Re: [PATCH v4 09/16] powerpc/mm: Add new hash_page_mm()
From: Aneesh Kumar K.V <hidden>
Date: 2014-10-09 15:28:52
Also in:
lkml
Michael Neuling [off-list ref] writes:
From: Ian Munsie <redacted> This adds a new function hash_page_mm() based on the existing hash_page(). This version allows any struct mm to be passed in, rather than assuming current. This is useful for servicing co-processor faults which are not in the context of the current running process. We need to be careful here as the current hash_page() assumes current in a few places.
if you move cxl_slbia patch before this, then we could add additonal information here. 1) We use this to insert hpte entries on-behalf of co-processor. 2) we don't need to flush cpu slb entries when adding new hpte entries 3) We do flush the co-processor slb cache, if adding hpte entry result in a segement demotion or have mmu_ci_restrictions enabled. 4) We do update the slice array to indicate the new base page size 5) w.r.t co-processor on segment miss we look at slice array and add new slb entry using newly added copro_calculate_slb "powerpc/cell: Move data segment faulting code out of cell platform"
quoted hunk ↗ jump to hunk
Signed-off-by: Ian Munsie <redacted> Signed-off-by: Michael Neuling <redacted> --- arch/powerpc/include/asm/mmu-hash64.h | 1 + arch/powerpc/mm/hash_utils_64.c | 24 +++++++++++++++++------- 2 files changed, 18 insertions(+), 7 deletions(-)diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h index aeabd02..764e141 100644 --- a/arch/powerpc/include/asm/mmu-hash64.h +++ b/arch/powerpc/include/asm/mmu-hash64.h@@ -324,6 +324,7 @@ extern int __hash_page_64K(unsigned long ea, unsigned long access, unsigned int local, int ssize); struct mm_struct; unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap); +extern int hash_page_mm(struct mm_struct *mm, unsigned long ea, unsigned long access, unsigned long trap); extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap); int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid, pte_t *ptep, unsigned long trap, int local, int ssize,diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index bbdb054..698834d 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c@@ -904,7 +904,7 @@ void demote_segment_4k(struct mm_struct *mm, unsigned long addr) return; slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K); copro_flush_all_slbs(mm); - if (get_paca_psize(addr) != MMU_PAGE_4K) { + if ((get_paca_psize(addr) != MMU_PAGE_4K) && (current->mm == mm)) { get_paca()->context = mm->context; slb_flush_and_rebolt(); }@@ -989,12 +989,11 @@ static void check_paca_psize(unsigned long ea, struct mm_struct *mm, * -1 - critical hash insertion error * -2 - access not permitted by subpage protection mechanism */ -int hash_page(unsigned long ea, unsigned long access, unsigned long trap) +int hash_page_mm(struct mm_struct *mm, unsigned long ea, unsigned long access, unsigned long trap) { enum ctx_state prev_state = exception_enter(); pgd_t *pgdir; unsigned long vsid; - struct mm_struct *mm; pte_t *ptep; unsigned hugeshift; const struct cpumask *tmp;@@ -1008,7 +1007,6 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) switch (REGION_ID(ea)) { case USER_REGION_ID: user_region = 1; - mm = current->mm; if (! mm) { DBG_LOW(" user region with no mm !\n"); rc = 1;@@ -1019,7 +1017,6 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) vsid = get_vsid(mm->context.id, ea, ssize); break; case VMALLOC_REGION_ID: - mm = &init_mm; vsid = get_kernel_vsid(ea, mmu_kernel_ssize); if (ea < VMALLOC_END) psize = mmu_vmalloc_psize;@@ -1104,7 +1101,8 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) WARN_ON(1); } #endif - check_paca_psize(ea, mm, psize, user_region); + if (current->mm == mm) + check_paca_psize(ea, mm, psize, user_region); goto bail; }@@ -1145,7 +1143,8 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) } } - check_paca_psize(ea, mm, psize, user_region); + if (current->mm == mm) + check_paca_psize(ea, mm, psize, user_region); #endif /* CONFIG_PPC_64K_PAGES */ #ifdef CONFIG_PPC_HAS_HASH_64K@@ -1180,6 +1179,17 @@ bail: exception_exit(prev_state); return rc; } +EXPORT_SYMBOL_GPL(hash_page_mm); + +int hash_page(unsigned long ea, unsigned long access, unsigned long trap) +{ + struct mm_struct *mm = current->mm; + + if (REGION_ID(ea) == VMALLOC_REGION_ID) + mm = &init_mm; + + return hash_page_mm(mm, ea, access, trap); +} EXPORT_SYMBOL_GPL(hash_page); void hash_preload(struct mm_struct *mm, unsigned long ea,-- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/