diff options
Diffstat (limited to 'arch/sparc/include/asm/mmu_context_64.h')
| -rw-r--r-- | arch/sparc/include/asm/mmu_context_64.h | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/mmu_context_64.h b/arch/sparc/include/asm/mmu_context_64.h new file mode 100644 index 000000000..312fcee8d --- /dev/null +++ b/arch/sparc/include/asm/mmu_context_64.h @@ -0,0 +1,192 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#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 <linux/mm_types.h> +#include <linux/smp.h> +#include <linux/sched.h> + +#include <asm/spitfire.h> +#include <asm/adi_64.h> +#include <asm-generic/mm_hooks.h> +#include <asm/percpu.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[]; + +DECLARE_PER_CPU(struct mm_struct *, per_cpu_secondary_mm); +void get_new_mmu_context(struct mm_struct *mm); +int init_new_context(struct task_struct *tsk, struct mm_struct *mm); +void destroy_context(struct mm_struct *mm); + +void __tsb_context_switch(unsigned long pgd_pa, + struct tsb_config *tsb_base, + struct tsb_config *tsb_huge, + unsigned long tsb_descr_pa, + unsigned long secondary_ctx); + +static inline void tsb_context_switch_ctx(struct mm_struct *mm, + unsigned long ctx) +{ + __tsb_context_switch(__pa(mm->pgd), + &mm->context.tsb_block[MM_TSB_BASE], +#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE) + (mm->context.tsb_block[MM_TSB_HUGE].tsb ? + &mm->context.tsb_block[MM_TSB_HUGE] : + NULL) +#else + NULL +#endif + , __pa(&mm->context.tsb_descr[MM_TSB_BASE]), + ctx); +} + +#define tsb_context_switch(X) tsb_context_switch_ctx(X, 0) + +void tsb_grow(struct mm_struct *mm, + unsigned long tsb_index, + unsigned long mm_rss); +#ifdef CONFIG_SMP +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)) + +void __flush_tlb_mm(unsigned long, unsigned long); + +/* Switch the current MM context. */ +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 = smp_processor_id(); + + per_cpu(per_cpu_secondary_mm, cpu) = mm; + 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. + */ + tsb_context_switch_ctx(mm, CTX_HWBITS(mm->context)); + + /* 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. + */ + if (!ctx_valid || !cpumask_test_cpu(cpu, mm_cpumask(mm))) { + cpumask_set_cpu(cpu, mm_cpumask(mm)); + __flush_tlb_mm(CTX_HWBITS(mm->context), + SECONDARY_CONTEXT); + } + spin_unlock_irqrestore(&mm->context.lock, flags); +} + +#define deactivate_mm(tsk,mm) do { } while (0) +#define activate_mm(active_mm, mm) switch_mm(active_mm, mm, NULL) + +#define __HAVE_ARCH_START_CONTEXT_SWITCH +static inline void arch_start_context_switch(struct task_struct *prev) +{ + /* Save the current state of MCDPER register for the process + * we are switching from + */ + if (adi_capable()) { + register unsigned long tmp_mcdper; + + __asm__ __volatile__( + ".word 0x83438000\n\t" /* rd %mcdper, %g1 */ + "mov %%g1, %0\n\t" + : "=r" (tmp_mcdper) + : + : "g1"); + if (tmp_mcdper) + set_tsk_thread_flag(prev, TIF_MCDPER); + else + clear_tsk_thread_flag(prev, TIF_MCDPER); + } +} + +#define finish_arch_post_lock_switch finish_arch_post_lock_switch +static inline void finish_arch_post_lock_switch(void) +{ + /* Restore the state of MCDPER register for the new process + * just switched to. + */ + if (adi_capable()) { + register unsigned long tmp_mcdper; + + tmp_mcdper = test_thread_flag(TIF_MCDPER); + __asm__ __volatile__( + "mov %0, %%g1\n\t" + ".word 0x9d800001\n\t" /* wr %g0, %g1, %mcdper" */ + ".word 0xaf902001\n\t" /* wrpr %g0, 1, %pmcdper */ + : + : "ir" (tmp_mcdper) + : "g1"); + if (current && current->mm && current->mm->context.adi) { + struct pt_regs *regs; + + regs = task_pt_regs(current); + regs->tstate |= TSTATE_MCDE; + } + } +} + +#endif /* !(__ASSEMBLY__) */ + +#endif /* !(__SPARC64_MMU_CONTEXT_H) */ |