/* * arch/sh/mm/consistent.c * * Copyright (C) 2004 - 2007 Paul Mundt * * Declared coherent memory functions based on arch/x86/kernel/pci-dma_32.c * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. */ #include <linux/mm.h> #include <linux/init.h> #include <linux/platform_device.h> #include <linux/dma-mapping.h> #include <linux/dma-debug.h> #include <linux/io.h> #include <linux/module.h> #include <asm/cacheflush.h> #include <asm/addrspace.h> #define PREALLOC_DMA_DEBUG_ENTRIES 4096 struct dma_map_ops *dma_ops; EXPORT_SYMBOL(dma_ops); static int __init dma_init(void) { dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); return 0; } fs_initcall(dma_init); void *dma_generic_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp) { void *ret, *ret_nocache; int order = get_order(size); ret = (void *)__get_free_pages(gfp, order); if (!ret) return NULL; memset(ret, 0, size); /* * Pages from the page allocator may have data present in * cache. So flush the cache before using uncached memory. */ dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL); ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size); if (!ret_nocache) { free_pages((unsigned long)ret, order); return NULL; } split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order); *dma_handle = virt_to_phys(ret); return ret_nocache; } void dma_generic_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle) { int order = get_order(size); unsigned long pfn = dma_handle >> PAGE_SHIFT; int k; for (k = 0; k < (1 << order); k++) __free_pages(pfn_to_page(pfn + k), 0); iounmap(vaddr); } void dma_cache_sync(struct device *dev, void *vaddr, size_t size, enum dma_data_direction direction) { #if defined(CONFIG_CPU_SH5) || defined(CONFIG_PMB) void *p1addr = vaddr; #else void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr); #endif switch (direction) { case DMA_FROM_DEVICE: /* invalidate only */ __flush_invalidate_region(p1addr, size); break; case DMA_TO_DEVICE: /* writeback only */ __flush_wback_region(p1addr, size); break; case DMA_BIDIRECTIONAL: /* writeback and invalidate */ __flush_purge_region(p1addr, size); break; default: BUG(); } } EXPORT_SYMBOL(dma_cache_sync); static int __init memchunk_setup(char *str) { return 1; /* accept anything that begins with "memchunk." */ } __setup("memchunk.", memchunk_setup); static void __init memchunk_cmdline_override(char *name, unsigned long *sizep) { char *p = boot_command_line; int k = strlen(name); while ((p = strstr(p, "memchunk."))) { p += 9; /* strlen("memchunk.") */ if (!strncmp(name, p, k) && p[k] == '=') { p += k + 1; *sizep = memparse(p, NULL); pr_info("%s: forcing memory chunk size to 0x%08lx\n", name, *sizep); break; } } } int __init platform_resource_setup_memory(struct platform_device *pdev, char *name, unsigned long memsize) { struct resource *r; dma_addr_t dma_handle; void *buf; r = pdev->resource + pdev->num_resources - 1; if (r->flags) { pr_warning("%s: unable to find empty space for resource\n", name); return -EINVAL; } memchunk_cmdline_override(name, &memsize); if (!memsize) return 0; buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL); if (!buf) { pr_warning("%s: unable to allocate memory\n", name); return -ENOMEM; } memset(buf, 0, memsize); r->flags = IORESOURCE_MEM; r->start = dma_handle; r->end = r->start + memsize - 1; r->name = name; return 0; }