Commit 37134cd5 authored by Kevin Hilman's avatar Kevin Hilman Committed by Russell King

[ARM] 3209/1: Configurable DMA-consistent memory region

Patch from Kevin Hilman

This patch increase available DMA-consistent memory allocated by dma_coherent_alloc(). The default remains at 2M (defined in asm/memory.h) and each platform has the ability to override in asm/arch-foo/memory.h.
Signed-off-by: default avatarKevin Hilman <kevin@hilman.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent a3e49436
...@@ -20,15 +20,25 @@ ...@@ -20,15 +20,25 @@
#include <asm/cacheflush.h> #include <asm/cacheflush.h>
#include <asm/tlbflush.h> #include <asm/tlbflush.h>
#include <asm/sizes.h>
/* Sanity check size */
#if (CONSISTENT_DMA_SIZE % SZ_2M)
#error "CONSISTENT_DMA_SIZE must be multiple of 2MiB"
#endif
#define CONSISTENT_BASE (0xffc00000)
#define CONSISTENT_END (0xffe00000) #define CONSISTENT_END (0xffe00000)
#define CONSISTENT_BASE (CONSISTENT_END - CONSISTENT_DMA_SIZE)
#define CONSISTENT_OFFSET(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT) #define CONSISTENT_OFFSET(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT)
#define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PGDIR_SHIFT)
#define NUM_CONSISTENT_PTES (CONSISTENT_DMA_SIZE >> PGDIR_SHIFT)
/* /*
* This is the page table (2MB) covering uncached, DMA consistent allocations * These are the page tables (2MB each) covering uncached, DMA consistent allocations
*/ */
static pte_t *consistent_pte; static pte_t *consistent_pte[NUM_CONSISTENT_PTES];
static DEFINE_SPINLOCK(consistent_lock); static DEFINE_SPINLOCK(consistent_lock);
/* /*
...@@ -142,7 +152,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, ...@@ -142,7 +152,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
unsigned long order; unsigned long order;
u64 mask = ISA_DMA_THRESHOLD, limit; u64 mask = ISA_DMA_THRESHOLD, limit;
if (!consistent_pte) { if (!consistent_pte[0]) {
printk(KERN_ERR "%s: not initialised\n", __func__); printk(KERN_ERR "%s: not initialised\n", __func__);
dump_stack(); dump_stack();
return NULL; return NULL;
...@@ -205,9 +215,12 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, ...@@ -205,9 +215,12 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
c = vm_region_alloc(&consistent_head, size, c = vm_region_alloc(&consistent_head, size,
gfp & ~(__GFP_DMA | __GFP_HIGHMEM)); gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
if (c) { if (c) {
pte_t *pte = consistent_pte + CONSISTENT_OFFSET(c->vm_start); pte_t *pte;
struct page *end = page + (1 << order); struct page *end = page + (1 << order);
int idx = CONSISTENT_PTE_INDEX(c->vm_start);
u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
pte = consistent_pte[idx] + off;
c->vm_pages = page; c->vm_pages = page;
/* /*
...@@ -226,6 +239,11 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, ...@@ -226,6 +239,11 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
set_pte(pte, mk_pte(page, prot)); set_pte(pte, mk_pte(page, prot));
page++; page++;
pte++; pte++;
off++;
if (off >= PTRS_PER_PTE) {
off = 0;
pte = consistent_pte[++idx];
}
} while (size -= PAGE_SIZE); } while (size -= PAGE_SIZE);
/* /*
...@@ -327,6 +345,8 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr ...@@ -327,6 +345,8 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
struct vm_region *c; struct vm_region *c;
unsigned long flags, addr; unsigned long flags, addr;
pte_t *ptep; pte_t *ptep;
int idx;
u32 off;
WARN_ON(irqs_disabled()); WARN_ON(irqs_disabled());
...@@ -347,7 +367,9 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr ...@@ -347,7 +367,9 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
size = c->vm_end - c->vm_start; size = c->vm_end - c->vm_start;
} }
ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start); idx = CONSISTENT_PTE_INDEX(c->vm_start);
off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
ptep = consistent_pte[idx] + off;
addr = c->vm_start; addr = c->vm_start;
do { do {
pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep); pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
...@@ -355,6 +377,11 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr ...@@ -355,6 +377,11 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
ptep++; ptep++;
addr += PAGE_SIZE; addr += PAGE_SIZE;
off++;
if (off >= PTRS_PER_PTE) {
off = 0;
ptep = consistent_pte[++idx];
}
if (!pte_none(pte) && pte_present(pte)) { if (!pte_none(pte) && pte_present(pte)) {
pfn = pte_pfn(pte); pfn = pte_pfn(pte);
...@@ -401,11 +428,12 @@ static int __init consistent_init(void) ...@@ -401,11 +428,12 @@ static int __init consistent_init(void)
pgd_t *pgd; pgd_t *pgd;
pmd_t *pmd; pmd_t *pmd;
pte_t *pte; pte_t *pte;
int ret = 0; int ret = 0, i = 0;
u32 base = CONSISTENT_BASE;
do { do {
pgd = pgd_offset(&init_mm, CONSISTENT_BASE); pgd = pgd_offset(&init_mm, base);
pmd = pmd_alloc(&init_mm, pgd, CONSISTENT_BASE); pmd = pmd_alloc(&init_mm, pgd, base);
if (!pmd) { if (!pmd) {
printk(KERN_ERR "%s: no pmd tables\n", __func__); printk(KERN_ERR "%s: no pmd tables\n", __func__);
ret = -ENOMEM; ret = -ENOMEM;
...@@ -413,15 +441,16 @@ static int __init consistent_init(void) ...@@ -413,15 +441,16 @@ static int __init consistent_init(void)
} }
WARN_ON(!pmd_none(*pmd)); WARN_ON(!pmd_none(*pmd));
pte = pte_alloc_kernel(pmd, CONSISTENT_BASE); pte = pte_alloc_kernel(pmd, base);
if (!pte) { if (!pte) {
printk(KERN_ERR "%s: no pte tables\n", __func__); printk(KERN_ERR "%s: no pte tables\n", __func__);
ret = -ENOMEM; ret = -ENOMEM;
break; break;
} }
consistent_pte = pte; consistent_pte[i++] = pte;
} while (0); base += (1 << PGDIR_SHIFT);
} while (base < CONSISTENT_END);
return ret; return ret;
} }
......
...@@ -25,6 +25,7 @@ ...@@ -25,6 +25,7 @@
#include <linux/config.h> #include <linux/config.h>
#include <linux/compiler.h> #include <linux/compiler.h>
#include <asm/arch/memory.h> #include <asm/arch/memory.h>
#include <asm/sizes.h>
#ifndef TASK_SIZE #ifndef TASK_SIZE
/* /*
...@@ -47,6 +48,14 @@ ...@@ -47,6 +48,14 @@
#define PAGE_OFFSET UL(0xc0000000) #define PAGE_OFFSET UL(0xc0000000)
#endif #endif
/*
* Size of DMA-consistent memory region. Must be multiple of 2M,
* between 2MB and 14MB inclusive.
*/
#ifndef CONSISTENT_DMA_SIZE
#define CONSISTENT_DMA_SIZE SZ_2M
#endif
/* /*
* Physical vs virtual RAM address space conversion. These are * Physical vs virtual RAM address space conversion. These are
* private definitions which should NOT be used outside memory.h * private definitions which should NOT be used outside memory.h
......
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