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| author |   Peter Zijlstra <peterz@infradead.org> | 2020-01-31 13:45:36 +0100 |
|---|---|---|
| committer |   Geert Uytterhoeven <geert@linux-m68k.org> | 2020-02-10 10:57:48 +0100 |
| commit | ef22d8abd876e805b604e8f655127de2beee2869 (patch) | |
| tree | d5a4ba746cf6d03a129d13183934f0a20dd1ee95 /arch/m68k/mm/motorola.c | |
| parent | m68k: mm: Move the pointer table allocator to motorola.c (diff) | |
| download | linux-dev-ef22d8abd876e805b604e8f655127de2beee2869.tar.xz linux-dev-ef22d8abd876e805b604e8f655127de2beee2869.zip | |
m68k: mm: Restructure Motorola MMU page-table layout
The Motorola 68xxx MMUs, 040 (and later) have a fixed 7,7,{5,6}
page-table setup, where the last depends on the page-size selected (8k
vs 4k resp.), and head.S selects 4K pages. For 030 (and earlier) we
explicitly program 7,7,6 and 4K pages in %tc.
However, the current code implements this mightily weird. What it does
is group 16 of those (6 bit) pte tables into one 4k page to not waste
space. The down-side is that that forces pmd_t to be a 16-tuple
pointing to consecutive pte tables.
This breaks the generic code which assumes READ_ONCE(*pmd) will be
word sized.
Therefore implement a straight forward 7,7,6 3 level page-table setup,
with the addition (for 020/030) of (partial) large-page support. For
now this increases the memory footprint for pte-tables 15 fold.
Tested with ARAnyM/68040 emulation.
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Greg Ungerer <gerg@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Greg Ungerer <gerg@linux-m68k.org>
Link: https://lore.kernel.org/r/20200131125403.711478295@infradead.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'arch/m68k/mm/motorola.c')
| -rw-r--r-- | arch/m68k/mm/motorola.c | 28 |
1 files changed, 13 insertions, 15 deletions
diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c index 2102f9397c94..c888ef46da3e 100644 --- a/arch/m68k/mm/motorola.c +++ b/arch/m68k/mm/motorola.c @@ -236,8 +236,6 @@ static pmd_t * __init kernel_ptr_table(void) static void __init map_node(int node) { -#define PTRTREESIZE (256*1024) -#define ROOTTREESIZE (32*1024*1024) unsigned long physaddr, virtaddr, size; pgd_t *pgd_dir; p4d_t *p4d_dir; @@ -255,21 +253,21 @@ static void __init map_node(int node) while (size > 0) { #ifdef DEBUG - if (!(virtaddr & (PTRTREESIZE-1))) + if (!(virtaddr & (PMD_SIZE-1))) printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK, virtaddr); #endif pgd_dir = pgd_offset_k(virtaddr); if (virtaddr && CPU_IS_020_OR_030) { - if (!(virtaddr & (ROOTTREESIZE-1)) && - size >= ROOTTREESIZE) { + if (!(virtaddr & (PGDIR_SIZE-1)) && + size >= PGDIR_SIZE) { #ifdef DEBUG printk ("[very early term]"); #endif pgd_val(*pgd_dir) = physaddr; - size -= ROOTTREESIZE; - virtaddr += ROOTTREESIZE; - physaddr += ROOTTREESIZE; + size -= PGDIR_SIZE; + virtaddr += PGDIR_SIZE; + physaddr += PGDIR_SIZE; continue; } } @@ -289,8 +287,8 @@ static void __init map_node(int node) #ifdef DEBUG printk ("[early term]"); #endif - pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr; - physaddr += PTRTREESIZE; + pmd_val(*pmd_dir) = physaddr; + physaddr += PMD_SIZE; } else { int i; #ifdef DEBUG @@ -298,15 +296,15 @@ static void __init map_node(int node) #endif zero_pgtable = kernel_ptr_table(); pte_dir = (pte_t *)zero_pgtable; - pmd_dir->pmd[0] = virt_to_phys(pte_dir) | - _PAGE_TABLE | _PAGE_ACCESSED; + pmd_set(pmd_dir, pte_dir); + pte_val(*pte_dir++) = 0; physaddr += PAGE_SIZE; - for (i = 1; i < 64; physaddr += PAGE_SIZE, i++) + for (i = 1; i < PTRS_PER_PTE; physaddr += PAGE_SIZE, i++) pte_val(*pte_dir++) = physaddr; } - size -= PTRTREESIZE; - virtaddr += PTRTREESIZE; + size -= PMD_SIZE; + virtaddr += PMD_SIZE; } else { if (!pmd_present(*pmd_dir)) { #ifdef DEBUG |