| Message ID | 1454988763-5580-4-git-send-email-david@gibson.dropbear.id.au (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
David Gibson <david@gibson.dropbear.id.au> writes: > This makes a number of cleanups to handling of mapping failures during > memory hotplug on Power: > > For errors creating the linear mapping for the hot-added region: > * This is now reported with EFAULT which is more appropriate than the > previous EINVAL (the failure is unlikely to be related to the > function's parameters) > * An error in this path now prints a warning message, rather than just > silently failing to add the extra memory. > * Previously a failure here could result in the region being partially > mapped. We now clean up any partial mapping before failing. > > For errors creating the vmemmap for the hot-added region: > * This is now reported with EFAULT instead of causing a BUG() - this > could happen for external reason (e.g. full hash table) so it's better > to handle this non-fatally > * An error message is also printed, so the failure won't be silent > * As above a failure could cause a partially mapped region, we now > clean this up. > Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > Reviewed-by: Paul Mackerras <paulus@samba.org> > --- > arch/powerpc/mm/hash_utils_64.c | 13 ++++++++++--- > arch/powerpc/mm/init_64.c | 38 ++++++++++++++++++++++++++------------ > arch/powerpc/mm/mem.c | 10 ++++++++-- > 3 files changed, 44 insertions(+), 17 deletions(-) > > diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c > index 99fbee0..fdcf9d1 100644 > --- a/arch/powerpc/mm/hash_utils_64.c > +++ b/arch/powerpc/mm/hash_utils_64.c > @@ -640,9 +640,16 @@ static unsigned long __init htab_get_table_size(void) > #ifdef CONFIG_MEMORY_HOTPLUG > int create_section_mapping(unsigned long start, unsigned long end) > { > - return htab_bolt_mapping(start, end, __pa(start), > - pgprot_val(PAGE_KERNEL), mmu_linear_psize, > - mmu_kernel_ssize); > + int rc = htab_bolt_mapping(start, end, __pa(start), > + pgprot_val(PAGE_KERNEL), mmu_linear_psize, > + mmu_kernel_ssize); > + > + if (rc < 0) { > + int rc2 = htab_remove_mapping(start, end, mmu_linear_psize, > + mmu_kernel_ssize); > + BUG_ON(rc2 && (rc2 != -ENOENT)); > + } > + return rc; > } > > int remove_section_mapping(unsigned long start, unsigned long end) > diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c > index baa1a23..fbc9448 100644 > --- a/arch/powerpc/mm/init_64.c > +++ b/arch/powerpc/mm/init_64.c > @@ -188,9 +188,9 @@ static int __meminit vmemmap_populated(unsigned long start, int page_size) > */ > > #ifdef CONFIG_PPC_BOOK3E > -static void __meminit vmemmap_create_mapping(unsigned long start, > - unsigned long page_size, > - unsigned long phys) > +static int __meminit vmemmap_create_mapping(unsigned long start, > + unsigned long page_size, > + unsigned long phys) > { > /* Create a PTE encoding without page size */ > unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED | > @@ -208,6 +208,8 @@ static void __meminit vmemmap_create_mapping(unsigned long start, > */ > for (i = 0; i < page_size; i += PAGE_SIZE) > BUG_ON(map_kernel_page(start + i, phys, flags)); > + > + return 0; > } > > #ifdef CONFIG_MEMORY_HOTPLUG > @@ -217,15 +219,20 @@ static void vmemmap_remove_mapping(unsigned long start, > } > #endif > #else /* CONFIG_PPC_BOOK3E */ > -static void __meminit vmemmap_create_mapping(unsigned long start, > - unsigned long page_size, > - unsigned long phys) > +static int __meminit vmemmap_create_mapping(unsigned long start, > + unsigned long page_size, > + unsigned long phys) > { > - int mapped = htab_bolt_mapping(start, start + page_size, phys, > - pgprot_val(PAGE_KERNEL), > - mmu_vmemmap_psize, > - mmu_kernel_ssize); > - BUG_ON(mapped < 0); > + int rc = htab_bolt_mapping(start, start + page_size, phys, > + pgprot_val(PAGE_KERNEL), > + mmu_vmemmap_psize, mmu_kernel_ssize); > + if (rc < 0) { > + int rc2 = htab_remove_mapping(start, start + page_size, > + mmu_vmemmap_psize, > + mmu_kernel_ssize); > + BUG_ON(rc2 && (rc2 != -ENOENT)); > + } > + return rc; > } > > #ifdef CONFIG_MEMORY_HOTPLUG > @@ -304,6 +311,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) > > for (; start < end; start += page_size) { > void *p; > + int rc; > > if (vmemmap_populated(start, page_size)) > continue; > @@ -317,7 +325,13 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) > pr_debug(" * %016lx..