>From abfe30ed0a7cd3ca97824d9062a655215ddee7f2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 14 Mar 2022 07:58:45 +0100 Subject: swiotlb: merge swiotlb-xen initialization into swiotlb Reuse the generic swiotlb initialization for xen-swiotlb. For ARM/ARM64 this works trivially, while for x86 xen_swiotlb_fixup needs to be passed as the remap argument to swiotlb_init_remap/swiotlb_init_late. Signed-off-by: Christoph Hellwig Reviewed-by: Stefano Stabellini --- arch/arm/xen/mm.c | 21 +++--- arch/x86/include/asm/xen/page.h | 5 -- arch/x86/kernel/pci-dma.c | 20 ++--- drivers/xen/swiotlb-xen.c | 128 +------------------------------- include/xen/arm/page.h | 1 - include/xen/swiotlb-xen.h | 8 +- 6 files changed, 28 insertions(+), 155 deletions(-) diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index 28c2070602535..ff05a7899cb86 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -23,22 +23,20 @@ #include #include -unsigned long xen_get_swiotlb_free_pages(unsigned int order) +static gfp_t xen_swiotlb_gfp(void) { phys_addr_t base; - gfp_t flags = __GFP_NOWARN|__GFP_KSWAPD_RECLAIM; u64 i; for_each_mem_range(i, &base, NULL) { if (base < (phys_addr_t)0xffffffff) { if (IS_ENABLED(CONFIG_ZONE_DMA32)) - flags |= __GFP_DMA32; - else - flags |= __GFP_DMA; - break; + return __GFP_DMA32; + return __GFP_DMA; } } - return __get_free_pages(flags, order); + + return GFP_KERNEL; } static bool hypercall_cflush = false; @@ -140,10 +138,13 @@ static int __init xen_mm_init(void) if (!xen_swiotlb_detect()) return 0; - rc = xen_swiotlb_init(); /* we can work with the default swiotlb */ - if (rc < 0 && rc != -EEXIST) - return rc; + if (!io_tlb_default_mem.nslabs) { + rc = swiotlb_init_late(swiotlb_size_or_default(), + xen_swiotlb_gfp(), NULL); + if (rc < 0) + return rc; + } cflush.op = 0; cflush.a.dev_bus_addr = 0; diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index e989bc2269f54..1fc67df500145 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -357,9 +357,4 @@ static inline bool xen_arch_need_swiotlb(struct device *dev, return false; } -static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order) -{ - return __get_free_pages(__GFP_NOWARN, order); -} - #endif /* _ASM_X86_XEN_PAGE_H */ diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index a705a199bf8a3..30bbe4abb5d61 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -72,15 +72,13 @@ static inline void __init pci_swiotlb_detect(void) #endif /* CONFIG_SWIOTLB */ #ifdef CONFIG_SWIOTLB_XEN -static bool xen_swiotlb; - static void __init pci_xen_swiotlb_init(void) { if (!xen_initial_domain() && !x86_swiotlb_enable) return; x86_swiotlb_enable = true; - xen_swiotlb = true; - xen_swiotlb_init_early(); + x86_swiotlb_flags |= SWIOTLB_ANY; + swiotlb_init_remap(true, x86_swiotlb_flags, xen_swiotlb_fixup); dma_ops = &xen_swiotlb_dma_ops; if (IS_ENABLED(CONFIG_PCI)) pci_request_acs(); @@ -88,14 +86,16 @@ static void __init pci_xen_swiotlb_init(void) int pci_xen_swiotlb_init_late(void) { - int rc; - - if (xen_swiotlb) + if (dma_ops == &xen_swiotlb_dma_ops) return 0; - rc = xen_swiotlb_init(); - if (rc) - return rc; + /* we can work with the default swiotlb */ + if (!io_tlb_default_mem.nslabs) { + int rc = swiotlb_init_late(swiotlb_size_or_default(), + GFP_KERNEL, xen_swiotlb_fixup); + if (rc < 0) + return rc; + } /* XXX: this switches the dma ops under live devices! */ dma_ops = &xen_swiotlb_dma_ops; diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index c2da3eb4826e8..df8085b50df10 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -104,7 +104,7 @@ static int is_xen_swiotlb_buffer(struct device *dev, dma_addr_t dma_addr) return 0; } -static int xen_swiotlb_fixup(void *buf, unsigned long nslabs) +int xen_swiotlb_fixup(void *buf, unsigned long nslabs) { int rc; unsigned int order = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT); @@ -130,132 +130,6 @@ static int xen_swiotlb_fixup(void *buf, unsigned long nslabs) return 0; } -enum xen_swiotlb_err { - XEN_SWIOTLB_UNKNOWN = 0, - XEN_SWIOTLB_ENOMEM, - XEN_SWIOTLB_EFIXUP -}; - -static const char *xen_swiotlb_error(enum xen_swiotlb_err err) -{ - switch (err) { - case XEN_SWIOTLB_ENOMEM: - return "Cannot allocate Xen-SWIOTLB buffer\n"; - case XEN_SWIOTLB_EFIXUP: - return "Failed to get contiguous memory for DMA from Xen!