[Blackfin] arch: fix bug - Make the MPU code aware of the async banks and the uncached DMA area.

Bug: CONFIG_MPU doesn't seem to handle access to ASYNC/IO Memory well
http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=3912

Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

1 files changed, 27 insertions, 19 deletions

diff --git a/arch/blackfin/kernel/cplb-mpu/cplbmgr.c b/arch/blackfin/kernel/cplb-mpu/cplbmgr.c
index 0a30d625607..6f1c053903c 100644
--- a/arch/blackfin/kernel/cplb-mpu/cplbmgr.c
+++ b/arch/blackfin/kernel/cplb-mpu/cplbmgr.c
@@ -143,30 +143,39 @@ static noinline int dcplb_miss(void)
         unsigned long d_data;
 
         nr_dcplb_miss++;
-        if (addr >= _ramend)
-                return CPLB_PROT_VIOL;
 
         d_data = CPLB_SUPV_WR | CPLB_VALID | CPLB_DIRTY | PAGE_SIZE_4KB;
 #ifdef CONFIG_BFIN_DCACHE
-        d_data |= CPLB_L1_CHBL | ANOMALY_05000158_WORKAROUND;
+        if (addr < _ramend - DMA_UNCACHED_REGION) {
+                d_data |= CPLB_L1_CHBL | ANOMALY_05000158_WORKAROUND;
 #ifdef CONFIG_BFIN_WT
-        d_data |= CPLB_L1_AOW | CPLB_WT;
-#endif
+                d_data |= CPLB_L1_AOW | CPLB_WT;
 #endif
-        mask = current_rwx_mask;
-        if (mask) {
-                int page = addr >> PAGE_SHIFT;
-                int offs = page >> 5;
-                int bit = 1 << (page & 31);
-
-                if (mask[offs] & bit)
-                        d_data |= CPLB_USER_RD;
-
-                mask += page_mask_nelts;
-                if (mask[offs] & bit)
-                        d_data |= CPLB_USER_WR;
         }
+#endif
+        if (addr >= _ramend) {
+                if (addr >= ASYNC_BANK0_BASE && addr < ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE
+                    && (status & FAULT_USERSUPV)) {
+                        addr &= ~0x3fffff;
+                        d_data &= ~PAGE_SIZE_4KB;
+                        d_data |= PAGE_SIZE_4MB;
+                } else
+                        return CPLB_PROT_VIOL;
+        } else {
+                mask = current_rwx_mask;
+                if (mask) {
+                        int page = addr >> PAGE_SHIFT;
+                        int offs = page >> 5;
+                        int bit = 1 << (page & 31);
+
+                        if (mask[offs] & bit)
+                                d_data |= CPLB_USER_RD;
 
+                        mask += page_mask_nelts;
+                        if (mask[offs] & bit)
+                                d_data |= CPLB_USER_WR;
+                }
+        }
         idx = evict_one_dcplb();
 
         addr &= PAGE_MASK;
@@ -280,8 +289,7 @@ int cplb_hdr(int seqstat, struct pt_regs *regs)
         case 0x26:
                 return dcplb_miss();
         default:
-            return 1;
-                panic_cplb_error(seqstat, regs);
+                return 1;
         }
 }