diff options
author | Michal Marek <mmarek@suse.cz> | 2010-08-04 13:59:13 +0200 |
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committer | Michal Marek <mmarek@suse.cz> | 2010-08-04 13:59:13 +0200 |
commit | 772320e84588dcbe1600ffb83e5f328f2209ac2a (patch) | |
tree | a7de21b79340aeaa17c58126f6b801b82c77b53a /arch/microblaze/mm/consistent.c | |
parent | 1ce53adf13a54375d2a5c7cdbe341b2558389615 (diff) | |
parent | 9fe6206f400646a2322096b56c59891d530e8d51 (diff) |
Merge commit 'v2.6.35' into kbuild/kbuild
Conflicts:
arch/powerpc/Makefile
Diffstat (limited to 'arch/microblaze/mm/consistent.c')
-rw-r--r-- | arch/microblaze/mm/consistent.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/arch/microblaze/mm/consistent.c b/arch/microblaze/mm/consistent.c new file mode 100644 index 00000000000..5a59dad62bd --- /dev/null +++ b/arch/microblaze/mm/consistent.c @@ -0,0 +1,255 @@ +/* + * Microblaze support for cache consistent memory. + * Copyright (C) 2010 Michal Simek <monstr@monstr.eu> + * Copyright (C) 2010 PetaLogix + * Copyright (C) 2005 John Williams <jwilliams@itee.uq.edu.au> + * + * Based on PowerPC version derived from arch/arm/mm/consistent.c + * Copyright (C) 2001 Dan Malek (dmalek@jlc.net) + * Copyright (C) 2000 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/ptrace.h> +#include <linux/mman.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/stddef.h> +#include <linux/vmalloc.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/bootmem.h> +#include <linux/highmem.h> +#include <linux/pci.h> +#include <linux/interrupt.h> +#include <linux/gfp.h> + +#include <asm/pgalloc.h> +#include <linux/io.h> +#include <linux/hardirq.h> +#include <asm/mmu_context.h> +#include <asm/mmu.h> +#include <linux/uaccess.h> +#include <asm/pgtable.h> +#include <asm/cpuinfo.h> +#include <asm/tlbflush.h> + +#ifndef CONFIG_MMU +/* I have to use dcache values because I can't relate on ram size */ +# define UNCACHED_SHADOW_MASK (cpuinfo.dcache_high - cpuinfo.dcache_base + 1) +#endif + +/* + * Consistent memory allocators. Used for DMA devices that want to + * share uncached memory with the processor core. + * My crufty no-MMU approach is simple. In the HW platform we can optionally + * mirror the DDR up above the processor cacheable region. So, memory accessed + * in this mirror region will not be cached. It's alloced from the same + * pool as normal memory, but the handle we return is shifted up into the + * uncached region. This will no doubt cause big problems if memory allocated + * here is not also freed properly. -- JW + */ +void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle) +{ + unsigned long order, vaddr; + void *ret; + unsigned int i, err = 0; + struct page *page, *end; + +#ifdef CONFIG_MMU + phys_addr_t pa; + struct vm_struct *area; + unsigned long va; +#endif + + if (in_interrupt()) + BUG(); + + /* Only allocate page size areas. */ + size = PAGE_ALIGN(size); + order = get_order(size); + + vaddr = __get_free_pages(gfp, order); + if (!vaddr) + return NULL; + + /* + * we need to ensure that there are no cachelines in use, + * or worse dirty in this area. + */ + flush_dcache_range(virt_to_phys((void *)vaddr), + virt_to_phys((void *)vaddr) + size); + +#ifndef CONFIG_MMU + ret = (void *)vaddr; + /* + * Here's the magic! Note if the uncached shadow is not implemented, + * it's up to the calling code to also test that condition and make + * other arranegments, such as manually flushing the cache and so on. + */ +# ifdef CONFIG_XILINX_UNCACHED_SHADOW + ret = (void *)((unsigned) ret | UNCACHED_SHADOW_MASK); +# endif + if ((unsigned int)ret > cpuinfo.dcache_base && + (unsigned int)ret < cpuinfo.dcache_high) + printk(KERN_WARNING + "ERROR: Your cache coherent area is CACHED!!!