diff options
Diffstat (limited to 'include/asm-sparc/mmu_context_64.h')
| -rw-r--r-- | include/asm-sparc/mmu_context_64.h | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/include/asm-sparc/mmu_context_64.h b/include/asm-sparc/mmu_context_64.h new file mode 100644 index 000000000000..5693ab482606 --- /dev/null +++ b/include/asm-sparc/mmu_context_64.h @@ -0,0 +1,155 @@ +#ifndef __SPARC64_MMU_CONTEXT_H +#define __SPARC64_MMU_CONTEXT_H + +/* Derived heavily from Linus's Alpha/AXP ASN code... */ + +#ifndef __ASSEMBLY__ + +#include <linux/spinlock.h> +#include <asm/system.h> +#include <asm/spitfire.h> +#include <asm-generic/mm_hooks.h> + +static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) +{ +} + +extern spinlock_t ctx_alloc_lock; +extern unsigned long tlb_context_cache; +extern unsigned long mmu_context_bmap[]; + +extern void get_new_mmu_context(struct mm_struct *mm); +#ifdef CONFIG_SMP +extern void smp_new_mmu_context_version(void); +#else +#define smp_new_mmu_context_version() do { } while (0) +#endif + +extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm); +extern void destroy_context(struct mm_struct *mm); + +extern void __tsb_context_switch(unsigned long pgd_pa, + struct tsb_config *tsb_base, + struct tsb_config *tsb_huge, + unsigned long tsb_descr_pa); + +static inline void tsb_context_switch(struct mm_struct *mm) +{ + __tsb_context_switch(__pa(mm->pgd), + &mm->context.tsb_block[0], +#ifdef CONFIG_HUGETLB_PAGE + (mm->context.tsb_block[1].tsb ? + &mm->context.tsb_block[1] : + NULL) +#else + NULL +#endif + , __pa(&mm->context.tsb_descr[0])); +} + +extern void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long mm_rss); +#ifdef CONFIG_SMP +extern void smp_tsb_sync(struct mm_struct *mm); +#else +#define smp_tsb_sync(__mm) do { } while (0) +#endif + +/* Set MMU context in the actual hardware. */ +#define load_secondary_context(__mm) \ + __asm__ __volatile__( \ + "\n661: stxa %0, [%1] %2\n" \ + " .section .sun4v_1insn_patch, \"ax\"\n" \ + " .word 661b\n" \ + " stxa %0, [%1] %3\n" \ + " .previous\n" \ + " flush %%g6\n" \ + : /* No outputs */ \ + : "r" (CTX_HWBITS((__mm)->context)), \ + "r" (SECONDARY_CONTEXT), "i" (ASI_DMMU), "i" (ASI_MMU)) + +extern void __flush_tlb_mm(unsigned long, unsigned long); + +/* Switch the current MM context. Interrupts are disabled. */ +static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk) +{ + unsigned long ctx_valid, flags; + int cpu; + + if (unlikely(mm == &init_mm)) + return; + + spin_lock_irqsave(&mm->context.lock, flags); + ctx_valid = CTX_VALID(mm->context); + if (!ctx_valid) + get_new_mmu_context(mm); + + /* We have to be extremely careful here or else we will miss + * a TSB grow if we switch back and forth between a kernel + * thread and an address space which has it's TSB size increased + * on another processor. + * + * It is possible to play some games in order to optimize the + * switch, but the safest thing to do is to unconditionally + * perform the secondary context load and the TSB context switch. + * + * For reference the bad case is, for address space "A": + * + * CPU 0 CPU 1 + * run address space A + * set cpu0's bits in cpu_vm_mask + * switch to kernel thread, borrow + * address space A via entry_lazy_tlb + * run address space A + * set cpu1's bit in cpu_vm_mask + * flush_tlb_pending() + * reset cpu_vm_mask to just cpu1 + * TSB grow + * run address space A + * context was valid, so skip + * TSB context switch + * + * At that point cpu0 continues to use a stale TSB, the one from + * before the TSB grow performed on cpu1. cpu1 did not cross-call + * cpu0 to update it's TSB because at that point the cpu_vm_mask + * only had cpu1 set in it. + */ + load_secondary_context(mm); + tsb_context_switch(mm); + + /* Any time a processor runs a context on an address space + * for the first time, we must flush that context out of the + * local TLB. + */ + cpu = smp_processor_id(); + if (!ctx_valid || !cpu_isset(cpu, mm->cpu_vm_mask)) { + cpu_set(cpu, mm->cpu_vm_mask); + __flush_tlb_mm(CTX_HWBITS(mm->context), + SECONDARY_CONTEXT); + } + spin_unlock_irqrestore(&mm->context.lock, flags); +} + +#define deactivate_mm(tsk,mm) do { } while (0) + +/* Activate a new MM instance for the current task. */ +static inline void activate_mm(struct mm_struct *active_mm, struct mm_struct *mm) +{ + unsigned long flags; + int cpu; + + spin_lock_irqsave(&mm->context.lock, flags); + if (!CTX_VALID(mm->context)) + get_new_mmu_context(mm); + cpu = smp_processor_id(); + if (!cpu_isset(cpu, mm->cpu_vm_mask)) + cpu_set(cpu, mm->cpu_vm_mask); + + load_secondary_context(mm); + __flush_tlb_mm(CTX_HWBITS(mm->context), SECONDARY_CONTEXT); + tsb_context_switch(mm); + spin_unlock_irqrestore(&mm->context.lock, flags); +} + +#endif /* !(__ASSEMBLY__) */ + +#endif /* !(__SPARC64_MMU_CONTEXT_H) */ |