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-rw-r--r--lib/pci_iomap.c180
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diff --git a/lib/pci_iomap.c b/lib/pci_iomap.c
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+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Implement the default iomap interfaces
+ *
+ * (C) Copyright 2004 Linus Torvalds
+ */
+#include <linux/pci.h>
+#include <linux/io.h>
+
+#include <linux/export.h>
+
+#ifdef CONFIG_PCI
+/**
+ * pci_iomap_range - create a virtual mapping cookie for a PCI BAR
+ * @dev: PCI device that owns the BAR
+ * @bar: BAR number
+ * @offset: map memory at the given offset in BAR
+ * @maxlen: max length of the memory to map
+ *
+ * Using this function you will get a __iomem address to your device BAR.
+ * You can access it using ioread*() and iowrite*(). These functions hide
+ * the details if this is a MMIO or PIO address space and will just do what
+ * you expect from them in the correct way.
+ *
+ * @maxlen specifies the maximum length to map. If you want to get access to
+ * the complete BAR from offset to the end, pass %0 here.
+ * */
+void __iomem *pci_iomap_range(struct pci_dev *dev,
+ int bar,
+ unsigned long offset,
+ unsigned long maxlen)
+{
+ resource_size_t start = pci_resource_start(dev, bar);
+ resource_size_t len = pci_resource_len(dev, bar);
+ unsigned long flags = pci_resource_flags(dev, bar);
+
+ if (len <= offset || !start)
+ return NULL;
+ len -= offset;
+ start += offset;
+ if (maxlen && len > maxlen)
+ len = maxlen;
+ if (flags & IORESOURCE_IO)
+ return __pci_ioport_map(dev, start, len);
+ if (flags & IORESOURCE_MEM)
+ return ioremap(start, len);
+ /* What? */
+ return NULL;
+}
+EXPORT_SYMBOL(pci_iomap_range);
+
+/**
+ * pci_iomap_wc_range - create a virtual WC mapping cookie for a PCI BAR
+ * @dev: PCI device that owns the BAR
+ * @bar: BAR number
+ * @offset: map memory at the given offset in BAR
+ * @maxlen: max length of the memory to map
+ *
+ * Using this function you will get a __iomem address to your device BAR.
+ * You can access it using ioread*() and iowrite*(). These functions hide
+ * the details if this is a MMIO or PIO address space and will just do what
+ * you expect from them in the correct way. When possible write combining
+ * is used.
+ *
+ * @maxlen specifies the maximum length to map. If you want to get access to
+ * the complete BAR from offset to the end, pass %0 here.
+ * */
+void __iomem *pci_iomap_wc_range(struct pci_dev *dev,
+ int bar,
+ unsigned long offset,
+ unsigned long maxlen)
+{
+ resource_size_t start = pci_resource_start(dev, bar);
+ resource_size_t len = pci_resource_len(dev, bar);
+ unsigned long flags = pci_resource_flags(dev, bar);
+
+
+ if (flags & IORESOURCE_IO)
+ return NULL;
+
+ if (len <= offset || !start)
+ return NULL;
+
+ len -= offset;
+ start += offset;
+ if (maxlen && len > maxlen)
+ len = maxlen;
+
+ if (flags & IORESOURCE_MEM)
+ return ioremap_wc(start, len);
+
+ /* What? */
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(pci_iomap_wc_range);
+
+/**
+ * pci_iomap - create a virtual mapping cookie for a PCI BAR
+ * @dev: PCI device that owns the BAR
+ * @bar: BAR number
+ * @maxlen: length of the memory to map
+ *
+ * Using this function you will get a __iomem address to your device BAR.
+ * You can access it using ioread*() and iowrite*(). These functions hide
+ * the details if this is a MMIO or PIO address space and will just do what
+ * you expect from them in the correct way.
+ *
+ * @maxlen specifies the maximum length to map. If you want to get access to
+ * the complete BAR without checking for its length first, pass %0 here.
+ * */
+void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
+{
+ return pci_iomap_range(dev, bar, 0, maxlen);
+}
+EXPORT_SYMBOL(pci_iomap);
+
+/**
+ * pci_iomap_wc - create a virtual WC mapping cookie for a PCI BAR
+ * @dev: PCI device that owns the BAR
+ * @bar: BAR number
+ * @maxlen: length of the memory to map
+ *
+ * Using this function you will get a __iomem address to your device BAR.
+ * You can access it using ioread*() and iowrite*(). These functions hide
+ * the details if this is a MMIO or PIO address space and will just do what
+ * you expect from them in the correct way. When possible write combining
+ * is used.
+ *
+ * @maxlen specifies the maximum length to map. If you want to get access to
+ * the complete BAR without checking for its length first, pass %0 here.
+ * */
+void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long maxlen)
+{
+ return pci_iomap_wc_range(dev, bar, 0, maxlen);
+}
+EXPORT_SYMBOL_GPL(pci_iomap_wc);
+
+/*
+ * pci_iounmap() somewhat illogically comes from lib/iomap.c for the
+ * CONFIG_GENERIC_IOMAP case, because that's the code that knows about
+ * the different IOMAP ranges.
+ *
+ * But if the architecture does not use the generic iomap code, and if
+ * it has _not_ defined it's own private pci_iounmap function, we define
+ * it here.
+ *
+ * NOTE! This default implementation assumes that if the architecture
+ * support ioport mapping (HAS_IOPORT_MAP), the ioport mapping will
+ * be fixed to the range [ PCI_IOBASE, PCI_IOBASE+IO_SPACE_LIMIT [,
+ * and does not need unmapping with 'ioport_unmap()'.
+ *
+ * If you have different rules for your architecture, you need to
+ * implement your own pci_iounmap() that knows the rules for where
+ * and how IO vs MEM get mapped.
+ *
+ * This code is odd, and the ARCH_HAS/ARCH_WANTS #define logic comes
+ * from legacy <asm-generic/io.h> header file behavior. In particular,
+ * it would seem to make sense to do the iounmap(p) for the non-IO-space
+ * case here regardless, but that's not what the old header file code
+ * did. Probably incorrectly, but this is meant to be bug-for-bug
+ * compatible.
+ */
+#if defined(ARCH_WANTS_GENERIC_PCI_IOUNMAP)
+
+void pci_iounmap(struct pci_dev *dev, void __iomem *p)
+{
+#ifdef ARCH_HAS_GENERIC_IOPORT_MAP
+ uintptr_t start = (uintptr_t) PCI_IOBASE;
+ uintptr_t addr = (uintptr_t) p;
+
+ if (addr >= start && addr < start + IO_SPACE_LIMIT)
+ return;
+ iounmap(p);
+#endif
+}
+EXPORT_SYMBOL(pci_iounmap);
+
+#endif /* ARCH_WANTS_GENERIC_PCI_IOUNMAP */
+
+#endif /* CONFIG_PCI */