diff options
| -rw-r--r-- | arch/microblaze/Kconfig | 24 | ||||
| -rw-r--r-- | arch/microblaze/include/asm/fixmap.h | 8 | ||||
| -rw-r--r-- | arch/microblaze/include/asm/highmem.h | 96 | ||||
| -rw-r--r-- | arch/microblaze/mm/Makefile | 1 | ||||
| -rw-r--r-- | arch/microblaze/mm/highmem.c | 88 | ||||
| -rw-r--r-- | arch/microblaze/mm/init.c | 68 |
6 files changed, 272 insertions, 13 deletions
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig index 3267cc5..86ae278 100644 --- a/arch/microblaze/Kconfig +++ b/arch/microblaze/Kconfig @@ -159,20 +159,18 @@ config XILINX_UNCACHED_SHADOW The feature requires the design to define the RAM memory controller window to be twice as large as the actual physical memory. -config HIGHMEM_START_BOOL - bool "Set high memory pool address" - depends on ADVANCED_OPTIONS && HIGHMEM - help - This option allows you to set the base address of the kernel virtual - area used to map high memory pages. This can be useful in - optimizing the layout of kernel virtual memory. - - Say N here unless you know what you are doing. - -config HIGHMEM_START - hex "Virtual start address of high memory pool" if HIGHMEM_START_BOOL +config HIGHMEM + bool "High memory support" depends on MMU - default "0xfe000000" + help + The address space of Microblaze processors is only 4 Gigabytes large + and it has to accommodate user address space, kernel address + space as well as some memory mapped IO. That means that, if you + have a large amount of physical memory and/or IO, not all of the + memory can be "permanently mapped" by the kernel. The physical + memory that is not permanently mapped is called "high memory". + + If unsure, say n. config LOWMEM_SIZE_BOOL bool "Set maximum low memory" diff --git a/arch/microblaze/include/asm/fixmap.h b/arch/microblaze/include/asm/fixmap.h index dd89754..f2b312e 100644 --- a/arch/microblaze/include/asm/fixmap.h +++ b/arch/microblaze/include/asm/fixmap.h @@ -21,6 +21,10 @@ #ifndef __ASSEMBLY__ #include <linux/kernel.h> #include <asm/page.h> +#ifdef CONFIG_HIGHMEM +#include <linux/threads.h> +#include <asm/kmap_types.h> +#endif #define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE)) @@ -44,6 +48,10 @@ */ enum fixed_addresses { FIX_HOLE, +#ifdef CONFIG_HIGHMEM + FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ + FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * num_possible_cpus()) - 1, +#endif __end_of_fixed_addresses }; diff --git a/arch/microblaze/include/asm/highmem.h b/arch/microblaze/include/asm/highmem.h new file mode 100644 index 0000000..2446a73 --- /dev/null +++ b/arch/microblaze/include/asm/highmem.h @@ -0,0 +1,96 @@ +/* + * highmem.h: virtual kernel memory mappings for high memory + * + * 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 Terabyte physical memory. With current x86 CPUs + * we now support up to 64 Gigabytes physical RAM. + * + * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com> + */ +#ifndef _ASM_HIGHMEM_H +#define _ASM_HIGHMEM_H + +#ifdef __KERNEL__ + +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/uaccess.h> +#include <asm/fixmap.h> + +extern pte_t *kmap_pte; +extern pgprot_t kmap_prot; +extern pte_t *pkmap_page_table; + +/* + * Right now we initialize only a single pte table. It can be extended + * easily, subsequent pte tables have to be allocated in one physical + * chunk of RAM. + */ +/* + * We use one full pte table with 4K pages. And with 16K/64K/256K pages pte + * table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP + * and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP + * in case of 16K/64K/256K page sizes. + */ + +#define PKMAP_ORDER PTE_SHIFT +#define LAST_PKMAP (1 << PKMAP_ORDER) + +#define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE * (LAST_PKMAP + 1)) \ + & PMD_MASK) + +#define LAST_PKMAP_MASK (LAST_PKMAP - 1) +#define PKMAP_NR(virt) ((virt - PKMAP_BASE) >> PAGE_SHIFT) +#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) + +extern void *kmap_high(struct page *page); +extern void kunmap_high(struct page *page); +extern void *kmap_atomic_prot(struct page *page, pgprot_t prot); +extern void __kunmap_atomic(void *kvaddr); + +static inline void *kmap(struct page *page) +{ + might_sleep(); + if (!PageHighMem(page)) + return page_address(page); + return kmap_high(page); +} + +static inline void kunmap(struct page *page) +{ + BUG_ON(in_interrupt()); + if (!PageHighMem(page)) + return; + kunmap_high(page); +} + +static inline void *__kmap_atomic(struct page *page) +{ + return kmap_atomic_prot(page, kmap_prot); +} + +static inline struct page *kmap_atomic_to_page(void *ptr) +{ + unsigned long idx, vaddr = (unsigned long) ptr; + pte_t *pte; + + if (vaddr < FIXADDR_START) + return virt_to_page(ptr); + + idx = virt_to_fix(vaddr); + pte = kmap_pte - (idx - FIX_KMAP_BEGIN); + return pte_page(*pte); +} + +#define flush_cache_kmaps() { flush_icache(); flush_dcache(); } + +#endif /* __KERNEL__ */ + +#endif /* _ASM_HIGHMEM_H */ diff --git a/arch/microblaze/mm/Makefile b/arch/microblaze/mm/Makefile index 09c49ed..7313bd8 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 0000000..7d78838 --- /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 <mingo@redhat.com> + * + * Reworked for PowerPC by various contributors. Moved from + * highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp. + */ + +#include <linux/highmem.h> +#include <linux/module.h> + +/* + * 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 <asm/tlbflush.h> + +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 43b3f60..95297b1 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(); |
