POWERPC: Allow 32-bit hashed pgtable code to support 36-bit physical
This rearranges a bit of code, and adds support for
36-bit physical addressing for configs that use a
hashed page table. The 36b physical support is not
enabled by default on any config - it must be
explicitly enabled via the config system.
This patch *only* expands the page table code to accomodate
large physical addresses on 32-bit systems and enables the
PHYS_64BIT config option for 86xx. It does *not*
allow you to boot a board with more than about 3.5GB of
RAM - for that, SWIOTLB support is also required (and
coming soon).
Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S
index c41d658..7bffb70 100644
--- a/arch/powerpc/mm/hash_low_32.S
+++ b/arch/powerpc/mm/hash_low_32.S
@@ -75,7 +75,7 @@
* Returns to the caller if the access is illegal or there is no
* mapping for the address. Otherwise it places an appropriate PTE
* in the hash table and returns from the exception.
- * Uses r0, r3 - r8, ctr, lr.
+ * Uses r0, r3 - r8, r10, ctr, lr.
*/
.text
_GLOBAL(hash_page)
@@ -106,9 +106,15 @@
addi r5,r5,swapper_pg_dir@l /* kernel page table */
rlwimi r3,r9,32-12,29,29 /* MSR_PR -> _PAGE_USER */
112: add r5,r5,r7 /* convert to phys addr */
+#ifndef CONFIG_PTE_64BIT
rlwimi r5,r4,12,20,29 /* insert top 10 bits of address */
lwz r8,0(r5) /* get pmd entry */
rlwinm. r8,r8,0,0,19 /* extract address of pte page */
+#else
+ rlwinm r8,r4,13,19,29 /* Compute pgdir/pmd offset */
+ lwzx r8,r8,r5 /* Get L1 entry */
+ rlwinm. r8,r8,0,0,20 /* extract pt base address */
+#endif
#ifdef CONFIG_SMP
beq- hash_page_out /* return if no mapping */
#else
@@ -118,7 +124,11 @@
to the address following the rfi. */
beqlr-
#endif
+#ifndef CONFIG_PTE_64BIT
rlwimi r8,r4,22,20,29 /* insert next 10 bits of address */
+#else
+ rlwimi r8,r4,23,20,28 /* compute pte address */
+#endif
rlwinm r0,r3,32-3,24,24 /* _PAGE_RW access -> _PAGE_DIRTY */
ori r0,r0,_PAGE_ACCESSED|_PAGE_HASHPTE
@@ -127,9 +137,15 @@
* because almost always, there won't be a permission violation
* and there won't already be an HPTE, and thus we will have
* to update the PTE to set _PAGE_HASHPTE. -- paulus.
+ *
+ * If PTE_64BIT is set, the low word is the flags word; use that
+ * word for locking since it contains all the interesting bits.
*/
+#if (PTE_FLAGS_OFFSET != 0)
+ addi r8,r8,PTE_FLAGS_OFFSET
+#endif
retry:
- lwarx r6,0,r8 /* get linux-style pte */
+ lwarx r6,0,r8 /* get linux-style pte, flag word */
andc. r5,r3,r6 /* check access & ~permission */
#ifdef CONFIG_SMP
bne- hash_page_out /* return if access not permitted */
@@ -137,6 +153,15 @@
bnelr-
#endif
or r5,r0,r6 /* set accessed/dirty bits */
+#ifdef CONFIG_PTE_64BIT
+#ifdef CONFIG_SMP
+ subf r10,r6,r8 /* create false data dependency */
+ subi r10,r10,PTE_FLAGS_OFFSET
+ lwzx r10,r6,r10 /* Get upper PTE word */
+#else
+ lwz r10,-PTE_FLAGS_OFFSET(r8)
+#endif /* CONFIG_SMP */
+#endif /* CONFIG_PTE_64BIT */
stwcx. r5,0,r8 /* attempt to update PTE */
bne- retry /* retry if someone got there first */
@@ -203,9 +228,9 @@
* we can't take a hash table miss (assuming the code is
* covered by a BAT). -- paulus
*/
- mfmsr r10
+ mfmsr r9
SYNC
- rlwinm r0,r10,0,17,15 /* clear bit 16 (MSR_EE) */
+ rlwinm r0,r9,0,17,15 /* clear bit 16 (MSR_EE) */
rlwinm r0,r0,0,28,26 /* clear MSR_DR */
mtmsr r0
SYNC_601
@@ -214,14 +239,14 @@
tophys(r7,0)
#ifdef CONFIG_SMP
- addis r9,r7,mmu_hash_lock@ha
- addi r9,r9,mmu_hash_lock@l
-10: lwarx r0,0,r9 /* take the mmu_hash_lock */
+ addis r6,r7,mmu_hash_lock@ha
+ addi r6,r6,mmu_hash_lock@l
+10: lwarx r0,0,r6 /* take the mmu_hash_lock */
cmpi 0,r0,0
bne- 11f
- stwcx. r8,0,r9
+ stwcx. r8,0,r6
beq+ 12f
-11: lwz r0,0(r9)
+11: lwz r0,0(r6)
cmpi 0,r0,0
beq 10b
b 11b
@@ -234,10 +259,24 @@
* HPTE, so we just unlock and return.
