| Message ID | 20150428182417.35812.92834.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Dan Williams |
| Headers | show |
On Tue, Apr 28, 2015 at 11:24 AM, Dan Williams <dan.j.williams@intel.com> wrote: > ACPI 6.0 formalizes e820-type-7 and efi-type-14 as persistent memory. > Mark it "reserved" and allow it to be claimed by a persistent memory > device driver. > > This definition is in addition to the Linux kernel's existing type-12 > definition that was recently added in support of shipping platforms with > NVDIMM support that predate ACPI 6.0 (which now classifies type-12 as > OEM reserved). We may choose to exploit this wealth of definitions for > NVDIMMs to differentiate E820_PRAM (type-12) from E820_PMEM (type-7). > One potential differentiation is that PMEM is not backed by struct page > by default in contrast to PRAM. For now, they are effectively treated > as aliases by the mm. > > Note, /proc/iomem can be consulted for differentiating legacy > "Persistent RAM" E820_PRAM vs standard "Persistent I/O Memory" > E820_PMEM. > > Cc: Boaz Harrosh <boaz@plexistor.com> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Borislav Petkov <bp@alien8.de> > Cc: H. Peter Anvin <hpa@zytor.com> > Cc: Jens Axboe <axboe@fb.com> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Matthew Wilcox <willy@linux.intel.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Acked-by: Andy Lutomirski <luto@amacapital.net> > Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > --- > arch/arm64/kernel/efi.c | 1 + > arch/ia64/kernel/efi.c | 4 ++++ > arch/x86/boot/compressed/eboot.c | 4 ++++ > arch/x86/include/uapi/asm/e820.h | 1 + > arch/x86/kernel/e820.c | 26 +++++++++++++++++++++++--- > arch/x86/platform/efi/efi.c | 3 +++ > include/linux/efi.h | 3 ++- > 7 files changed, 38 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c > index ab21e0d58278..9d4aa18f2a82 100644 > --- a/arch/arm64/kernel/efi.c > +++ b/arch/arm64/kernel/efi.c > @@ -158,6 +158,7 @@ static __init int is_reserve_region(efi_memory_desc_t *md) > case EFI_BOOT_SERVICES_CODE: > case EFI_BOOT_SERVICES_DATA: > case EFI_CONVENTIONAL_MEMORY: > + case EFI_PERSISTENT_MEMORY: > return 0; > default: > break; > diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c > index c52d7540dc05..9028bc268cd7 100644 > --- a/arch/ia64/kernel/efi.c > +++ b/arch/ia64/kernel/efi.c > @@ -1223,6 +1223,10 @@ efi_initialize_iomem_resources(struct resource *code_resource, > flags |= IORESOURCE_DISABLED; > break; > > + case EFI_PERSISTENT_MEMORY: > + name = "persistent"; > + break; > + > case EFI_RESERVED_TYPE: > case EFI_RUNTIME_SERVICES_CODE: > case EFI_RUNTIME_SERVICES_DATA: > diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c > index ef17683484e9..dde5bf7726f4 100644 > --- a/arch/x86/boot/compressed/eboot.c > +++ b/arch/x86/boot/compressed/eboot.c > @@ -1222,6 +1222,10 @@ static efi_status_t setup_e820(struct boot_params *params, > e820_type = E820_NVS; > break; > > + case EFI_PERSISTENT_MEMORY: > + e820_type = E820_PMEM; > + break; > + > default: > continue; > } > diff --git a/arch/x86/include/uapi/asm/e820.h b/arch/x86/include/uapi/asm/e820.h > index 960a8a9dc4ab..0f457e6eab18 100644 > --- a/arch/x86/include/uapi/asm/e820.h > +++ b/arch/x86/include/uapi/asm/e820.h > @@ -32,6 +32,7 @@ > #define E820_ACPI 3 > #define E820_NVS 4 > #define E820_UNUSABLE 5 > +#define E820_PMEM 7 > > /* > * This is a non-standardized way to represent ADR or NVDIMM regions that > diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c > index 11cc7d54ec3f..d38b53a7e9b2 100644 > --- a/arch/x86/kernel/e820.c > +++ b/arch/x86/kernel/e820.c > @@ -149,6 +149,7 @@ static void __init e820_print_type(u32 type) > case E820_UNUSABLE: > printk(KERN_CONT "unusable"); > break; > + case E820_PMEM: > case E820_PRAM: > printk(KERN_CONT "persistent (type %u)", type); > break; I'd kind of like to make it more clear what's going on here. It doesn't help that the spec chose poor names. How about "NVDIMM physical aperture" for E820_PMEM and "legacy persistent RAM" for E820_PRAM? Otherwise this looks generaly sensible, although I don't really understand why e820_type_to_string and e820_print_type are different. --Andy
On Tue, Apr 28, 2015 at 1:49 PM, Andy Lutomirski <luto@amacapital.net> wrote: > On Tue, Apr 28, 2015 at 11:24 AM, Dan Williams <dan.j.williams@intel.com> wrote: >> diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c >> index 11cc7d54ec3f..d38b53a7e9b2 100644 >> --- a/arch/x86/kernel/e820.c >> +++ b/arch/x86/kernel/e820.c >> @@ -149,6 +149,7 @@ static void __init e820_print_type(u32 type) >> case E820_UNUSABLE: >> printk(KERN_CONT "unusable"); >> break; >> + case E820_PMEM: >> case E820_PRAM: >> printk(KERN_CONT "persistent (type %u)", type); >> break; > > I'd kind of like to make it more clear what's going on here. It > doesn't help that the spec chose poor names. > > How about "NVDIMM physical aperture" for E820_PMEM and "legacy > persistent RAM" for E820_PRAM? The term "aperture" to me implies this BLK (mmio-windowed) mode of accessing persistent media that the NFIT specification introduces. In fact, those ranges are mapped E820_RESERVED. E820_PMEM really is a memory range that happens to be persistent. > Otherwise this looks generaly sensible, although I don't really > understand why e820_type_to_string and e820_print_type are different. e820_type_to_string() appears in /proc/iomem and seems to afford being more descriptive than e820_print_type() that just scrolls by in dmesg, but I'm just guessing.
