![Stefano Stabellini](/assets/img/avatar_default.png)
Make sure that xen_swiotlb_init allocates buffers that are DMA capable when at least one memblock is available below 4G. Otherwise we assume that all devices on the SoC can cope with >4G addresses. We do this on ARM and ARM64, where dom0 is mapped 1:1, so pfn == mfn in this case. No functional changes on x86. From: Chen Baozi <baozich@gmail.com> Signed-off-by: Chen Baozi <baozich@gmail.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Tested-by: Chen Baozi <baozich@gmail.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
689 lines
19 KiB
C
689 lines
19 KiB
C
/*
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* Copyright 2010
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* by Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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*
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* This code provides a IOMMU for Xen PV guests with PCI passthrough.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License v2.0 as published by
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* the Free Software Foundation
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* PV guests under Xen are running in an non-contiguous memory architecture.
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*
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* When PCI pass-through is utilized, this necessitates an IOMMU for
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* translating bus (DMA) to virtual and vice-versa and also providing a
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* mechanism to have contiguous pages for device drivers operations (say DMA
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* operations).
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*
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* Specifically, under Xen the Linux idea of pages is an illusion. It
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* assumes that pages start at zero and go up to the available memory. To
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* help with that, the Linux Xen MMU provides a lookup mechanism to
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* translate the page frame numbers (PFN) to machine frame numbers (MFN)
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* and vice-versa. The MFN are the "real" frame numbers. Furthermore
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* memory is not contiguous. Xen hypervisor stitches memory for guests
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* from different pools, which means there is no guarantee that PFN==MFN
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* and PFN+1==MFN+1. Lastly with Xen 4.0, pages (in debug mode) are
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* allocated in descending order (high to low), meaning the guest might
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* never get any MFN's under the 4GB mark.
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*
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*/
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#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
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#include <linux/bootmem.h>
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#include <linux/dma-mapping.h>
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#include <linux/export.h>
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#include <xen/swiotlb-xen.h>
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#include <xen/page.h>
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#include <xen/xen-ops.h>
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#include <xen/hvc-console.h>
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#include <asm/dma-mapping.h>
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#include <asm/xen/page-coherent.h>
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#include <trace/events/swiotlb.h>
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/*
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* Used to do a quick range check in swiotlb_tbl_unmap_single and
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* swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this
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* API.
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*/
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#ifndef CONFIG_X86
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static unsigned long dma_alloc_coherent_mask(struct device *dev,
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gfp_t gfp)
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{
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unsigned long dma_mask = 0;
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dma_mask = dev->coherent_dma_mask;
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if (!dma_mask)
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dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32);
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return dma_mask;
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}
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#endif
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static char *xen_io_tlb_start, *xen_io_tlb_end;
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static unsigned long xen_io_tlb_nslabs;
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/*
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* Quick lookup value of the bus address of the IOTLB.
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*/
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static u64 start_dma_addr;
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/*
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* Both of these functions should avoid PFN_PHYS because phys_addr_t
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* can be 32bit when dma_addr_t is 64bit leading to a loss in
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* information if the shift is done before casting to 64bit.
