diff options
Diffstat (limited to 'arch/powerpc/lib')
| -rw-r--r-- | arch/powerpc/lib/Makefile | 2 | ||||
| -rw-r--r-- | arch/powerpc/lib/dma-noncoherent.c | 418 |
2 files changed, 420 insertions, 0 deletions
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile index a0360ae..e2d4141 100644 --- a/arch/powerpc/lib/Makefile +++ b/arch/powerpc/lib/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_PPC64) += checksum_64.o copypage_64.o copyuser_64.o \ strcase.o obj-$(CONFIG_QUICC_ENGINE) += rheap.o obj-$(CONFIG_XMON) += sstep.o +obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o ifeq ($(CONFIG_PPC64),y) obj-$(CONFIG_SMP) += locks.o @@ -24,5 +25,6 @@ endif # Temporary hack until we have migrated to asm-powerpc ifeq ($(CONFIG_PPC_MERGE),y) +obj-$(CONFIG_8xx) += rheap.o obj-$(CONFIG_CPM2) += rheap.o endif diff --git a/arch/powerpc/lib/dma-noncoherent.c b/arch/powerpc/lib/dma-noncoherent.c new file mode 100644 index 0000000..48f3d13 --- /dev/null +++ b/arch/powerpc/lib/dma-noncoherent.c @@ -0,0 +1,418 @@ +/* + * PowerPC version derived from arch/arm/mm/consistent.c + * Copyright (C) 2001 Dan Malek (dmalek@jlc.net) + * + * Copyright (C) 2000 Russell King + * + * Consistent memory allocators. Used for DMA devices that want to + * share uncached memory with the processor core. The function return + * is the virtual address and 'dma_handle' is the physical address. + * Mostly stolen from the ARM port, with some changes for PowerPC. + * -- Dan + * + * Reorganized to get rid of the arch-specific consistent_* functions + * and provide non-coherent implementations for the DMA API. -Matt + * + * Added in_interrupt() safe dma_alloc_coherent()/dma_free_coherent() + * implementation. This is pulled straight from ARM and barely + * modified. -Matt + * + * 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/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/highmem.h> +#include <linux/dma-mapping.h> + +#include <asm/tlbflush.h> + +/* + * This address range defaults to a value that is safe for all + * platforms which currently set CONFIG_NOT_COHERENT_CACHE. It + * can be further configured for specific applications under + * the "Advanced Setup" menu. -Matt + */ +#define CONSISTENT_BASE (CONFIG_CONSISTENT_START) +#define CONSISTENT_END (CONFIG_CONSISTENT_START + CONFIG_CONSISTENT_SIZE) +#define CONSISTENT_OFFSET(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT) + +/* + * This is the page table (2MB) covering uncached, DMA consistent allocations + */ +static pte_t *consistent_pte; +static DEFINE_SPINLOCK(consistent_lock); + +/* + * VM region handling support. + * + * This should become something generic, handling VM region allocations for + * vmalloc and similar (ioremap, module space, etc). + * + * I envisage vmalloc()'s supporting vm_struct becoming: + * + * struct vm_struct { + * struct vm_region region; + * unsigned long flags; + * struct page **pages; + * unsigned int nr_pages; + * unsigned long phys_addr; + * }; + * + * get_vm_area() would then call vm_region_alloc with an appropriate + * struct vm_region head (eg): + * + * struct vm_region vmalloc_head = { + * .vm_list = LIST_HEAD_INIT(vmalloc_head.vm_list), + * .vm_start = VMALLOC_START, + * .vm_end = VMALLOC_END, + * }; + * + * However, vmalloc_head.vm_start is variable (typically, it is dependent on + * the amount of RAM found at boot time.) I would imagine that get_vm_area() + * would have to initialise this each time prior to calling vm_region_alloc(). + */ +struct vm_region { + struct list_head vm_list; + unsigned long vm_start; + unsigned long vm_end; +}; + +static struct vm_region consistent_head = { + .vm_list = LIST_HEAD_INIT(consistent_head.vm_list), + .vm_start = CONSISTENT_BASE, + .vm_end = CONSISTENT_END, +}; + +static struct vm_region * +vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp) +{ + unsigned long addr = head->vm_start, end = head->vm_end - size; + unsigned long flags; + struct vm_region *c, *new; + + new = kmalloc(sizeof(struct vm_region), gfp); + if (!new) + goto out; + + spin_lock_irqsave(&consistent_lock, flags); + + list_for_each_entry(c, &head->vm_list, vm_list) { + if ((addr + size) < addr) + goto nospc; + if ((addr + size) <= c->vm_start) + goto found; + addr = c->vm_end; + if (addr > end) + goto nospc; + } + + found: + /* + * Insert this entry _before_ the one we found. + */ + list_add_tail(&new->vm_list, &c->vm_list); + new->vm_start = addr; + new->vm_end = addr + size; + + spin_unlock_irqrestore(&consistent_lock, flags); + return new; + + nospc: + spin_unlock_irqrestore(&consistent_lock, flags); + kfree(new); + out: + return NULL; +} + +static struct vm_region *vm_region_find(struct vm_region *head, unsigned long addr) +{ + struct vm_region *c; + + list_for_each_entry(c, &head->vm_list, vm_list) { + if (c->vm_start == addr) + goto out; + } + c = NULL; + out: + return c; +} + +/* + * Allocate DMA-coherent memory space and return both the kernel remapped + * virtual and bus address for that space. + */ +void * +__dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp) +{ + struct page *page; + struct vm_region *c; + unsigned long order; + u64 mask = 0x00ffffff, limit; /* ISA default */ + + if (!consistent_pte) { + printk(KERN_ERR "%s: not initialised\n", __func__); + dump_stack(); + return NULL; + } + + size = PAGE_ALIGN(size); + limit = (mask + 1) & ~mask; + if ((limit && size >= limit) || size >= (CONSISTENT_END - CONSISTENT_BASE)) { + printk(KERN_WARNING "coherent allocation too big (requested %#x mask %#Lx)\n", + size, mask); + return NULL; + } + + order = get_order(size); + + if (mask != 0xffffffff) + gfp |= GFP_DMA; + + page = alloc_pages(gfp, order); + if (!page) + goto no_page; + + /* + * Invalidate any data that might be lurking in the + * kernel direct-mapped region for device DMA. + */ + { + unsigned long kaddr = (unsigned long)page_address(page); + memset(page_address(page), 0, size); + flush_dcache_range(kaddr, kaddr + size); + } + + /* + * Allocate a virtual address in the consistent mapping region. + */ + c = vm_region_alloc(&consistent_head, size, + gfp & ~(__GFP_DMA | __GFP_HIGHMEM)); + if (c) { + unsigned long vaddr = c->vm_start; + pte_t *pte = consistent_pte + CONSISTENT_OFFSET(vaddr); + struct page *end = page + (1 << order); + + split_page(page, order); + + /* + * Set the "dma handle" + */ + *handle = page_to_bus(page); + + do { + BUG_ON(!pte_none(*pte)); + + SetPageReserved(page); + set_pte_at(&init_mm, vaddr, + pte, mk_pte(page, pgprot_noncached(PAGE_KERNEL))); + page++; + pte++; + vaddr += PAGE_SIZE; + } while (size -= PAGE_SIZE); + + /* + * Free the otherwise unused pages. + */ + while (page < end) { + __free_page(page); + page++; + } + + return (void *)c->vm_start; + } + + if (page) + __free_pages(page, order); + no_page: + return NULL; +} +EXPORT_SYMBOL(__dma_alloc_coherent); + +/* + * free a page as defined by the above mapping. + */ +void __dma_free_coherent(size_t size, void *vaddr) +{ + struct vm_region *c; + unsigned long flags, addr; + pte_t *ptep; + + size = PAGE_ALIGN(size); + + spin_lock_irqsave(&consistent_lock, flags); + + c = vm_region_find(&consistent_head, (unsigned long)vaddr); + if (!c) + goto no_area; + + if ((c->vm_end - c->vm_start) != size) { + printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n", + __func__, c->vm_end - c->vm_start, size); + dump_stack(); + size = c->vm_end - c->vm_start; + } + + ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start); + addr = c->vm_start; + do { + pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep); + unsigned long pfn; + + ptep++; + addr += PAGE_SIZE; + + if (!pte_none(pte) && pte_present(pte)) { + pfn = pte_pfn(pte); + + if (pfn_valid(pfn)) { + struct page *page = pfn_to_page(pfn); + ClearPageReserved(page); + + __free_page(page); + continue; + } + } + + printk(KERN_CRIT "%s: bad page in kernel page table\n", + __func__); + } while (size -= PAGE_SIZE); + + flush_tlb_kernel_range(c->vm_start, c->vm_end); + + list_del(&c->vm_list); + + spin_unlock_irqrestore(&consistent_lock, flags); + + kfree(c); + return; + + no_area: + spin_unlock_irqrestore(&consistent_lock, flags); + printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n", + __func__, vaddr); + dump_stack(); +} +EXPORT_SYMBOL(__dma_free_coherent); + +/* + * Initialise the consistent memory allocation. + */ +static int __init dma_alloc_init(void) +{ + pgd_t *pgd; + pmd_t *pmd; + pte_t *pte; + int ret = 0; + + do { + pgd = pgd_offset(&init_mm, CONSISTENT_BASE); + pmd = pmd_alloc(&init_mm, pgd, CONSISTENT_BASE); + if (!pmd) { + printk(KERN_ERR "%s: no pmd tables\n", __func__); + ret = -ENOMEM; + break; + } + WARN_ON(!pmd_none(*pmd)); + + pte = pte_alloc_kernel(pmd, CONSISTENT_BASE); + if (!pte) { + printk(KERN_ERR "%s: no pte tables\n", __func__); + ret = -ENOMEM; + break; + } + + consistent_pte = pte; + } while (0); + + return ret; +} + +core_initcall(dma_alloc_init); + +/* + * make an area consistent. + */ +void __dma_sync(void *vaddr, size_t size, int direction) +{ + unsigned long start = (unsigned long)vaddr; + unsigned long end = start + size; + + switch (direction) { + case DMA_NONE: + BUG(); + case DMA_FROM_DEVICE: /* invalidate only */ + invalidate_dcache_range(start, end); + break; + case DMA_TO_DEVICE: /* writeback only */ + clean_dcache_range(start, end); + break; + case DMA_BIDIRECTIONAL: /* writeback and invalidate */ + flush_dcache_range(start, end); + break; + } +} +EXPORT_SYMBOL(__dma_sync); + +#ifdef CONFIG_HIGHMEM +/* + * __dma_sync_page() implementation for systems using highmem. + * In this case, each page of a buffer must be kmapped/kunmapped + * in order to have a virtual address for __dma_sync(). This must + * not sleep so kmap_atomic()/kunmap_atomic() are used. + * + * Note: yes, it is possible and correct to have a buffer extend + * beyond the first page. + */ +static inline void __dma_sync_page_highmem(struct page *page, + unsigned long offset, size_t size, int direction) +{ + size_t seg_size = min((size_t)(PAGE_SIZE - offset), size); + size_t cur_size = seg_size; + unsigned long flags, start, seg_offset = offset; + int nr_segs = 1 + ((size - seg_size) + PAGE_SIZE - 1)/PAGE_SIZE; + int seg_nr = 0; + + local_irq_save(flags); + + do { + start = (unsigned long)kmap_atomic(page + seg_nr, + KM_PPC_SYNC_PAGE) + seg_offset; + + /* Sync this buffer segment */ + __dma_sync((void *)start, seg_size, direction); + kunmap_atomic((void *)start, KM_PPC_SYNC_PAGE); + seg_nr++; + + /* Calculate next buffer segment size */ + seg_size = min((size_t)PAGE_SIZE, size - cur_size); + + /* Add the segment size to our running total */ + cur_size += seg_size; + seg_offset = 0; + } while (seg_nr < nr_segs); + + local_irq_restore(flags); +} +#endif /* CONFIG_HIGHMEM */ + +/* + * __dma_sync_page makes memory consistent. identical to __dma_sync, but + * takes a struct page instead of a virtual address + */ +void __dma_sync_page(struct page *page, unsigned long offset, + size_t size, int direction) +{ +#ifdef CONFIG_HIGHMEM + __dma_sync_page_highmem(page, offset, size, direction); +#else + unsigned long start = (unsigned long)page_address(page) + offset; + __dma_sync((void *)start, size, direction); +#endif +} +EXPORT_SYMBOL(__dma_sync_page); |
