summaryrefslogtreecommitdiff
path: root/arch/sh/mm/ioremap.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/sh/mm/ioremap.c')
-rw-r--r--arch/sh/mm/ioremap.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/arch/sh/mm/ioremap.c b/arch/sh/mm/ioremap.c
new file mode 100644
index 000000000000..c68d2d7d00a9
--- /dev/null
+++ b/arch/sh/mm/ioremap.c
@@ -0,0 +1,162 @@
+/*
+ * arch/sh/mm/ioremap.c
+ *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ * (C) Copyright 2005 - 2010 Paul Mundt
+ *
+ * Re-map IO memory to kernel address space so that we can access it.
+ * This is needed for high PCI addresses that aren't mapped in the
+ * 640k-1MB IO memory area on PC's
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ */
+#include <linux/vmalloc.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/pci.h>
+#include <linux/io.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/addrspace.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu.h>
+
+/*
+ * Remap an arbitrary physical address space into the kernel virtual
+ * address space. Needed when the kernel wants to access high addresses
+ * directly.
+ *
+ * NOTE! We need to allow non-page-aligned mappings too: we will obviously
+ * have to convert them into an offset in a page-aligned mapping, but the
+ * caller shouldn't need to know that small detail.
+ */
+void __iomem * __init_refok
+__ioremap_caller(unsigned long phys_addr, unsigned long size,
+ pgprot_t pgprot, void *caller)
+{
+ struct vm_struct *area;
+ unsigned long offset, last_addr, addr, orig_addr;
+
+ /* Don't allow wraparound or zero size */
+ last_addr = phys_addr + size - 1;
+ if (!size || last_addr < phys_addr)
+ return NULL;
+
+ /*
+ * Mappings have to be page-aligned
+ */
+ offset = phys_addr & ~PAGE_MASK;
+ phys_addr &= PAGE_MASK;
+ size = PAGE_ALIGN(last_addr+1) - phys_addr;
+
+ /*
+ * If we can't yet use the regular approach, go the fixmap route.
+ */
+ if (!mem_init_done)
+ return ioremap_fixed(phys_addr, offset, size, pgprot);
+
+ /*
+ * Ok, go for it..
+ */
+ area = get_vm_area_caller(size, VM_IOREMAP, caller);
+ if (!area)
+ return NULL;
+ area->phys_addr = phys_addr;
+ orig_addr = addr = (unsigned long)area->addr;
+
+#ifdef CONFIG_PMB
+ /*
+ * First try to remap through the PMB once a valid VMA has been
+ * established. Smaller allocations (or the rest of the size
+ * remaining after a PMB mapping due to the size not being
+ * perfectly aligned on a PMB size boundary) are then mapped
+ * through the UTLB using conventional page tables.
+ *
+ * PMB entries are all pre-faulted.
+ */
+ if (unlikely(phys_addr >= P1SEG)) {
+ unsigned long mapped;
+
+ mapped = pmb_remap(addr, phys_addr, size, pgprot);
+ if (likely(mapped)) {
+ addr += mapped;
+ phys_addr += mapped;
+ size -= mapped;
+ }
+ }
+#endif
+
+ if (likely(size))
+ if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) {
+ vunmap((void *)orig_addr);
+ return NULL;
+ }
+
+ return (void __iomem *)(offset + (char *)orig_addr);
+}
+EXPORT_SYMBOL(__ioremap_caller);
+
+/*
+ * Simple checks for non-translatable mappings.
+ */
+static inline int iomapping_nontranslatable(unsigned long offset)
+{
+#ifdef CONFIG_29BIT
+ /*
+ * In 29-bit mode this includes the fixed P1/P2 areas, as well as
+ * parts of P3.
+ */
+ if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX)
+ return 1;
+#endif
+
+ return 0;
+}
+
+void __iounmap(void __iomem *addr)
+{
+ unsigned long vaddr = (unsigned long __force)addr;
+ struct vm_struct *p;
+
+ /*
+ * Nothing to do if there is no translatable mapping.
+ */
+ if (iomapping_nontranslatable(vaddr))
+ return;
+
+ /*
+ * There's no VMA if it's from an early fixed mapping.
+ */
+ if (iounmap_fixed(addr) == 0)
+ return;
+
+#ifdef CONFIG_PMB
+ /*
+ * Purge any PMB entries that may have been established for this
+ * mapping, then proceed with conventional VMA teardown.
+ *
+ * XXX: Note that due to the way that remove_vm_area() does
+ * matching of the resultant VMA, we aren't able to fast-forward
+ * the address past the PMB space until the end of the VMA where
+ * the page tables reside. As such, unmap_vm_area() will be
+ * forced to linearly scan over the area until it finds the page
+ * tables where PTEs that need to be unmapped actually reside,
+ * which is far from optimal. Perhaps we need to use a separate
+ * VMA for the PMB mappings?
+ * -- PFM.
+ */
+ pmb_unmap(vaddr);
+#endif
+
+ p = remove_vm_area((void *)(vaddr & PAGE_MASK));
+ if (!p) {
+ printk(KERN_ERR "%s: bad address %p\n", __func__, addr);
+ return;
+ }
+
+ kfree(p);
+}
+EXPORT_SYMBOL(__iounmap);