On Tue, Apr 28, 2015 at 1:57 PM, Dan Williams <dan.j.williams@intel.com> wrote: > On Tue, Apr 28, 2015 at 1:49 PM, Andy Lutomirski <luto@amacapital.net> wrote: >> On Tue, Apr 28, 2015 at 11:24 AM, Dan Williams <dan.j.williams@intel.com> wrote: >>> diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c >>> index 11cc7d54ec3f..d38b53a7e9b2 100644 >>> --- a/arch/x86/kernel/e820.c >>> +++ b/arch/x86/kernel/e820.c >>> @@ -149,6 +149,7 @@ static void __init e820_print_type(u32 type) >>> case E820_UNUSABLE: >>> printk(KERN_CONT "unusable"); >>> break; >>> + case E820_PMEM: >>> case E820_PRAM: >>> printk(KERN_CONT "persistent (type %u)", type); >>> break; >> >> I'd kind of like to make it more clear what's going on here. It >> doesn't help that the spec chose poor names. >> >> How about "NVDIMM physical aperture" for E820_PMEM and "legacy >> persistent RAM" for E820_PRAM? > > The term "aperture" to me implies this BLK (mmio-windowed) mode of > accessing persistent media that the NFIT specification introduces. In > fact, those ranges are mapped E820_RESERVED. E820_PMEM really is a > memory range that happens to be persistent. Oh, I missed that. Yuck. What happens when you repartition one of these things? (Can you even do that?) > >> Otherwise this looks generaly sensible, although I don't really >> understand why e820_type_to_string and e820_print_type are different. > > e820_type_to_string() appears in /proc/iomem and seems to afford > being more descriptive than e820_print_type() that just scrolls by in > dmesg, but I'm just guessing. Can we change that?
Dan Williams <dan.j.williams@intel.com> writes: > @@ -919,10 +920,31 @@ static inline const char *e820_type_to_string(int e820_type) > case E820_NVS: return "ACPI Non-volatile Storage"; > case E820_UNUSABLE: return "Unusable memory"; > case E820_PRAM: return "Persistent RAM"; > + case E820_PMEM: return "Persistent I/O Memory"; Minor nit, but nobody refers to this stuff as persistent I/O memory. I've heard it referred to as persistent memory or storage class memory. In the end, I doubt it matters. Acked-by: Jeff Moyer <jmoyer@redhat.com>
On Fri, May 15, 2015 at 8:43 AM, Jeff Moyer <jmoyer@redhat.com> wrote: > Dan Williams <dan.j.williams@intel.com> writes: > >> @@ -919,10 +920,31 @@ static inline const char *e820_type_to_string(int e820_type) >> case E820_NVS: return "ACPI Non-volatile Storage"; >> case E820_UNUSABLE: return "Unusable memory"; >> case E820_PRAM: return "Persistent RAM"; >> + case E820_PMEM: return "Persistent I/O Memory"; > > Minor nit, but nobody refers to this stuff as persistent I/O memory. > I've heard it referred to as persistent memory or storage class memory. > In the end, I doubt it matters. Had we not polluted the waters with E820_PRAM I would have chosen "Persistent Memory", but as we now need to support both I'd assume they need different names. > Acked-by: Jeff Moyer <jmoyer@redhat.com> Thanks Jeff.
