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| author |   Ross Zwisler <ross.zwisler@linux.intel.com> | 2015-07-10 11:06:14 -0600 |
|---|---|---|
| committer |   Dan Williams <dan.j.williams@intel.com> | 2015-07-10 14:43:50 -0400 |
| commit | f0f2c072cf530d5b8890be5051cc8b36b0c54cce (patch) | |
| tree | 3f57708f1babe641e193e06dbb433fd5bb8fea0e /drivers | |
| parent | nfit: update block I/O path to use PMEM API (diff) | |
| download | linux-dev-f0f2c072cf530d5b8890be5051cc8b36b0c54cce.tar.xz linux-dev-f0f2c072cf530d5b8890be5051cc8b36b0c54cce.zip | |
nfit: add support for NVDIMM "latch" flag
Add support in the NFIT BLK I/O path for the "latch" flag
defined in the "Get Block NVDIMM Flags" _DSM function:
http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf
This flag requires the driver to read back the command register after it
is written in the block I/O path. This ensures that the hardware has
fully processed the new command and moved the aperture appropriately.
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/acpi/nfit.c | 33 | ||||
| -rw-r--r-- | drivers/acpi/nfit.h | 5 |
2 files changed, 37 insertions, 1 deletions
diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c index 11aa513f2fda..628a42c41ab1 100644 --- a/drivers/acpi/nfit.c +++ b/drivers/acpi/nfit.c @@ -1059,7 +1059,9 @@ static void write_blk_ctl(struct nfit_blk *nfit_blk, unsigned int bw, writeq(cmd, mmio->base + offset); wmb_blk(nfit_blk); - /* FIXME: conditionally perform read-back if mandated by firmware */ + + if (nfit_blk->dimm_flags & ND_BLK_DCR_LATCH) + readq(mmio->base + offset); } static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk, @@ -1266,6 +1268,28 @@ static int nfit_blk_init_interleave(struct nfit_blk_mmio *mmio, return 0; } +static int acpi_nfit_blk_get_flags(struct nvdimm_bus_descriptor *nd_desc, + struct nvdimm *nvdimm, struct nfit_blk *nfit_blk) +{ + struct nd_cmd_dimm_flags flags; + int rc; + + memset(&flags, 0, sizeof(flags)); + rc = nd_desc->ndctl(nd_desc, nvdimm, ND_CMD_DIMM_FLAGS, &flags, + sizeof(flags)); + + if (rc >= 0 && flags.status == 0) + nfit_blk->dimm_flags = flags.flags; + else if (rc == -ENOTTY) { + /* fall back to a conservative default */ + nfit_blk->dimm_flags = ND_BLK_DCR_LATCH; + rc = 0; + } else + rc = -ENXIO; + + return rc; +} + static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus, struct device *dev) { @@ -1340,6 +1364,13 @@ static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus, return rc; } + rc = acpi_nfit_blk_get_flags(nd_desc, nvdimm, nfit_blk); + if (rc < 0) { + dev_dbg(dev, "%s: %s failed get DIMM flags\n", + __func__, nvdimm_name(nvdimm)); + 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, diff --git a/drivers/acpi/nfit.h b/drivers/acpi/nfit.h index 815cb561cdba..79b6d83875c1 100644 --- a/drivers/acpi/nfit.h +++ b/drivers/acpi/nfit.h @@ -40,6 +40,10 @@ enum nfit_uuids { NFIT_UUID_MAX, }; +enum { + ND_BLK_DCR_LATCH = 2, +}; + struct nfit_spa { struct acpi_nfit_system_address *spa; struct list_head list; @@ -131,6 +135,7 @@ struct nfit_blk { u64 stat_offset; u64 cmd_offset; void __iomem *nvdimm_flush; + u32 dimm_flags; }; enum spa_map_type { |