When allocating DMA memory from a pool, the core can only guess which
atomic pool will fit a device's constraints. If it doesn't, get a safer
atomic pool and try again.
Fixes: c84dc6e68a1d ("dma-pool: add additional coherent pools to map to gfp mask")
Reported-by: Jeremy Linton <[email protected]>
Suggested-by: Robin Murphy <[email protected]>
Signed-off-by: Nicolas Saenz Julienne <[email protected]>
---
Changes since v1:
- Rebase to linus' master
kernel/dma/pool.c | 57 ++++++++++++++++++++++++++++++-----------------
1 file changed, 37 insertions(+), 20 deletions(-)
diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
index 5b9eaa2b498d..d48d9acb585f 100644
--- a/kernel/dma/pool.c
+++ b/kernel/dma/pool.c
@@ -240,39 +240,56 @@ static inline struct gen_pool *dma_guess_pool(struct device *dev,
void *dma_alloc_from_pool(struct device *dev, size_t size,
struct page **ret_page, gfp_t flags)
{
- struct gen_pool *pool = dma_guess_pool(dev, NULL);
- unsigned long val;
+ struct gen_pool *pool = NULL;
+ unsigned long val = 0;
void *ptr = NULL;
-
- if (!pool) {
- WARN(1, "%pGg atomic pool not initialised!\n", &flags);
- return NULL;
+ phys_addr_t phys;
+
+ while (1) {
+ pool = dma_guess_pool(dev, pool);
+ if (!pool) {
+ WARN(1, "Failed to get suitable pool for %s\n",
+ dev_name(dev));
+ break;
+ }
+
+ val = gen_pool_alloc(pool, size);
+ if (!val)
+ continue;
+
+ phys = gen_pool_virt_to_phys(pool, val);
+ if (dma_coherent_ok(dev, phys, size))
+ break;
+
+ gen_pool_free(pool, val, size);
+ val = 0;
}
- val = gen_pool_alloc(pool, size);
- if (likely(val)) {
- phys_addr_t phys = gen_pool_virt_to_phys(pool, val);
+ if (val) {
*ret_page = pfn_to_page(__phys_to_pfn(phys));
ptr = (void *)val;
memset(ptr, 0, size);
- } else {
- WARN_ONCE(1, "DMA coherent pool depleted, increase size "
- "(recommended min coherent_pool=%zuK)\n",
- gen_pool_size(pool) >> 9);
+
+ if (gen_pool_avail(pool) < atomic_pool_size)
+ schedule_work(&atomic_pool_work);
}
- if (gen_pool_avail(pool) < atomic_pool_size)
- schedule_work(&atomic_pool_work);
return ptr;
}
bool dma_free_from_pool(struct device *dev, void *start, size_t size)
{
- struct gen_pool *pool = dma_guess_pool(dev, NULL);
+ struct gen_pool *pool = NULL;
- if (!pool || !gen_pool_has_addr(pool, (unsigned long)start, size))
- return false;
- gen_pool_free(pool, (unsigned long)start, size);
- return true;
+ while (1) {
+ pool = dma_guess_pool(dev, pool);
+ if (!pool)
+ return false;
+
+ if (gen_pool_has_addr(pool, (unsigned long)start, size)) {
+ gen_pool_free(pool, (unsigned long)start, size);
+ return true;
+ }
+ }
}
--
2.27.0