On May 16, 2015 12:48 AM, "Dan Williams" <dan.j.williams@intel.com> wrote: > > On Fri, May 15, 2015 at 8:43 AM, Jeff Moyer <jmoyer@redhat.com> wrote: > > Dan Williams <dan.j.williams@intel.com> writes: > > > >> @@ -919,10 +920,31 @@ static inline const char *e820_type_to_string(int e820_type) > >> case E820_NVS: return "ACPI Non-volatile Storage"; > >> case E820_UNUSABLE: return "Unusable memory"; > >> case E820_PRAM: return "Persistent RAM"; > >> + case E820_PMEM: return "Persistent I/O Memory"; > > > > Minor nit, but nobody refers to this stuff as persistent I/O memory. > > I've heard it referred to as persistent memory or storage class memory. > > In the end, I doubt it matters. > > Had we not polluted the waters with E820_PRAM I would have chosen > "Persistent Memory", but as we now need to support both I'd assume > they need different names. We could reverse it and call E820_PRAM "legacy persistent RAM" or something similar. </bikeshed> > > > Acked-by: Jeff Moyer <jmoyer@redhat.com> > > Thanks Jeff.
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index ab21e0d58278..9d4aa18f2a82 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -158,6 +158,7 @@ static __init int is_reserve_region(efi_memory_desc_t *md) case EFI_BOOT_SERVICES_CODE: case EFI_BOOT_SERVICES_DATA: case EFI_CONVENTIONAL_MEMORY: + case EFI_PERSISTENT_MEMORY: return 0; default: break; diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c index c52d7540dc05..9028bc268cd7 100644 --- a/arch/ia64/kernel/efi.c +++ b/arch/ia64/kernel/efi.c @@ -1223,6 +1223,10 @@ efi_initialize_iomem_resources(struct resource *code_resource, flags |= IORESOURCE_DISABLED; break; + case EFI_PERSISTENT_MEMORY: + name = "persistent"; + break; + case EFI_RESERVED_TYPE: case EFI_RUNTIME_SERVICES_CODE: case EFI_RUNTIME_SERVICES_DATA: diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index ef17683484e9..dde5bf7726f4 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -1222,6 +1222,10 @@ static efi_status_t setup_e820(struct boot_params *params, e820_type = E820_NVS; break; + case EFI_PERSISTENT_MEMORY: + e820_type = E820_PMEM; + break; + default: continue; } diff --git a/arch/x86/include/uapi/asm/e820.h b/arch/x86/include/uapi/asm/e820.h index 960a8a9dc4ab..0f457e6eab18 100644 --- a/arch/x86/include/uapi/asm/e820.h +++ b/arch/x86/include/uapi/asm/e820.h @@ -32,6 +32,7 @@ #define E820_ACPI 3 #define E820_NVS 4 #define E820_UNUSABLE 5 +#define E820_PMEM 7 /* * This is a non-standardized way to represent ADR or NVDIMM regions that diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 11cc7d54ec3f..d38b53a7e9b2 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -149,6 +149,7 @@ static void __init e820_print_type(u32 type) case E820_UNUSABLE: printk(KERN_CONT "unusable"); break; + case E820_PMEM: case E820_PRAM: printk(KERN_CONT "persistent (type %u)", type); break; @@ -919,10 +920,31 @@ static inline const char *e820_type_to_string(int e820_type) case E820_NVS: return "ACPI Non-volatile Storage"; case E820_UNUSABLE: return "Unusable memory"; case E820_PRAM: return "Persistent RAM"; + case E820_PMEM: return "Persistent I/O Memory"; default: return "reserved"; } } +static bool do_mark_busy(u32 type, struct resource *res) +{ + /* this is the legacy bios/dos rom-shadow + mmio region */ + if (res->start < (1ULL<<20)) + return true; + + /* + * Treat persistent memory like device memory, i.e. reserve it + * for exclusive use of a driver + */ + switch (type) { + case E820_RESERVED: + case E820_PRAM: + case E820_PMEM: + return false; + default: + return true; + } +} + /* * Mark e820 reserved areas as busy for the resource manager. */ @@ -952,9 +974,7 @@ void __init e820_reserve_resources(void) * pci device BAR resource and insert them later in * pcibios_resource_survey() */ - if (((e820.map[i].type != E820_RESERVED) && - (e820.map[i].type != E820_PRAM)) || - res->start < (1ULL<<20)) { + if (do_mark_busy(e820.map[i].type, res)) { res->flags |= IORESOURCE_BUSY; insert_resource(&iomem_resource, res); } diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index dbc8627a5cdf..a116e236ac3f 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -145,6 +145,9 @@ static void __init do_add_efi_memmap(void) case EFI_UNUSABLE_MEMORY: e820_type = E820_UNUSABLE; break; + case EFI_PERSISTENT_MEMORY: + e820_type = E820_PMEM; + break; default: /* * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE diff --git a/include/linux/efi.h b/include/linux/efi.h index cf7e431cbc73..28868504aa17 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -85,7 +85,8 @@ typedef struct { #define EFI_MEMORY_MAPPED_IO 11 #define EFI_MEMORY_MAPPED_IO_PORT_SPACE 12 #define EFI_PAL_CODE 13 -#define EFI_MAX_MEMORY_TYPE 14 +#define EFI_PERSISTENT_MEMORY 14 +#define EFI_MAX_MEMORY_TYPE 15 /* Attribute values: */ #define EFI_MEMORY_UC ((u64)0x0000000000000001ULL) /* uncached */