diff options
Diffstat (limited to 'arch/metag/mm')
| -rw-r--r-- | arch/metag/mm/ioremap.c | 89 | ||||
| -rw-r--r-- | arch/metag/mm/maccess.c | 68 |
2 files changed, 157 insertions, 0 deletions
diff --git a/arch/metag/mm/ioremap.c b/arch/metag/mm/ioremap.c new file mode 100644 index 000000000000..a136a435fdaa --- /dev/null +++ b/arch/metag/mm/ioremap.c @@ -0,0 +1,89 @@ +/* + * Re-map IO memory to kernel address space so that we can access it. + * Needed for memory-mapped I/O devices mapped outside our normal DRAM + * window (that is, all memory-mapped I/O devices). + * + * Copyright (C) 1995,1996 Linus Torvalds + * + * Meta port based on CRIS-port by Axis Communications AB + */ + +#include <linux/vmalloc.h> +#include <linux/io.h> +#include <linux/export.h> +#include <linux/slab.h> +#include <linux/mm.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. + */ +void __iomem *__ioremap(unsigned long phys_addr, size_t size, + unsigned long flags) +{ + unsigned long addr; + struct vm_struct *area; + unsigned long offset, last_addr; + pgprot_t prot; + + /* Don't allow wraparound or zero size */ + last_addr = phys_addr + size - 1; + if (!size || last_addr < phys_addr) + return NULL; + + /* Custom region addresses are accessible and uncached by default. */ + if (phys_addr >= LINSYSCUSTOM_BASE && + phys_addr < (LINSYSCUSTOM_BASE + LINSYSCUSTOM_LIMIT)) + return (__force void __iomem *) phys_addr; + + /* + * Mappings have to be page-aligned + */ + offset = phys_addr & ~PAGE_MASK; + phys_addr &= PAGE_MASK; + size = PAGE_ALIGN(last_addr+1) - phys_addr; + prot = __pgprot(_PAGE_PRESENT | _PAGE_WRITE | _PAGE_DIRTY | + _PAGE_ACCESSED | _PAGE_KERNEL | _PAGE_CACHE_WIN0 | + flags); + + /* + * Ok, go for it.. + */ + area = get_vm_area(size, VM_IOREMAP); + if (!area) + return NULL; + area->phys_addr = phys_addr; + addr = (unsigned long) area->addr; + if (ioremap_page_range(addr, addr + size, phys_addr, prot)) { + vunmap((void *) addr); + return NULL; + } + return (__force void __iomem *) (offset + (char *)addr); +} +EXPORT_SYMBOL(__ioremap); + +void __iounmap(void __iomem *addr) +{ + struct vm_struct *p; + + if ((__force unsigned long)addr >= LINSYSCUSTOM_BASE && + (__force unsigned long)addr < (LINSYSCUSTOM_BASE + + LINSYSCUSTOM_LIMIT)) + return; + + p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr)); + if (unlikely(!p)) { + pr_err("iounmap: bad address %p\n", addr); + return; + } + + kfree(p); +} +EXPORT_SYMBOL(__iounmap); diff --git a/arch/metag/mm/maccess.c b/arch/metag/mm/maccess.c new file mode 100644 index 000000000000..eba2cfc935b1 --- /dev/null +++ b/arch/metag/mm/maccess.c @@ -0,0 +1,68 @@ +/* + * safe read and write memory routines callable while atomic + * + * Copyright 2012 Imagination Technologies + */ + +#include <linux/uaccess.h> +#include <asm/io.h> + +/* + * The generic probe_kernel_write() uses the user copy code which can split the + * writes if the source is unaligned, and repeats writes to make exceptions + * precise. We override it here to avoid these things happening to memory mapped + * IO memory where they could have undesired effects. + * Due to the use of CACHERD instruction this only works on Meta2 onwards. + */ +#ifdef CONFIG_METAG_META21 +long probe_kernel_write(void *dst, const void *src, size_t size) +{ + unsigned long ldst = (unsigned long)dst; + void __iomem *iodst = (void __iomem *)dst; + unsigned long lsrc = (unsigned long)src; + const u8 *psrc = (u8 *)src; + unsigned int pte, i; + u8 bounce[8] __aligned(8); + + if (!size) + return 0; + + /* Use the write combine bit to decide is the destination is MMIO. */ + pte = __builtin_meta2_cacherd(dst); + + /* Check the mapping is valid and writeable. */ + if ((pte & (MMCU_ENTRY_WR_BIT | MMCU_ENTRY_VAL_BIT)) + != (MMCU_ENTRY_WR_BIT | MMCU_ENTRY_VAL_BIT)) + return -EFAULT; + + /* Fall back to generic version for cases we're not interested in. */ + if (pte & MMCU_ENTRY_WRC_BIT || /* write combined memory */ + (ldst & (size - 1)) || /* destination unaligned */ + size > 8 || /* more than max write size */ + (size & (size - 1))) /* non power of 2 size */ + return __probe_kernel_write(dst, src, size); + + /* If src is unaligned, copy to the aligned bounce buffer first. */ + if (lsrc & (size - 1)) { + for (i = 0; i < size; ++i) + bounce[i] = psrc[i]; + psrc = bounce; + } + + switch (size) { + case 1: + writeb(*psrc, iodst); + break; + case 2: + writew(*(const u16 *)psrc, iodst); + break; + case 4: + writel(*(const u32 *)psrc, iodst); + break; + case 8: + writeq(*(const u64 *)psrc, iodst); + break; + } + return 0; +} +#endif |