From 8cb63b78791eef67ea95831c6ef5e6039c572b14 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Wed, 17 Aug 2016 13:51:11 +0200 Subject: [PATCH] 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 Reviewed-by: Gerald Schaefer Signed-off-by: Martin Schwidefsky --- arch/s390/pci/pci_dma.c | 37 ++++++++++++++++++------------------- 1 file changed, 18 insertions(+), 19 deletions(-) diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c index 658123961f42..12b58b6b7f79 100644 --- a/arch/s390/pci/pci_dma.c +++ b/arch/s390/pci/pci_dma.c @@ -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, -- 2.30.2