Fixed MTP to work with TWRP

arch/sh/mm/ioremap_fixed.c

@@ -0,0 +1,134 @@
+/*
+ * 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/bootmem.h>
+#include <linux/proc_fs.h>
+#include <asm/fixmap.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>
+#include <asm/mmu_context.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;
+}