From cbaa118ecfd99fc5ed7adbd9c34a30e1c05e3c93 Mon Sep 17 00:00:00 2001 From: Stuart Menefy Date: Fri, 30 Nov 2007 17:06:36 +0900 Subject: sh: Preparation for uncached jumps through PMB. Presently most of the 29-bit physical parts do P1/P2 segmentation with a 1:1 cached/uncached mapping, jumping between the two to control the caching behaviour. This provides the basic infrastructure to maintain this behaviour on 32-bit physical parts that don't map P1/P2 at all, using a shiny new linker section and corresponding fixmap entry. Signed-off-by: Stuart Menefy Signed-off-by: Paul Mundt --- arch/sh/mm/init.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'arch/sh/mm/init.c') diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c index 79c309780f95..094225e0d722 100644 --- a/arch/sh/mm/init.c +++ b/arch/sh/mm/init.c @@ -23,6 +23,7 @@ DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); pgd_t swapper_pg_dir[PTRS_PER_PGD]; +unsigned long cached_to_uncached = 0; void show_mem(void) { @@ -99,7 +100,8 @@ static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot) set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot)); - flush_tlb_one(get_asid(), addr); + if (cached_to_uncached) + flush_tlb_one(get_asid(), addr); } /* @@ -164,6 +166,18 @@ void __init paging_init(void) } free_area_init_nodes(max_zone_pfns); + + /* Set up the uncached fixmap */ + set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start)); + +#ifdef CONFIG_29BIT + /* + * Handle trivial transitions between cached and uncached + * segments, making use of the 1:1 mapping relationship in + * 512MB lowmem. + */ + cached_to_uncached = P2SEG - P1SEG; +#endif } static struct kcore_list kcore_mem, kcore_vmalloc; -- cgit v1.2.2