diff options
| author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2005-11-17 22:43:30 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2005-11-17 22:43:30 +0000 |
| commit | 02b30839220fa3ef80a34ed6ee174fa2d9937eac (patch) | |
| tree | faac60850e1e51b892622887c9f7cc37e2891e5e | |
| parent | 67a1901ff498363e253b90ba132e336c925203ed (diff) | |
[ARM] Fix some corner cases in new mm initialisation
Document that the VMALLOC_END address must be aligned to 2MB since
it must align with a PGD boundary.
Allocate the vectors page early so that the flush_cache_all() later
will cause any dirty cache lines in the direct mapping will be safely
written back.
Move the flush_cache_all() to the second local_flush_cache_tlb() and
remove the now redundant first local_flush_cache_tlb().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | Documentation/arm/memory.txt | 4 | ||||
| -rw-r--r-- | arch/arm/mm/init.c | 24 |
2 files changed, 16 insertions, 12 deletions
diff --git a/Documentation/arm/memory.txt b/Documentation/arm/memory.txt index 4b1c93a8177..dc6045577a8 100644 --- a/Documentation/arm/memory.txt +++ b/Documentation/arm/memory.txt @@ -1,7 +1,7 @@ Kernel Memory Layout on ARM Linux Russell King <rmk@arm.linux.org.uk> - May 21, 2004 (2.6.6) + November 17, 2005 (2.6.15) This document describes the virtual memory layout which the Linux kernel uses for ARM processors. It indicates which regions are @@ -37,6 +37,8 @@ ff000000 ffbfffff Reserved for future expansion of DMA mapping region. VMALLOC_END feffffff Free for platform use, recommended. + VMALLOC_END must be aligned to a 2MB + boundary. VMALLOC_START VMALLOC_END-1 vmalloc() / ioremap() space. Memory returned by vmalloc/ioremap will diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index c168f322ef8..8b276ee38ac 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -420,7 +420,8 @@ static void __init bootmem_init(struct meminfo *mi) * Set up device the mappings. Since we clear out the page tables for all * mappings above VMALLOC_END, we will remove any debug device mappings. * This means you have to be careful how you debug this function, or any - * called function. (Do it by code inspection!) + * called function. This means you can't use any function or debugging + * method which may touch any device, otherwise the kernel _will_ crash. */ static void __init devicemaps_init(struct machine_desc *mdesc) { @@ -428,6 +429,12 @@ static void __init devicemaps_init(struct machine_desc *mdesc) unsigned long addr; void *vectors; + /* + * Allocate the vector page early. + */ + vectors = alloc_bootmem_low_pages(PAGE_SIZE); + BUG_ON(!vectors); + for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE) pmd_clear(pmd_off_k(addr)); @@ -461,12 +468,6 @@ static void __init devicemaps_init(struct machine_desc *mdesc) create_mapping(&map); #endif - flush_cache_all(); - local_flush_tlb_all(); - - vectors = alloc_bootmem_low_pages(PAGE_SIZE); - BUG_ON(!vectors); - /* * Create a mapping for the machine vectors at the high-vectors * location (0xffff0000). If we aren't using high-vectors, also @@ -491,12 +492,13 @@ static void __init devicemaps_init(struct machine_desc *mdesc) mdesc->map_io(); /* - * Finally flush the tlb again - this ensures that we're in a - * consistent state wrt the writebuffer if the writebuffer needs - * draining. After this point, we can start to touch devices - * again. + * Finally flush the caches and tlb to ensure that we're in a + * consistent state wrt the writebuffer. This also ensures that + * any write-allocated cache lines in the vector page are written + * back. After this point, we can start to touch devices again. */ local_flush_tlb_all(); + flush_cache_all(); } /* |