From c2ad29540cb913bd9e526fae77c35c7fb45f24a3 Mon Sep 17 00:00:00 2001 From: Ross Zwisler Date: Fri, 10 Jul 2015 11:06:13 -0600 Subject: [PATCH] nfit: update block I/O path to use PMEM API Update the nfit block I/O path to use the new PMEM API and to adhere to the read/write flows outlined in the "NVDIMM Block Window Driver Writer's Guide": http://pmem.io/documents/NVDIMM_Driver_Writers_Guide.pdf This includes adding support for targeted NVDIMM flushes called "flush hints" in the ACPI 6.0 specification: http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf For performance and media durability the mapping for a BLK aperture is moved to a write-combining mapping which is consistent with memcpy_to_pmem() and wmb_blk(). Signed-off-by: Ross Zwisler Acked-by: Rafael J. Wysocki Signed-off-by: Dan Williams --- drivers/acpi/nfit.c | 97 ++++++++++++++++++++++++++++++++++++++++----- drivers/acpi/nfit.h | 15 ++++++- 2 files changed, 100 insertions(+), 12 deletions(-) diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c index a20b7c883ca0..11aa513f2fda 100644 --- a/drivers/acpi/nfit.c +++ b/drivers/acpi/nfit.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include "nfit.h" @@ -305,6 +306,23 @@ static bool add_idt(struct acpi_nfit_desc *acpi_desc, return true; } +static bool add_flush(struct acpi_nfit_desc *acpi_desc, + struct acpi_nfit_flush_address *flush) +{ + struct device *dev = acpi_desc->dev; + struct nfit_flush *nfit_flush = devm_kzalloc(dev, sizeof(*nfit_flush), + GFP_KERNEL); + + if (!nfit_flush) + return false; + INIT_LIST_HEAD(&nfit_flush->list); + nfit_flush->flush = flush; + list_add_tail(&nfit_flush->list, &acpi_desc->flushes); + dev_dbg(dev, "%s: nfit_flush handle: %d hint_count: %d\n", __func__, + flush->device_handle, flush->hint_count); + return true; +} + static void *add_table(struct acpi_nfit_desc *acpi_desc, void *table, const void *end) { @@ -338,7 +356,8 @@ static void *add_table(struct acpi_nfit_desc *acpi_desc, void *table, return err; break; case ACPI_NFIT_TYPE_FLUSH_ADDRESS: - dev_dbg(dev, "%s: flush\n", __func__); + if (!add_flush(acpi_desc, table)) + return err; break; case ACPI_NFIT_TYPE_SMBIOS: dev_dbg(dev, "%s: smbios\n", __func__); @@ -389,6 +408,7 @@ static int nfit_mem_add(struct acpi_nfit_desc *acpi_desc, { u16 dcr = __to_nfit_memdev(nfit_mem)->region_index; struct nfit_memdev *nfit_memdev; + struct nfit_flush *nfit_flush; struct nfit_dcr *nfit_dcr; struct nfit_bdw *nfit_bdw; struct nfit_idt *nfit_idt; @@ -442,6 +462,14 @@ static int nfit_mem_add(struct acpi_nfit_desc *acpi_desc, nfit_mem->idt_bdw = nfit_idt->idt; break; } + + list_for_each_entry(nfit_flush, &acpi_desc->flushes, list) { + if (nfit_flush->flush->device_handle != + nfit_memdev->memdev->device_handle) + continue; + nfit_mem->nfit_flush = nfit_flush; + break; + } break; } @@ -978,6 +1006,24 @@ static u64 to_interleave_offset(u64 offset, struct nfit_blk_mmio *mmio) return mmio->base_offset + line_offset + table_offset + sub_line_offset; } +static void wmb_blk(struct nfit_blk *nfit_blk) +{ + + if (nfit_blk->nvdimm_flush) { + /* + * The first wmb() is needed to 'sfence' all previous writes + * such that they are architecturally visible for the platform + * buffer flush. Note that we've already