From 52d43d8184b1840c7cf6136724223585f51a1074 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Mon, 26 Oct 2015 11:20:44 +0100 Subject: [PATCH] s390/pci_dma: improve debugging of errors during dma map Improve debugging to find out what went wrong during a failed dma map/unmap operation. Signed-off-by: Sebastian Ott Reviewed-by: Gerald Schaefer Signed-off-by: Martin Schwidefsky --- arch/s390/pci/pci_dma.c | 41 ++++++++++++++++++++++++++++++----------- 1 file changed, 30 insertions(+), 11 deletions(-) diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c index f137949c9abf..d348f2c09a1e 100644 --- a/arch/s390/pci/pci_dma.c +++ b/arch/s390/pci/pci_dma.c @@ -269,6 +269,16 @@ out: spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags); } +static inline void zpci_err_dma(unsigned long rc, unsigned long addr) +{ + struct { + unsigned long rc; + unsigned long addr; + } __packed data = {rc, addr}; + + zpci_err_hex(&data, sizeof(data)); +} + 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, @@ -279,33 +289,40 @@ static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page, unsigned long pa = page_to_phys(page) + offset; int flags = ZPCI_PTE_VALID; 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(zdev, nr_pages); - if (iommu_page_index == -1) + if (iommu_page_index == -1) { + 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 (dma_addr + size > zdev->end_dma) + if (dma_addr + size > zdev->end_dma) { + ret = -ERANGE; 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, &zdev->mapped_pages); - return dma_addr + (offset & ~PAGE_MASK); - } + ret = dma_update_trans(zdev, pa, dma_addr, size, flags); + if (ret) + goto out_free; + + atomic64_add(nr_pages, &zdev->mapped_pages); + return dma_addr + (offset & ~PAGE_MASK); out_free: dma_free_iommu(zdev, iommu_page_index, nr_pages); out_err: zpci_err("map error:\n"); - zpci_err_hex(&pa, sizeof(pa)); + zpci_err_dma(ret, pa); return DMA_ERROR_CODE; } @@ -315,14 +332,16 @@ static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr, { struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); unsigned long iommu_page_index; - int npages; + int npages, ret; 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_PTE_INVALID)) { + ret = dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE, + ZPCI_PTE_INVALID); + if (ret) { zpci_err("unmap error:\n"); - zpci_err_hex(&dma_addr, sizeof(dma_addr)); + zpci_err_dma(ret, dma_addr); + return; } atomic64_add(npages, &zdev->unmapped_pages); -- 2.30.2