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-rw-r--r--arch/mips/include/asm/pgtable.h31
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index 9d8106758142..ae8569475264 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -182,8 +182,39 @@ 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;
+
+ __asm__ __volatile__ (
+ " .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"
+ : [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
}