arranged for pmem + * writes to avoid the cache via arch_memcpy_to_pmem(). The + * final wmb() ensures ordering for the NVDIMM flush write. + */ + wmb(); + writeq(1, nfit_blk->nvdimm_flush); + wmb(); + } else + wmb_pmem(); +} + static u64 read_blk_stat(struct nfit_blk *nfit_blk, unsigned int bw) { struct nfit_blk_mmio *mmio = &nfit_blk->mmio[DCR]; @@ -1012,6 +1058,7 @@ static void write_blk_ctl(struct nfit_blk *nfit_blk, unsigned int bw, offset = to_interleave_offset(offset, mmio); writeq(cmd, mmio->base + offset); + wmb_blk(nfit_blk); /* FIXME: conditionally perform read-back if mandated by firmware */ } @@ -1026,7 +1073,6 @@ static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk, base_offset = nfit_blk->bdw_offset + dpa % L1_CACHE_BYTES + lane * mmio->size; - /* TODO: non-temporal access, flush hints, cache management etc... */ write_blk_ctl(nfit_blk, lane, dpa, len, rw); while (len) { unsigned int c; @@ -1045,13 +1091,19 @@ static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk, } if (rw) - memcpy(mmio->aperture + offset, iobuf + copied, c); + memcpy_to_pmem(mmio->aperture + offset, + iobuf + copied, c); else - memcpy(iobuf + copied, mmio->aperture + offset, c); + memcpy_from_pmem(iobuf + copied, + mmio->aperture + offset, c); copied += c; len -= c; } + + if (rw) + wmb_blk(nfit_blk); + rc = read_blk_stat(nfit_blk, lane) ? -EIO : 0; return rc; } @@ -1124,7 +1176,7 @@ static void nfit_spa_unmap(struct acpi_nfit_desc *acpi_desc, } static void __iomem *__nfit_spa_map(struct acpi_nfit_desc *acpi_desc, - struct acpi_nfit_system_address *spa) + struct acpi_nfit_system_address *spa, enum spa_map_type type) { resource_size_t start = spa->address; resource_size_t n = spa->length; @@ -1152,8 +1204,15 @@ static void __iomem *__nfit_spa_map(struct acpi_nfit_desc *acpi_desc, if (!res) goto err_mem; - /* TODO: cacheability based on the spa type */ - spa_map->iomem = ioremap_nocache(start, n); + if (type == SPA_MAP_APERTURE) { + /* + * TODO: memremap_pmem() support, but that requires cache + * flushing when the aperture is moved. + */ + spa_map->iomem = ioremap_wc(start, n); + } else + spa_map->iomem = ioremap_nocache(start, n); + if (!spa_map->iomem) goto err_map; @@ -1171,6 +1230,7 @@ static void __iomem *__nfit_spa_map(struct acpi_nfit_desc *acpi_desc, * nfit_spa_map - interleave-aware managed-mappings of acpi_nfit_system_address ranges * @nvdimm_bus: NFIT-bus that provided the spa table entry * @nfit_spa: spa table to map + * @type: aperture or control region * * In the case where block-data-window apertures and * dimm-control-regions are interleaved they will end up sharing a @@ -1180,12 +1240,12 @@ static void __iomem *__nfit_spa_map(struct acpi_nfit_desc *acpi_desc, * unbound. */ static void __iomem *nfit_spa_map(struct acpi_nfit_desc *acpi_desc, - struct acpi_nfit_system_address *spa) + struct acpi_nfit_system_address *spa, enum spa_map_type type) { void __iomem *iomem; mutex_lock(&acpi_desc->spa_map_mutex); - iomem = __nfit_spa_map(acpi_desc, spa); + iomem = __nfit_spa_map(acpi_desc, spa, type); mutex_unlock(&acpi_desc->spa_map_mutex); return iomem; @@ -1212,6 +1272,7 @@ static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus, struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus); struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc); struct