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s390/pci_dma: simplify dma address calculation 

Simplify the code we use to calculate dma addresses by putting
everything related in a dma_alloc_address function. Also provide
a dma_free_address counterpart.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Sebastian Ott 2016-08-17 13:51:11 +02:00 committed by Martin Schwidefsky
parent 3b13f1fea1
commit 8cb63b7879
1 changed files with 18 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
arch/s390/pci/pci_dma.c
View File

@ -230,34 +230,36 @@ static unsigned long __dma_alloc_iommu(struct device *dev,
boundary_size, 0);
}
static unsigned long dma_alloc_iommu(struct device *dev, int size)
static dma_addr_t dma_alloc_address(struct device *dev, int size)
{
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
unsigned long offset, flags;
int wrap = 0;
spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
offset = __dma_alloc_iommu(dev, zdev->next_bit, size);
if (offset == -1) {
/* wrap-around */
offset = __dma_alloc_iommu(dev, 0, size);
wrap = 1;
}
if (offset != -1) {
zdev->next_bit = offset + size;
if (!zdev->tlb_refresh && !s390_iommu_strict && wrap)
if (offset == -1) {
spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
return DMA_ERROR_CODE;
}
if (!zdev->tlb_refresh && !s390_iommu_strict)
/* global flush after wrap-around with lazy unmap */
zpci_refresh_global(zdev);
}
zdev->next_bit = offset + size;
spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
return offset;
return zdev->start_dma + offset * PAGE_SIZE;
}
static void dma_free_iommu(struct device *dev, unsigned long offset, int size)
static void dma_free_address(struct device *dev, dma_addr_t dma_addr, int size)
{
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
unsigned long flags;
unsigned long flags, offset;
offset = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
if (!zdev->iommu_bitmap)
@ -289,23 +291,22 @@ static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
unsigned long attrs)
{
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
unsigned long nr_pages, iommu_page_index;
unsigned long pa = page_to_phys(page) + offset;
int flags = ZPCI_PTE_VALID;
unsigned long nr_pages;
dma_addr_t dma_addr;
int ret;
/* 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(dev, nr_pages);
if (iommu_page_index == -1) {
dma_addr = dma_alloc_address(dev, nr_pages);
if (dma_addr == DMA_ERROR_CODE) {
ret = -ENOSPC;
goto out_err;
}
/* Use rounded up size */
size = nr_pages * PAGE_SIZE;
dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
flags |= ZPCI_TABLE_PROTECTED;
@ -318,7 +319,7 @@ static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
return dma_addr + (offset & ~PAGE_MASK);
out_free:
dma_free_iommu(dev, iommu_page_index, nr_pages);
dma_free_address(dev, dma_addr, nr_pages);
out_err:
zpci_err("map error:\n");
zpci_err_dma(ret, pa);
@ -330,7 +331,6 @@ static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
unsigned long attrs)
{
struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
unsigned long iommu_page_index;
int npages, ret;
npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
@ -344,8 +344,7 @@ static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
}
atomic64_add(npages, &zdev->unmapped_pages);
iommu_page_index = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
dma_free_iommu(dev, iommu_page_index, npages);
dma_free_address(dev, dma_addr, npages);
}
static void *s390_dma_alloc(struct device *dev, size_t size,