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| author | Vincent Whitchurch <vincent.whitchurch@axis.com> | 2019-01-16 13:31:41 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@armlinux.org.uk> | 2019-02-01 21:44:11 +0000 |
| commit | 58ca33824ff850bee93c850830a7b180486f3371 (patch) | |
| tree | e2c9050c7216042b84321bfede3ac4b22aac2422 | |
| parent | fec9eac6594750ee74c99549f13de3aa9de91b18 (diff) | |
| download | lwn-58ca33824ff850bee93c850830a7b180486f3371.tar.gz lwn-58ca33824ff850bee93c850830a7b180486f3371.zip | |
ARM: 8823/1: Implement pgprot_device()
This is used when mmapping the PCI resource* files in sys. Because ARM
currently lacks an implementation of pgprot_device(), it falls back to
pgprot_uncached() (Strongly Ordered), but we should be able to use
Device memory instead.
Doing this speeds up large writes to the resource files by about 40% on
one of my systems. It also ensures that mmaps on these resources use
the same memory type as ioremap().
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
| -rw-r--r-- | arch/arm/include/asm/pgtable.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index a757401129f9..48ce1b19069b 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -125,6 +125,9 @@ extern pgprot_t pgprot_s2_device; #define pgprot_stronglyordered(prot) \ __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED) +#define pgprot_device(prot) \ + __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_DEV_SHARED | L_PTE_SHARED | L_PTE_DIRTY | L_PTE_XN) + #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE #define pgprot_dmacoherent(prot) \ __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN) |