\n"); + + /* dma_handle is same as physical (shadowed) address */ + *dma_handle = (dma_addr_t)ret; +#else + /* Allocate some common virtual space to map the new pages. */ + area = get_vm_area(size, VM_ALLOC); + if (!area) { + free_pages(vaddr, order); + return NULL; + } + va = (unsigned long) area->addr; + ret = (void *)va; + + /* This gives us the real physical address of the first page. */ + *dma_handle = pa = virt_to_bus((void *)vaddr); +#endif + + /* + * free wasted pages. We skip the first page since we know + * that it will have count = 1 and won't require freeing. + * We also mark the pages in use as reserved so that + * remap_page_range works. + */ + page = virt_to_page(vaddr); + end = page + (1 << order); + + split_page(page, order); + + for (i = 0; i < size && err == 0; i += PAGE_SIZE) { +#ifdef CONFIG_MMU + /* MS: This is the whole magic - use cache inhibit pages */ + err = map_page(va + i, pa + i, _PAGE_KERNEL | _PAGE_NO_CACHE); +#endif + + SetPageReserved(page); + page++; + } + + /* Free the otherwise unused pages. */ + while (page < end) { + __free_page(page); + page++; + } + + if (err) { + free_pages(vaddr, order); + return NULL; + } + + return ret; +} +EXPORT_SYMBOL(consistent_alloc); + +/* + * free page(s) as defined by the above mapping. + */ +void consistent_free(size_t size, void *vaddr) +{ + struct page *page; + + if (in_interrupt()) + BUG(); + + size = PAGE_ALIGN(size); + +#ifndef CONFIG_MMU + /* Clear SHADOW_MASK bit in address, and free as per usual */ +# ifdef CONFIG_XILINX_UNCACHED_SHADOW + vaddr = (void *)((unsigned)vaddr & ~UNCACHED_SHADOW_MASK); +# endif + page = virt_to_page(vaddr); + + do { + ClearPageReserved(page); + __free_page(page); + page++; + } while (size -= PAGE_SIZE); +#else + do { + pte_t *ptep; + unsigned long pfn; + + ptep = pte_offset_kernel(pmd_offset(pgd_offset_k( + (unsigned int)vaddr), + (unsigned int)vaddr), + (unsigned int)vaddr); + if (!pte_none(*ptep) && pte_present(*ptep)) { + pfn = pte_pfn(*ptep); + pte_clear(&init_mm, (unsigned int)vaddr, ptep); + if (pfn_valid(pfn)) { + page = pfn_to_page(pfn); + + ClearPageReserved(page); + __free_page(page); + } + } + vaddr += PAGE_SIZE; + } while (size -= PAGE_SIZE); + + /* flush tlb */ + flush_tlb_all(); +#endif +} +EXPORT_SYMBOL(consistent_free); + +/* + * make an area consistent. + */ +void consistent_sync(void *vaddr, size_t size, int direction) +{ + unsigned long start; + unsigned long end; + + start = (unsigned long)vaddr; + + /* Convert start address back down to unshadowed memory region */ +#ifdef CONFIG_XILINX_UNCACHED_SHADOW + start &= ~UNCACHED_SHADOW_MASK; +#endif + end = start + size; + + switch (direction) { + case PCI_DMA_NONE: + BUG(); + case PCI_DMA_FROMDEVICE: /* invalidate only */ + invalidate_dcache_range(start, end); + break; + case PCI_DMA_TODEVICE: /* writeback only */ + flush_dcache_range(start, end); + break; + case PCI_DMA_BIDIRECTIONAL: /* writeback and invalidate */ + flush_dcache_range(start, end); + break; + } +} +EXPORT_SYMBOL(consistent_sync); + +/* + * consistent_sync_page makes memory consistent. identical + * to consistent_sync, but takes a struct page instead of a + * virtual address + */ +void consistent_sync_page(struct page *page, unsigned long offset, + size_t size, int direction) +{ + unsigned long start = (unsigned long)page_address(page) + offset; + consistent_sync((void *)start, size, direction); +} +EXPORT_SYMBOL(consistent_sync_page); |