[POWERPC] 64K page support for kexec

[powerpc.git] / arch / powerpc / mm / hash_native_64.c

diff --git a/arch/powerpc/mm/hash_native_64.c b/arch/powerpc/mm/hash_native_64.c
index 79aedaf..7b7fe2d 100644 (file)
--- a/arch/powerpc/mm/hash_native_64.c
+++ b/arch/powerpc/mm/hash_native_64.c
@@ -26,6 +26,7 @@
 #include <asm/tlb.h>
 #include <asm/cputable.h>
 #include <asm/udbg.h>
+#include <asm/kexec.h>
 
 #ifdef DEBUG_LOW
 #define DBG_LOW(fmt...) udbg_printf(fmt)
@@ -340,31 +341,70 @@ static void native_hpte_invalidate(unsigned long slot, unsigned long va,
        local_irq_restore(flags);
 }
 
-/*
- * XXX This need fixing based on page size. It's only used by
- * native_hpte_clear() for now which needs fixing too so they
- * make a good pair...
- */
-static unsigned long slot2va(unsigned long hpte_v, unsigned long slot)
-{
-       unsigned long avpn = HPTE_V_AVPN_VAL(hpte_v);
-       unsigned long va;
+#define LP_SHIFT       12
+#define LP_BITS                8
+#define LP_MASK(i)     ((0xFF >> (i)) << LP_SHIFT)
 
-       va = avpn << 23;
+static void hpte_decode(hpte_t *hpte, unsigned long slot,
+                       int *psize, unsigned long *va)
+{
+       unsigned long hpte_r = hpte->r;
+       unsigned long hpte_v = hpte->v;
+       unsigned long avpn;
+       int i, size, shift, penc, avpnm_bits;
+
+       if (!(hpte_v & HPTE_V_LARGE))
+               size = MMU_PAGE_4K;
+       else {
+               for (i = 0; i < LP_BITS; i++) {
+                       if ((hpte_r & LP_MASK(i+1)) == LP_MASK(i+1))
+                               break;
+               }
+               penc = LP_MASK(i+1) >> LP_SHIFT;
+               for (size = 0; size < MMU_PAGE_COUNT; size++) {
 
-       if (! (hpte_v & HPTE_V_LARGE)) {
-               unsigned long vpi, pteg;
+                       /* 4K pages are not represented by LP */
+                       if (size == MMU_PAGE_4K)
+                               continue;
 
-               pteg = slot / HPTES_PER_GROUP;
-               if (hpte_v & HPTE_V_SECONDARY)
-                       pteg = ~pteg;
+                       /* valid entries have a shift value */
+                       if (!mmu_psize_defs[size].shift)
+                               continue;
 
-               vpi = ((va >> 28) ^ pteg) & htab_hash_mask;
+                       if (penc == mmu_psize_defs[size].penc)
+                               break;
+               }
+       }
 
-               va |= vpi << PAGE_SHIFT;
+       /*
+        * FIXME, the code below works for 16M, 64K, and 4K pages as these
+        * fall under the p<=23 rules for calculating the virtual address.
+        * In the case of 16M pages, an extra bit is stolen from the AVPN
+        * field to achieve the requisite 24 bits.
+        *
+        * Does not work for 16G pages or 1 TB segments.
+        */
+       shift = mmu_psize_defs[size].shift;
+       if (mmu_psize_defs[size].avpnm)
+               avpnm_bits = __ilog2_u64(mmu_psize_defs[size].avpnm) + 1;
+       else
+               avpnm_bits = 0;
+       if (shift - avpnm_bits <= 23) {
+               avpn = HPTE_V_AVPN_VAL(hpte_v) << 23;
+
+               if (shift < 23) {
+                       unsigned long vpi, pteg;
+
+                       pteg = slot / HPTES_PER_GROUP;
+                       if (hpte_v & HPTE_V_SECONDARY)
+                               pteg = ~pteg;
+                       vpi = ((avpn >> 28) ^ pteg) & htab_hash_mask;
+                       avpn |= (vpi << mmu_psize_defs[size].shift);
+               }
        }
 
-       return va;
+       *va = avpn;
+       *psize = size;
 }
 
 /*
@@ -374,15 +414,14 @@ static unsigned long slot2va(unsigned long hpte_v, unsigned long slot)
  *
  * TODO: add batching support when enabled.  remember, no dynamic memory here,
  * athough there is the control page available...
- *
- * XXX FIXME: 4k only for now !
  */
 static void native_hpte_clear(void)
 {
        unsigned long slot, slots, flags;
        hpte_t *hptep = htab_address;
-       unsigned long hpte_v;
+       unsigned long hpte_v, va;
        unsigned long pteg_count;
+       int psize;
 
        pteg_count = htab_hash_mask + 1;
 
@@ -408,8 +447,9 @@ static void native_hpte_clear(void)
                 * already hold the native_tlbie_lock.
                 */
                if (hpte_v & HPTE_V_VALID) {
+                       hpte_decode(hptep, slot, &psize, &va);
                        hptep->v = 0;
-                       __tlbie(slot2va(hpte_v, slot), MMU_PAGE_4K);
+                       __tlbie(va, psize);
                }
        }