- 根目录:
- arch
- s390
- pci
- pci_dma.c
/*
* Copyright IBM Corp. 2012
*
* Author(s):
* Jan Glauber <jang@linux.vnet.ibm.com>
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/iommu-helper.h>
#include <linux/dma-mapping.h>
#include <linux/pci.h>
#include <asm/pci_dma.h>
static struct kmem_cache *dma_region_table_cache;
static struct kmem_cache *dma_page_table_cache;
static unsigned long *dma_alloc_cpu_table(void)
{
unsigned long *table, *entry;
table = kmem_cache_alloc(dma_region_table_cache, GFP_ATOMIC);
if (!table)
return NULL;
for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
*entry = ZPCI_TABLE_INVALID | ZPCI_TABLE_PROTECTED;
return table;
}
static void dma_free_cpu_table(void *table)
{
kmem_cache_free(dma_region_table_cache, table);
}
static unsigned long *dma_alloc_page_table(void)
{
unsigned long *table, *entry;
table = kmem_cache_alloc(dma_page_table_cache, GFP_ATOMIC);
if (!table)
return NULL;
for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
*entry = ZPCI_PTE_INVALID | ZPCI_TABLE_PROTECTED;
return table;
}
static void dma_free_page_table(void *table)
{
kmem_cache_free(dma_page_table_cache, table);
}
static unsigned long *dma_get_seg_table_origin(unsigned long *entry)
{
unsigned long *sto;
if (reg_entry_isvalid(*entry))
sto = get_rt_sto(*entry);
else {
sto = dma_alloc_cpu_table();
if (!sto)
return NULL;
set_rt_sto(entry, sto);
validate_rt_entry(entry);
entry_clr_protected(entry);
}
return sto;
}
static unsigned long *dma_get_page_table_origin(unsigned long *entry)
{
unsigned long *pto;
if (reg_entry_isvalid(*entry))
pto = get_st_pto(*entry);
else {
pto = dma_alloc_page_table();
if (!pto)
return NULL;
set_st_pto(entry, pto);
validate_st_entry(entry);
entry_clr_protected(entry);
}
return pto;
}
static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
{
unsigned long *sto, *pto;
unsigned int rtx, sx, px;
rtx = calc_rtx(dma_addr);
sto = dma_get_seg_table_origin(&rto[rtx]);
if (!sto)
return NULL;
sx = calc_sx(dma_addr);
pto = dma_get_page_table_origin(&sto[sx]);
if (!pto)
return NULL;
px = calc_px(dma_addr);
return &pto[px];
}
static void dma_update_cpu_trans(struct zpci_dev *zdev, void *page_addr,
dma_addr_t dma_addr, int flags)
{
unsigned long *entry;
entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
if (!entry) {
WARN_ON_ONCE(1);
return;
}
if (flags & ZPCI_PTE_INVALID) {
invalidate_pt_entry(entry);
return;
} else {
set_pt_pfaa(entry, page_addr);
validate_pt_entry(entry);
}
if (flags & ZPCI_TABLE_PROTECTED)
entry_set_protected(entry);
else
entry_clr_protected(entry);
}
static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
dma_addr_t dma_addr, size_t size, int flags)
{
unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
u8 *page_addr = (u8 *) (pa & PAGE_MASK);
dma_addr_t start_dma_addr = dma_addr;
unsigned long irq_flags;
int i, rc = 0;
if (!nr_pages)
return -EINVAL;
spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
if (!zdev->dma_table) {
dev_err(&zdev->pdev->dev, "Missing DMA table\n");
goto no_refresh;
}
for (i = 0; i < nr_pages; i++) {
dma_update_cpu_trans(zdev, page_addr, dma_addr, flags);
page_addr += PAGE_SIZE;
dma_addr += PAGE_SIZE;
}
/*
* rpcit is not required to establish new translations when previously
* invalid translation-table entries are validated, however it is
* required when altering previously valid entries.
*/
if (!zdev->tlb_refresh &&
((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID))
/*
* TODO: also need to check that the old entry is indeed INVALID
* and not only for one page but for the whole range...
* -> now we WARN_ON in that case but with lazy unmap that
* needs to be redone!
