1 files changed, 147 insertions, 0 deletions
diff --git a/kernel/lib/ioremap.c b/kernel/lib/ioremap.c
new file mode 100644
index 000000000..86c8911b0
--- /dev/null
+++ b/kernel/lib/ioremap.c
@@ -0,0 +1,147 @@
+/*
+ * 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
+ *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ */
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/io.h>
+#include <linux/export.h>
+#include <asm/cacheflush.h>
+#include <asm/pgtable.h>
+
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
+static int __read_mostly ioremap_pud_capable;
+static int __read_mostly ioremap_pmd_capable;
+static int __read_mostly ioremap_huge_disabled;
+
+static int __init set_nohugeiomap(char *str)
+{
+	ioremap_huge_disabled = 1;
+	return 0;
+}
+early_param("nohugeiomap", set_nohugeiomap);
+
+void __init ioremap_huge_init(void)
+{
+	if (!ioremap_huge_disabled) {
+		if (arch_ioremap_pud_supported())
+			ioremap_pud_capable = 1;
+		if (arch_ioremap_pmd_supported())
+			ioremap_pmd_capable = 1;
+	}
+}
+
+static inline int ioremap_pud_enabled(void)
+{
+	return ioremap_pud_capable;
+}
+
+static inline int ioremap_pmd_enabled(void)
+{
+	return ioremap_pmd_capable;
+}
+
+#else	/* !CONFIG_HAVE_ARCH_HUGE_VMAP */
+static inline int ioremap_pud_enabled(void) { return 0; }
+static inline int ioremap_pmd_enabled(void) { return 0; }
+#endif	/* CONFIG_HAVE_ARCH_HUGE_VMAP */
+
+static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
+		unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
+{
+	pte_t *pte;
+	u64 pfn;
+
+	pfn = phys_addr >> PAGE_SHIFT;
+	pte = pte_alloc_kernel(pmd, addr);
+	if (!pte)
+		return -ENOMEM;
+	do {
+		BUG_ON(!pte_none(*pte));
+		set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
+		pfn++;
+	} while (pte++, addr += PAGE_SIZE, addr != end);
+	return 0;
+}
+
+static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
+		unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
+{
+	pmd_t *pmd;
+	unsigned long next;
+
+	phys_addr -= addr;
+	pmd = pmd_alloc(&init_mm, pud, addr);
+	if (!pmd)
+		return -ENOMEM;
+	do {
+		next = pmd_addr_end(addr, end);
+
+		if (ioremap_pmd_enabled() &&
+		    ((next - addr) == PMD_SIZE) &&
+		    IS_ALIGNED(phys_addr + addr, PMD_SIZE)) {
+			if (pmd_set_huge(pmd, phys_addr + addr, prot))
+				continue;
+		}
+
+		if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
+			return -ENOMEM;
+	} while (pmd++, addr = next, addr != end);
+	return 0;
+}
+
+static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
+		unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
+{
+	pud_t *pud;
+	unsigned long next;
+
+	phys_addr -= addr;
+	pud = pud_alloc(&init_mm, pgd, addr);
+	if (!pud)
+		return -ENOMEM;
+	do {
+		next = pud_addr_end(addr, end);
+
+		if (ioremap_pud_enabled() &&
+		    ((next - addr) == PUD_SIZE) &&
+		    IS_ALIGNED(phys_addr + addr, PUD_SIZE)) {
+			if (pud_set_huge(pud, phys_addr + addr, prot))
+				continue;
+		}
+
+		if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
+			return -ENOMEM;
+	} while (pud++, addr = next, addr != end);
+	return 0;
+}
+
+int ioremap_page_range(unsigned long addr,
+		       unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
+{
+	pgd_t *pgd;
+	unsigned long start;
+	unsigned long next;
+	int err;
+
+	BUG_ON(addr >= end);
+
+	start = addr;
+	phys_addr -= addr;
+	pgd = pgd_offset_k(addr);
+	do {
+		next = pgd_addr_end(addr, end);
+		err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot);
+		if (err)
+			break;
+	} while (pgd++, addr = next, addr != end);
+
+	flush_cache_vmap(start, end);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(ioremap_page_range);