From 2f2f371f8907d169650f594850ca6096e2f73b77 Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Thu, 15 Dec 2011 15:02:37 +0100 Subject: microblaze: Highmem support The first highmem implementation. Signed-off-by: Michal Simek --- arch/microblaze/mm/Makefile | 1 + arch/microblaze/mm/highmem.c | 88 ++++++++++++++++++++++++++++++++++++++++++++ arch/microblaze/mm/init.c | 68 ++++++++++++++++++++++++++++++++++ 3 files changed, 157 insertions(+) create mode 100644 arch/microblaze/mm/highmem.c (limited to 'arch/microblaze/mm') diff --git a/arch/microblaze/mm/Makefile b/arch/microblaze/mm/Makefile index 09c49ed87235..7313bd8acbb7 100644 --- a/arch/microblaze/mm/Makefile +++ b/arch/microblaze/mm/Makefile @@ -5,3 +5,4 @@ obj-y := consistent.o init.o obj-$(CONFIG_MMU) += pgtable.o mmu_context.o fault.o +obj-$(CONFIG_HIGHMEM) += highmem.o diff --git a/arch/microblaze/mm/highmem.c b/arch/microblaze/mm/highmem.c new file mode 100644 index 000000000000..7d78838e8bfa --- /dev/null +++ b/arch/microblaze/mm/highmem.c @@ -0,0 +1,88 @@ +/* + * highmem.c: virtual kernel memory mappings for high memory + * + * PowerPC version, stolen from the i386 version. + * + * Used in CONFIG_HIGHMEM systems for memory pages which + * are not addressable by direct kernel virtual addresses. + * + * Copyright (C) 1999 Gerhard Wichert, Siemens AG + * Gerhard.Wichert@pdb.siemens.de + * + * + * Redesigned the x86 32-bit VM architecture to deal with + * up to 16 Terrabyte physical memory. With current x86 CPUs + * we now support up to 64 Gigabytes physical RAM. + * + * Copyright (C) 1999 Ingo Molnar + * + * Reworked for PowerPC by various contributors. Moved from + * highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp. + */ + +#include +#include + +/* + * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap + * gives a more generic (and caching) interface. But kmap_atomic can + * be used in IRQ contexts, so in some (very limited) cases we need + * it. + */ +#include + +void *kmap_atomic_prot(struct page *page, pgprot_t prot) +{ + + unsigned long vaddr; + int idx, type; + + /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ + pagefault_disable(); + if (!PageHighMem(page)) + return page_address(page); + + + type = kmap_atomic_idx_push(); + idx = type + KM_TYPE_NR*smp_processor_id(); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); +#ifdef CONFIG_DEBUG_HIGHMEM + BUG_ON(!pte_none(*(kmap_pte-idx))); +#endif + set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot)); + local_flush_tlb_page(NULL, vaddr); + + return (void *) vaddr; +} +EXPORT_SYMBOL(kmap_atomic_prot); + +void __kunmap_atomic(void *kvaddr) +{ + unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; + int type; + + if (vaddr < __fix_to_virt(FIX_KMAP_END)) { + pagefault_enable(); + return; + } + + type = kmap_atomic_idx(); +#ifdef CONFIG_DEBUG_HIGHMEM + { + unsigned int idx; + + idx = type + KM_TYPE_NR * smp_processor_id(); + BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); + + /* + * force other mappings to Oops if they'll try to access + * this pte without first remap it + */ + pte_clear(&init_mm, vaddr, kmap_pte-idx); + local_flush_tlb_page(NULL, vaddr); + } +#endif + kmap_atomic_idx_pop(); + pagefault_enable(); +} +EXPORT_SYMBOL(__kunmap_atomic); diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c index 43b3f604bafe..95297b13dd9e 100644 --- a/arch/microblaze/mm/init.c +++ b/arch/microblaze/mm/init.c @@ -49,6 +49,53 @@ unsigned long memory_size; EXPORT_SYMBOL(memory_size); unsigned long lowmem_size; +#ifdef CONFIG_HIGHMEM +pte_t *kmap_pte; +EXPORT_SYMBOL(kmap_pte); +pgprot_t kmap_prot; +EXPORT_SYMBOL(kmap_prot); + +static inline pte_t *virt_to_kpte(unsigned long vaddr) +{ + return pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr), + vaddr), vaddr); +} + +static void __init highmem_init(void) +{ + pr_debug("%x\n", (u32)PKMAP_BASE); + map_page(PKMAP_BASE, 0, 0); /* XXX gross */ + pkmap_page_table = virt_to_kpte(PKMAP_BASE); + + kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN)); + kmap_prot = PAGE_KERNEL; +} + +static unsigned long highmem_setup(void) +{ + unsigned long pfn; + unsigned long reservedpages = 0; + + for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) { + struct page *page = pfn_to_page(pfn); + + /* FIXME not sure about */ + if (memblock_is_reserved(pfn << PAGE_SHIFT)) + continue; + ClearPageReserved(page); + init_page_count(page); + __free_page(page); + totalhigh_pages++; + reservedpages++; + } + totalram_pages += totalhigh_pages; + printk(KERN_INFO "High memory: %luk\n", + totalhigh_pages << (PAGE_SHIFT-10)); + + return reservedpages; +} +#endif /* CONFIG_HIGHMEM */ + /* * paging_init() sets up the page tables - in fact we've already done this. */ @@ -66,7 +113,14 @@ static void __init paging_init(void) /* Clean every zones */ memset(zones_size, 0, sizeof(zones_size)); +#ifdef CONFIG_HIGHMEM + highmem_init(); + + zones_size[ZONE_DMA] = max_low_pfn; + zones_size[ZONE_HIGHMEM] = max_pfn; +#else zones_size[ZONE_DMA] = max_pfn; +#endif /* We don't have holes in memory map */ free_area_init_nodes(zones_size); @@ -241,6 +295,10 @@ void __init mem_init(void) } } +#ifdef CONFIG_HIGHMEM + reservedpages -= highmem_setup(); +#endif + codesize = (unsigned long)&_sdata - (unsigned long)&_stext; datasize = (unsigned long)&_edata - (unsigned long)&_sdata; initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin; @@ -259,6 +317,10 @@ void __init mem_init(void) #ifdef CONFIG_MMU pr_info("Kernel virtual memory layout:\n"); pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP); +#ifdef CONFIG_HIGHMEM + pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n", + PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP)); +#endif /* CONFIG_HIGHMEM */ pr_info(" * 0x%08lx..0x%08lx : early ioremap\n", ioremap_bot, ioremap_base); pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n", @@ -346,7 +408,9 @@ asmlinkage void __init mmu_init(void) if (lowmem_size > CONFIG_LOWMEM_SIZE) { lowmem_size = CONFIG_LOWMEM_SIZE; +#ifndef CONFIG_HIGHMEM memory_size = lowmem_size; +#endif } mm_cmdline_setup(); /* FIXME parse args from command line - not used */ @@ -375,7 +439,11 @@ asmlinkage void __init mmu_init(void) mapin_ram(); /* Extend vmalloc and ioremap area as big as possible */ +#ifdef CONFIG_HIGHMEM + ioremap_base = ioremap_bot = PKMAP_BASE; +#else ioremap_base = ioremap_bot = FIXADDR_START; +#endif /* Initialize the context management stuff */ mmu_context_init(); -- cgit v1.2.3