summaryrefslogtreecommitdiffstats
path: root/arch/sh/mm/ioremap_fixed.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/sh/mm/ioremap_fixed.c')
-rw-r--r--arch/sh/mm/ioremap_fixed.c135
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/sh/mm/ioremap_fixed.c b/arch/sh/mm/ioremap_fixed.c
new file mode 100644
index 000000000..136113bca
--- /dev/null
+++ b/arch/sh/mm/ioremap_fixed.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Re-map IO memory to kernel address space so that we can access it.
+ *
+ * These functions should only be used when it is necessary to map a
+ * physical address space into the kernel address space before ioremap()
+ * can be used, e.g. early in boot before paging_init().
+ *
+ * Copyright (C) 2009 Matt Fleming
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+#include <linux/memblock.h>
+#include <linux/proc_fs.h>
+#include <asm/fixmap.h>
+#include <asm/page.h>
+#include <asm/addrspace.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu.h>
+#include <asm/mmu_context.h>
+#include "ioremap.h"
+
+struct ioremap_map {
+ void __iomem *addr;
+ unsigned long size;
+ unsigned long fixmap_addr;
+};
+
+static struct ioremap_map ioremap_maps[FIX_N_IOREMAPS];
+
+void __init ioremap_fixed_init(void)
+{
+ struct ioremap_map *map;
+ int i;
+
+ for (i = 0; i < FIX_N_IOREMAPS; i++) {
+ map = &ioremap_maps[i];
+ map->fixmap_addr = __fix_to_virt(FIX_IOREMAP_BEGIN + i);
+ }
+}
+
+void __init __iomem *
+ioremap_fixed(phys_addr_t phys_addr, unsigned long size, pgprot_t prot)
+{
+ enum fixed_addresses idx0, idx;
+ struct ioremap_map *map;
+ unsigned int nrpages;
+ unsigned long offset;
+ int i, slot;
+
+ /*
+ * Mappings have to be page-aligned
+ */
+ offset = phys_addr & ~PAGE_MASK;
+ phys_addr &= PAGE_MASK;
+ size = PAGE_ALIGN(phys_addr + size) - phys_addr;
+
+ slot = -1;
+ for (i = 0; i < FIX_N_IOREMAPS; i++) {
+ map = &ioremap_maps[i];
+ if (!map->addr) {
+ map->size = size;
+ slot = i;
+ break;
+ }
+ }
+
+ if (slot < 0)
+ return NULL;
+
+ /*
+ * Mappings have to fit in the FIX_IOREMAP area.
+ */
+ nrpages = size >> PAGE_SHIFT;
+ if (nrpages > FIX_N_IOREMAPS)
+ return NULL;
+
+ /*
+ * Ok, go for it..
+ */
+ idx0 = FIX_IOREMAP_BEGIN + slot;
+ idx = idx0;
+ while (nrpages > 0) {
+ pgprot_val(prot) |= _PAGE_WIRED;
+ __set_fixmap(idx, phys_addr, prot);
+ phys_addr += PAGE_SIZE;
+ idx++;
+ --nrpages;
+ }
+
+ map->addr = (void __iomem *)(offset + map->fixmap_addr);
+ return map->addr;
+}
+
+int iounmap_fixed(void __iomem *addr)
+{
+ enum fixed_addresses idx;
+ struct ioremap_map *map;
+ unsigned int nrpages;
+ int i, slot;
+
+ slot = -1;
+ for (i = 0; i < FIX_N_IOREMAPS; i++) {
+ map = &ioremap_maps[i];
+ if (map->addr == addr) {
+ slot = i;
+ break;
+ }
+ }
+
+ /*
+ * If we don't match, it's not for us.
+ */
+ if (slot < 0)
+ return -EINVAL;
+
+ nrpages = map->size >> PAGE_SHIFT;
+
+ idx = FIX_IOREMAP_BEGIN + slot + nrpages - 1;
+ while (nrpages > 0) {
+ __clear_fixmap(idx, __pgprot(_PAGE_WIRED));
+ --idx;
+ --nrpages;
+ }
+
+ map->size = 0;
+ map->addr = NULL;
+
+ return 0;
+}