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authorRoss Zwisler <ross.zwisler@linux.intel.com>2015-07-10 11:06:13 -0600
committerDan Williams <dan.j.williams@intel.com>2015-07-10 14:35:45 -0400
commitc2ad29540cb913bd9e526fae77c35c7fb45f24a3 (patch)
tree739e9d071388ca1e53238a3e5f76d716b5597f48
parent9d27a87ec9e1317d368b1e5e3f4808078baa8c4c (diff)
downloadlinux-c2ad29540cb913bd9e526fae77c35c7fb45f24a3.tar.bz2
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 <ross.zwisler@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
-rw-r--r--drivers/acpi/nfit.c97
-rw-r--r--drivers/acpi/nfit.h15
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 <linux/list.h>
#include <linux/acpi.h>
#include <linux/sort.h>
+#include <linux/pmem.h>
#include <linux/io.h>
#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 {