[PATCH v2] POWERPC: Allow 32-bit pgtable code to support 36-bit physical
Becky Bruce
becky.bruce at freescale.com
Thu Aug 28 08:38:10 EST 2008
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 6xx. 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 at freescale.com>
---
NOTE: This patch is now based against Kumar's mmu tree,
as we had conflicting edits. Kumar will pick this up into his
tree if it looks OK.
Cheers,
Becky
arch/powerpc/include/asm/io.h | 2 +-
arch/powerpc/include/asm/page_32.h | 10 ++++-
arch/powerpc/include/asm/pgtable-ppc32.h | 30 +++++++++++-
arch/powerpc/kernel/head_32.S | 4 +-
arch/powerpc/kernel/head_fsl_booke.S | 2 -
arch/powerpc/mm/hash_low_32.S | 78 +++++++++++++++++++++++------
arch/powerpc/mm/pgtable_32.c | 4 +-
arch/powerpc/platforms/Kconfig.cputype | 14 ++++--
8 files changed, 114 insertions(+), 30 deletions(-)
diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index 77c7fa0..08266d2 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -711,7 +711,7 @@ static inline void * phys_to_virt(unsigned long address)
/*
* Change "struct page" to physical address.
*/
-#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
+#define page_to_phys(page) ((phys_addr_t)page_to_pfn(page) << PAGE_SHIFT)
/* We do NOT want virtual merging, it would put too much pressure on
* our iommu allocator. Instead, we want drivers to be smart enough
diff --git a/arch/powerpc/include/asm/page_32.h b/arch/powerpc/include/asm/page_32.h
index ebfae53..0b253f6 100644
--- a/arch/powerpc/include/asm/page_32.h
+++ b/arch/powerpc/include/asm/page_32.h
@@ -13,10 +13,18 @@
#define ARCH_KMALLOC_MINALIGN L1_CACHE_BYTES
#endif
+#ifdef CONFIG_PTE_64BIT
+#define PTE_FLAGS_OFFSET 4 /* offset of PTE flags, in bytes */
+#define LNX_PTE_SIZE 8 /* size of a linux PTE, in bytes */
+#else
+#define PTE_FLAGS_OFFSET 0
+#define LNX_PTE_SIZE 4
+#endif
+
#ifndef __ASSEMBLY__
/*
* The basic type of a PTE - 64 bits for those CPUs with > 32 bit
- * physical addressing. For now this just the IBM PPC440.
+ * physical addressing.
*/
#ifdef CONFIG_PTE_64BIT
typedef unsigned long long pte_basic_t;
diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h
index 82bf914..4a7055a 100644
--- a/arch/powerpc/include/asm/pgtable-ppc32.h
+++ b/arch/powerpc/include/asm/pgtable-ppc32.h
@@ -369,7 +369,12 @@ extern int icache_44x_need_flush;
#define _PAGE_RW 0x400 /* software: user write access allowed */
#define _PAGE_SPECIAL 0x800 /* software: Special page */
+#ifdef CONFIG_PTE_64BIT
+/* We never clear the high word of the pte, mask those off */
+#define _PTE_NONE_MASK (0xffffffff00000000ULL | _PAGE_HASHPTE)
+#else
#define _PTE_NONE_MASK _PAGE_HASHPTE
+#endif
#define _PMD_PRESENT 0
#define _PMD_PRESENT_MASK (PAGE_MASK)
@@ -528,7 +533,8 @@ extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
#define pte_none(pte) ((pte_val(pte) & ~_PTE_NONE_MASK) == 0)
#define pte_present(pte) (pte_val(pte) & _PAGE_PRESENT)
-#define pte_clear(mm,addr,ptep) do { pte_update(ptep, ~0, 0); } while (0)
+#define pte_clear(mm, addr, ptep) \
+ do { pte_update(ptep, ~_PAGE_HASHPTE, 0); } while (0)
#define pmd_none(pmd) (!pmd_val(pmd))
#define pmd_bad(pmd) (pmd_val(pmd) & _PMD_BAD)
@@ -664,8 +670,30 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
#if _PAGE_HASHPTE != 0
+#ifndef CONFIG_PTE_64BIT
pte_update(ptep, ~_PAGE_HASHPTE, pte_val(pte) & ~_PAGE_HASHPTE);
#else
+ /*
+ * We have to do the write of the 64b pte as 2 stores. This
+ * code assumes that the entry we're storing to is currently
+ * not valid and that all callers have the page table lock.
+ * Having the entry be not valid protects readers who might read
+ * between the first and second stores.