nd_blk_region *ndbr = to_nd_blk_region(dev); + struct nfit_flush *nfit_flush; struct nfit_blk_mmio *mmio; struct nfit_blk *nfit_blk; struct nfit_mem *nfit_mem; @@ -1237,7 +1298,8 @@ static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus, /* map block aperture memory */ nfit_blk->bdw_offset = nfit_mem->bdw->offset; mmio = &nfit_blk->mmio[BDW]; - mmio->base = nfit_spa_map(acpi_desc, nfit_mem->spa_bdw); + mmio->base = nfit_spa_map(acpi_desc, nfit_mem->spa_bdw, + SPA_MAP_APERTURE); if (!mmio->base) { dev_dbg(dev, "%s: %s failed to map bdw\n", __func__, nvdimm_name(nvdimm)); @@ -1259,7 +1321,8 @@ static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus, nfit_blk->cmd_offset = nfit_mem->dcr->command_offset; nfit_blk->stat_offset = nfit_mem->dcr->status_offset; mmio = &nfit_blk->mmio[DCR]; - mmio->base = nfit_spa_map(acpi_desc, nfit_mem->spa_dcr); + mmio->base = nfit_spa_map(acpi_desc, nfit_mem->spa_dcr, + SPA_MAP_CONTROL); if (!mmio->base) { dev_dbg(dev, "%s: %s failed to map dcr\n", __func__, nvdimm_name(nvdimm)); @@ -1277,6 +1340,17 @@ static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus, return rc; } + nfit_flush = nfit_mem->nfit_flush; + if (nfit_flush && nfit_flush->flush->hint_count != 0) { + nfit_blk->nvdimm_flush = devm_ioremap_nocache(dev, + nfit_flush->flush->hint_address[0], 8); + if (!nfit_blk->nvdimm_flush) + return -ENOMEM; + } + + if (!arch_has_pmem_api() && !nfit_blk->nvdimm_flush) + dev_warn(dev, "unable to guarantee persistence of writes\n"); + if (mmio->line_size == 0) return 0; @@ -1459,6 +1533,7 @@ int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, acpi_size sz) INIT_LIST_HEAD(&acpi_desc->dcrs); INIT_LIST_HEAD(&acpi_desc->bdws); INIT_LIST_HEAD(&acpi_desc->idts); + INIT_LIST_HEAD(&acpi_desc->flushes); INIT_LIST_HEAD(&acpi_desc->memdevs); INIT_LIST_HEAD(&acpi_desc->dimms); mutex_init(&acpi_desc->spa_map_mutex); diff --git a/drivers/acpi/nfit.h b/drivers/acpi/nfit.h index 81f2e8c5a79c..815cb561cdba 100644 --- a/drivers/acpi/nfit.h +++ b/drivers/acpi/nfit.h @@ -60,6 +60,11 @@ struct nfit_idt { struct list_head list; }; +struct nfit_flush { + struct acpi_nfit_flush_address *flush; + struct list_head list; +}; + struct nfit_memdev { struct acpi_nfit_memory_map *memdev; struct list_head list; @@ -77,6 +82,7 @@ struct nfit_mem { struct acpi_nfit_system_address *spa_bdw; struct acpi_nfit_interleave *idt_dcr; struct acpi_nfit_interleave *idt_bdw; + struct nfit_flush *nfit_flush; struct list_head list; struct acpi_device *adev; unsigned long dsm_mask; @@ -88,6 +94,7 @@ struct acpi_nfit_desc { struct mutex spa_map_mutex; struct list_head spa_maps; struct list_head memdevs; + struct list_head flushes; struct list_head dimms; struct list_head spas; struct list_head dcrs; @@ -109,7 +116,7 @@ struct nfit_blk { struct nfit_blk_mmio { union { void __iomem *base; - void *aperture; + void __pmem *aperture; }; u64 size; u64 base_offset; @@ -123,6 +130,12 @@ struct nfit_blk { u64 bdw_offset; /* post interleave offset */ u64 stat_offset; u64 cmd_offset; + void __iomem *nvdimm_flush; +}; + +enum spa_map_type { + SPA_MAP_CONTROL, + SPA_MAP_APERTURE, }; struct nfit_spa_mapping { -- 2.30.2