*/
goto no_refresh;
rc = s390pci_refresh_trans((u64) zdev->fh << 32, start_dma_addr,
nr_pages * PAGE_SIZE);
no_refresh:
spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
return rc;
}
static void dma_free_seg_table(unsigned long entry)
{
unsigned long *sto = get_rt_sto(entry);
int sx;
for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
if (reg_entry_isvalid(sto[sx]))
dma_free_page_table(get_st_pto(sto[sx]));
dma_free_cpu_table(sto);
}
static void dma_cleanup_tables(struct zpci_dev *zdev)
{
unsigned long *table;
int rtx;
if (!zdev || !zdev->dma_table)
return;
table = zdev->dma_table;
for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
if (reg_entry_isvalid(table[rtx]))
dma_free_seg_table(table[rtx]);
dma_free_cpu_table(table);
zdev->dma_table = NULL;
}
static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev, unsigned long start,
int size)
{
unsigned long boundary_size = 0x1000000;
return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
start, size, 0, boundary_size, 0);
}
static unsigned long dma_alloc_iommu(struct zpci_dev *zdev, int size)
{
unsigned long offset, flags;
spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
offset = __dma_alloc_iommu(zdev, zdev->next_bit, size);
if (offset == -1)
offset = __dma_alloc_iommu(zdev, 0, size);
if (offset != -1) {
zdev->next_bit = offset + size;
if (zdev->next_bit >= zdev->iommu_pages)
zdev->next_bit = 0;
}
spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
return offset;
}
static void dma_free_iommu(struct zpci_dev *zdev, unsigned long offset, int size)
{
unsigned long flags;
spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
if (!zdev->iommu_bitmap)
goto out;
bitmap_clear(zdev->iommu_bitmap, offset, size);
if (offset >= zdev->next_bit)
zdev->next_bit = offset + size;
out:
spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
}
int dma_set_mask(struct device *dev, u64 mask)
{
if (!dev->dma_mask || !dma_supported(dev, mask))
return -EIO;
*dev->dma_mask = mask;
return 0;
}
EXPORT_SYMBOL_GPL(dma_set_mask);
static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction direction,
struct dma_attrs *attrs)
{
struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
unsigned long nr_pages, iommu_page_index;
unsigned long pa = page_to_phys(page) + offset;
int flags = ZPCI_PTE_VALID;
dma_addr_t dma_addr;
/* This rounds up number of pages based on size and offset */
nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
iommu_page_index = dma_alloc_iommu(zdev, nr_pages);
if (iommu_page_index == -1)
goto out_err;
/* Use rounded up size */
size = nr_pages * PAGE_SIZE;
dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
if (dma_addr + size > zdev->end_dma) {
dev_err(dev, "(dma_addr: 0x%16.16LX + size: 0x%16.16lx) > end_dma: 0x%16.16Lx\n",
dma_addr, size, zdev->end_dma);
goto out_free;
}
if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
flags |= ZPCI_TABLE_PROTECTED;
if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) {
atomic64_add(nr_pages, (atomic64_t *) &zdev->fmb->mapped_pages);
return dma_addr + (offset & ~PAGE_MASK);
}
out_free:
dma_free_iommu(zdev, iommu_page_index, nr_pages);
out_err:
dev_err(dev, "Failed to map addr: %lx\n", pa);
return DMA_ERROR_CODE;
}
static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
size_t size, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
unsigned long iommu_page_index;
int npages;
npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
dma_addr = dma_addr & PAGE_MASK;
if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
ZPCI_TABLE_PROTECTED | ZPCI_PTE_INVALID))
dev_err(dev, "Failed to unmap addr: %Lx\n", dma_addr);
atomic64_add(npages, (atomic64_t *) &zdev->fmb->unmapped_pages);
iommu_page_index = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
dma_free_iommu(zdev, iommu_page_index, npages);
}
static void *s390_dma_alloc(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag,
struct dma_attrs *attrs)
{
struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
