From 82f4f66ddf11fd4bd2e9b589fd69d0ec6ea777fc Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Sat, 2 Feb 2019 02:01:02 +0000 Subject: [PATCH] MIPS: Remove open-coded cmpxchg() in set_pte() set_pte() contains an open coded version of cmpxchg() - it atomically replaces the buddy pte's value if it is currently zero. Simplify the code considerably by just using cmpxchg() instead of reinventing it. Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org --- arch/mips/include/asm/pgtable.h | 45 ++------------------------------- 1 file changed, 2 insertions(+), 43 deletions(-) diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h index 57933fc8fd98..6c13c1d44045 100644 --- a/arch/mips/include/asm/pgtable.h +++ b/arch/mips/include/asm/pgtable.h @@ -17,6 +17,7 @@ #include #endif +#include #include #include @@ -204,49 +205,7 @@ static inline void set_pte(pte_t *ptep, pte_t pteval) * Make sure the buddy is global too (if it's !none, * it better already be global) */ -#ifdef CONFIG_SMP - /* - * For SMP, multiple CPUs can race, so we need to do - * this atomically. - */ - unsigned long page_global = _PAGE_GLOBAL; - unsigned long tmp; - - if (kernel_uses_llsc && R10000_LLSC_WAR) { - __asm__ __volatile__ ( - " .set push \n" - " .set arch=r4000 \n" - " .set noreorder \n" - "1:" __LL "%[tmp], %[buddy] \n" - " bnez %[tmp], 2f \n" - " or %[tmp], %[tmp], %[global] \n" - __SC "%[tmp], %[buddy] \n" - " beqzl %[tmp], 1b \n" - " nop \n" - "2: \n" - " .set pop \n" - : [buddy] "+m" (buddy->pte), [tmp] "=&r" (tmp) - : [global] "r" (page_global)); - } else if (kernel_uses_llsc) { - __asm__ __volatile__ ( - " .set push \n" - " .set "MIPS_ISA_ARCH_LEVEL" \n" - " .set noreorder \n" - "1:" __LL "%[tmp], %[buddy] \n" - " bnez %[tmp], 2f \n" - " or %[tmp], %[tmp], %[global] \n" - __SC "%[tmp], %[buddy] \n" - " beqz %[tmp], 1b \n" - " nop \n" - "2: \n" - " .set pop \n" - : [buddy] "+m" (buddy->pte), [tmp] "=&r" (tmp) - : [global] "r" (page_global)); - } -#else /* !CONFIG_SMP */ - if (pte_none(*buddy)) - pte_val(*buddy) = pte_val(*buddy) | _PAGE_GLOBAL; -#endif /* CONFIG_SMP */ + cmpxchg(&buddy->pte, 0, _PAGE_GLOBAL); } #endif }