%016lx allocated at %p\n", > start, start + page_size, p); > > - vmemmap_create_mapping(start, page_size, __pa(p)); > + rc = vmemmap_create_mapping(start, page_size, __pa(p)); > + if (rc < 0) { > + pr_warning( > + "vmemmap_populate: Unable to create vmemmap mapping: %d\n", > + rc); > + return -EFAULT; > + } > } > > return 0; > diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c > index d0f0a51..f980da6 100644 > --- a/arch/powerpc/mm/mem.c > +++ b/arch/powerpc/mm/mem.c > @@ -119,12 +119,18 @@ int arch_add_memory(int nid, u64 start, u64 size, bool for_device) > struct zone *zone; > unsigned long start_pfn = start >> PAGE_SHIFT; > unsigned long nr_pages = size >> PAGE_SHIFT; > + int rc; > > pgdata = NODE_DATA(nid); > > start = (unsigned long)__va(start); > - if (create_section_mapping(start, start + size)) > - return -EINVAL; > + rc = create_section_mapping(start, start + size); > + if (rc) { > + pr_warning( > + "Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n", > + start, start + size, rc); > + return -EFAULT; > + } > > /* this should work for most non-highmem platforms */ > zone = pgdata->node_zones + > -- > 2.5.0 > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev
On Tue, 2016-09-02 at 03:32:42 UTC, David Gibson wrote: > This makes a number of cleanups to handling of mapping failures during > memory hotplug on Power: > > For errors creating the linear mapping for the hot-added region: > * This is now reported with EFAULT which is more appropriate than the > previous EINVAL (the failure is unlikely to be related to the > function's parameters) > * An error in this path now prints a warning message, rather than just > silently failing to add the extra memory. > * Previously a failure here could result in the region being partially > mapped. We now clean up any partial mapping before failing. > > For errors creating the vmemmap for the hot-added region: > * This is now reported with EFAULT instead of causing a BUG() - this > could happen for external reason (e.g. full hash table) so it's better > to handle this non-fatally > * An error message is also printed, so the failure won't be silent > * As above a failure could cause a partially mapped region, we now > clean this up. > ... > diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c > index baa1a23..fbc9448 100644 > --- a/arch/powerpc/mm/init_64.c > +++ b/arch/powerpc/mm/init_64.c > @@ -217,15 +219,20 @@ static void vmemmap_remove_mapping(unsigned long start, > } > #endif > #else /* CONFIG_PPC_BOOK3E */ > -static void __meminit vmemmap_create_mapping(unsigned long start, > - unsigned long page_size, > - unsigned long phys) > +static int __meminit vmemmap_create_mapping(unsigned long start, > + unsigned long page_size, > + unsigned long phys) > { > - int mapped = htab_bolt_mapping(start, start + page_size, phys, > - pgprot_val(PAGE_KERNEL), > - mmu_vmemmap_psize, > - mmu_kernel_ssize); > - BUG_ON(mapped < 0); > + int rc = htab_bolt_mapping(start, start + page_size, phys, > + pgprot_val(PAGE_KERNEL), > + mmu_vmemmap_psize, mmu_kernel_ssize); > + if (rc < 0) { > + int rc2 = htab_remove_mapping(start, start + page_size, > + mmu_vmemmap_psize, > + mmu_kernel_ssize); This breaks the build when CONFIG_MEMORY_HOTPLUG=n, because htab_remove_mapping() is not defined. The obvious fix of moving htab_remove_mapping() out of CONFIG_MEMORY_HOTPLUG works, so I'll do that unless anyone objects. cheers
