[PATCH v4 12/13] dma-direct: return struct page from dma_direct_alloc_from_pool()

[Aneesh Kumar K.V (Arm)]

Commit 5b138c534fda ("dma-direct: factor out a dma_direct_alloc_from_pool
helper") changed dma_direct_alloc_from_pool() to return the CPU address
from dma_alloc_from_pool(). That fits dma_direct_alloc(), but
dma_direct_alloc_pages() also uses the helper and expects a struct page *.

Fix this by making dma_direct_alloc_from_pool() return the struct page *
again, and pass the CPU address back through an out-parameter for the
dma_direct_alloc() caller.

Fixes: 5b138c534fda ("dma-direct: factor out a dma_direct_alloc_from_pool 
helper")
Cc: sta...@vger.kernel.org

Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.ku...@kernel.org>
---
 kernel/dma/direct.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 902008e40ea1..5103a04df99f 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -165,24 +165,24 @@ static bool dma_direct_use_pool(struct device *dev, gfp_t 
gfp)
        return !gfpflags_allow_blocking(gfp) && !is_swiotlb_for_alloc(dev);
 }
 
-static void *dma_direct_alloc_from_pool(struct device *dev, size_t size,
-               dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+static struct page *dma_direct_alloc_from_pool(struct device *dev, size_t size,
+               dma_addr_t *dma_handle, void **cpu_addr, gfp_t gfp,
+               unsigned long attrs)
 {
        struct page *page;
        u64 phys_limit;
-       void *ret;
 
        if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_DMA_COHERENT_POOL)))
                return NULL;
 
        gfp |= dma_direct_optimal_gfp_mask(dev, &phys_limit);
-       page = dma_alloc_from_pool(dev, size, &ret, gfp, attrs,
+       page = dma_alloc_from_pool(dev, size, cpu_addr, gfp, attrs,
                                   dma_coherent_ok);
        if (!page)
                return NULL;
        *dma_handle = phys_to_dma_direct(dev, page_to_phys(page),
                                         !!(attrs & DMA_ATTR_CC_SHARED));
-       return ret;
+       return page;
 }
 
 static void *dma_direct_alloc_no_mapping(struct device *dev, size_t size,
@@ -278,9 +278,12 @@ void *dma_direct_alloc(struct device *dev, size_t size,
         * the atomic pools instead if we aren't allowed block.
         */
        if ((remap || (attrs & DMA_ATTR_CC_SHARED)) &&
-           dma_direct_use_pool(dev, gfp))
-               return dma_direct_alloc_from_pool(dev, size, dma_handle,
-                                                 gfp, attrs);
+           dma_direct_use_pool(dev, gfp)) {
+               page = dma_direct_alloc_from_pool(dev, size,
+                                       dma_handle, &cpu_addr,
+                                       gfp, attrs);
+               return page ? cpu_addr : NULL;
+       }
 
        if (is_swiotlb_for_alloc(dev)) {
                page = dma_direct_alloc_swiotlb(dev, size, attrs);
@@ -443,7 +446,7 @@ struct page *dma_direct_alloc_pages(struct device *dev, 
size_t size,
 
        if ((attrs & DMA_ATTR_CC_SHARED) && dma_direct_use_pool(dev, gfp))
                return dma_direct_alloc_from_pool(dev, size, dma_handle,
-                                                 gfp, attrs);
+                                                 &cpu_addr, gfp, attrs);
 
        if (is_swiotlb_for_alloc(dev)) {
                page = dma_direct_alloc_swiotlb(dev, size, attrs);
-- 
2.43.0