From efa631c26d3bb1162b8f95008801db602217f52b Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Thu, 26 Aug 2010 13:57:59 -0400 Subject: [PATCH] x86, swiotlb: Simplify SWIOTLB pci_swiotlb_detect routine. In 'pci_swiotlb_detect' we used to do two different things: a). If user provided 'iommu=soft' or 'swiotlb=force' we would set swiotlb=1 and return 1 (and forcing pci-dma.c to call pci_swiotlb_init() immediately). b). If 4GB or more would be detected and if user did not specify iommu=off, we would set 'swiotlb=1' and return whatever 'a)' figured out. We simplify this by splitting a) and b) in two different routines. CC: Fujita Tomonori Signed-off-by: Konrad Rzeszutek Wilk LKML-Reference: <1282845485-8991-5-git-send-email-konrad.wilk@oracle.com> Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/iommu_table.h | 4 ++-- arch/x86/include/asm/swiotlb.h | 13 ++++++++++-- arch/x86/kernel/pci-dma.c | 4 +++- arch/x86/kernel/pci-swiotlb.c | 33 ++++++++++++++++++++++++------ 4 files changed, 43 insertions(+), 11 deletions(-) diff --git a/arch/x86/include/asm/iommu_table.h b/arch/x86/include/asm/iommu_table.h index 2124e3ef6f9..df55a78888e 100644 --- a/arch/x86/include/asm/iommu_table.h +++ b/arch/x86/include/asm/iommu_table.h @@ -64,10 +64,10 @@ struct iommu_table_entry { * to stop detecting the other IOMMUs after yours has been detected. */ #define IOMMU_INIT_POST(_detect) \ - __IOMMU_INIT(_detect, pci_swiotlb_detect, 0, 0, 0) + __IOMMU_INIT(_detect, pci_swiotlb_detect_4gb, 0, 0, 0) #define IOMMU_INIT_POST_FINISH(detect) \ - __IOMMU_INIT(_detect, pci_swiotlb_detect, 0, 0, 1) + __IOMMU_INIT(_detect, pci_swiotlb_detect_4gb, 0, 0, 1) /* * A more sophisticated version of IOMMU_INIT. This variant requires: diff --git a/arch/x86/include/asm/swiotlb.h b/arch/x86/include/asm/swiotlb.h index 8085277e1b8..977f1761a25 100644 --- a/arch/x86/include/asm/swiotlb.h +++ b/arch/x86/include/asm/swiotlb.h @@ -5,17 +5,26 @@ #ifdef CONFIG_SWIOTLB extern int swiotlb; -extern int __init pci_swiotlb_detect(void); +extern int __init pci_swiotlb_detect_override(void); +extern int __init pci_swiotlb_detect_4gb(void); extern void __init pci_swiotlb_init(void); +extern void __init pci_swiotlb_late_init(void); #else #define swiotlb 0 -static inline int pci_swiotlb_detect(void) +static inline int pci_swiotlb_detect_override(void) +{ + return 0; +} +static inline int pci_swiotlb_detect_4gb(void) { return 0; } static inline void pci_swiotlb_init(void) { } +static inline void pci_swiotlb_late_init(void) +{ +} #endif static inline void dma_mark_clean(void *addr, size_t size) {} diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 9f07cfcbd3a..1b3beb5075e 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -133,9 +133,11 @@ void __init pci_iommu_alloc(void) /* free the range so iommu could get some range less than 4G */ dma32_free_bootmem(); - if (pci_xen_swiotlb_detect() || pci_swiotlb_detect()) + if (pci_xen_swiotlb_detect() || pci_swiotlb_detect_override()) goto out; + pci_swiotlb_detect_4gb(); + gart_iommu_hole_init(); detect_calgary(); diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c index a5bc528d432..c7a72faeb14 100644 --- a/arch/x86/kernel/pci-swiotlb.c +++ b/arch/x86/kernel/pci-swiotlb.c @@ -41,24 +41,33 @@ static struct dma_map_ops swiotlb_dma_ops = { }; /* - * pci_swiotlb_detect - set swiotlb to 1 if necessary + * pci_swiotlb_detect_override - set swiotlb to 1 if necessary * * This returns non-zero if we are forced to use swiotlb (by the boot * option). */ -int __init pci_swiotlb_detect(void) +int __init pci_swiotlb_detect_override(void) { int use_swiotlb = swiotlb | swiotlb_force; + if (swiotlb_force) + swiotlb = 1; + + return use_swiotlb; +} + +/* + * if 4GB or more detected (and iommu=off not set) return 1 + * and set swiotlb to 1. + */ +int __init pci_swiotlb_detect_4gb(void) +{ /* don't initialize swiotlb if iommu=off (no_iommu=1) */ #ifdef CONFIG_X86_64 if (!no_iommu && max_pfn > MAX_DMA32_PFN) swiotlb = 1; #endif - if (swiotlb_force) - swiotlb = 1; - - return use_swiotlb; + return swiotlb; } void __init pci_swiotlb_init(void) @@ -68,3 +77,15 @@ void __init pci_swiotlb_init(void) dma_ops = &swiotlb_dma_ops; } } + +void __init pci_swiotlb_late_init(void) +{ + /* An IOMMU turned us off. */ + if (!swiotlb) + swiotlb_free(); + else { + printk(KERN_INFO "PCI-DMA: " + "Using software bounce buffering for IO (SWIOTLB)\n"); + swiotlb_print_info(); + } +}