448 lines
11 KiB
C
448 lines
11 KiB
C
|
/*
|
||
|
|
* 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/config.h>
|
||
|
|
#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/dma-mapping.h>
|
||
|
|
#include <linux/hardirq.h>
|
||
|
|
|
||
|
|
#include <asm/pgalloc.h>
|
||
|
|
#include <asm/prom.h>
|
||
|
|
#include <asm/io.h>
|
||
|
|
#include <asm/mmu_context.h>
|
||
|
|
#include <asm/pgtable.h>
|
||
|
|
#include <asm/mmu.h>
|
||
|
|
#include <asm/uaccess.h>
|
||
|
|
#include <asm/smp.h>
|
||
|
|
#include <asm/machdep.h>
|
||
|
|
|
||
|
|
int map_page(unsigned long va, phys_addr_t pa, int flags);
|
||
|
|
|
||
|
|
#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, int 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, int 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);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Set the "dma handle"
|
||
|
|
*/
|
||
|
|
*handle = page_to_bus(page);
|
||
|
|
|
||
|
|
do {
|
||
|
|
BUG_ON(!pte_none(*pte));
|
||
|
|
|
||
|
|
set_page_count(page, 1);
|
||
|
|
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) {
|
||
|
|
set_page_count(page, 1);
|
||
|
|
__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;
|
||
|
|
|
||
|
|
spin_lock(&init_mm.page_table_lock);
|
||
|
|
|
||
|
|
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(&init_mm, pmd, CONSISTENT_BASE);
|
||
|
|
if (!pte) {
|
||
|
|
printk(KERN_ERR "%s: no pte tables\n", __func__);
|
||
|
|
ret = -ENOMEM;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
consistent_pte = pte;
|
||
|
|
} while (0);
|
||
|
|
|
||
|
|
spin_unlock(&init_mm.page_table_lock);
|
||
|
|
|
||
|
|
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_atmomic()/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, size) - offset;
|
||
|
|
size_t cur_size = seg_size;
|
||
|
|
unsigned long flags, start, seg_offset = offset;
|
||
|
|
int nr_segs = PAGE_ALIGN(size + (PAGE_SIZE - offset))/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);
|