diff options
Diffstat (limited to 'arch/sh/mm/ioremap.c')
| -rw-r--r-- | arch/sh/mm/ioremap.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/sh/mm/ioremap.c b/arch/sh/mm/ioremap.c index d9ec85b6bb21..69e55939e48a 100644 --- a/arch/sh/mm/ioremap.c +++ b/arch/sh/mm/ioremap.c @@ -27,6 +27,51 @@ #include "ioremap.h" /* + * On 32-bit SH, we traditionally have the whole physical address space mapped + * at all times (as MIPS does), so "ioremap()" and "iounmap()" do not need to do + * anything but place the address in the proper segment. This is true for P1 + * and P2 addresses, as well as some P3 ones. However, most of the P3 addresses + * and newer cores using extended addressing need to map through page tables, so + * the ioremap() implementation becomes a bit more complicated. + */ +#ifdef CONFIG_29BIT +static void __iomem * +__ioremap_29bit(phys_addr_t offset, unsigned long size, pgprot_t prot) +{ + phys_addr_t last_addr = offset + size - 1; + + /* + * For P1 and P2 space this is trivial, as everything is already + * mapped. Uncached access for P1 addresses are done through P2. + * In the P3 case or for addresses outside of the 29-bit space, + * mapping must be done by the PMB or by using page tables. + */ + if (likely(PXSEG(offset) < P3SEG && PXSEG(last_addr) < P3SEG)) { + u64 flags = pgprot_val(prot); + + /* + * Anything using the legacy PTEA space attributes needs + * to be kicked down to page table mappings. + */ + if (unlikely(flags & _PAGE_PCC_MASK)) + return NULL; + if (unlikely(flags & _PAGE_CACHABLE)) + return (void __iomem *)P1SEGADDR(offset); + + return (void __iomem *)P2SEGADDR(offset); + } + + /* P4 above the store queues are always mapped. */ + if (unlikely(offset >= P3_ADDR_MAX)) + return (void __iomem *)P4SEGADDR(offset); + + return NULL; +} +#else +#define __ioremap_29bit(offset, size, prot) NULL +#endif /* CONFIG_29BIT */ + +/* * Remap an arbitrary physical address space into the kernel virtual * address space. Needed when the kernel wants to access high addresses * directly. @@ -43,6 +88,14 @@ __ioremap_caller(phys_addr_t phys_addr, unsigned long size, unsigned long offset, last_addr, addr, orig_addr; void __iomem *mapped; + mapped = __ioremap_trapped(phys_addr, size); + if (mapped) + return mapped; + + mapped = __ioremap_29bit(phys_addr, size, pgprot); + if (mapped) + return mapped; + /* Don't allow wraparound or zero size */ last_addr = phys_addr + size - 1; if (!size || last_addr < phys_addr) |