diff options
| author | Stuart Menefy <stuart.menefy@st.com> | 2006-11-21 13:53:44 +0900 |
|---|---|---|
| committer | Paul Mundt <lethal@linux-sh.org> | 2006-12-06 10:45:38 +0900 |
| commit | 6e4662ff49c6b94e16a47bfddb920576963b5a20 (patch) | |
| tree | b53bcf136cc8df9e09f63f06321cad3622694c70 /arch | |
| parent | b5a1bcbee434b843c8850a968d9a6c7541f1be9d (diff) | |
sh: Use MMU.TTB register as pointer to current pgd.
Add TTB accessor functions and give it a sensible default
value. We will use this later for optimizing the fault
path.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/sh/mm/init.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c index 8b275166f40..8c8d3911838 100644 --- a/arch/sh/mm/init.c +++ b/arch/sh/mm/init.c @@ -155,9 +155,6 @@ extern char __init_begin, __init_end; /* * paging_init() sets up the page tables - * - * This routines also unmaps the page at virtual kernel address 0, so - * that we can trap those pesky NULL-reference errors in the kernel. */ void __init paging_init(void) { @@ -180,14 +177,11 @@ void __init paging_init(void) */ { unsigned long max_dma, low, start_pfn; - pgd_t *pg_dir; - int i; - - /* We don't need kernel mapping as hardware support that. */ - pg_dir = swapper_pg_dir; - for (i = 0; i < PTRS_PER_PGD; i++) - pgd_val(pg_dir[i]) = 0; + /* We don't need to map the kernel through the TLB, as + * it is permanatly mapped using P1. So clear the + * entire pgd. */ + memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir)); /* Turn on the MMU */ enable_mmu(); @@ -206,6 +200,10 @@ void __init paging_init(void) } } + /* Set an initial value for the MMU.TTB so we don't have to + * check for a null value. */ + set_TTB(swapper_pg_dir); + #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4) /* * If we don't have CONFIG_MMU set and the processor in question |