistent memory blocks, for dma.
* @name: name of pool, for diagnostics
@@ -223,9 +295,7 @@ static struct dma_page *pool_alloc_page(
page->vaddr = dma_alloc_coherent(pool->dev, pool->allocation,
&page->dma, mem_flags);
if (page->vaddr) {
-#ifdef DMAPOOL_DEBUG
- memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
-#endif
+ pool_init_page(pool, page);
pool_initialise_page(pool, page);
page->in_use = 0;
page->offset = 0;
@@ -245,9 +315,7 @@ static void pool_free_page(struct dma_po
{
dma_addr_t dma = page->dma;
-#ifdef DMAPOOL_DEBUG
- memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
-#endif
+ pool_init_page(pool, page);
dma_free_coherent(pool->dev, pool->allocation, page->vaddr, dma);
list_del(&page->page_list);
kfree(page);
@@ -336,29 +404,7 @@ void *dma_pool_alloc(struct dma_pool *po
page->offset = *(int *)(page->vaddr + offset);
retval = offset + page->vaddr;
*handle = offset + page->dma;
-#ifdef DMAPOOL_DEBUG
- {
- int i;
- u8 *data = retval;
- /* page->offset is stored in first 4 bytes */
- for (i = sizeof(page->offset); i < pool->size; i++) {
- if (data[i] == POOL_POISON_FREED)
- continue;
- dev_err(pool->dev, "%s %s, %p (corrupted)\n",
- __func__, pool->name, retval);
-
- /*
- * Dump the first 4 bytes even if they are not
- * POOL_POISON_FREED
- */
- print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1,
- data, pool->size, 1);
- break;
- }
- }
- if (!want_init_on_alloc(mem_flags))
- memset(retval, POOL_POISON_ALLOCATED, pool->size);
-#endif
+ pool_check_block(pool, retval, offset, mem_flags);
spin_unlock_irqrestore(&pool->lock, flags);
if (want_init_on_alloc(mem_flags))
@@ -394,7 +440,6 @@ void dma_pool_free(struct dma_pool *pool
{
struct dma_page *page;
unsigned long flags;
- unsigned int offset;
spin_lock_irqsave(&pool->lock, flags);
page = pool_find_page(pool, dma);
@@ -405,35 +450,16 @@ void dma_pool_free(struct dma_pool *pool
return;
}
- offset = vaddr - page->vaddr;
if (want_init_on_free())
memset(vaddr, 0, pool->size);
-#ifdef DMAPOOL_DEBUG
- if ((dma - page->dma) != offset) {
+ if (pool_page_err(pool, page, vaddr, dma)) {
spin_unlock_irqrestore(&pool->lock, flags);
- dev_err(pool->dev, "%s %s, %p (bad vaddr)/%pad\n",
- __func__, pool->name, vaddr, &dma);
return;
}
- {
- unsigned int chain = page->offset;
- while (chain < pool->allocation) {
- if (chain != offset) {
- chain = *(int *)(page->vaddr + chain);
- continue;
- }
- spin_unlock_irqrestore(&pool->lock, flags);
- dev_err(pool->dev, "%s %s, dma %pad already free\n",
- __func__, pool->name, &dma);
- return;
- }
- }
- memset(vaddr, POOL_POISON_FREED, pool->size);
-#endif
page->in_use--;
*(int *)vaddr = page->offset;
- page->offset = offset;
+ page->offset = vaddr - page->vaddr;
/*
* Resist a temptation to do
* if (!is_page_busy(page)) pool_free_page(pool, page);
_
Patches currently in -mm which might be from kbusch@xxxxxxxxxx are
dmapool-add-alloc-free-performance-test.patch
dmapool-move-debug-code-to-own-functions.patch
dmapool-rearrange-page-alloc-failure-handling.patch
dmapool-consolidate-page-initialization.patch
dmapool-simplify-freeing.patch
dmapool-dont-memset-on-free-twice.patch
dmapool-link-blocks-across-pages.patch
dmapool-create-destroy-cleanup.patch
