diff options
| -rw-r--r-- | arch/arm/include/asm/smp_plat.h | 16 | ||||
| -rw-r--r-- | arch/arm/kernel/smp.c | 7 | ||||
| -rw-r--r-- | arch/arm/mm/mmu.c | 37 |
3 files changed, 50 insertions, 10 deletions
diff --git a/arch/arm/include/asm/smp_plat.h b/arch/arm/include/asm/smp_plat.h new file mode 100644 index 00000000000..59303e20084 --- /dev/null +++ b/arch/arm/include/asm/smp_plat.h @@ -0,0 +1,16 @@ +/* + * ARM specific SMP header, this contains our implementation + * details. + */ +#ifndef __ASMARM_SMP_PLAT_H +#define __ASMARM_SMP_PLAT_H + +#include <asm/cputype.h> + +/* all SMP configurations have the extended CPUID registers */ +static inline int tlb_ops_need_broadcast(void) +{ + return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 2; +} + +#endif diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index e0d32770bb3..9d015ee5747 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -36,6 +36,7 @@ #include <asm/tlbflush.h> #include <asm/ptrace.h> #include <asm/localtimer.h> +#include <asm/smp_plat.h> /* * as from 2.5, kernels no longer have an init_tasks structure @@ -586,12 +587,6 @@ struct tlb_args { unsigned long ta_end; }; -/* all SMP configurations have the extended CPUID registers */ -static inline int tlb_ops_need_broadcast(void) -{ - return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 2; -} - static inline void ipi_flush_tlb_all(void *ignored) { local_flush_tlb_all(); diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index ce551ec2cb2..02243eeccf5 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -21,6 +21,7 @@ #include <asm/cachetype.h> #include <asm/setup.h> #include <asm/sizes.h> +#include <asm/smp_plat.h> #include <asm/tlb.h> #include <asm/highmem.h> @@ -709,10 +710,6 @@ static void __init sanity_check_meminfo(void) if (meminfo.nr_banks >= NR_BANKS) { printk(KERN_CRIT "NR_BANKS too low, " "ignoring high memory\n"); - } else if (cache_is_vipt_aliasing()) { - printk(KERN_CRIT "HIGHMEM is not yet supported " - "with VIPT aliasing cache, " - "ignoring high memory\n"); } else { memmove(bank + 1, bank, (meminfo.nr_banks - i) * sizeof(*bank)); @@ -756,6 +753,38 @@ static void __init sanity_check_meminfo(void) #endif j++; } +#ifdef CONFIG_HIGHMEM + if (highmem) { + const char *reason = NULL; + + if (cache_is_vipt_aliasing()) { + /* + * Interactions between kmap and other mappings + * make highmem support with aliasing VIPT caches + * rather difficult. + */ + reason = "with VIPT aliasing cache"; +#ifdef CONFIG_SMP + } else if (tlb_ops_need_broadcast()) { + /* + * kmap_high needs to occasionally flush TLB entries, + * however, if the TLB entries need to be broadcast + * we may deadlock: + * kmap_high(irqs off)->flush_all_zero_pkmaps-> + * flush_tlb_kernel_range->smp_call_function_many + * (must not be called with irqs off) + */ + reason = "without hardware TLB ops broadcasting"; +#endif + } + if (reason) { + printk(KERN_CRIT "HIGHMEM is not supported %s, ignoring high memory\n", + reason); + while (j > 0 && meminfo.bank[j - 1].highmem) + j--; + } + } +#endif meminfo.nr_banks = j; } |