diff options
Diffstat (limited to 'arch/arc/mm/ioremap.c')
-rw-r--r-- | arch/arc/mm/ioremap.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/arch/arc/mm/ioremap.c b/arch/arc/mm/ioremap.c new file mode 100644 index 000000000..712c2311d --- /dev/null +++ b/arch/arc/mm/ioremap.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + */ + +#include <linux/vmalloc.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/cache.h> + +static inline bool arc_uncached_addr_space(phys_addr_t paddr) +{ + if (is_isa_arcompact()) { + if (paddr >= ARC_UNCACHED_ADDR_SPACE) + return true; + } else if (paddr >= perip_base && paddr <= perip_end) { + return true; + } + + return false; +} + +void __iomem *ioremap(phys_addr_t paddr, unsigned long size) +{ + phys_addr_t end; + + /* Don't allow wraparound or zero size */ + end = paddr + size - 1; + if (!size || (end < paddr)) + return NULL; + + /* + * If the region is h/w uncached, MMU mapping can be elided as optim + * The cast to u32 is fine as this region can only be inside 4GB + */ + if (arc_uncached_addr_space(paddr)) + return (void __iomem *)(u32)paddr; + + return ioremap_prot(paddr, size, + pgprot_val(pgprot_noncached(PAGE_KERNEL))); +} +EXPORT_SYMBOL(ioremap); + +/* + * ioremap with access flags + * Cache semantics wise it is same as ioremap - "forced" uncached. + * However unlike vanilla ioremap which bypasses ARC MMU for addresses in + * ARC hardware uncached region, this one still goes thru the MMU as caller + * might need finer access control (R/W/X) + */ +void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size, + unsigned long flags) +{ + unsigned int off; + unsigned long vaddr; + struct vm_struct *area; + phys_addr_t end; + pgprot_t prot = __pgprot(flags); + + /* Don't allow wraparound, zero size */ + end = paddr + size - 1; + if ((!size) || (end < paddr)) + return NULL; + + /* An early platform driver might end up here */ + if (!slab_is_available()) + return NULL; + + /* force uncached */ + prot = pgprot_noncached(prot); + + /* Mappings have to be page-aligned */ + off = paddr & ~PAGE_MASK; + paddr &= PAGE_MASK_PHYS; + size = PAGE_ALIGN(end + 1) - paddr; + + /* + * Ok, go for it.. + */ + area = get_vm_area(size, VM_IOREMAP); + if (!area) + return NULL; + area->phys_addr = paddr; + vaddr = (unsigned long)area->addr; + if (ioremap_page_range(vaddr, vaddr + size, paddr, prot)) { + vunmap((void __force *)vaddr); + return NULL; + } + return (void __iomem *)(off + (char __iomem *)vaddr); +} +EXPORT_SYMBOL(ioremap_prot); + + +void iounmap(const volatile void __iomem *addr) +{ + /* weird double cast to handle phys_addr_t > 32 bits */ + if (arc_uncached_addr_space((phys_addr_t)(u32)addr)) + return; + + vfree((void *)(PAGE_MASK & (unsigned long __force)addr)); +} +EXPORT_SYMBOL(iounmap); |