On Tue, Mar 01, 2016 at 12:59:07PM +1100, Michael Ellerman wrote: > On Tue, 2016-09-02 at 03:32:42 UTC, David Gibson wrote: > > This makes a number of cleanups to handling of mapping failures during > > memory hotplug on Power: > > > > For errors creating the linear mapping for the hot-added region: > > * This is now reported with EFAULT which is more appropriate than the > > previous EINVAL (the failure is unlikely to be related to the > > function's parameters) > > * An error in this path now prints a warning message, rather than just > > silently failing to add the extra memory. > > * Previously a failure here could result in the region being partially > > mapped. We now clean up any partial mapping before failing. > > > > For errors creating the vmemmap for the hot-added region: > > * This is now reported with EFAULT instead of causing a BUG() - this > > could happen for external reason (e.g. full hash table) so it's better > > to handle this non-fatally > > * An error message is also printed, so the failure won't be silent > > * As above a failure could cause a partially mapped region, we now > > clean this up. > > > ... > > diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c > > index baa1a23..fbc9448 100644 > > --- a/arch/powerpc/mm/init_64.c > > +++ b/arch/powerpc/mm/init_64.c > > @@ -217,15 +219,20 @@ static void vmemmap_remove_mapping(unsigned long start, > > } > > #endif > > #else /* CONFIG_PPC_BOOK3E */ > > -static void __meminit vmemmap_create_mapping(unsigned long start, > > - unsigned long page_size, > > - unsigned long phys) > > +static int __meminit vmemmap_create_mapping(unsigned long start, > > + unsigned long page_size, > > + unsigned long phys) > > { > > - int mapped = htab_bolt_mapping(start, start + page_size, phys, > > - pgprot_val(PAGE_KERNEL), > > - mmu_vmemmap_psize, > > - mmu_kernel_ssize); > > - BUG_ON(mapped < 0); > > + int rc = htab_bolt_mapping(start, start + page_size, phys, > > + pgprot_val(PAGE_KERNEL), > > + mmu_vmemmap_psize, mmu_kernel_ssize); > > + if (rc < 0) { > > + int rc2 = htab_remove_mapping(start, start + page_size, > > + mmu_vmemmap_psize, > > + mmu_kernel_ssize); > > This breaks the build when CONFIG_MEMORY_HOTPLUG=n, because > htab_remove_mapping() is not defined. > > The obvious fix of moving htab_remove_mapping() out of CONFIG_MEMORY_HOTPLUG > works, so I'll do that unless anyone objects. Sounds good, thanks for the catch.
On Tue, 2016-09-02 at 03:32:42 UTC, David Gibson wrote: > This makes a number of cleanups to handling of mapping failures during > memory hotplug on Power: > > For errors creating the linear mapping for the hot-added region: > * This is now reported with EFAULT which is more appropriate than the > previous EINVAL (the failure is unlikely to be related to the > function's parameters) > * An error in this path now prints a warning message, rather than just > silently failing to add the extra memory. > * Previously a failure here could result in the region being partially > mapped. We now clean up any partial mapping before failing. > > For errors creating the vmemmap for the hot-added region: > * This is now reported with EFAULT instead of causing a BUG() - this > could happen for external reason (e.g. full hash table) so it's better > to handle this non-fatally > * An error message is also printed, so the failure won't be silent > * As above a failure could cause a partially mapped region, we now > clean this up. > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > Reviewed-by: Paul Mackerras <paulus@samba.org> > Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/1dace6c665ec59bdc4eeafa4db cheers
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index 99fbee0..fdcf9d1 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -640,9 +640,16 @@ static unsigned long __init htab_get_table_size(void) #ifdef CONFIG_MEMORY_HOTPLUG int create_section_mapping(unsigned long start, unsigned long end) { - return htab_bolt_mapping(start, end, __pa(start), - pgprot_val(PAGE_KERNEL), mmu_linear_psize, - mmu_kernel_ssize); + int rc = htab_bolt_mapping(start, end, __pa(start), + pgprot_val(PAGE_KERNEL), mmu_linear_psize, + mmu_kernel_ssize); + + if (rc < 0) { + int rc2 = htab_remove_mapping(start, end, mmu_linear_psize, + mmu_kernel_ssize); + BUG_ON(rc2 && (rc2 != -ENOENT)); + } + return rc; } int remove_section_mapping(unsigned long start, unsigned long end) diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c index baa1a23..fbc9448 