From b82776005369899c1c7ca2e4b2414bb64b538d2c Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Thu, 23 Aug 2012 14:36:15 -0400 Subject: [PATCH] xen/swiotlb: Use the swiotlb_late_init_with_tbl to init Xen-SWIOTLB late when PV PCI is used. With this patch we provide the functionality to initialize the Xen-SWIOTLB late in the bootup cycle - specifically for Xen PCI-frontend. We still will work if the user had supplied 'iommu=soft' on the Linux command line. Note: We cannot depend on after_bootmem to automatically determine whether this is early or not. This is because when PCI IOMMUs are initialized it is after after_bootmem but before a lot of "other" subsystems are initialized. CC: FUJITA Tomonori [v1: Fix smatch warnings] [v2: Added check for xen_swiotlb] [v3: Rebased with new xen-swiotlb changes] [v4: squashed xen/swiotlb: Depending on after_bootmem is not correct in] Reviewed-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/include/asm/xen/swiotlb-xen.h | 2 ++ arch/x86/xen/pci-swiotlb-xen.c | 24 +++++++++++-- drivers/xen/swiotlb-xen.c | 48 ++++++++++++++++++++------ include/xen/swiotlb-xen.h | 2 +- 4 files changed, 63 insertions(+), 13 deletions(-) diff --git a/arch/x86/include/asm/xen/swiotlb-xen.h b/arch/x86/include/asm/xen/swiotlb-xen.h index 1be1ab7d6a41..ee52fcac6f72 100644 --- a/arch/x86/include/asm/xen/swiotlb-xen.h +++ b/arch/x86/include/asm/xen/swiotlb-xen.h @@ -5,10 +5,12 @@ extern int xen_swiotlb; extern int __init pci_xen_swiotlb_detect(void); extern void __init pci_xen_swiotlb_init(void); +extern int pci_xen_swiotlb_init_late(void); #else #define xen_swiotlb (0) static inline int __init pci_xen_swiotlb_detect(void) { return 0; } static inline void __init pci_xen_swiotlb_init(void) { } +static inline int pci_xen_swiotlb_init_late(void) { return -ENXIO; } #endif #endif /* _ASM_X86_SWIOTLB_XEN_H */ diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c index 1c1722761eec..b152640d8388 100644 --- a/arch/x86/xen/pci-swiotlb-xen.c +++ b/arch/x86/xen/pci-swiotlb-xen.c @@ -12,7 +12,7 @@ #include #include #endif - +#include int xen_swiotlb __read_mostly; static struct dma_map_ops xen_swiotlb_dma_ops = { @@ -69,13 +69,33 @@ int __init pci_xen_swiotlb_detect(void) void __init pci_xen_swiotlb_init(void) { if (xen_swiotlb) { - xen_swiotlb_init(1); + xen_swiotlb_init(1, true /* early */); dma_ops = &xen_swiotlb_dma_ops; /* Make sure ACS will be enabled */ pci_request_acs(); } } + +int pci_xen_swiotlb_init_late(void) +{ + int rc; + + if (xen_swiotlb) + return 0; + + rc = xen_swiotlb_init(1, false /* late */); + if (rc) + return rc; + + dma_ops = &xen_swiotlb_dma_ops; + /* Make sure ACS will be enabled */ + pci_request_acs(); + + return 0; +} +EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late); + IOMMU_INIT_FINISH(pci_xen_swiotlb_detect, 0, pci_xen_swiotlb_init, diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 701b1035fa6f..7461edb5118e 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -176,9 +176,9 @@ static const char *xen_swiotlb_error(enum xen_swiotlb_err err) } return ""; } -void __init xen_swiotlb_init(int verbose) +int __ref xen_swiotlb_init(int verbose, bool early) { - unsigned long bytes; + unsigned long bytes, order; int rc = -ENOMEM; enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN; unsigned int repeat = 3; @@ -186,10 +186,28 @@ void __init xen_swiotlb_init(int verbose) xen_io_tlb_nslabs = swiotlb_nr_tbl(); retry: bytes = xen_set_nslabs(xen_io_tlb_nslabs); + order = get_order(xen_io_tlb_nslabs << IO_TLB_SHIFT); /* * Get IO TLB memory from any location. */ - xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes)); + if (early) + xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes)); + else { +#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT)) +#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT) + while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) { + xen_io_tlb_start = (void *)__get_free_pages(__GFP_NOWARN, order); + if (xen_io_tlb_start) + break; + order--; + } + if (order != get_order(bytes)) { + pr_warn("Warning: only able to allocate %ld MB " + "for software IO TLB\n", (PAGE_SIZE << order) >> 20); + xen_io_tlb_nslabs = SLABS_PER_PAGE << order; + bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT; + } + } if (!xen_io_tlb_start) { m_ret = XEN_SWIOTLB_ENOMEM; goto error; @@ -202,14 +220,21 @@ retry: bytes, xen_io_tlb_nslabs); if (rc) { - free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes)); + if (early) + free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes)); + else { + free_pages((unsigned long)xen_io_tlb_start, order); + xen_io_tlb_start = NULL; + } m_ret = XEN_SWIOTLB_EFIXUP; goto error; } start_dma_addr = xen_virt_to_bus(xen_io_tlb_start); - swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, verbose); - - return; + if (early) + swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, verbose); + else + rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs); + return rc; error: if (repeat--) { xen_io_tlb_nslabs = max(1024UL, /* Min is 2MB */ @@ -218,10 +243,13 @@ error: (xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20); goto retry; } - xen_raw_printk("%s (rc:%d)", xen_swiotlb_error(m_ret), rc); - panic("%s (rc:%d)", xen_swiotlb_error(m_ret), rc); + pr_err("%s (rc:%d)", xen_swiotlb_error(m_ret), rc); + if (early) + panic("%s (rc:%d)", xen_swiotlb_error(m_ret), rc); + else + free_pages((unsigned long)xen_io_tlb_start, order); + return rc; } - void * xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t flags, diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h index 4f4d449f00f6..289ee509bda9 100644 --- a/include/xen/swiotlb-xen.h +++ b/include/xen/swiotlb-xen.h @@ -3,7 +3,7 @@ #include -extern void xen_swiotlb_init(int verbose); +extern int xen_swiotlb_init(int verbose, bool early); extern void *xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,