diff options
Diffstat (limited to 'arch/powerpc/mm/book3s64/hash_pgtable.c')
| -rw-r--r-- | arch/powerpc/mm/book3s64/hash_pgtable.c | 165 |
1 files changed, 134 insertions, 31 deletions
diff --git a/arch/powerpc/mm/book3s64/hash_pgtable.c b/arch/powerpc/mm/book3s64/hash_pgtable.c index 64733b9cb20a..988948d69bc1 100644 --- a/arch/powerpc/mm/book3s64/hash_pgtable.c +++ b/arch/powerpc/mm/book3s64/hash_pgtable.c @@ -8,16 +8,15 @@ #include <linux/sched.h> #include <linux/mm_types.h> #include <linux/mm.h> +#include <linux/stop_machine.h> -#include <asm/pgalloc.h> -#include <asm/pgtable.h> #include <asm/sections.h> #include <asm/mmu.h> #include <asm/tlb.h> +#include <asm/firmware.h> #include <mm/mmu_decl.h> -#define CREATE_TRACE_POINTS #include <trace/events/thp.h> #if H_PGTABLE_RANGE > (USER_VSID_RANGE * (TASK_SIZE_USER64 / TASK_CONTEXT_SIZE)) @@ -148,6 +147,7 @@ void hash__vmemmap_remove_mapping(unsigned long start, int hash__map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t prot) { pgd_t *pgdp; + p4d_t *p4dp; pud_t *pudp; pmd_t *pmdp; pte_t *ptep; @@ -155,7 +155,8 @@ int hash__map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t prot) BUILD_BUG_ON(TASK_SIZE_USER64 > H_PGTABLE_RANGE); if (slab_is_available()) { pgdp = pgd_offset_k(ea); - pudp = pud_alloc(&init_mm, pgdp, ea); + p4dp = p4d_offset(pgdp, ea); + pudp = pud_alloc(&init_mm, p4dp, ea); if (!pudp) return -ENOMEM; pmdp = pmd_alloc(&init_mm, pudp, ea); @@ -213,7 +214,7 @@ unsigned long hash__pmd_hugepage_update(struct mm_struct *mm, unsigned long addr old = be64_to_cpu(old_be); - trace_hugepage_update(addr, old, clr, set); + trace_hugepage_update_pmd(addr, old, clr, set); if (old & H_PAGE_HASHPTE) hpte_do_hugepage_flush(mm, addr, pmdp, old); return old; @@ -236,7 +237,7 @@ pmd_t hash__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long addres * to hugepage, we first clear the pmd, then invalidate all * the PTE entries. The assumption here is that any low level * page fault will see a none pmd and take the slow path that - * will wait on mmap_sem. But we could very well be in a + * will wait on mmap_lock. But we could very well be in a * hash_page with local ptep pointer value. Such a hash page * can result in adding new HPTE entries for normal subpages. * That means we could be modifying the page content as we @@ -250,12 +251,12 @@ pmd_t hash__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long addres * Now invalidate the hpte entries in the range * covered by pmd. This make sure we take a * fault and will find the pmd as none, which will - * result in a major fault which takes mmap_sem and + * result in a major fault which takes mmap_lock and * hence wait for collapse to complete. Without this * the __collapse_huge_page_copy can result in copying * the old content. */ - flush_tlb_pmd_range(vma->vm_mm, &pmd, address); + flush_hash_table_pmd_range(vma->vm_mm, &pmd, address); return pmd; } @@ -363,17 +364,6 @@ pmd_t hash__pmdp_huge_get_and_clear(struct mm_struct *mm, * hash fault look at them. */ memset(pgtable, 0, PTE_FRAG_SIZE); - /* - * Serialize against find_current_mm_pte variants which does lock-less - * lookup in page tables with local interrupts disabled. For huge pages - * it casts pmd_t to pte_t. Since format of pte_t is different from - * pmd_t we want to prevent transit from pmd pointing to page table - * to pmd pointing to huge page (and back) while interrupts are disabled. - * We clear pmd to possibly replace it with page table pointer in - * different code paths. So make sure we wait for the parallel - * find_curren_mm_pte to finish. - */ - serialize_against_pte_lookup(mm); return old_pmd; } @@ -388,7 +378,7 @@ int hash__has_transparent_hugepage(void) if (mmu_psize_defs[MMU_PAGE_16M].shift != PMD_SHIFT) return 0; /* - * We need to make sure that we support 16MB hugepage in a segement + * We need to make sure that we support 16MB hugepage in a segment * with base page size 64K or 4K. We only enable THP with a PAGE_SIZE * of 64K. */ @@ -411,10 +401,105 @@ EXPORT_SYMBOL_GPL(hash__has_transparent_hugepage); #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #ifdef CONFIG_STRICT_KERNEL_RWX + +struct change_memory_parms { + unsigned