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/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h
index c2e58b4..29c83d8 100644
--- a/arch/powerpc/include/asm/pgtable-ppc32.h
+++ b/arch/powerpc/include/asm/pgtable-ppc32.h
@@ -369,7 +369,12 @@
#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 */
+#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)
@@ -587,6 +592,10 @@
extern void add_hash_page(unsigned context, unsigned long va,
unsigned long pmdval);
+/* Flush an entry from the TLB/hash table */
+extern void flush_hash_entry(struct mm_struct *mm, pte_t *ptep,
+ unsigned long address);
+
/*
* Atomic PTE updates.
*
@@ -665,9 +674,13 @@
static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
-#if _PAGE_HASHPTE != 0
+#if (_PAGE_HASHPTE != 0) && defined(CONFIG_SMP) && !defined(CONFIG_PTE_64BIT)
pte_update(ptep, ~_PAGE_HASHPTE, pte_val(pte) & ~_PAGE_HASHPTE);
#elif defined(CONFIG_PTE_64BIT) && defined(CONFIG_SMP)
+#if _PAGE_HASHPTE != 0
+ if (pte_val(*ptep) & _PAGE_HASHPTE)
+ flush_hash_entry(mm, ptep, addr);
+#endif
__asm__ __volatile__("\
stw%U0%X0 %2,%0\n\
eieio\n\
@@ -675,7 +688,7 @@
: "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
: "r" (pte) : "memory");
#else
- *ptep = pte;
+ *ptep = (*ptep & _PAGE_HASHPTE) | (pte & ~_PAGE_HASHPTE);
#endif
}