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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2005-11-06 19:06:55 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2005-11-06 19:56:47 -0500
commit3c726f8dee6f55e96475574e9f645327e461884c (patch)
treef67c381e8f57959aa4a94bda4c68e24253cd8171 /arch/powerpc/mm/mem.c
parentf912696ab330bf539231d1f8032320f2a08b850f (diff)
[PATCH] ppc64: support 64k pages
Adds a new CONFIG_PPC_64K_PAGES which, when enabled, changes the kernel base page size to 64K. The resulting kernel still boots on any hardware. On current machines with 4K pages support only, the kernel will maintain 16 "subpages" for each 64K page transparently. Note that while real 64K capable HW has been tested, the current patch will not enable it yet as such hardware is not released yet, and I'm still verifying with the firmware architects the proper to get the information from the newer hypervisors. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/powerpc/mm/mem.c')
-rw-r--r--arch/powerpc/mm/mem.c56
1 files changed, 21 insertions, 35 deletions
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 117b00012e14..7faa46b71f21 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -61,6 +61,9 @@ int init_bootmem_done;
61int mem_init_done; 61int mem_init_done;
62unsigned long memory_limit; 62unsigned long memory_limit;
63 63
64extern void hash_preload(struct mm_struct *mm, unsigned long ea,
65 unsigned long access, unsigned long trap);
66
64/* 67/*
65 * This is called by /dev/mem to know if a given address has to 68 * This is called by /dev/mem to know if a given address has to
66 * be mapped non-cacheable or not 69 * be mapped non-cacheable or not
@@ -493,18 +496,10 @@ EXPORT_SYMBOL(flush_icache_user_range);
493void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, 496void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
494 pte_t pte) 497 pte_t pte)
495{ 498{
496 /* handle i-cache coherency */ 499#ifdef CONFIG_PPC_STD_MMU
497 unsigned long pfn = pte_pfn(pte); 500 unsigned long access = 0, trap;
498#ifdef CONFIG_PPC32
499 pmd_t *pmd;
500#else
501 unsigned long vsid;
502 void *pgdir;
503 pte_t *ptep;
504 int local = 0;
505 cpumask_t tmp;
506 unsigned long flags;
507#endif 501#endif
502 unsigned long pfn = pte_pfn(pte);
508 503
509 /* handle i-cache coherency */ 504 /* handle i-cache coherency */
510 if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) && 505 if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
@@ -535,30 +530,21 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
535 /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */ 530 /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
536 if (!pte_young(pte) || address >= TASK_SIZE) 531 if (!pte_young(pte) || address >= TASK_SIZE)
537 return; 532 return;
538#ifdef CONFIG_PPC32
539 if (Hash == 0)
540 return;
541 pmd = pmd_offset(pgd_offset(vma->vm_mm, address), address);
542 if (!pmd_none(*pmd))
543 add_hash_page(vma->vm_mm->context, address, pmd_val(*pmd));
544#else
545 pgdir = vma->vm_mm->pgd;
546 if (pgdir == NULL)
547 return;
548 533
549 ptep = find_linux_pte(pgdir, address); 534 /* We try to figure out if we are coming from an instruction
550 if (!ptep) 535 * access fault and pass that down to __hash_page so we avoid
536 * double-faulting on execution of fresh text. We have to test
537 * for regs NULL since init will get here first thing at boot
538 *
539 * We also avoid filling the hash if not coming from a fault
540 */
541 if (current->thread.regs == NULL)
551 return; 542 return;
552 543 trap = TRAP(current->thread.regs);
553 vsid = get_vsid(vma->vm_mm->context.id, address); 544 if (trap == 0x400)
554 545 access |= _PAGE_EXEC;
555 local_irq_save(flags); 546 else if (trap != 0x300)
556 tmp = cpumask_of_cpu(smp_processor_id()); 547 return;
557 if (cpus_equal(vma->vm_mm->cpu_vm_mask, tmp)) 548 hash_preload(vma->vm_mm, address, access, trap);
558 local = 1; 549#endif /* CONFIG_PPC_STD_MMU */
559
560 __hash_page(address, 0, vsid, ptep, 0x300, local);
561 local_irq_restore(flags);
562#endif
563#endif
564} 550}