From 66728eeea6d80060e4b9df55c7845c838ff2799f Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Mon, 26 Oct 2015 11:19:13 +0100 Subject: [PATCH] s390/pci_dma: handle dma table failures We use lazy allocation for translation table entries but don't handle allocation (and other) failures during translation table updates. Handle these failures and undo translation table updates when it's meaningful. Signed-off-by: Sebastian Ott Reviewed-by: Gerald Schaefer Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/pci_dma.h | 4 +++- arch/s390/pci/pci_dma.c | 38 +++++++++++++++++++++------------ drivers/iommu/s390-iommu.c | 23 ++++++++++++++++++-- 3 files changed, 48 insertions(+), 17 deletions(-) diff --git a/arch/s390/include/asm/pci_dma.h b/arch/s390/include/asm/pci_dma.h index 7a7abf1a5537..1aac41e83ea1 100644 --- a/arch/s390/include/asm/pci_dma.h +++ b/arch/s390/include/asm/pci_dma.h @@ -195,5 +195,7 @@ void zpci_dma_exit_device(struct zpci_dev *); void dma_free_seg_table(unsigned long); unsigned long *dma_alloc_cpu_table(void); void dma_cleanup_tables(unsigned long *); -void dma_update_cpu_trans(unsigned long *, void *, dma_addr_t, int); +unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr); +void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags); + #endif diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c index e4a3a31fd59a..f137949c9abf 100644 --- a/arch/s390/pci/pci_dma.c +++ b/arch/s390/pci/pci_dma.c @@ -95,7 +95,7 @@ static unsigned long *dma_get_page_table_origin(unsigned long *entry) return pto; } -static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr) +unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr) { unsigned long *sto, *pto; unsigned int rtx, sx, px; @@ -114,17 +114,8 @@ static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr return &pto[px]; } -void dma_update_cpu_trans(unsigned long *dma_table, void *page_addr, - dma_addr_t dma_addr, int flags) +void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags) { - unsigned long *entry; - - entry = dma_walk_cpu_trans(dma_table, dma_addr); - if (!entry) { - WARN_ON_ONCE(1); - return; - } - if (flags & ZPCI_PTE_INVALID) { invalidate_pt_entry(entry); } else { @@ -145,18 +136,25 @@ static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa, u8 *page_addr = (u8 *) (pa & PAGE_MASK); dma_addr_t start_dma_addr = dma_addr; unsigned long irq_flags; + unsigned long *entry; int i, rc = 0; if (!nr_pages) return -EINVAL; spin_lock_irqsave(&zdev->dma_table_lock, irq_flags); - if (!zdev->dma_table) + if (!zdev->dma_table) { + rc = -EINVAL; goto no_refresh; + } for (i = 0; i < nr_pages; i++) { - dma_update_cpu_trans(zdev->dma_table, page_addr, dma_addr, - flags); + entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr); + if (!entry) { + rc = -ENOMEM; + goto undo_cpu_trans; + } + dma_update_cpu_trans(entry, page_addr, flags); page_addr += PAGE_SIZE; dma_addr += PAGE_SIZE; } @@ -175,6 +173,18 @@ static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa, rc = zpci_refresh_trans((u64) zdev->fh << 32, start_dma_addr, nr_pages * PAGE_SIZE); +undo_cpu_trans: + if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) { + flags = ZPCI_PTE_INVALID; + while (i-- > 0) { + page_addr -= PAGE_SIZE; + dma_addr -= PAGE_SIZE; + entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr); + if (!entry) + break; + dma_update_cpu_trans(entry, page_addr, flags); + } + } no_refresh: spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags); diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c index cbe198cb3699..471ee36b9c6e 100644 --- a/drivers/iommu/s390-iommu.c +++ b/drivers/iommu/s390-iommu.c @@ -216,6 +216,7 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain, u8 *page_addr = (u8 *) (pa & PAGE_MASK); dma_addr_t start_dma_addr = dma_addr; unsigned long irq_flags, nr_pages, i; + unsigned long *entry; int rc = 0; if (dma_addr < s390_domain->domain.geometry.aperture_start || @@ -228,8 +229,12 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain, spin_lock_irqsave(&s390_domain->dma_table_lock, irq_flags); for (i = 0; i < nr_pages; i++) { - dma_update_cpu_trans(s390_domain->dma_table, page_addr, - dma_addr, flags); + entry = dma_walk_cpu_trans(s390_domain->dma_table, dma_addr); + if (!entry) { + rc = -ENOMEM; + goto undo_cpu_trans; + } + dma_update_cpu_trans(entry, page_addr, flags); page_addr += PAGE_SIZE; dma_addr += PAGE_SIZE; } @@ -242,6 +247,20 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain, break; } spin_unlock(&s390_domain->list_lock); + +undo_cpu_trans: + if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) { + flags = ZPCI_PTE_INVALID; + while (i-- > 0) { + page_addr -= PAGE_SIZE; + dma_addr -= PAGE_SIZE; + entry = dma_walk_cpu_trans(s390_domain->dma_table, + dma_addr); + if (!entry) + break; + dma_update_cpu_trans(entry, page_addr, flags); + } + } spin_unlock_irqrestore(&s390_domain->dma_table_lock, irq_flags); return rc; -- 2.20.1