long start, end, newpp; + unsigned int step, nr_cpus; + atomic_t master_cpu; + atomic_t cpu_counter; +}; + +// We'd rather this was on the stack but it has to be in the RMO +static struct change_memory_parms chmem_parms; + +// And therefore we need a lock to protect it from concurrent use +static DEFINE_MUTEX(chmem_lock); + +static void change_memory_range(unsigned long start, unsigned long end, + unsigned int step, unsigned long newpp) +{ + unsigned long idx; + + pr_debug("Changing page protection on range 0x%lx-0x%lx, to 0x%lx, step 0x%x\n", + start, end, newpp, step); + + for (idx = start; idx < end; idx += step) + /* Not sure if we can do much with the return value */ + mmu_hash_ops.hpte_updateboltedpp(newpp, idx, mmu_linear_psize, + mmu_kernel_ssize); +} + +static int notrace chmem_secondary_loop(struct change_memory_parms *parms) +{ + unsigned long msr, tmp, flags; + int *p; + + p = &parms->cpu_counter.counter; + + local_irq_save(flags); + hard_irq_disable(); + + asm volatile ( + // Switch to real mode and leave interrupts off + "mfmsr %[msr] ;" + "li %[tmp], %[MSR_IR_DR] ;" + "andc %[tmp], %[msr], %[tmp] ;" + "mtmsrd %[tmp] ;" + + // Tell the master we are in real mode + "1: " + "lwarx %[tmp], 0, %[p] ;" + "addic %[tmp], %[tmp], -1 ;" + "stwcx. %[tmp], 0, %[p] ;" + "bne- 1b ;" + + // Spin until the counter goes to zero + "2: ;" + "lwz %[tmp], 0(%[p]) ;" + "cmpwi %[tmp], 0 ;" + "bne- 2b ;" + + // Switch back to virtual mode + "mtmsrd %[msr] ;" + + : // outputs + [msr] "=&r" (msr), [tmp] "=&b" (tmp), "+m" (*p) + : // inputs + [p] "b" (p), [MSR_IR_DR] "i" (MSR_IR | MSR_DR) + : // clobbers + "cc", "xer" + ); + + local_irq_restore(flags); + + return 0; +} + +static int change_memory_range_fn(void *data) +{ + struct change_memory_parms *parms = data; + + // First CPU goes through, all others wait. + if (atomic_xchg(&parms->master_cpu, 1) == 1) + return chmem_secondary_loop(parms); + + // Wait for all but one CPU (this one) to call-in + while (atomic_read(&parms->cpu_counter) > 1) + barrier(); + + change_memory_range(parms->start, parms->end, parms->step, parms->newpp); + + mb(); + + // Signal the other CPUs that we're done + atomic_dec(&parms->cpu_counter); + + return 0; +} + static bool hash__change_memory_range(unsigned long start, unsigned long end, unsigned long newpp) { - unsigned long idx; unsigned int step, shift; shift = mmu_psize_defs[mmu_linear_psize].shift; @@ -426,25 +511,43 @@ static bool hash__change_memory_range(unsigned long start, unsigned long end, if (start >= end) return false; - pr_debug("Changing page protection on range 0x%lx-0x%lx, to 0x%lx, step 0x%x\n", - start, end, newpp, step); + if (firmware_has_feature(FW_FEATURE_LPAR)) { + mutex_lock(&chmem_lock); - for (idx = start; idx < end; idx += step) - /* Not sure if we can do much with the return value */ - mmu_hash_ops.hpte_updateboltedpp(newpp, idx, mmu_linear_psize, - mmu_kernel_ssize); + chmem_parms.start = start; + chmem_parms.end = end; + chmem_parms.step = step; + chmem_parms.newpp = newpp; + atomic_set(&chmem_parms.master_cpu, 0); + + cpus_read_lock(); + + atomic_set(&chmem_parms.cpu_counter, num_online_cpus()); + + // Ensure state is consistent before we call the other CPUs + mb(); + + stop_machine_cpuslocked(change_memory_range_fn, &chmem_parms, + cpu_online_mask); + + cpus_read_unlock(); + mutex_unlock(&chmem_lock); + } else + change_memory_range(start, end, step, newpp); return true; } void hash__mark_rodata_ro(void) { - unsigned long start, end; + unsigned long start, end, pp; start = (unsigned long)_stext; - end = (unsigned long)__init_begin; + end = (unsigned long)__end_rodata; + + pp = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL_ROX), HPTE_USE_KERNEL_KEY); - WARN_ON(!hash__change_memory_range(start, end, PP_RXXX)); + WARN_ON(!hash__change_memory_range(start, end, pp)); } void hash__mark_initmem_nx(void) @@ -454,7 +557,7 @@ void hash__mark_initmem_nx(void) start = (unsigned long)__init_begin; end = (unsigned long)__init_end; - pp = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL)); + pp = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL), HPTE_USE_KERNEL_KEY); WARN_ON(!hash__change_memory_range(start, end, pp)); } |