diff options
Diffstat (limited to 'arch/sh/kernel/head_32.S')
| -rw-r--r-- | arch/sh/kernel/head_32.S | 42 |
1 files changed, 38 insertions, 4 deletions
diff --git a/arch/sh/kernel/head_32.S b/arch/sh/kernel/head_32.S index 79ff39517f8..fe0b743881b 100644 --- a/arch/sh/kernel/head_32.S +++ b/arch/sh/kernel/head_32.S @@ -85,7 +85,7 @@ ENTRY(_stext) ldc r0, r7_bank ! ... and initial thread_info #endif -#if defined(CONFIG_PMB) && !defined(CONFIG_PMB_LEGACY) +#ifdef CONFIG_PMB /* * Reconfigure the initial PMB mappings setup by the hardware. * @@ -139,7 +139,6 @@ ENTRY(_stext) mov.l r0, @r1 mov.l .LMEMORY_SIZE, r5 - mov r5, r7 mov #PMB_E_SHIFT, r0 mov #0x1, r4 @@ -150,6 +149,40 @@ ENTRY(_stext) mov.l .LFIRST_ADDR_ENTRY, r2 mov.l .LPMB_ADDR, r3 + /* + * First we need to walk the PMB and figure out if there are any + * existing mappings that match the initial mappings VPN/PPN. + * If these have already been established by the bootloader, we + * don't bother setting up new entries here, and let the late PMB + * initialization take care of things instead. + * + * Note that we may need to coalesce and merge entries in order + * to reclaim more available PMB slots, which is much more than + * we want to do at this early stage. + */ + mov #0, r10 + mov #NR_PMB_ENTRIES, r9 + + mov r1, r7 /* temporary PMB_DATA iter */ + +.Lvalidate_existing_mappings: + + mov.l @r7, r8 + and r0, r8 + cmp/eq r0, r8 /* Check for valid __MEMORY_START mappings */ + bt .Lpmb_done + + add #1, r10 /* Increment the loop counter */ + cmp/eq r9, r10 + bf/s .Lvalidate_existing_mappings + add r4, r7 /* Increment to the next PMB_DATA entry */ + + /* + * If we've fallen through, continue with setting up the initial + * mappings. + */ + + mov r5, r7 /* cached_to_uncached */ mov #0, r10 #ifdef CONFIG_UNCACHED_MAPPING @@ -252,7 +285,8 @@ ENTRY(_stext) mov.l 6f, r0 icbi @r0 -#endif /* !CONFIG_PMB_LEGACY */ +.Lpmb_done: +#endif /* CONFIG_PMB */ #ifndef CONFIG_SH_NO_BSS_INIT /* @@ -304,7 +338,7 @@ ENTRY(stack_start) 6: .long sh_cpu_init 7: .long init_thread_union -#if defined(CONFIG_PMB) && !defined(CONFIG_PMB_LEGACY) +#ifdef CONFIG_PMB .LPMB_ADDR: .long PMB_ADDR .LPMB_DATA: .long PMB_DATA .LFIRST_ADDR_ENTRY: .long PAGE_OFFSET | PMB_V |