From a1f242ff460e4b50a045fa237c3c56cce9eabf83 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 23 Jul 2008 21:27:08 -0700 Subject: powerpc ioremap_prot This adds ioremap_prot and pte_pgprot() so that one can extract protection bits from a PTE and use them to ioremap_prot() (in order to support ptrace of VM_IO | VM_PFNMAP as per Rik's patch). This moves a couple of flag checks around in the ioremap implementations of arch/powerpc. There's a side effect of allowing non-cacheable and non-guarded mappings on ppc32 which before would always have _PAGE_GUARDED set whenever _PAGE_NO_CACHE is. (standard ioremap will still set _PAGE_GUARDED, but ioremap_prot will be capable of setting such a non guarded mapping). Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Rik van Riel Cc: Dave Airlie Cc: Hugh Dickins Cc: Paul Mackerras Cc: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/powerpc/mm/pgtable_64.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'arch/powerpc/mm/pgtable_64.c') diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c index 3ef0ad2f9ca0..365e61ae5dbc 100644 --- a/arch/powerpc/mm/pgtable_64.c +++ b/arch/powerpc/mm/pgtable_64.c @@ -107,9 +107,18 @@ void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size, { unsigned long i; + /* Make sure we have the base flags */ if ((flags & _PAGE_PRESENT) == 0) flags |= pgprot_val(PAGE_KERNEL); + /* Non-cacheable page cannot be coherent */ + if (flags & _PAGE_NO_CACHE) + flags &= ~_PAGE_COHERENT; + + /* We don't support the 4K PFN hack with ioremap */ + if (flags & _PAGE_4K_PFN) + return NULL; + WARN_ON(pa & ~PAGE_MASK); WARN_ON(((unsigned long)ea) & ~PAGE_MASK); WARN_ON(size & ~PAGE_MASK); @@ -190,6 +199,13 @@ void __iomem * ioremap(phys_addr_t addr, unsigned long size) void __iomem * ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags) { + /* writeable implies dirty for kernel addresses */ + if (flags & _PAGE_RW) + flags |= _PAGE_DIRTY; + + /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */ + flags &= ~(_PAGE_USER | _PAGE_EXEC); + if (ppc_md.ioremap) return ppc_md.ioremap(addr, size, flags); return __ioremap(addr, size, flags); -- cgit v1.2.3