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*/
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static inline dma_addr_t xen_phys_to_bus(phys_addr_t paddr)
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{
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unsigned long mfn = pfn_to_mfn(PFN_DOWN(paddr));
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dma_addr_t dma = (dma_addr_t)mfn << PAGE_SHIFT;
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dma |= paddr & ~PAGE_MASK;
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return dma;
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}
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static inline phys_addr_t xen_bus_to_phys(dma_addr_t baddr)
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{
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unsigned long pfn = mfn_to_pfn(PFN_DOWN(baddr));
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dma_addr_t dma = (dma_addr_t)pfn << PAGE_SHIFT;
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phys_addr_t paddr = dma;
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paddr |= baddr & ~PAGE_MASK;
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return paddr;
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}
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static inline dma_addr_t xen_virt_to_bus(void *address)
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{
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return xen_phys_to_bus(virt_to_phys(address));
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}
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static int check_pages_physically_contiguous(unsigned long pfn,
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unsigned int offset,
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size_t length)
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{
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unsigned long next_mfn;
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int i;
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int nr_pages;
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next_mfn = pfn_to_mfn(pfn);
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nr_pages = (offset + length + PAGE_SIZE-1) >> PAGE_SHIFT;
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for (i = 1; i < nr_pages; i++) {
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if (pfn_to_mfn(++pfn) != ++next_mfn)
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return 0;
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}
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return 1;
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}
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static inline int range_straddles_page_boundary(phys_addr_t p, size_t size)
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{
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unsigned long pfn = PFN_DOWN(p);
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unsigned int offset = p & ~PAGE_MASK;
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if (offset + size <= PAGE_SIZE)
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return 0;
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if (check_pages_physically_contiguous(pfn, offset, size))
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return 0;
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return 1;
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}
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static int is_xen_swiotlb_buffer(dma_addr_t dma_addr)
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{
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unsigned long mfn = PFN_DOWN(dma_addr);
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unsigned long pfn = mfn_to_local_pfn(mfn);
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phys_addr_t paddr;
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/* If the address is outside our domain, it CAN
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* have the same virtual address as another address
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* in our domain. Therefore _only_ check address within our domain.
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*/
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if (pfn_valid(pfn)) {
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paddr = PFN_PHYS(pfn);
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return paddr >= virt_to_phys(xen_io_tlb_start) &&
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paddr < virt_to_phys(xen_io_tlb_end);
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}
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return 0;
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}
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static int max_dma_bits = 32;
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static int
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xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
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{
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int i, rc;
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int dma_bits;
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dma_addr_t dma_handle;
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phys_addr_t p = virt_to_phys(buf);
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dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT;
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i = 0;
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do {
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int slabs = min(nslabs - i, (unsigned long)IO_TLB_SEGSIZE);
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do {
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rc = xen_create_contiguous_region(
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p + (i << IO_TLB_SHIFT),
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get_order(slabs << IO_TLB_SHIFT),
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dma_bits, &dma_handle);
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} while (rc && dma_bits++ < max_dma_bits);
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if (rc)
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return rc;
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i += slabs;
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} while (i < nslabs);
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return 0;
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}
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static unsigned long xen_set_nslabs(unsigned long nr_tbl)
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{
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if (!nr_tbl) {
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xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT);
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xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
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} else
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xen_io_tlb_nslabs = nr_tbl;
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return xen_io_tlb_nslabs << IO_TLB_SHIFT;
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}
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enum xen_swiotlb_err {
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XEN_SWIOTLB_UNKNOWN = 0,
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XEN_SWIOTLB_ENOMEM,
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XEN_SWIOTLB_EFIXUP
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};
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static const char *xen_swiotlb_error(enum xen_swiotlb_err err)
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{
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switch (err) {
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case XEN_SWIOTLB_ENOMEM:
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return "Cannot allocate Xen-SWIOTLB buffer\n";
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case XEN_SWIOTLB_EFIXUP:
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return "Failed to get contiguous memory for DMA from Xen!\n"\
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"You either: don't have the permissions, do not have"\
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" enough free memory under 4GB, or the hypervisor memory"\
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" is too fragmented!";
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default:
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break;
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}
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return "";
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}
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int __ref xen_swiotlb_init(int verbose, bool early)
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{
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unsigned long bytes, order;
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int rc = -ENOMEM;
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enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN;
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unsigned int repeat = 3;
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xen_io_tlb_nslabs = swiotlb_nr_tbl();
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retry:
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bytes = xen_set_nslabs(xen_io_tlb_nslabs);
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order = get_order(xen_io_tlb_nslabs << IO_TLB_SHIFT);
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/*
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* Get IO TLB memory from any location.