100644 --- a/arch/powerpc/mm/init_64.c +++ b/arch/powerpc/mm/init_64.c @@ -188,9 +188,9 @@ static int __meminit vmemmap_populated(unsigned long start, int page_size) */ #ifdef CONFIG_PPC_BOOK3E -static void __meminit vmemmap_create_mapping(unsigned long start, - unsigned long page_size, - unsigned long phys) +static int __meminit vmemmap_create_mapping(unsigned long start, + unsigned long page_size, + unsigned long phys) { /* Create a PTE encoding without page size */ unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED | @@ -208,6 +208,8 @@ static void __meminit vmemmap_create_mapping(unsigned long start, */ for (i = 0; i < page_size; i += PAGE_SIZE) BUG_ON(map_kernel_page(start + i, phys, flags)); + + return 0; } #ifdef CONFIG_MEMORY_HOTPLUG @@ -217,15 +219,20 @@ static void vmemmap_remove_mapping(unsigned long start, } #endif #else /* CONFIG_PPC_BOOK3E */ -static void __meminit vmemmap_create_mapping(unsigned long start, - unsigned long page_size, - unsigned long phys) +static int __meminit vmemmap_create_mapping(unsigned long start, + unsigned long page_size, + unsigned long phys) { - int mapped = htab_bolt_mapping(start, start + page_size, phys, - pgprot_val(PAGE_KERNEL), - mmu_vmemmap_psize, - mmu_kernel_ssize); - BUG_ON(mapped < 0); + int rc = htab_bolt_mapping(start, start + page_size, phys, + pgprot_val(PAGE_KERNEL), + mmu_vmemmap_psize, mmu_kernel_ssize); + if (rc < 0) { + int rc2 = htab_remove_mapping(start, start + page_size, + mmu_vmemmap_psize, + mmu_kernel_ssize); + BUG_ON(rc2 && (rc2 != -ENOENT)); + } + return rc; } #ifdef CONFIG_MEMORY_HOTPLUG @@ -304,6 +311,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) for (; start < end; start += page_size) { void *p; + int rc; if (vmemmap_populated(start, page_size)) continue; @@ -317,7 +325,13 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) pr_debug(" * %016lx..%016lx allocated at %p\n", start, start + page_size, p); - vmemmap_create_mapping(start, page_size, __pa(p)); + rc = vmemmap_create_mapping(start, page_size, __pa(p)); + if (rc < 0) { + pr_warning( + "vmemmap_populate: Unable to create vmemmap mapping: %d\n", + rc); + return -EFAULT; + } } return 0; diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index d0f0a51..f980da6 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -119,12 +119,18 @@ int arch_add_memory(int nid, u64 start, u64 size, bool for_device) struct zone *zone; unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; + int rc; pgdata = NODE_DATA(nid); start = (unsigned long)__va(start); - if (create_section_mapping(start, start + size)) - return -EINVAL; + rc = create_section_mapping(start, start + size); + if (rc) { + pr_warning( + "Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n", + start, start + size, rc); + return -EFAULT; + } /* this should work for most non-highmem platforms */ zone = pgdata->node_zones +
This makes a number of cleanups to handling of mapping failures during memory hotplug on Power: For errors creating the linear mapping for the hot-added region: * This is now reported with EFAULT which is more appropriate than the previous EINVAL (the failure is unlikely to be related to the function's parameters) * An error in this path now prints a warning message, rather than just silently failing to add the extra memory. * Previously a failure here could result in the region being partially mapped. We now clean up any partial mapping before failing. For errors creating the vmemmap for the hot-added region: * This is now reported with EFAULT instead of causing a BUG() - this could happen for external reason (e.g. full hash table) so it's better to handle this non-fatally * An error message is also printed, so the failure won't be silent * As above a failure could cause a partially mapped region, we now clean this up. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Paul Mackerras <paulus@samba.org> --- arch/powerpc/mm/hash_utils_64.c | 13 ++++++++++--- arch/powerpc/mm/init_64.c | 38 ++++++++++++++++++++++++++------------ arch/powerpc/mm/mem.c | 10 ++++++++-- 3 files changed, 44 insertions(+), 17 deletions(-)