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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/riscv/mm/ioremap.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/riscv/mm/ioremap.c')
-rw-r--r-- | arch/riscv/mm/ioremap.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/riscv/mm/ioremap.c b/arch/riscv/mm/ioremap.c new file mode 100644 index 000000000..bd2f2db55 --- /dev/null +++ b/arch/riscv/mm/ioremap.c @@ -0,0 +1,92 @@ +/* + * (C) Copyright 1995 1996 Linus Torvalds + * (C) Copyright 2012 Regents of the University of California + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/export.h> +#include <linux/mm.h> +#include <linux/vmalloc.h> +#include <linux/io.h> + +#include <asm/pgtable.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. + */ +static void __iomem *__ioremap_caller(phys_addr_t addr, size_t size, + pgprot_t prot, void *caller) +{ + phys_addr_t last_addr; + unsigned long offset, vaddr; + struct vm_struct *area; + + /* Disallow wrap-around or zero size */ + last_addr = addr + size - 1; + if (!size || last_addr < addr) + return NULL; + + /* Page-align mappings */ + offset = addr & (~PAGE_MASK); + addr -= offset; + size = PAGE_ALIGN(size + offset); + + area = get_vm_area_caller(size, VM_IOREMAP, caller); + if (!area) + return NULL; + vaddr = (unsigned long)area->addr; + + if (ioremap_page_range(vaddr, vaddr + size, addr, prot)) { + free_vm_area(area); + return NULL; + } + + return (void __iomem *)(vaddr + offset); +} + +/* + * ioremap - map bus memory into CPU space + * @offset: bus address of the memory + * @size: size of the resource to map + * + * ioremap performs a platform specific sequence of operations to + * make bus memory CPU accessible via the readb/readw/readl/writeb/ + * writew/writel functions and the other mmio helpers. The returned + * address is not guaranteed to be usable directly as a virtual + * address. + * + * Must be freed with iounmap. + */ +void __iomem *ioremap(phys_addr_t offset, unsigned long size) +{ + return __ioremap_caller(offset, size, PAGE_KERNEL, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(ioremap); + + +/** + * iounmap - Free a IO remapping + * @addr: virtual address from ioremap_* + * + * Caller must ensure there is only one unmapping for the same pointer. + */ +void iounmap(volatile void __iomem *addr) +{ + vunmap((void *)((unsigned long)addr & PAGE_MASK)); +} +EXPORT_SYMBOL(iounmap); |