*/
mr r8,r5
+#ifndef CONFIG_PTE_64BIT
rlwimi r8,r4,22,20,29
+#else
+ rlwimi r8,r4,23,20,28
+ addi r8,r8,PTE_FLAGS_OFFSET
+#endif
1: lwarx r6,0,r8
andi. r0,r6,_PAGE_HASHPTE
bne 9f /* if HASHPTE already set, done */
+#ifdef CONFIG_PTE_64BIT
+#ifdef CONFIG_SMP
+ subf r10,r6,r8 /* create false data dependency */
+ subi r10,r10,PTE_FLAGS_OFFSET
+ lwzx r10,r6,r10 /* Get upper PTE word */
+#else
+ lwz r10,-PTE_FLAGS_OFFSET(r8)
+#endif /* CONFIG_SMP */
+#endif /* CONFIG_PTE_64BIT */
ori r5,r6,_PAGE_HASHPTE
stwcx. r5,0,r8
bne- 1b
@@ -246,13 +285,15 @@
9:
#ifdef CONFIG_SMP
+ addis r6,r7,mmu_hash_lock@ha
+ addi r6,r6,mmu_hash_lock@l
eieio
li r0,0
- stw r0,0(r9) /* clear mmu_hash_lock */
+ stw r0,0(r6) /* clear mmu_hash_lock */
#endif
/* reenable interrupts and DR */
- mtmsr r10
+ mtmsr r9
SYNC_601
isync
@@ -267,7 +308,8 @@
* r5 contains the linux PTE, r6 contains the old value of the
* linux PTE (before setting _PAGE_HASHPTE) and r7 contains the
* offset to be added to addresses (0 if the MMU is on,
- * -KERNELBASE if it is off).
+ * -KERNELBASE if it is off). r10 contains the upper half of
+ * the PTE if CONFIG_PTE_64BIT.
* On SMP, the caller should have the mmu_hash_lock held.
* We assume that the caller has (or will) set the _PAGE_HASHPTE
* bit in the linux PTE in memory. The value passed in r6 should
@@ -313,6 +355,11 @@
BEGIN_FTR_SECTION
ori r8,r8,_PAGE_COHERENT /* set M (coherence required) */
END_FTR_SECTION_IFSET(CPU_FTR_NEED_COHERENT)
+#ifdef CONFIG_PTE_64BIT
+ /* Put the XPN bits into the PTE */
+ rlwimi r8,r10,8,20,22
+ rlwimi r8,r10,2,29,29
+#endif
/* Construct the high word of the PPC-style PTE (r5) */
rlwinm r5,r3,7,1,24 /* put VSID in 0x7fffff80 bits */
@@ -499,14 +546,18 @@
isync
/* First find a PTE in the range that has _PAGE_HASHPTE set */
+#ifndef CONFIG_PTE_64BIT
rlwimi r5,r4,22,20,29
-1: lwz r0,0(r5)
+#else
+ rlwimi r5,r4,23,20,28
+#endif
+1: lwz r0,PTE_FLAGS_OFFSET(r5)
cmpwi cr1,r6,1
andi. r0,r0,_PAGE_HASHPTE
bne 2f
ble cr1,19f
addi r4,r4,0x1000
- addi r5,r5,4
+ addi r5,r5,PTE_SIZE
addi r6,r6,-1
b 1b
@@ -545,7 +596,10 @@
* already clear, we're done (for this pte). If not,
* clear it (atomically) and proceed. -- paulus.
*/
-33: lwarx r8,0,r5 /* fetch the pte */
+#if (PTE_FLAGS_OFFSET != 0)
+ addi r5,r5,PTE_FLAGS_OFFSET
+#endif
+33: lwarx r8,0,r5 /* fetch the pte flags word */
andi. r0,r8,_PAGE_HASHPTE
beq 8f /* done if HASHPTE is already clear */
rlwinm r8,r8,0,31,29 /* clear HASHPTE bit */
@@ -590,7 +644,7 @@
8: ble cr1,9f /* if all ptes checked */
81: addi r6,r6,-1
- addi r5,r5,4 /* advance to next pte */
+ addi r5,r5,PTE_SIZE
addi r4,r4,0x1000
lwz r0,0(r5) /* check next pte */
cmpwi cr1,r6,1