struct page *page;
unsigned long pa;
dma_addr_t map;
size = PAGE_ALIGN(size);
page = alloc_pages(flag, get_order(size));
if (!page)
return NULL;
atomic64_add(size / PAGE_SIZE, (atomic64_t *) &zdev->fmb->allocated_pages);
pa = page_to_phys(page);
memset((void *) pa, 0, size);
map = s390_dma_map_pages(dev, page, pa % PAGE_SIZE,
size, DMA_BIDIRECTIONAL, NULL);
if (dma_mapping_error(dev, map)) {
free_pages(pa, get_order(size));
return NULL;
}
if (dma_handle)
*dma_handle = map;
return (void *) pa;
}
static void s390_dma_free(struct device *dev, size_t size,
void *pa, dma_addr_t dma_handle,
struct dma_attrs *attrs)
{
s390_dma_unmap_pages(dev, dma_handle, PAGE_ALIGN(size),
DMA_BIDIRECTIONAL, NULL);
free_pages((unsigned long) pa, get_order(size));
}
static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
int nr_elements, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
int mapped_elements = 0;
struct scatterlist *s;
int i;
for_each_sg(sg, s, nr_elements, i) {
struct page *page = sg_page(s);
s->dma_address = s390_dma_map_pages(dev, page, s->offset,
s->length, dir, NULL);
if (!dma_mapping_error(dev, s->dma_address)) {
s->dma_length = s->length;
mapped_elements++;
} else
goto unmap;
}
out:
return mapped_elements;
unmap:
for_each_sg(sg, s, mapped_elements, i) {
if (s->dma_address)
s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
dir, NULL);
s->dma_address = 0;
s->dma_length = 0;
}
mapped_elements = 0;
goto out;
}
static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
int nr_elements, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
struct scatterlist *s;
int i;
for_each_sg(sg, s, nr_elements, i) {
s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL);
s->dma_address = 0;
s->dma_length = 0;
}
}
int zpci_dma_init_device(struct zpci_dev *zdev)
{
unsigned int bitmap_order;
int rc;
spin_lock_init(&zdev->iommu_bitmap_lock);
spin_lock_init(&zdev->dma_table_lock);
zdev->dma_table = dma_alloc_cpu_table();
if (!zdev->dma_table) {
rc = -ENOMEM;
goto out_clean;
}
zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET;
zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
bitmap_order = get_order(zdev->iommu_pages / 8);
pr_info("iommu_size: 0x%lx iommu_pages: 0x%lx bitmap_order: %i\n",
zdev->iommu_size, zdev->iommu_pages, bitmap_order);
zdev->iommu_bitmap = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
bitmap_order);
if (!zdev->iommu_bitmap) {
rc = -ENOMEM;
goto out_reg;
}
rc = zpci_register_ioat(zdev,
0,
zdev->start_dma + PAGE_OFFSET,
zdev->start_dma + zdev->iommu_size - 1,
(u64) zdev->dma_table);
if (rc)
goto out_reg;
return 0;
out_reg:
dma_free_cpu_table(zdev->dma_table);
out_clean:
return rc;
}
void zpci_dma_exit_device(struct zpci_dev *zdev)
{
zpci_unregister_ioat(zdev, 0);
dma_cleanup_tables(zdev);
free_pages((unsigned long) zdev->iommu_bitmap,
get_order(zdev->iommu_pages / 8));
zdev->iommu_bitmap = NULL;
zdev->next_bit = 0;
}
static int __init dma_alloc_cpu_table_caches(void)
{
dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
0, NULL);
if (!dma_region_table_cache)
return -ENOMEM;
dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
0, NULL);
if (!dma_page_table_cache) {
kmem_cache_destroy(dma_region_table_cache);
return -ENOMEM;
}
return 0;
}
int __init zpci_dma_init(void)
{
return dma_alloc_cpu_table_caches();
}
void zpci_dma_exit(void)
{
kmem_cache_destroy(dma_page_table_cache);
kmem_cache_destroy(dma_region_table_cache);
}
#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
static int __init dma_debug_do_init(void)
{
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
return 0;
}
fs_initcall(dma_debug_do_init);
struct dma_map_ops s390_dma_ops = {
.alloc = s390_dma_alloc,
.free = s390_dma_free,
.map_sg = s390_dma_map_sg,
.unmap_sg = s390_dma_unmap_sg,
.map_page = s390_dma_map_pages,
.unmap_page = s390_dma_unmap_pages,
/* if we support direct DMA this must be conditional */
.is_phys = 0,
/* dma_supported is unconditionally true without a callback */
};
EXPORT_SYMBOL_GPL(s390_dma_ops);