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*/
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if (early)
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xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
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else {
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#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
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#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
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while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
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xen_io_tlb_start = (void *)xen_get_swiotlb_free_pages(order);
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if (xen_io_tlb_start)
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break;
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order--;
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}
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if (order != get_order(bytes)) {
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pr_warn("Warning: only able to allocate %ld MB for software IO TLB\n",
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(PAGE_SIZE << order) >> 20);
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xen_io_tlb_nslabs = SLABS_PER_PAGE << order;
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bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;
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}
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}
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if (!xen_io_tlb_start) {
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m_ret = XEN_SWIOTLB_ENOMEM;
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goto error;
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}
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xen_io_tlb_end = xen_io_tlb_start + bytes;
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/*
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* And replace that memory with pages under 4GB.
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*/
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rc = xen_swiotlb_fixup(xen_io_tlb_start,
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bytes,
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xen_io_tlb_nslabs);
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if (rc) {
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if (early)
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free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
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else {
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free_pages((unsigned long)xen_io_tlb_start, order);
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xen_io_tlb_start = NULL;
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}
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m_ret = XEN_SWIOTLB_EFIXUP;
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goto error;
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}
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start_dma_addr = xen_virt_to_bus(xen_io_tlb_start);
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if (early) {
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if (swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs,
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verbose))
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panic("Cannot allocate SWIOTLB buffer");
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rc = 0;
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} else
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rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs);
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return rc;
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error:
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if (repeat--) {
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xen_io_tlb_nslabs = max(1024UL, /* Min is 2MB */
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(xen_io_tlb_nslabs >> 1));
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pr_info("Lowering to %luMB\n",
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(xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20);
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goto retry;
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}
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pr_err("%s (rc:%d)\n", xen_swiotlb_error(m_ret), rc);
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if (early)
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panic("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
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else
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free_pages((unsigned long)xen_io_tlb_start, order);
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return rc;
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}
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void *
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xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
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dma_addr_t *dma_handle, gfp_t flags,
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struct dma_attrs *attrs)
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{
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void *ret;
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int order = get_order(size);
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u64 dma_mask = DMA_BIT_MASK(32);
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phys_addr_t phys;
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dma_addr_t dev_addr;
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/*
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* Ignore region specifiers - the kernel's ideas of
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* pseudo-phys memory layout has nothing to do with the
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* machine physical layout. We can't allocate highmem
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* because we can't return a pointer to it.
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*/
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flags &= ~(__GFP_DMA | __GFP_HIGHMEM);
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if (dma_alloc_from_coherent(hwdev, size, dma_handle, &ret))
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return ret;
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/* On ARM this function returns an ioremap'ped virtual address for
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* which virt_to_phys doesn't return the corresponding physical
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* address. In fact on ARM virt_to_phys only works for kernel direct
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* mapped RAM memory. Also see comment below.
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*/
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ret = xen_alloc_coherent_pages(hwdev, size, dma_handle, flags, attrs);
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if (!ret)
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return ret;
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if (hwdev && hwdev->coherent_dma_mask)
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dma_mask = dma_alloc_coherent_mask(hwdev, flags);
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/* At this point dma_handle is the physical address, next we are
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* going to set it to the machine address.
