From 7a67832c7e44c20935c5d6f2264035a0f7bf0d8f Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 19 Aug 2015 00:34:34 -0400 Subject: libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option We currently register a platform device for e820 type-12 memory and register a nvdimm bus beneath it. Registering the platform device triggers the device-core machinery to probe for a driver, but that search currently comes up empty. Building the nvdimm-bus registration into the e820_pmem platform device registration in this way forces libnvdimm to be built-in. Instead, convert the built-in portion of CONFIG_X86_PMEM_LEGACY to simply register a platform device and move the rest of the logic to the driver for e820_pmem, for the following reasons: 1/ Letting e820_pmem support be a module allows building and testing libnvdimm.ko changes without rebooting 2/ All the normal policy around modules can be applied to e820_pmem (unbind to disable and/or blacklisting the module from loading by default) 3/ Moving the driver to a generic location and converting it to scan "iomem_resource" rather than "e820.map" means any other architecture can take advantage of this simple nvdimm resource discovery mechanism by registering a resource named "Persistent Memory (legacy)" Cc: Christoph Hellwig Signed-off-by: Dan Williams --- arch/x86/Kconfig | 6 ++- arch/x86/include/uapi/asm/e820.h | 2 +- arch/x86/kernel/Makefile | 2 +- arch/x86/kernel/pmem.c | 79 ++++------------------------------------ 4 files changed, 15 insertions(+), 74 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index b3a1a5d77d92..76c61154ed50 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1426,10 +1426,14 @@ config ILLEGAL_POINTER_VALUE source "mm/Kconfig" +config X86_PMEM_LEGACY_DEVICE + bool + config X86_PMEM_LEGACY - bool "Support non-standard NVDIMMs and ADR protected memory" + tristate "Support non-standard NVDIMMs and ADR protected memory" depends on PHYS_ADDR_T_64BIT depends on BLK_DEV + select X86_PMEM_LEGACY_DEVICE select LIBNVDIMM help Treat memory marked using the non-standard e820 type of 12 as used diff --git a/arch/x86/include/uapi/asm/e820.h b/arch/x86/include/uapi/asm/e820.h index 0f457e6eab18..9dafe59cf6e2 100644 --- a/arch/x86/include/uapi/asm/e820.h +++ b/arch/x86/include/uapi/asm/e820.h @@ -37,7 +37,7 @@ /* * This is a non-standardized way to represent ADR or NVDIMM regions that * persist over a reboot. The kernel will ignore their special capabilities - * unless the CONFIG_X86_PMEM_LEGACY=y option is set. + * unless the CONFIG_X86_PMEM_LEGACY option is set. * * ( Note that older platforms also used 6 for the same type of memory, * but newer versions switched to 12 as 6 was assigned differently. Some diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 0f15af41bd80..ac2bb7e28ba2 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -92,7 +92,7 @@ obj-$(CONFIG_KVM_GUEST) += kvm.o kvmclock.o obj-$(CONFIG_PARAVIRT) += paravirt.o paravirt_patch_$(BITS).o obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= paravirt-spinlocks.o obj-$(CONFIG_PARAVIRT_CLOCK) += pvclock.o -obj-$(CONFIG_X86_PMEM_LEGACY) += pmem.o +obj-$(CONFIG_X86_PMEM_LEGACY_DEVICE) += pmem.o obj-$(CONFIG_PCSPKR_PLATFORM) += pcspeaker.o diff --git a/arch/x86/kernel/pmem.c b/arch/x86/kernel/pmem.c index 64f90f53bb85..4f00b63d7ff3 100644 --- a/arch/x86/kernel/pmem.c +++ b/arch/x86/kernel/pmem.c @@ -3,80 +3,17 @@ * Copyright (c) 2015, Intel Corporation. */ #include -#include #include -#include - -static void e820_pmem_release(struct device *dev) -{ - struct nvdimm_bus *nvdimm_bus = dev->platform_data; - - if (nvdimm_bus) - nvdimm_bus_unregister(nvdimm_bus); -} - -static struct platform_device e820_pmem = { - .name = "e820_pmem", - .id = -1, - .dev = { - .release = e820_pmem_release, - }, -}; - -static const struct attribute_group *e820_pmem_attribute_groups[] = { - &nvdimm_bus_attribute_group, - NULL, -}; - -static const struct attribute_group *e820_pmem_region_attribute_groups[] = { - &nd_region_attribute_group, - &nd_device_attribute_group, - NULL, -}; static __init int register_e820_pmem(void) { - static struct nvdimm_bus_descriptor nd_desc; - struct device *dev = &e820_pmem.dev; - struct nvdimm_bus *nvdimm_bus; - int rc, i; - - rc = platform_device_register(&e820_pmem); - if (rc) - return rc; - - nd_desc.attr_groups = e820_pmem_attribute_groups; - nd_desc.provider_name = "e820"; - nvdimm_bus = nvdimm_bus_register(dev, &nd_desc); - if (!nvdimm_bus) - goto err; - dev->platform_data = nvdimm_bus; - - for (i = 0; i < e820.nr_map; i++) { - struct e820entry *ei = &e820.map[i]; - struct resource res = { - .flags = IORESOURCE_MEM, - .start = ei->addr, - .end = ei->addr + ei->size - 1, - }; - struct nd_region_desc ndr_desc; - - if (ei->type != E820_PRAM) - continue; - - memset(&ndr_desc, 0, sizeof(ndr_desc)); - ndr_desc.res = &res; - ndr_desc.attr_groups = e820_pmem_region_attribute_groups; - ndr_desc.numa_node = NUMA_NO_NODE; - if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc)) - goto err; - } - - return 0; - - err: - dev_err(dev, "failed to register legacy persistent memory ranges\n"); - platform_device_unregister(&e820_pmem); - return -ENXIO; + struct platform_device *pdev; + + /* + * See drivers/nvdimm/e820.c for the implementation, this is + * simply here to trigger the module to load on demand. + */ + pdev = platform_device_alloc("e820_pmem", -1); + return platform_device_add(pdev); } device_initcall(register_e820_pmem); -- cgit v1.2.1