diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/microblaze/Kconfig | 9 | ||||
| -rw-r--r-- | arch/microblaze/mm/Makefile | 2 | ||||
| -rw-r--r-- | arch/microblaze/mm/consistent.c | 246 |
3 files changed, 256 insertions, 1 deletions
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig index e451c0898e7..203ec61c6d4 100644 --- a/arch/microblaze/Kconfig +++ b/arch/microblaze/Kconfig @@ -156,6 +156,15 @@ config ADVANCED_OPTIONS comment "Default settings for advanced configuration options are used" depends on !ADVANCED_OPTIONS +config XILINX_UNCACHED_SHADOW + bool "Are you using uncached shadow for RAM ?" + depends on ADVANCED_OPTIONS && !MMU + default n + help + This is needed to be able to allocate uncachable memory regions. + 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 diff --git a/arch/microblaze/mm/Makefile b/arch/microblaze/mm/Makefile index 6c8a924d9e2..09c49ed8723 100644 --- a/arch/microblaze/mm/Makefile +++ b/arch/microblaze/mm/Makefile @@ -2,6 +2,6 @@ # Makefile # -obj-y := init.o +obj-y := consistent.o init.o obj-$(CONFIG_MMU) += pgtable.o mmu_context.o fault.o diff --git a/arch/microblaze/mm/consistent.c b/arch/microblaze/mm/consistent.c new file mode 100644 index 00000000000..a9b443e3fb9 --- /dev/null +++ b/arch/microblaze/mm/consistent.c @@ -0,0 +1,246 @@ +/* + * 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 <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> + +#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) + +/* + * 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) +{ + struct page *page, *end, *free; + unsigned long order; + void *ret, *virt; + + if (in_interrupt()) + BUG(); + + size = PAGE_ALIGN(size); + order = get_order(size); + + page = alloc_pages(gfp, order); + if (!page) + goto no_page; + + /* We could do with a page_to_phys and page_to_bus here. */ + virt = page_address(page); + ret = ioremap(virt_to_phys(virt), size); + if (!ret) + goto no_remap; + + /* + * 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 + /* dma_handle is same as physical (shadowed) address */ + *dma_handle = (dma_addr_t)ret; + + /* + * 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(virt); + free = page + (size >> PAGE_SHIFT); + end = page + (1 << order); + + for (; page < end; page++) { + init_page_count(page); + if (page >= free) + __free_page(page); + else + SetPageReserved(page); + } + + return ret; +no_remap: + __free_pages(page, order); +no_page: + return NULL; +} + +#else + +void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle) +{ + int order, err, i; + unsigned long page, va, flags; + phys_addr_t pa; + struct vm_struct *area; + void *ret; + + if (in_interrupt()) + BUG(); + + /* Only allocate page size areas. */ + size = PAGE_ALIGN(size); + order = get_order(size); + + page = __get_free_pages(gfp, order); + if (!page) { + BUG(); + 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(page), virt_to_phys(page) + size); + + /* Allocate some common virtual space to map the new pages. */ + area = get_vm_area(size, VM_ALLOC); + if (area == NULL) { + free_pages(page, 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 *)page); + + /* MS: This is the whole magic - use cache inhibit pages */ + flags = _PAGE_KERNEL | _PAGE_NO_CACHE; + + /* + * Set refcount=1 on all pages in an order>0 + * allocation so that vfree() will actually + * free all pages that were allocated. + */ + if (order > 0) { + struct page *rpage = virt_to_page(page); + for (i = 1; i < (1 << order); i++) + init_page_count(rpage+i); + } + + err = 0; + for (i = 0; i < size && err == 0; i += PAGE_SIZE) + err = map_page(va+i, pa+i, flags); + + if (err) { + vfree((void *)va); + return NULL; + } + + return ret; +} +#endif /* CONFIG_MMU */ +EXPORT_SYMBOL(consistent_alloc); + +/* + * free page(s) as defined by the above mapping. + */ +void consistent_free(void *vaddr) +{ + if (in_interrupt()) + BUG(); + + /* Clear SHADOW_MASK bit in address, and free as per usual */ +#ifdef CONFIG_XILINX_UNCACHED_SHADOW + vaddr = (void *)((unsigned)vaddr & ~UNCACHED_SHADOW_MASK); +#endif + vfree(vaddr); +} +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 */ + flush_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); |