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* Do not use virt_to_phys(ret) because on ARM it doesn't correspond
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* to *dma_handle. */
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phys = *dma_handle;
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dev_addr = xen_phys_to_bus(phys);
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if (((dev_addr + size - 1 <= dma_mask)) &&
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!range_straddles_page_boundary(phys, size))
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*dma_handle = dev_addr;
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else {
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if (xen_create_contiguous_region(phys, order,
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fls64(dma_mask), dma_handle) != 0) {
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xen_free_coherent_pages(hwdev, size, ret, (dma_addr_t)phys, attrs);
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return NULL;
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}
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}
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memset(ret, 0, size);
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return ret;
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}
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EXPORT_SYMBOL_GPL(xen_swiotlb_alloc_coherent);
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void
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xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
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dma_addr_t dev_addr, struct dma_attrs *attrs)
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{
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int order = get_order(size);
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phys_addr_t phys;
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u64 dma_mask = DMA_BIT_MASK(32);
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if (dma_release_from_coherent(hwdev, order, vaddr))
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return;
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if (hwdev && hwdev->coherent_dma_mask)
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dma_mask = hwdev->coherent_dma_mask;
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/* do not use virt_to_phys because on ARM it doesn't return you the
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* physical address */
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phys = xen_bus_to_phys(dev_addr);
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if (((dev_addr + size - 1 > dma_mask)) ||
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range_straddles_page_boundary(phys, size))
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xen_destroy_contiguous_region(phys, order);
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xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs);
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}
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EXPORT_SYMBOL_GPL(xen_swiotlb_free_coherent);
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/*
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* Map a single buffer of the indicated size for DMA in streaming mode. The
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* physical address to use is returned.
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*
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* Once the device is given the dma address, the device owns this memory until
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* either xen_swiotlb_unmap_page or xen_swiotlb_dma_sync_single is performed.
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*/
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dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
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unsigned long offset, size_t size,
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enum dma_data_direction dir,
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struct dma_attrs *attrs)
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{
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phys_addr_t map, phys = page_to_phys(page) + offset;
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dma_addr_t dev_addr = xen_phys_to_bus(phys);
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BUG_ON(dir == DMA_NONE);
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/*
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* If the address happens to be in the device's DMA window,
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* we can safely return the device addr and not worry about bounce
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* buffering it.
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*/
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if (dma_capable(dev, dev_addr, size) &&
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!range_straddles_page_boundary(phys, size) &&
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!xen_arch_need_swiotlb(dev, PFN_DOWN(phys), PFN_DOWN(dev_addr)) &&
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!swiotlb_force) {
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/* we are not interested in the dma_addr returned by
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* xen_dma_map_page, only in the potential cache flushes executed
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* by the function. */
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xen_dma_map_page(dev, page, dev_addr, offset, size, dir, attrs);
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return dev_addr;
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}
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/*
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* Oh well, have to allocate and map a bounce buffer.
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*/
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trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force);
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map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir);
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if (map == SWIOTLB_MAP_ERROR)
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return DMA_ERROR_CODE;
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xen_dma_map_page(dev, pfn_to_page(map >> PAGE_SHIFT),
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dev_addr, map & ~PAGE_MASK, size, dir, attrs);
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dev_addr = xen_phys_to_bus(map);
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/*
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* Ensure that the address returned is DMA'ble
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*/
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if (!dma_capable(dev, dev_addr, size)) {
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swiotlb_tbl_unmap_single(dev, map, size, dir);
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dev_addr = 0;
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}
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return dev_addr;
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}
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EXPORT_SYMBOL_GPL(xen_swiotlb_map_page);
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/*
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* Unmap a single streaming mode DMA translation. The dma_addr and size must
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* match what was provided for in a previous xen_swiotlb_map_page call. All
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* other usages are undefined.
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*
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* After this call, reads by the cpu to the buffer are guaranteed to see
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* whatever the device wrote there.
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*/
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static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr,
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size_t size, enum dma_data_direction dir,
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struct dma_attrs *attrs)
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{
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phys_addr_t paddr = xen_bus_to_phys(dev_addr);
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BUG_ON(dir == DMA_NONE);
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xen_dma_unmap_page(hwdev, dev_addr, size, dir, attrs);
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/* NOTE: We use dev_addr here, not paddr! */
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if (is_xen_swiotlb_buffer(dev_addr)) {
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swiotlb_tbl_unmap_single(hwdev, paddr, size, dir);
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return;
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}
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if (dir != DMA_FROM_DEVICE)
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return;
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/*
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* phys_to_virt doesn't work with hihgmem page but we could
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* call dma_mark_clean() with hihgmem page here. However, we
|
|
* are fine since dma_mark_clean() is null on POWERPC. We can
|
|
* make dma_mark_clean() take a physical address if necessary.
