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author | Glauber Costa <gcosta@redhat.com> | 2008-03-03 17:12:54 (GMT) |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-04-17 15:40:56 (GMT) |
commit | c048fdfe6178e082be918d4062c86d9764979112 (patch) | |
tree | 51814f6d4c259bd5a6c3eaa02c3fb5ff7f844228 /arch/x86/kernel/tlb_64.c | |
parent | 8202350367ac11d571f6dd4c21c2027a4d235276 (diff) | |
download | linux-fsl-qoriq-c048fdfe6178e082be918d4062c86d9764979112.tar.xz |
x86: create tlb files
this patch creates tlb_32.c and tlb_64.c, with
tlb-related functions that used to live in smp*.c files.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/tlb_64.c')
-rw-r--r-- | arch/x86/kernel/tlb_64.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/arch/x86/kernel/tlb_64.c b/arch/x86/kernel/tlb_64.c new file mode 100644 index 0000000..615d848 --- /dev/null +++ b/arch/x86/kernel/tlb_64.c @@ -0,0 +1,273 @@ +#include <linux/init.h> + +#include <linux/mm.h> +#include <linux/delay.h> +#include <linux/spinlock.h> +#include <linux/smp.h> +#include <linux/kernel_stat.h> +#include <linux/mc146818rtc.h> +#include <linux/interrupt.h> + +#include <asm/mtrr.h> +#include <asm/pgalloc.h> +#include <asm/tlbflush.h> +#include <asm/mach_apic.h> +#include <asm/mmu_context.h> +#include <asm/proto.h> +#include <asm/apicdef.h> +#include <asm/idle.h> +/* + * Smarter SMP flushing macros. + * c/o Linus Torvalds. + * + * These mean you can really definitely utterly forget about + * writing to user space from interrupts. (Its not allowed anyway). + * + * Optimizations Manfred Spraul <manfred@colorfullife.com> + * + * More scalable flush, from Andi Kleen + * + * To avoid global state use 8 different call vectors. + * Each CPU uses a specific vector to trigger flushes on other + * CPUs. Depending on the received vector the target CPUs look into + * the right per cpu variable for the flush data. + * + * With more than 8 CPUs they are hashed to the 8 available + * vectors. The limited global vector space forces us to this right now. + * In future when interrupts are split into per CPU domains this could be + * fixed, at the cost of triggering multiple IPIs in some cases. + */ + +union smp_flush_state { + struct { + cpumask_t flush_cpumask; + struct mm_struct *flush_mm; + unsigned long flush_va; + spinlock_t tlbstate_lock; + }; + char pad[SMP_CACHE_BYTES]; +} ____cacheline_aligned; + +/* State is put into the per CPU data section, but padded + to a full cache line because other CPUs can access it and we don't + want false sharing in the per cpu data segment. */ +static DEFINE_PER_CPU(union smp_flush_state, flush_state); + +/* + * We cannot call mmdrop() because we are in interrupt context, + * instead update mm->cpu_vm_mask. + */ +void leave_mm(int cpu) +{ + if (read_pda(mmu_state) == TLBSTATE_OK) + BUG(); + cpu_clear(cpu, read_pda(active_mm)->cpu_vm_mask); + load_cr3(swapper_pg_dir); +} +EXPORT_SYMBOL_GPL(leave_mm); + +/* + * + * The flush IPI assumes that a thread switch happens in this order: + * [cpu0: the cpu that switches] + * 1) switch_mm() either 1a) or 1b) + * 1a) thread switch to a different mm + * 1a1) cpu_clear(cpu, old_mm->cpu_vm_mask); + * Stop ipi delivery for the old mm. This is not synchronized with + * the other cpus, but smp_invalidate_interrupt ignore flush ipis + * for the wrong mm, and in the worst case we perform a superfluous + * tlb flush. + * 1a2) set cpu mmu_state to TLBSTATE_OK + * Now the smp_invalidate_interrupt won't call leave_mm if cpu0 + * was in lazy tlb mode. + * 1a3) update cpu active_mm + * Now cpu0 accepts tlb flushes for the new mm. + * 1a4) cpu_set(cpu, new_mm->cpu_vm_mask); + * Now the other cpus will send tlb flush ipis. + * 1a4) change cr3. + * 1b) thread switch without mm change + * cpu active_mm is correct, cpu0 already handles + * flush ipis. + * 1b1) set cpu mmu_state to TLBSTATE_OK + * 1b2) test_and_set the cpu bit in cpu_vm_mask. + * Atomically set the bit [other cpus will start sending flush ipis], + * and test the bit. + * 1b3) if the bit was 0: leave_mm was called, flush the