From 1bd46782d08b01b73df0085b51ea1021b19b44fd Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 3 Jul 2015 15:22:54 +0100 Subject: ARM: avoid unwanted GCC memset()/memcpy() optimisations for IO variants We don't want GCC optimising our memset_io(), memcpy_fromio() or memcpy_toio() variants, so we must not call one of the standard functions. Provide a separate name for our assembly memcpy() and memset() functions, and use that instead, thereby bypassing GCC's ability to optimise these operations. GCCs optimisation may introduce unaligned accesses which are invalid for device mappings. Signed-off-by: Russell King --- arch/arm/kernel/armksyms.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/arm/kernel/armksyms.c') diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c index a88671cfe1ff..5e5a51a99e68 100644 --- a/arch/arm/kernel/armksyms.c +++ b/arch/arm/kernel/armksyms.c @@ -50,6 +50,9 @@ extern void __aeabi_ulcmp(void); extern void fpundefinstr(void); +void mmioset(void *, unsigned int, size_t); +void mmiocpy(void *, const void *, size_t); + /* platform dependent support */ EXPORT_SYMBOL(arm_delay_ops); @@ -88,6 +91,9 @@ EXPORT_SYMBOL(memmove); EXPORT_SYMBOL(memchr); EXPORT_SYMBOL(__memzero); +EXPORT_SYMBOL(mmioset); +EXPORT_SYMBOL(mmiocpy); + #ifdef CONFIG_MMU EXPORT_SYMBOL(copy_page); -- cgit