+ */
+ unsigned int tmp;
+
+ __asm__ __volatile__("\
+1: lwarx %0,0,%4\n\
+ rlwimi %L2,%0,0,30,30\n\
+ stw %2,0(%3)\n\
+ eieio\n\
+ stwcx. %L2,0,%4\n\
+ bne- 1b"
+ : "=&r" (tmp), "=m" (*ptep)
+ : "r" (pte), "r" (ptep), "r" ((unsigned long)(ptep) + 4), "m" (*ptep)
+ : "cc");
+#endif /* CONFIG_PTE_64BIT */
+#else /* _PAGE_HASHPTE == 0 */
#if defined(CONFIG_PTE_64BIT) && defined(CONFIG_SMP)
__asm__ __volatile__("\
stw%U0%X0 %2,%0\n\
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 8bb6575..a6de6db 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -369,13 +369,13 @@ i##n: \
DataAccess:
EXCEPTION_PROLOG
mfspr r10,SPRN_DSISR
+ stw r10,_DSISR(r11)
andis. r0,r10,0xa470 /* weird error? */
bne 1f /* if not, try to put a PTE */
mfspr r4,SPRN_DAR /* into the hash table */
rlwinm r3,r10,32-15,21,21 /* DSISR_STORE -> _PAGE_RW */
bl hash_page
-1: stw r10,_DSISR(r11)
- mr r5,r10
+1: lwz r5,_DSISR(r11) /* get DSISR value */
mfspr r4,SPRN_DAR
EXC_XFER_EE_LITE(0x300, handle_page_fault)
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index fa39cce..9000891 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -422,7 +422,6 @@ skpinv: addi r6,r6,1 /* Increment */
* r12 is pointer to the pte
*/
#ifdef CONFIG_PTE_64BIT
-#define PTE_FLAGS_OFFSET 4
#define FIND_PTE \
rlwinm r12, r10, 13, 19, 29; /* Compute pgdir/pmd offset */ \
lwzx r11, r12, r11; /* Get pgd/pmd entry */ \
@@ -431,7 +430,6 @@ skpinv: addi r6,r6,1 /* Increment */
rlwimi r12, r10, 23, 20, 28; /* Compute pte address */ \
lwz r11, 4(r12); /* Get pte entry */
#else
-#define PTE_FLAGS_OFFSET 0
#define FIND_PTE \
rlwimi r11, r10, 12, 20, 29; /* Create L1 (pgdir/pmd) address */ \
lwz r11, 0(r11); /* Get L1 entry */ \
diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S
index b9ba7d9..d63e20a 100644
--- a/arch/powerpc/mm/hash_low_32.S
+++ b/arch/powerpc/mm/hash_low_32.S
@@ -75,7 +75,7 @@ _GLOBAL(hash_page_sync)
* 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 @@ _GLOBAL(hash_page)
addi r5,r5,swapper_pg_dir at 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 @@ _GLOBAL(hash_page)
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 @@ _GLOBAL(hash_page)
* 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 +153,11 @@ retry:
bnelr-
#endif
or r5,r0,r6 /* set accessed/dirty bits */
+#ifdef CONFIG_PTE_64BIT
+ subf r10,r6,r8 /* create false data dependency */
+ subi r10,r10,PTE_FLAGS_OFFSET
+ lwzx r10,r6,r10 /* Get upper PTE word */
+#endif
stwcx. r5,0,r8 /* attempt to update PTE */
bne- retry /* retry if someone got there first */
@@ -203,9 +224,9 @@ _GLOBAL(add_hash_page)
* 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 +235,14 @@ _GLOBAL(add_hash_page)
tophys(r7,0)
#ifdef CONFIG_SMP
- addis r9,r7,mmu_hash_lock at ha
- addi r9,r9,mmu_hash_lock at l
-10: lwarx r0,0,r9 /* take the mmu_hash_lock */
+ addis r6,r7,mmu_hash_lock at ha
+ addi r6,r6,mmu_hash_lock at 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 +255,20 @@ _GLOBAL(add_hash_page)
* 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
+ subf r10,r6,r8 /* create false data dependency */
+ subi r10,r10,PTE_FLAGS_OFFSET
+ lwzx r10,r6,r10 /* Get upper PTE word */
+#endif
ori r5,r6,_PAGE_HASHPTE
stwcx. r5,0,r8
bne- 1b
@@ -246,13 +277,15 @@ _GLOBAL(add_hash_page)
9:
#ifdef CONFIG_SMP
+ addis r6,r7,mmu_hash_lock at ha
+ addi r6,r6,mmu_hash_lock at 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 +300,8 @@ _GLOBAL(add_hash_page)
* 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 +347,11 @@ _GLOBAL(create_hpte)
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 +538,18 @@ _GLOBAL(flush_hash_pages)
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,LNX_PTE_SIZE
addi r6,r6,-1
b 1b
@@ -545,7 +588,10 @@ _GLOBAL(flush_hash_pages)
* 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 +636,7 @@ _GLOBAL(flush_hash_patch_B)
8: ble cr1,9f /* if all ptes checked */
81: addi r6,r6,-1
- addi r5,r5,4 /* advance to next pte */
+ addi r5,r5,LNX_PTE_SIZE /* go to next linux pte flag word */
addi r4,r4,0x1000
lwz r0,0(r5) /* check next pte */
cmpwi cr1,r6,1
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index 2001abd..c31d6d2 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -73,7 +73,7 @@ extern unsigned long p_mapped_by_tlbcam(unsigned long pa);
#endif /* HAVE_TLBCAM */
#ifdef CONFIG_PTE_64BIT
-/* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */
+/* Some processors use an 8kB pgdir because they have 8-byte Linux PTEs. */
#define PGDIR_ORDER 1
#else
#define PGDIR_ORDER 0
@@ -288,7 +288,7 @@ int map_page(unsigned long va, phys_addr_t pa, int flags)
}
/*
- * Map in all of physical memory starting at KERNELBASE.
+ * Map in a big chunk of physical memory starting at KERNELBASE.
*/
void __init mapin_ram(void)
{
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 7f65127..ca5b58b 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -128,18 +128,22 @@ config FSL_EMB_PERFMON
config PTE_64BIT
bool
- depends on 44x || E500
+ depends on 44x || E500 || 6xx
default y if 44x
- default y if E500 && PHYS_64BIT
+ default y if PHYS_64BIT
config PHYS_64BIT
- bool 'Large physical address support' if E500
- depends on 44x || E500
+ bool 'Large physical address support' if E500 || 6xx
+ depends on 44x || E500 || 6xx
select RESOURCES_64BIT
default y if 44x
---help---
This option enables kernel support for larger than 32-bit physical
- addresses. This features is not be available on all e500 cores.
+ addresses. This features is not be available on all cores.
+
+ If you have more than 3.5GB of RAM or so, you also need to enable
+ SWIOTLB under Kernel Options for this to work. The actual number
+ is platform-dependent.
If in doubt, say N here.
--
1.5.5.1
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