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baa676fcf8
Adapt core x86 and IA64 architecture code for dma_map_ops changes: replace alloc/free_coherent with generic alloc/free methods. Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> [removed swiotlb related changes and replaced it with wrappers, merged with IA64 patch to avoid inter-patch dependences in intel-iommu code] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Tony Luck <tony.luck@intel.com>
560 lines
16 KiB
C
560 lines
16 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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#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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/*
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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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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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u64 start_dma_addr;
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static dma_addr_t xen_phys_to_bus(phys_addr_t paddr)
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{
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return phys_to_machine(XPADDR(paddr)).maddr;
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}
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static phys_addr_t xen_bus_to_phys(dma_addr_t baddr)
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{
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return machine_to_phys(XMADDR(baddr)).paddr;
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}
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static 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 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_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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(unsigned long)buf + (i << IO_TLB_SHIFT),
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get_order(slabs << IO_TLB_SHIFT),
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dma_bits);
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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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void __init xen_swiotlb_init(int verbose)
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{
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unsigned long bytes;
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int rc = -ENOMEM;
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unsigned long nr_tbl;
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char *m = NULL;
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unsigned int repeat = 3;
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nr_tbl = swiotlb_nr_tbl();
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if (nr_tbl)
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xen_io_tlb_nslabs = nr_tbl;
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else {
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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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}
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retry:
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bytes = 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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xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
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if (!xen_io_tlb_start) {
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m = "Cannot allocate Xen-SWIOTLB buffer!\n";
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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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free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
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m = "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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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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swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, verbose);
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return;
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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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printk(KERN_INFO "Xen-SWIOTLB: 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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xen_raw_printk("%s (rc:%d)", m, rc);
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panic("%s (rc:%d)", m, 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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unsigned long vstart;
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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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vstart = __get_free_pages(flags, order);
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ret = (void *)vstart;
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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 = hwdev->coherent_dma_mask;
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phys = virt_to_phys(ret);
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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(vstart, order,
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fls64(dma_mask)) != 0) {
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free_pages(vstart, order);
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return NULL;
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}
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*dma_handle = virt_to_machine(ret).maddr;
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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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phys = virt_to_phys(vaddr);
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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((unsigned long)vaddr, order);
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free_pages((unsigned long)vaddr, order);
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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 phys = page_to_phys(page) + offset;
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dma_addr_t dev_addr = xen_phys_to_bus(phys);
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void *map;
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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) && !swiotlb_force)
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return dev_addr;
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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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map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir);
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if (!map)
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return DMA_ERROR_CODE;
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dev_addr = xen_virt_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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{
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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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/* 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, phys_to_virt(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
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* are fine since dma_mark_clean() is null on POWERPC. We can
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* make dma_mark_clean() take a physical address if necessary.
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*/
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dma_mark_clean(phys_to_virt(paddr), size);
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}
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void xen_swiotlb_unmap_page(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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xen_unmap_single(hwdev, dev_addr, size, dir);
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}
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EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_page);
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/*
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* Make physical memory consistent for a single streaming mode DMA translation
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* after a transfer.
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*
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* If you perform a xen_swiotlb_map_page() but wish to interrogate the buffer
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* using the cpu, yet do not wish to teardown the dma mapping, you must
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* call this function before doing so. At the next point you give the dma
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* address back to the card, you must first perform a
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* xen_swiotlb_dma_sync_for_device, and then the device again owns the buffer
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*/
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static void
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xen_swiotlb_sync_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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enum dma_sync_target target)
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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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/* 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_sync_single(hwdev, phys_to_virt(paddr), size, dir,
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target);
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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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dma_mark_clean(phys_to_virt(paddr), size);
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}
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void
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xen_swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
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size_t size, enum dma_data_direction dir)
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{
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xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
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}
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EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_cpu);
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void
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xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
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size_t size, enum dma_data_direction dir)
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{
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xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
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}
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EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_device);
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/*
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* Map a set of buffers described by scatterlist in streaming mode for DMA.
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* This is the scatter-gather version of the above xen_swiotlb_map_page
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* interface. Here the scatter gather list elements are each tagged with the
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* appropriate dma address and length. They are obtained via
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* sg_dma_{address,length}(SG).
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*
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* NOTE: An implementation may be able to use a smaller number of
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* DMA address/length pairs than there are SG table elements.
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* (for example via virtual mapping capabilities)
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* The routine returns the number of addr/length pairs actually
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* used, at most nents.
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*
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* Device ownership issues as mentioned above for xen_swiotlb_map_page are the
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* same here.
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*/
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int
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xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
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int nelems, enum dma_data_direction dir,
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struct dma_attrs *attrs)
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{
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struct scatterlist *sg;
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int i;
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BUG_ON(dir == DMA_NONE);
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for_each_sg(sgl, sg, nelems, i) {
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phys_addr_t paddr = sg_phys(sg);
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dma_addr_t dev_addr = xen_phys_to_bus(paddr);
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if (swiotlb_force ||
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!dma_capable(hwdev, dev_addr, sg->length) ||
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range_straddles_page_boundary(paddr, sg->length)) {
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void *map = swiotlb_tbl_map_single(hwdev,
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start_dma_addr,
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sg_phys(sg),
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sg->length, dir);
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if (!map) {
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/* Don't panic here, we expect map_sg users
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to do proper error handling. */
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xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
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attrs);
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sgl[0].dma_length = 0;
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return DMA_ERROR_CODE;
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}
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sg->dma_address = xen_virt_to_bus(map);
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} else
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sg->dma_address = dev_addr;
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sg->dma_length = sg->length;
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}
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return nelems;
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}
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EXPORT_SYMBOL_GPL(xen_swiotlb_map_sg_attrs);
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int
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xen_swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
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enum dma_data_direction dir)
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{
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return xen_swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_map_sg);
|
|
|
|
/*
|
|
* 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_length, dir);
|
|
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg_attrs);
|
|
|
|
void
|
|
xen_swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
|
|
enum dma_data_direction dir)
|
|
{
|
|
return xen_swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg);
|
|
|
|
/*
|
|
* 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_length, 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);
|