[POWERPC] U4 DART improvements

Better late than never...

Respin based on previous comment. Only remaining issue last time was an
extra mb() that I've taken out.

Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/sysdev/dart.h b/arch/powerpc/sysdev/dart.h
index c2d0576..1c8817c 100644 (file)
--- a/arch/powerpc/sysdev/dart.h
+++ b/arch/powerpc/sysdev/dart.h
@@ -47,8 +47,12 @@
 /* U4 registers */
 #define DART_BASE_U4_BASE_MASK 0xffffff
 #define DART_BASE_U4_BASE_SHIFT        0
-#define DART_CNTL_U4_FLUSHTLB  0x20000000
 #define DART_CNTL_U4_ENABLE    0x80000000
+#define DART_CNTL_U4_IONE      0x40000000
+#define DART_CNTL_U4_FLUSHTLB  0x20000000
+#define DART_CNTL_U4_IDLE      0x10000000
+#define DART_CNTL_U4_PAR_EN    0x08000000
+#define DART_CNTL_U4_IONE_MASK 0x07ffffff
 #define DART_SIZE_U4_SIZE_MASK 0x1fff
 #define DART_SIZE_U4_SIZE_SHIFT        0
 

diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c
index 6232091..7c7f34c 100644 (file)
--- a/arch/powerpc/sysdev/dart_iommu.c
+++ b/arch/powerpc/sysdev/dart_iommu.c
@@ -101,8 +101,8 @@ retry:
        if (l == (1L << limit)) {
                if (limit < 4) {
                        limit++;
-                       reg = DART_IN(DART_CNTL);
-                       reg &= ~inv_bit;
+                       reg = DART_IN(DART_CNTL);
+                       reg &= ~inv_bit;
                        DART_OUT(DART_CNTL, reg);
                        goto retry;
                } else
@@ -111,11 +111,39 @@ retry:
        }
 }
 
+static inline void dart_tlb_invalidate_one(unsigned long bus_rpn)
+{
+       unsigned int reg;
+       unsigned int l, limit;
+
+       reg = DART_CNTL_U4_ENABLE | DART_CNTL_U4_IONE |
+               (bus_rpn & DART_CNTL_U4_IONE_MASK);
+       DART_OUT(DART_CNTL, reg);
+
+       limit = 0;
+wait_more:
+       l = 0;
+       while ((DART_IN(DART_CNTL) & DART_CNTL_U4_IONE) && l < (1L << limit)) {
+               rmb();
+               l++;
+       }
+
+       if (l == (1L << limit)) {
+               if (limit < 4) {
+                       limit++;
+                       goto wait_more;
+               } else
+                       panic("DART: TLB did not flush after waiting a long "
+                             "time. Buggy U4 ?");
+       }
+}
+
 static void dart_flush(struct iommu_table *tbl)
 {
-       if (dart_dirty)
+       if (dart_dirty) {
                dart_tlb_invalidate_all();
-       dart_dirty = 0;
+               dart_dirty = 0;
+       }
 }
 
 static void dart_build(struct iommu_table *tbl, long index,
@@ -124,6 +152,7 @@ static void dart_build(struct iommu_table *tbl, long index,
 {
        unsigned int *dp;
        unsigned int rpn;
+       long l;
 
        DBG("dart: build at: %lx, %lx, addr: %x\n", index, npages, uaddr);
 
@@ -135,7 +164,8 @@ static void dart_build(struct iommu_table *tbl, long index,
        /* On U3, all memory is contigous, so we can move this
         * out of the loop.
         */
-       while (npages--) {
+       l = npages;
+       while (l--) {
                rpn = virt_to_abs(uaddr) >> DART_PAGE_SHIFT;
 
                *(dp++) = DARTMAP_VALID | (rpn & DARTMAP_RPNMASK);
@@ -143,7 +173,14 @@ static void dart_build(struct iommu_table *tbl, long index,
                uaddr += DART_PAGE_SIZE;
        }
 
-       dart_dirty = 1;
+       if (dart_is_u4) {
+               rpn = index;
+               mb(); /* make sure all updates have reached memory */
+               while (npages--)
+                       dart_tlb_invalidate_one(rpn++);
+       } else {
+               dart_dirty = 1;
+       }
 }