|
|
*/
|
|
dma_mark_clean(phys_to_virt(paddr), size);
|
|
}
|
|
|
|
void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
|
|
size_t size, enum dma_data_direction dir,
|
|
struct dma_attrs *attrs)
|
|
{
|
|
xen_unmap_single(hwdev, dev_addr, size, dir, attrs);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_page);
|
|
|
|
/*
|
|
* Make physical memory consistent for a single streaming mode DMA translation
|
|
* after a transfer.
|
|
*
|
|
* If you perform a xen_swiotlb_map_page() but wish to interrogate the buffer
|
|
* using the cpu, yet do not wish to teardown the dma mapping, you must
|
|
* call this function before doing so. At the next point you give the dma
|
|
* address back to the card, you must first perform a
|
|
* xen_swiotlb_dma_sync_for_device, and then the device again owns the buffer
|
|
*/
|
|
static void
|
|
xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
|
|
size_t size, enum dma_data_direction dir,
|
|
enum dma_sync_target target)
|
|
{
|
|
phys_addr_t paddr = xen_bus_to_phys(dev_addr);
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
|
|
if (target == SYNC_FOR_CPU)
|
|
xen_dma_sync_single_for_cpu(hwdev, dev_addr, size, dir);
|
|
|
|
/* NOTE: We use dev_addr here, not paddr! */
|
|
if (is_xen_swiotlb_buffer(dev_addr))
|
|
swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target);
|
|
|
|
if (target == SYNC_FOR_DEVICE)
|
|
xen_dma_sync_single_for_device(hwdev, dev_addr, size, dir);
|
|
|
|
if (dir != DMA_FROM_DEVICE)
|
|
return;
|
|
|
|
dma_mark_clean(phys_to_virt(paddr), size);
|
|
}
|
|
|
|
void
|
|
xen_swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
|
|
size_t size, enum dma_data_direction dir)
|
|
{
|
|
xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_cpu);
|
|
|
|
void
|
|
xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
|
|
size_t size, enum dma_data_direction dir)
|
|
{
|
|
xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_device);
|
|
|
|
/*
|
|
* Map a set of buffers described by scatterlist in streaming mode for DMA.
|
|
* This is the scatter-gather version of the above xen_swiotlb_map_page
|
|
* interface. Here the scatter gather list elements are each tagged with the
|
|
* appropriate dma address and length. They are obtained via
|
|
* sg_dma_{address,length}(SG).
|
|
*
|
|
* NOTE: An implementation may be able to use a smaller number of
|
|
* DMA address/length pairs than there are SG table elements.
|
|
* (for example via virtual mapping capabilities)
|
|
* The routine returns the number of addr/length pairs actually
|
|
* used, at most nents.
|
|
*
|
|
* Device ownership issues as mentioned above for xen_swiotlb_map_page are the
|
|
* same here.
