MIPS: Adjust set_pte() SMP fix to handle R10000_LLSC_WAR

[pandora-kernel.git] / arch / mips / include / asm / pgtable.h

diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index b2202a6..d9e9925 100644 (file)
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -153,8 +153,58 @@ 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.
+                */
+#ifdef CONFIG_64BIT
+#define LL_INSN "lld"
+#define SC_INSN "scd"
+#else /* CONFIG_32BIT */
+#define LL_INSN "ll"
+#define SC_INSN "sc"
+#endif
+               unsigned long page_global = _PAGE_GLOBAL;
+               unsigned long tmp;
+
+               if (kernel_uses_llsc && R10000_LLSC_WAR) {
+                       __asm__ __volatile__ (
+                       "       .set    arch=r4000                      \n"
+                       "       .set    push                            \n"
+                       "       .set    noreorder                       \n"
+                       "1:"    LL_INSN " %[tmp], %[buddy]              \n"
+                       "       bnez    %[tmp], 2f                      \n"
+                       "        or     %[tmp], %[tmp], %[global]       \n"
+                               SC_INSN " %[tmp], %[buddy]              \n"
+                       "       beqzl   %[tmp], 1b                      \n"
+                       "       nop                                     \n"
+                       "2:                                             \n"
+                       "       .set    pop                             \n"
+                       "       .set    mips0                           \n"
+                       : [buddy] "+m" (buddy->pte), [tmp] "=&r" (tmp)
+                       : [global] "r" (page_global));
+               } else if (kernel_uses_llsc) {
+                       __asm__ __volatile__ (
+                       "       .set    arch=r4000                      \n"
+                       "       .set    push                            \n"
+                       "       .set    noreorder                       \n"
+                       "1:"    LL_INSN " %[tmp], %[buddy]              \n"
+                       "       bnez    %[tmp], 2f                      \n"
+                       "        or     %[tmp], %[tmp], %[global]       \n"
+                               SC_INSN " %[tmp], %[buddy]              \n"
+                       "       beqz    %[tmp], 1b                      \n"
+                       "       nop                                     \n"
+                       "2:                                             \n"
+                       "       .set    pop                             \n"
+                       "       .set    mips0                           \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 */
        }
 #endif
 }