On 10/01/18 08:09, Christoph Hellwig wrote:
arm64 uses ZONE_DMA for allocations below 32-bits. These days we
name the zone for that ZONE_DMA32, which will allow to use the
dma-direct and generic swiotlb code as-is, so rename it.
I do wonder if we could also "upgrade" GFP_DMA to GFP_DMA32 somehow when
!ZONE_DMA - there are almost certainly arm64 drivers out there using a
combination of GFP_DMA and streaming mappings which will no longer get
the guaranteed 32-bit addresses they expect after this. I'm not sure
quite how feasible that is, though :/
That said, I do agree that this is an appropriate change (the legacy of
GFP_DMA is obviously horrible), so, provided we get plenty of time to
find and fix the fallout when it lands:
Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
Robin.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/arm64/Kconfig | 2 +-
arch/arm64/mm/dma-mapping.c | 6 +++---
arch/arm64/mm/init.c | 16 ++++++++--------
3 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index c9a7e9e1414f..6b6985f15d02 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -227,7 +227,7 @@ config GENERIC_CSUM
config GENERIC_CALIBRATE_DELAY
def_bool y
-config ZONE_DMA
+config ZONE_DMA32
def_bool y
config HAVE_GENERIC_GUP
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 6840426bbe77..0d641875b20e 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -95,9 +95,9 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flags,
unsigned long attrs)
{
- if (IS_ENABLED(CONFIG_ZONE_DMA) &&
+ if (IS_ENABLED(CONFIG_ZONE_DMA32) &&
dev->coherent_dma_mask <= DMA_BIT_MASK(32))
- flags |= GFP_DMA;
+ flags |= GFP_DMA32;
if (dev_get_cma_area(dev) && gfpflags_allow_blocking(flags)) {
struct page *page;
void *addr;
@@ -397,7 +397,7 @@ static int __init atomic_pool_init(void)
page = dma_alloc_from_contiguous(NULL, nr_pages,
pool_size_order, GFP_KERNEL);
else
- page = alloc_pages(GFP_DMA, pool_size_order);
+ page = alloc_pages(GFP_DMA32, pool_size_order);
if (page) {
int ret;
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 00e7b900ca41..8f03276443c9 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -217,7 +217,7 @@ static void __init reserve_elfcorehdr(void)
}
#endif /* CONFIG_CRASH_DUMP */
/*
- * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
+ * Return the maximum physical address for ZONE_DMA32 (DMA_BIT_MASK(32)). It
* currently assumes that for memory starting above 4G, 32-bit devices will
* use a DMA offset.
*/
@@ -233,8 +233,8 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
{
unsigned long max_zone_pfns[MAX_NR_ZONES] = {0};
- if (IS_ENABLED(CONFIG_ZONE_DMA))
- max_zone_pfns[ZONE_DMA] = PFN_DOWN(max_zone_dma_phys());
+ if (IS_ENABLED(CONFIG_ZONE_DMA32))
+ max_zone_pfns[ZONE_DMA32] = PFN_DOWN(max_zone_dma_phys());
max_zone_pfns[ZONE_NORMAL] = max;
free_area_init_nodes(max_zone_pfns);
@@ -251,9 +251,9 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
memset(zone_size, 0, sizeof(zone_size));
/* 4GB maximum for 32-bit only capable devices */
-#ifdef CONFIG_ZONE_DMA
+#ifdef CONFIG_ZONE_DMA32
max_dma = PFN_DOWN(arm64_dma_phys_limit);
- zone_size[ZONE_DMA] = max_dma - min;
+ zone_size[ZONE_DMA32] = max_dma - min;
#endif
zone_size[ZONE_NORMAL] = max - max_dma;
@@ -266,10 +266,10 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
if (start >= max)
continue;
-#ifdef CONFIG_ZONE_DMA
+#ifdef CONFIG_ZONE_DMA32
if (start < max_dma) {
unsigned long dma_end = min(end, max_dma);
- zhole_size[ZONE_DMA] -= dma_end - start;
+ zhole_size[ZONE_DMA32] -= dma_end - start;
}
#endif
if (end > max_dma) {
@@ -467,7 +467,7 @@ void __init arm64_memblock_init(void)
early_init_fdt_scan_reserved_mem();
/* 4GB maximum for 32-bit only capable devices */
- if (IS_ENABLED(CONFIG_ZONE_DMA))
+ if (IS_ENABLED(CONFIG_ZONE_DMA32))
arm64_dma_phys_limit = max_zone_dma_phys();
else
arm64_dma_phys_limit = PHYS_MASK + 1;
