diff options
| -rw-r--r-- | arch/powerpc/mm/ppc_mmu_32.c | 63 |
1 files changed, 41 insertions, 22 deletions
diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c index 2d4d4bf9a63d..621392e6d466 100644 --- a/arch/powerpc/mm/ppc_mmu_32.c +++ b/arch/powerpc/mm/ppc_mmu_32.c @@ -73,39 +73,58 @@ unsigned long p_block_mapped(phys_addr_t pa) return 0; } +static int find_free_bat(void) +{ + int b; + + if (cpu_has_feature(CPU_FTR_601)) { + for (b = 0; b < 4; b++) { + struct ppc_bat *bat = BATS[b]; + + if (!(bat[0].batl & 0x40)) + return b; + } + } else { + int n = mmu_has_feature(MMU_FTR_USE_HIGH_BATS) ? 8 : 4; + + for (b = 0; b < n; b++) { + struct ppc_bat *bat = BATS[b]; + + if (!(bat[1].batu & 3)) + return b; + } + } + return -1; +} + +static unsigned int block_size(unsigned long base, unsigned long top) +{ + unsigned int max_size = (cpu_has_feature(CPU_FTR_601) ? 8 : 256) << 20; + unsigned int base_shift = (fls(base) - 1) & 31; + unsigned int block_shift = (fls(top - base) - 1) & 31; + + return min3(max_size, 1U << base_shift, 1U << block_shift); +} + unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top) { - unsigned long tot, bl, done; - unsigned long max_size = (256<<20); + int idx; if (__map_without_bats) { printk(KERN_DEBUG "RAM mapped without BATs\n"); - return 0; + return base; } - /* Set up BAT2 and if necessary BAT3 to cover RAM. */ + while ((idx = find_free_bat()) != -1 && base != top) { + unsigned int size = block_size(base, top); - /* Make sure we don't map a block larger than the - smallest alignment of the physical address. */ - tot = top; - for (bl = 128<<10; bl < max_size; bl <<= 1) { - if (bl * 2 > tot) + if (size < 128 << 10) break; + setbat(idx, PAGE_OFFSET + base, base, size, PAGE_KERNEL_X); + base += size; } - setbat(2, PAGE_OFFSET, 0, bl, PAGE_KERNEL_X); - done = (unsigned long)bat_addrs[2].limit - PAGE_OFFSET + 1; - if ((done < tot) && !bat_addrs[3].limit) { - /* use BAT3 to cover a bit more */ - tot -= done; - for (bl = 128<<10; bl < max_size; bl <<= 1) - if (bl * 2 > tot) - break; - setbat(3, PAGE_OFFSET+done, done, bl, PAGE_KERNEL_X); - done = (unsigned long)bat_addrs[3].limit - PAGE_OFFSET + 1; - } - - return done; + return base; } /* |