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96 lines
2.6 KiB
96 lines
2.6 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Generic PCI resource mmap helper |
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* |
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* Copyright © 2017 Amazon.com, Inc. or its affiliates. |
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* |
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* Author: David Woodhouse <[email protected]> |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/mm.h> |
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#include <linux/pci.h> |
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#ifdef ARCH_GENERIC_PCI_MMAP_RESOURCE |
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/* |
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* Modern setup: generic pci_mmap_resource_range(), and implement the legacy |
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* pci_mmap_page_range() (if needed) as a wrapper round it. |
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*/ |
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#ifdef HAVE_PCI_MMAP |
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int pci_mmap_page_range(struct pci_dev *pdev, int bar, |
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struct vm_area_struct *vma, |
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enum pci_mmap_state mmap_state, int write_combine) |
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{ |
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resource_size_t start, end; |
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pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end); |
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/* Adjust vm_pgoff to be the offset within the resource */ |
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vma->vm_pgoff -= start >> PAGE_SHIFT; |
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return pci_mmap_resource_range(pdev, bar, vma, mmap_state, |
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write_combine); |
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} |
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#endif |
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static const struct vm_operations_struct pci_phys_vm_ops = { |
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#ifdef CONFIG_HAVE_IOREMAP_PROT |
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.access = generic_access_phys, |
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#endif |
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}; |
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int pci_mmap_resource_range(struct pci_dev *pdev, int bar, |
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struct vm_area_struct *vma, |
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enum pci_mmap_state mmap_state, int write_combine) |
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{ |
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unsigned long size; |
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int ret; |
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size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1; |
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if (vma->vm_pgoff + vma_pages(vma) > size) |
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return -EINVAL; |
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if (write_combine) |
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vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); |
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else |
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vma->vm_page_prot = pgprot_device(vma->vm_page_prot); |
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if (mmap_state == pci_mmap_io) { |
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ret = pci_iobar_pfn(pdev, bar, vma); |
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if (ret) |
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return ret; |
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} else |
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vma->vm_pgoff += (pci_resource_start(pdev, bar) >> PAGE_SHIFT); |
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vma->vm_ops = &pci_phys_vm_ops; |
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return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, |
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vma->vm_end - vma->vm_start, |
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vma->vm_page_prot); |
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} |
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#elif defined(HAVE_PCI_MMAP) /* && !ARCH_GENERIC_PCI_MMAP_RESOURCE */ |
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/* |
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* Legacy setup: Implement pci_mmap_resource_range() as a wrapper around |
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* the architecture's pci_mmap_page_range(), converting to "user visible" |
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* addresses as necessary. |
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*/ |
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int pci_mmap_resource_range(struct pci_dev *pdev, int bar, |
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struct vm_area_struct *vma, |
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enum pci_mmap_state mmap_state, int write_combine) |
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{ |
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resource_size_t start, end; |
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/* |
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* pci_mmap_page_range() expects the same kind of entry as coming |
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* from /proc/bus/pci/ which is a "user visible" value. If this is |
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* different from the resource itself, arch will do necessary fixup. |
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*/ |
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pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end); |
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vma->vm_pgoff += start >> PAGE_SHIFT; |
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return pci_mmap_page_range(pdev, bar, vma, mmap_state, write_combine); |
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} |
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#endif
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