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 <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: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

7 files changed, 39 insertions, 5 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..5f6be9dd6968 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 Memory";
+                                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 48304b89b601..2c82bd150d43 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -1224,6 +1224,10 @@ 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 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);
                 }
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 02744df576d5..fe01ae37a2a4 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -153,6 +153,9 @@ 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 af5be0368dec..825b6e3d69cb 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 */