diff options
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/Kconfig | 25 | ||||
| -rw-r--r-- | arch/powerpc/lib/dma-noncoherent.c | 303 |
2 files changed, 271 insertions, 57 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index a0d1146a0578..3bb43adce44d 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -868,6 +868,31 @@ config TASK_SIZE default "0x80000000" if PPC_PREP || PPC_8xx default "0xc0000000" +config CONSISTENT_START_BOOL + bool "Set custom consistent memory pool address" + depends on ADVANCED_OPTIONS && NOT_COHERENT_CACHE + help + This option allows you to set the base virtual address + of the consistent memory pool. This pool of virtual + memory is used to make consistent memory allocations. + +config CONSISTENT_START + hex "Base virtual address of consistent memory pool" if CONSISTENT_START_BOOL + default "0xfd000000" if (NOT_COHERENT_CACHE && 8xx) + default "0xff100000" if NOT_COHERENT_CACHE + +config CONSISTENT_SIZE_BOOL + bool "Set custom consistent memory pool size" + depends on ADVANCED_OPTIONS && NOT_COHERENT_CACHE + help + This option allows you to set the size of the + consistent memory pool. This pool of virtual memory + is used to make consistent memory allocations. + +config CONSISTENT_SIZE + hex "Size of consistent memory pool" if CONSISTENT_SIZE_BOOL + default "0x00200000" if NOT_COHERENT_CACHE + config PIN_TLB bool "Pinned Kernel TLBs (860 ONLY)" depends on ADVANCED_OPTIONS && 8xx diff --git a/arch/powerpc/lib/dma-noncoherent.c b/arch/powerpc/lib/dma-noncoherent.c index 005a28d380af..b7dc4c19f582 100644 --- a/arch/powerpc/lib/dma-noncoherent.c +++ b/arch/powerpc/lib/dma-noncoherent.c @@ -29,11 +29,121 @@ #include <linux/types.h> #include <linux/highmem.h> #include <linux/dma-mapping.h> -#include <linux/vmalloc.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 ppc_vm_region { + struct list_head vm_list; + unsigned long vm_start; + unsigned long vm_end; +}; + +static struct ppc_vm_region consistent_head = { + .vm_list = LIST_HEAD_INIT(consistent_head.vm_list), + .vm_start = CONSISTENT_BASE, + .vm_end = CONSISTENT_END, +}; + +static struct ppc_vm_region * +ppc_vm_region_alloc(struct ppc_vm_region *head, size_t size, gfp_t gfp) +{ + unsigned long addr = head->vm_start, end = head->vm_end - size; + unsigned long flags; + struct ppc_vm_region *c, *new; + + new = kmalloc(sizeof(struct ppc_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 ppc_vm_region *ppc_vm_region_find(struct ppc_vm_region *head, unsigned long addr) +{ + struct ppc_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. */ @@ -41,21 +151,21 @@ void * __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp) { struct page *page; + struct ppc_vm_region *c; unsigned long order; - int i; - unsigned int nr_pages = PAGE_ALIGN(size)>>PAGE_SHIFT; - unsigned int array_size = nr_pages * sizeof(struct page *); - struct page **pages; - struct page *end; u64 mask = 0x00ffffff, limit; /* ISA default */ - struct vm_struct *area; - BUG_ON(!mem_init_done); + 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) { - printk(KERN_WARNING "coherent allocation too big (requested " - "%#x mask %#Lx)\n", size, 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; } @@ -68,8 +178,6 @@ __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp) if (!page) goto no_page; - end = page + (1 << order); - /* * Invalidate any data that might be lurking in the * kernel direct-mapped region for device DMA. @@ -80,59 +188,48 @@ __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp) flush_dcache_range(kaddr, kaddr + size); } - split_page(page, order); - /* - * Set the "dma handle" + * Allocate a virtual address in the consistent mapping region. */ - *handle = page_to_phys(page); - - area = get_vm_area_caller(size, VM_IOREMAP, - __builtin_return_address(1)); - if (!area) - goto out_free_pages; - - if (array_size > PAGE_SIZE) { - pages = vmalloc(array_size); - area->flags |= VM_VPAGES; - } else { - pages = kmalloc(array_size, GFP_KERNEL); - } - if (!pages) - goto out_free_area; + c = ppc_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); - area->pages = pages; - area->nr_pages = nr_pages; + split_page(page, order); - for (i = 0; i < nr_pages; i++) - pages[i] = page + i; + /* + * Set the "dma handle" + */ + *handle = page_to_phys(page); - if (map_vm_area(area, pgprot_noncached(PAGE_KERNEL), &pages)) - goto out_unmap; + do { + BUG_ON(!pte_none(*pte)); - /* - * Free the otherwise unused pages. - */ - page += nr_pages; - while (page < end) { - __free_page(page); - page++; + 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; } - return area->addr; -out_unmap: - vunmap(area->addr); - if (array_size > PAGE_SIZE) - vfree(pages); - else - kfree(pages); - goto out_free_pages; -out_free_area: - free_vm_area(area); -out_free_pages: if (page) __free_pages(page, order); -no_page: + no_page: return NULL; } EXPORT_SYMBOL(__dma_alloc_coherent); @@ -142,12 +239,104 @@ EXPORT_SYMBOL(__dma_alloc_coherent); */ void __dma_free_coherent(size_t size, void *vaddr) { - vfree(vaddr); + struct ppc_vm_region *c; + unsigned long flags, addr; + pte_t *ptep; + + size = PAGE_ALIGN(size); + + spin_lock_irqsave(&consistent_lock, flags); + + c = ppc_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; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + int ret = 0; + + do { + pgd = pgd_offset(&init_mm, CONSISTENT_BASE); + pud = pud_alloc(&init_mm, pgd, CONSISTENT_BASE); + pmd = pmd_alloc(&init_mm, pud, CONSISTENT_BASE); + if (!pmd) { + printk(KERN_ERR "%s: no pmd tables\n", __func__); + ret = -ENOMEM; + break; + } + + 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) |