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Date: Wed, 8 Jul 2015 10:00:20 -0600
From: Ross Zwisler <ross.zwisler@...ux.intel.com>
To: linux-kernel@...r.kernel.org
Cc: Ross Zwisler <ross.zwisler@...ux.intel.com>,
linux-nvdimm@...ts.01.org, linux-acpi@...r.kernel.org,
"Rafael J. Wysocki" <rjw@...ysocki.net>,
Dan Williams <dan.j.williams@...el.com>,
Len Brown <lenb@...nel.org>, Christoph Hellwig <hch@....de>,
Jeff Moyer <jmoyer@...hat.com>, Toshi Kani <toshi.kani@...com>
Subject: [PATCH 2/3] 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
Signed-off-by: Ross Zwisler <ross.zwisler@...ux.intel.com>
Cc: linux-nvdimm@...ts.01.org
Cc: linux-acpi@...r.kernel.org
Cc: "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc: Dan Williams <dan.j.williams@...el.com>
Cc: Len Brown <lenb@...nel.org>
Cc: Christoph Hellwig <hch@....de>
Cc: Jeff Moyer <jmoyer@...hat.com>
Cc: Toshi Kani <toshi.kani@...com>
---
drivers/acpi/nfit.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++---
drivers/acpi/nfit.h | 10 ++++++-
2 files changed, 86 insertions(+), 5 deletions(-)
diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index a20b7c883ca0..b3c446412f61 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;
}
@@ -1212,12 +1264,16 @@ 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;
struct nvdimm *nvdimm;
int rc;
+ if (!arch_has_pmem_api())
+ dev_warn(dev, "unable to guarantee persistence of writes\n");
+
nvdimm = nd_blk_region_to_dimm(ndbr);
nfit_mem = nvdimm_provider_data(nvdimm);
if (!nfit_mem || !nfit_mem->dcr || !nfit_mem->bdw) {
@@ -1277,6 +1333,22 @@ 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) {
+ struct acpi_nfit_flush_address *flush = nfit_flush->flush;
+ struct resource res;
+
+ res.start = flush->hint_address[0];
+ res.end = flush->hint_address[0] + sizeof(u64) - 1;
+ res.name = dev_name(dev);
+ res.flags = IORESOURCE_MEM;
+
+ /* only need a single NVDIMM flush address. map uncacheable */
+ nfit_blk->nvdimm_flush = devm_ioremap_resource(dev, &res);
+ if (IS_ERR(nfit_blk->nvdimm_flush))
+ return -ENOMEM;
+ }
+
if (mmio->line_size == 0)
return 0;
@@ -1459,6 +1531,7 @@ 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..d284729cc37c 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 +130,7 @@ struct nfit_blk {
u64 bdw_offset; /* post interleave offset */
u64 stat_offset;
u64 cmd_offset;
+ void __iomem *nvdimm_flush;
};
struct nfit_spa_mapping {
--
1.9.3
--
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