Add support in the ND_BLK I/O path for the "latch" and "flush" flags defined in the "Get Block NVDIMM Flags" _DSM function: http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> Cc: linux-nvdimm@xxxxxxxxxxxx Cc: linux-acpi@xxxxxxxxxxxxxxx Cc: linux-api@xxxxxxxxxxxxxxx --- drivers/acpi/nfit.c | 26 ++++++++++++++++++++++++-- drivers/acpi/nfit.h | 1 + include/uapi/linux/ndctl.h | 5 +++++ 3 files changed, 30 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c index 6cca50d1c690..0da84e067643 100644 --- a/drivers/acpi/nfit.c +++ b/drivers/acpi/nfit.c @@ -951,7 +951,9 @@ static void write_blk_ctl(struct nfit_blk *nfit_blk, unsigned int bw, /* mmio->base must be mapped uncacheable */ writeq(cmd, mmio->base + offset); nfit_blk->psync(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, void *iobuf, @@ -983,8 +985,12 @@ static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk, void *iobuf, if (write) persistent_copy(mmio->aperture + offset, iobuf + copied, c); - else + else { + if (nfit_blk->dimm_flags & ND_BLK_FLUSH_REQUIRED) + persistent_flush(mmio->aperture + offset, c); + memcpy(iobuf + copied, mmio->aperture + offset, c); + } copied += c; len -= c; @@ -1146,6 +1152,20 @@ static int nfit_blk_init_interleave(struct nfit_blk_mmio *mmio, return 0; } +static void nd_acpi_blk_get_flags(struct nd_bus_descriptor *nd_desc, + struct nd_dimm *nd_dimm, struct nfit_blk *nfit_blk) +{ + struct nd_cmd_dimm_flags flags; + int rc; + + memset(&flags, 0, sizeof(flags)); + rc = nd_desc->ndctl(nd_desc, nd_dimm, ND_CMD_DIMM_FLAGS, &flags, + sizeof(flags)); + + if (rc >= 0 && !flags.status) + nfit_blk->dimm_flags = flags.flags; +} + static int acpi_nfit_blk_region_enable(struct nd_bus *nd_bus, struct device *dev) { struct nd_bus_descriptor *nd_desc = to_nd_desc(nd_bus); @@ -1217,6 +1237,8 @@ static int acpi_nfit_blk_region_enable(struct nd_bus *nd_bus, struct device *dev return rc; } + nd_acpi_blk_get_flags(nd_desc, nd_dimm, nfit_blk); + nfit_flush = nfit_mem->nfit_flush; if (nfit_flush && nfit_flush->flush->hint_count != 0) { struct acpi_nfit_flush_address *flush = nfit_flush->flush; diff --git a/drivers/acpi/nfit.h b/drivers/acpi/nfit.h index 858719017bef..d22b04ac3d2c 100644 --- a/drivers/acpi/nfit.h +++ b/drivers/acpi/nfit.h @@ -139,6 +139,7 @@ struct nfit_blk { u64 bdw_offset; /* post interleave offset */ u64 stat_offset; u64 cmd_offset; + u32 dimm_flags; void __iomem *flush_hint; void (*psync)(struct nfit_blk *nfit_blk); }; diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h index e595751c613d..bb0fa1c611e0 100644 --- a/include/uapi/linux/ndctl.h +++ b/include/uapi/linux/ndctl.h @@ -30,6 +30,11 @@ struct nd_cmd_dimm_flags { __u32 flags; } __packed; +enum { + ND_BLK_FLUSH_REQUIRED = 1, + ND_BLK_DCR_LATCH = 2, +}; + struct nd_cmd_get_config_size { __u32 status; __u32 config_size; -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
