2 files changed, 40 insertions, 0 deletions

diff --git a/arch/mips/sgi-ip22/ip22-mc.c b/arch/mips/sgi-ip22/ip22-mc.c
index 3f35d6367bec..5268ac187bbd 100644
--- a/arch/mips/sgi-ip22/ip22-mc.c
+++ b/arch/mips/sgi-ip22/ip22-mc.c
@@ -208,4 +208,30 @@ void __init sgimc_init(void)
 void __init prom_meminit(void) {}
 void __init prom_free_prom_memory(void)
 {
+#ifdef CONFIG_SGI_IP28
+        u32 mconfig1;
+        unsigned long flags;
+        spinlock_t lock;
+
+        /*
+         * because ARCS accesses memory uncached we wait until ARCS
+         * isn't needed any longer, before we switch from slow to
+         * normal mode
+         */
+        spin_lock_irqsave(&lock, flags);
+        mconfig1 = sgimc->mconfig1;
+        /* map ECC register */
+        sgimc->mconfig1 = (mconfig1 & 0xffff0000) | 0x2060;
+        iob();
+        /* switch to normal mode */
+        *(unsigned long *)PHYS_TO_XKSEG_UNCACHED(0x60000000) = 0;
+        iob();
+        /* reduce WR_COL */
+        sgimc->cmacc = (sgimc->cmacc & ~0xf) | 4;
+        iob();
+        /* restore old config */
+        sgimc->mconfig1 = mconfig1;
+        iob();
+        spin_unlock_irqrestore(&lock, flags);
+#endif
 }
diff --git a/include/asm-mips/barrier.h b/include/asm-mips/barrier.h
index 9d8cfbb5e796..8e9ac313ca3b 100644
--- a/include/asm-mips/barrier.h
+++ b/include/asm-mips/barrier.h
@@ -92,11 +92,25 @@
 #define fast_wmb()      __sync()
 #define fast_rmb()      __sync()
 #define fast_mb()       __sync()
+#ifdef CONFIG_SGI_IP28
+#define fast_iob()                              \
+        __asm__ __volatile__(                   \
+                ".set   push\n\t"               \
+                ".set   noreorder\n\t"          \
+                "lw     $0,%0\n\t"              \
+                "sync\n\t"                      \
+                "lw     $0,%0\n\t"              \
+                ".set   pop"                    \
+                : /* no output */               \
+                : "m" (*(int *)CKSEG1ADDR(0x1fa00004)) \
+                : "memory")
+#else
 #define fast_iob()                              \
         do {                                    \
                 __sync();                       \
                 __fast_iob();                   \
         } while (0)
+#endif
 
 #ifdef CONFIG_CPU_HAS_WB