From ad5fb870c486d932a1749d7853dd70f436a7e03f Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 3 Apr 2015 12:05:28 -0400 Subject: e820, efi: add ACPI 6.0 persistent memory types 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). Note, /proc/iomem can be consulted for differentiating legacy "Persistent Memory (legacy)" E820_PRAM vs standard "Persistent Memory" E820_PMEM. Cc: Boaz Harrosh Cc: Ingo Molnar Cc: Christoph Hellwig Cc: Andrew Morton Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Jens Axboe Cc: Linus Torvalds Cc: Matthew Wilcox Cc: Thomas Gleixner Acked-by: Jeff Moyer Acked-by: Andy Lutomirski Reviewed-by: Ross Zwisler Acked-by: Christoph Hellwig Tested-by: Toshi Kani Signed-off-by: Dan Williams --- arch/x86/kernel/e820.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) (limited to 'arch/x86/kernel/e820.c') diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index e2ce85db2283..c857d53269dd 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; @@ -918,11 +919,32 @@ static inline const char *e820_type_to_string(int e820_type) case E820_ACPI: return "ACPI Tables"; case E820_NVS: return "ACPI Non-volatile Storage"; case E820_UNUSABLE: return "Unusable memory"; - case E820_PRAM: return "Persistent RAM"; + case E820_PRAM: return "Persistent Memory (legacy)"; + case E820_PMEM: return "Persistent 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); } -- cgit v1.2.3