|
|
*/
|
|
int
|
|
xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
|
|
int nelems, enum dma_data_direction dir,
|
|
struct dma_attrs *attrs)
|
|
{
|
|
struct scatterlist *sg;
|
|
int i;
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
|
|
for_each_sg(sgl, sg, nelems, i) {
|
|
phys_addr_t paddr = sg_phys(sg);
|
|
dma_addr_t dev_addr = xen_phys_to_bus(paddr);
|
|
|
|
if (swiotlb_force ||
|
|
xen_arch_need_swiotlb(hwdev, PFN_DOWN(paddr), PFN_DOWN(dev_addr)) ||
|
|
!dma_capable(hwdev, dev_addr, sg->length) ||
|
|
range_straddles_page_boundary(paddr, sg->length)) {
|
|
phys_addr_t map = swiotlb_tbl_map_single(hwdev,
|
|
start_dma_addr,
|
|
sg_phys(sg),
|
|
sg->length,
|
|
dir);
|
|
if (map == SWIOTLB_MAP_ERROR) {
|
|
dev_warn(hwdev, "swiotlb buffer is full\n");
|
|
/* Don't panic here, we expect map_sg users
|
|
to do proper error handling. */
|
|
xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
|
|
attrs);
|
|
sg_dma_len(sgl) = 0;
|
|
return 0;
|
|
}
|
|
xen_dma_map_page(hwdev, pfn_to_page(map >> PAGE_SHIFT),
|
|
dev_addr,
|
|
map & ~PAGE_MASK,
|
|
sg->length,
|
|
dir,
|
|
attrs);
|
|
sg->dma_address = xen_phys_to_bus(map);
|
|
} else {
|
|
/* we are not interested in the dma_addr returned by
|
|
* xen_dma_map_page, only in the potential cache flushes executed
|
|
* by the function. */
|
|
xen_dma_map_page(hwdev, pfn_to_page(paddr >> PAGE_SHIFT),
|
|
dev_addr,
|
|
paddr & ~PAGE_MASK,
|
|
sg->length,
|
|
dir,
|
|
attrs);
|
|
sg->dma_address = dev_addr;
|
|
}
|
|
sg_dma_len(sg) = sg->length;
|
|
}
|
|
return nelems;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_map_sg_attrs);
|
|
|
|
/*
|
|
* Unmap a set of streaming mode DMA translations. Again, cpu read rules
|
|
* concerning calls here are the same as for swiotlb_unmap_page() above.
|
|
*/
|
|
void
|
|
xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
|
|
int nelems, enum dma_data_direction dir,
|
|
struct dma_attrs *attrs)
|
|
{
|
|
struct scatterlist *sg;
|
|
int i;
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
|
|
for_each_sg(sgl, sg, nelems, i)
|
|
xen_unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir, attrs);
|
|
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg_attrs);
|
|
|
|
/*
|
|
* Make physical memory consistent for a set of streaming mode DMA translations
|
|
* after a transfer.
|
|
*
|
|
* The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
|
|
* and usage.
|
|
*/
|
|
static void
|
|
xen_swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
|
|
int nelems, enum dma_data_direction dir,
|
|
enum dma_sync_target target)
|
|
{
|
|
struct scatterlist *sg;
|
|
int i;
|
|
|
|
for_each_sg(sgl, sg, nelems, i)
|
|
xen_swiotlb_sync_single(hwdev, sg->dma_address,
|
|
sg_dma_len(sg), dir, target);
|
|
}
|
|
|
|
void
|
|
xen_swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
|
|
int nelems, enum dma_data_direction dir)
|
|
{
|
|
xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_cpu);
|
|
|
|
void
|
|
xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
|
|
int nelems, enum dma_data_direction dir)
|
|
{
|
|
xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_device);
|
|
|
|
int
|
|
xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
|
|
{
|
|
return !dma_addr;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_dma_mapping_error);
|
|
|
|
/*
|
|
* Return whether the given device DMA address mask can be supported
|
|
* properly. For example, if your device can only drive the low 24-bits
|
|
* during bus mastering, then you would pass 0x00ffffff as the mask to
|
|
* this function.
|
|
*/
|
|
int
|
|
xen_swiotlb_dma_supported(struct device *hwdev, u64 mask)
|
|
{
|
|
return xen_virt_to_bus(xen_io_tlb_end - 1) <= mask;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_dma_supported);
|
|
|
|
int
|
|
xen_swiotlb_set_dma_mask(struct device *dev, u64 dma_mask)
|
|
{
|
|
if (!dev->dma_mask || !xen_swiotlb_dma_supported(dev, dma_mask))
|
|
return -EIO;
|
|
|
|
*dev->dma_mask = dma_mask;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_set_dma_mask);
|