tlb. + * 2) switch %%esp, ie current + * + * The interrupt must handle 2 special cases: + * - cr3 is changed before %%esp, ie. it cannot use current->{active_,}mm. + * - the cpu performs speculative tlb reads, i.e. even if the cpu only + * runs in kernel space, the cpu could load tlb entries for user space + * pages. + * + * The good news is that cpu mmu_state is local to each cpu, no + * write/read ordering problems. + */ + +/* + * TLB flush IPI: + * + * 1) Flush the tlb entries if the cpu uses the mm that's being flushed. + * 2) Leave the mm if we are in the lazy tlb mode. + * + * Interrupts are disabled. + */ + +asmlinkage void smp_invalidate_interrupt(struct pt_regs *regs) +{ + int cpu; + int sender; + union smp_flush_state *f; + + cpu = smp_processor_id(); + /* + * orig_rax contains the negated interrupt vector. + * Use that to determine where the sender put the data. + */ + sender = ~regs->orig_ax - INVALIDATE_TLB_VECTOR_START; + f = &per_cpu(flush_state, sender); + + if (!cpu_isset(cpu, f->flush_cpumask)) + goto out; + /* + * This was a BUG() but until someone can quote me the + * line from the intel manual that guarantees an IPI to + * multiple CPUs is retried _only_ on the erroring CPUs + * its staying as a return + * + * BUG(); + */ + + if (f->flush_mm == read_pda(active_mm)) { + if (read_pda(mmu_state) == TLBSTATE_OK) { + if (f->flush_va == TLB_FLUSH_ALL) + local_flush_tlb(); + else + __flush_tlb_one(f->flush_va); + } else + leave_mm(cpu); + } +out: + ack_APIC_irq(); + cpu_clear(cpu, f->flush_cpumask); + add_pda(irq_tlb_count, 1); +} + +void native_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm, + unsigned long va) +{ + int sender; + union smp_flush_state *f; + cpumask_t cpumask = *cpumaskp; + + /* Caller has disabled preemption */ + sender = smp_processor_id() % NUM_INVALIDATE_TLB_VECTORS; + f = &per_cpu(flush_state, sender); + + /* + * Could avoid this lock when + * num_online_cpus() <= NUM_INVALIDATE_TLB_VECTORS, but it is + * probably not worth checking this for a cache-hot lock. + */ + spin_lock(&f->tlbstate_lock); + + f->flush_mm = mm; + f->flush_va = va; + cpus_or(f->flush_cpumask, cpumask, f->flush_cpumask); + + /* + * We have to send the IPI only to + * CPUs affected. + */ + send_IPI_mask(cpumask, INVALIDATE_TLB_VECTOR_START + sender); + + while (!cpus_empty(f->flush_cpumask)) + cpu_relax(); + + f->flush_mm = NULL; + f->flush_va = 0; + spin_unlock(&f->tlbstate_lock); +} + +int __cpuinit init_smp_flush(void) +{ + int i; + + for_each_cpu_mask(i, cpu_possible_map) { + spin_lock_init(&per_cpu(flush_state, i).tlbstate_lock); + } + return 0; +} +core_initcall(init_smp_flush); + +void flush_tlb_current_task(void) +{ + struct mm_struct *mm = current->mm; + cpumask_t cpu_mask; + + preempt_disable(); + cpu_mask = mm->cpu_vm_mask; + cpu_clear(smp_processor_id(), cpu_mask); + + local_flush_tlb(); + if (!cpus_empty(cpu_mask)) + flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL); + preempt_enable(); +} + +void flush_tlb_mm(struct mm_struct *mm) +{ + cpumask_t cpu_mask; + + preempt_disable(); + cpu_mask = mm->cpu_vm_mask; + cpu_clear(smp_processor_id(), cpu_mask); + + if (current->active_mm == mm) { + if (current->mm) + local_flush_tlb(); + else + leave_mm(smp_processor_id()); + } + if (!cpus_empty(cpu_mask)) + flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL); + + preempt_enable(); +} + +void flush_tlb_page(struct vm_area_struct *vma, unsigned long va) +{ + struct mm_struct *mm = vma->vm_mm; + cpumask_t cpu_mask; + + preempt_disable(); + cpu_mask = mm->cpu_vm_mask; + cpu_clear(smp_processor_id(), cpu_mask); + + if (current->active_mm == mm) { + if (current->mm) + __flush_tlb_one(va); + else + leave_mm(smp_processor_id()); + } + + if (!cpus_empty(cpu_mask)) + flush_tlb_others(cpu_mask, mm, va); + + preempt_enable(); +} + +static void do_flush_tlb_all(void *info) +{ + unsigned long cpu = smp_processor_id(); + + __flush_tlb_all(); + if (read_pda(mmu_state) == TLBSTATE_LAZY) + leave_mm(cpu); +} + +void flush_tlb_all(void) +{ + on_each_cpu(do_flush_tlb_all, NULL, 1, 1); +} |