diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 7 | ||||
| -rw-r--r-- | arch/s390/pci/pci_dma.c | 50 |
2 files changed, 43 insertions, 14 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index b7fa2f599459..c848095f2cb0 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3023,6 +3023,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. S [KNL] Run init in single mode + s390_iommu= [HW,S390] + Set s390 IOTLB flushing mode + strict + With strict flushing every unmap operation will result in + an IOTLB flush. Default is lazy flushing before reuse, + which is faster. + sa1100ir [NET] See drivers/net/irda/sa1100_ir.c. diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c index f91c03119804..4cbb29a4d615 100644 --- a/arch/s390/pci/pci_dma.c +++ b/arch/s390/pci/pci_dma.c @@ -16,6 +16,13 @@ static struct kmem_cache *dma_region_table_cache; static struct kmem_cache *dma_page_table_cache; +static int s390_iommu_strict; + +static int zpci_refresh_global(struct zpci_dev *zdev) +{ + return zpci_refresh_trans((u64) zdev->fh << 32, zdev->start_dma, + zdev->iommu_pages * PAGE_SIZE); +} static unsigned long *dma_alloc_cpu_table(void) { @@ -155,18 +162,15 @@ static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa, } /* - * 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. + * With zdev->tlb_refresh == 0, rpcit is not required to establish new + * translations when previously invalid translation-table entries are + * validated. With lazy unmap, it also is skipped for previously valid + * entries, but a global rpcit is then required before any address can + * be re-used, i.e. after each iommu bitmap wrap-around. */ 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! - */ + (!s390_iommu_strict || + ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID))) goto no_refresh; rc = zpci_refresh_trans((u64) zdev->fh << 32, start_dma_addr, @@ -220,16 +224,21 @@ static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev, static unsigned long dma_alloc_iommu(struct zpci_dev *zdev, int size) { unsigned long offset, flags; + int wrap = 0; spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags); offset = __dma_alloc_iommu(zdev, zdev->next_bit, size); - if (offset == -1) + if (offset == -1) { + /* wrap-around */ offset = __dma_alloc_iommu(zdev, 0, size); + wrap = 1; + } if (offset != -1) { zdev->next_bit = offset + size; - if (zdev->next_bit >= zdev->iommu_pages) - zdev->next_bit = 0; + if (!zdev->tlb_refresh && !s390_iommu_strict && wrap) + /* global flush after wrap-around with lazy unmap */ + zpci_refresh_global(zdev); } spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags); return offset; @@ -243,7 +252,11 @@ static void dma_free_iommu(struct zpci_dev *zdev, unsigned long offset, int size if (!zdev->iommu_bitmap) goto out; bitmap_clear(zdev->iommu_bitmap, offset, size); - if (offset >= zdev->next_bit) + /* + * Lazy flush for unmap: need to move next_bit to avoid address re-use + * until wrap-around. + */ + if (!s390_iommu_strict && offset >= zdev->next_bit) zdev->next_bit = offset + size; out: spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags); @@ -504,3 +517,12 @@ struct dma_map_ops s390_dma_ops = { /* dma_supported is unconditionally true without a callback */ }; EXPORT_SYMBOL_GPL(s390_dma_ops); + +static int __init s390_iommu_setup(char *str) +{ + if (!strncmp(str, "strict", 6)) + s390_iommu_strict = 1; + return 0; +} + +__setup("s390_iommu=", s390_iommu_setup); |