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author | Stuart Menefy <stuart.menefy@st.com> | 2007-11-30 17:06:36 +0900 |
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committer | Paul Mundt <lethal@linux-sh.org> | 2008-01-28 13:18:59 +0900 |
commit | cbaa118ecfd99fc5ed7adbd9c34a30e1c05e3c93 (patch) | |
tree | e60db5c0f3573558c97f39cfab78732220a72e6d /arch/sh/mm/init.c | |
parent | 325df7f20467da07901c4f2b006d3457bba0adec (diff) | |
download | kernel_samsung_espresso10-cbaa118ecfd99fc5ed7adbd9c34a30e1c05e3c93.zip kernel_samsung_espresso10-cbaa118ecfd99fc5ed7adbd9c34a30e1c05e3c93.tar.gz kernel_samsung_espresso10-cbaa118ecfd99fc5ed7adbd9c34a30e1c05e3c93.tar.bz2 |
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 <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/mm/init.c')
-rw-r--r-- | arch/sh/mm/init.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c index 79c3097..094225e 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; |