\n"\ - "You either: don't have the permissions, do not have"\ - " enough free memory under 4GB, or the hypervisor memory"\ - " is too fragmented!"; - default: - break; - } - return ""; -} - -int xen_swiotlb_init(void) -{ - enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN; - unsigned long bytes = swiotlb_size_or_default(); - unsigned long nslabs = bytes >> IO_TLB_SHIFT; - unsigned int order, repeat = 3; - int rc = -ENOMEM; - char *start; - - if (io_tlb_default_mem.nslabs) { - pr_warn("swiotlb buffer already initialized\n"); - return -EEXIST; - } - -retry: - m_ret = XEN_SWIOTLB_ENOMEM; - order = get_order(bytes); - - /* - * Get IO TLB memory from any location. - */ -#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) { - start = (void *)xen_get_swiotlb_free_pages(order); - if (start) - break; - order--; - } - if (!start) - goto exit; - if (order != get_order(bytes)) { - pr_warn("Warning: only able to allocate %ld MB for software IO TLB\n", - (PAGE_SIZE << order) >> 20); - nslabs = SLABS_PER_PAGE << order; - bytes = nslabs << IO_TLB_SHIFT; - } - - /* - * And replace that memory with pages under 4GB. - */ - rc = xen_swiotlb_fixup(start, nslabs); - if (rc) { - free_pages((unsigned long)start, order); - m_ret = XEN_SWIOTLB_EFIXUP; - goto error; - } - rc = swiotlb_late_init_with_tbl(start, nslabs); - if (rc) - return rc; - return 0; -error: - if (nslabs > 1024 && repeat--) { - /* Min is 2MB */ - nslabs = max(1024UL, ALIGN(nslabs >> 1, IO_TLB_SEGSIZE)); - bytes = nslabs << IO_TLB_SHIFT; - pr_info("Lowering to %luMB\n", bytes >> 20); - goto retry; - } -exit: - pr_err("%s (rc:%d)\n", xen_swiotlb_error(m_ret), rc); - return rc; -} - -#ifdef CONFIG_X86 -void __init xen_swiotlb_init_early(void) -{ - unsigned long bytes = swiotlb_size_or_default(); - unsigned long nslabs = bytes >> IO_TLB_SHIFT; - unsigned int repeat = 3; - char *start; - int rc; - -retry: - /* - * Get IO TLB memory from any location. - */ - start = memblock_alloc(PAGE_ALIGN(bytes), - IO_TLB_SEGSIZE << IO_TLB_SHIFT); - if (!start) - panic("%s: Failed to allocate %lu bytes\n", - __func__, PAGE_ALIGN(bytes)); - - /* - * And replace that memory with pages under 4GB. - */ - rc = xen_swiotlb_fixup(start, nslabs); - if (rc) { - memblock_free(start, PAGE_ALIGN(bytes)); - if (nslabs > 1024 && repeat--) { - /* Min is 2MB */ - nslabs = max(1024UL, ALIGN(nslabs >> 1, IO_TLB_SEGSIZE)); - bytes = nslabs << IO_TLB_SHIFT; - pr_info("Lowering to %luMB\n", bytes >> 20); - goto retry; - } - panic("%s (rc:%d)", xen_swiotlb_error(XEN_SWIOTLB_EFIXUP), rc); - } - - if (swiotlb_init_with_tbl(start, nslabs, SWIOTLB_VERBOSE)) - panic("Cannot allocate SWIOTLB buffer"); -} -#endif /* CONFIG_X86 */ - static void * xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t flags, diff --git a/include/xen/arm/page.h b/include/xen/arm/page.h index ac1b654705631..7e199c6656b90 100644 --- a/include/xen/arm/page.h +++ b/include/xen/arm/page.h @@ -115,6 +115,5 @@ static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn) bool xen_arch_need_swiotlb(struct device *dev, phys_addr_t phys, dma_addr_t dev_addr); -unsigned long xen_get_swiotlb_free_pages(unsigned int order); #endif /* _ASM_ARM_XEN_PAGE_H */ diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h index b3e647f86e3e2..590ceb923f0c8 100644 --- a/include/xen/swiotlb-xen.h +++ b/include/xen/swiotlb-xen.h @@ -10,8 +10,12 @@ void xen_dma_sync_for_cpu(struct device *dev, dma_addr_t handle, void xen_dma_sync_for_device(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir); -int xen_swiotlb_init(void); -void __init xen_swiotlb_init_early(void); +#ifdef CONFIG_SWIOTLB_XEN +int xen_swiotlb_fixup(void *buf, unsigned long nslabs); +#else +#define xen_swiotlb_fixup NULL +#endif + extern const struct dma_map_ops xen_swiotlb_dma_ops; #endif /* __LINUX_SWIOTLB_XEN_H */ -- 2.30.2