| Message ID | 20160802182653.6647-1-ross.zwisler@linux.intel.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 68202c9f0ad6 |
| Headers | show |
On Tue, Aug 02, 2016 at 12:26:53PM -0600, Ross Zwisler wrote: > The "NVDIMM Block Window Driver Writer's Guide": > > http://pmem.io/documents/ > http://pmem.io/documents/NVDIMM_DriverWritersGuide-July-2016.pdf > > defines the layout of the block window status register. For the July 2016 > version of the spec linked to above, this happens in Figure 4 on page 26. > > The only bits defined in this spec are bits 31, 5, 4, 2, 1 and 0. The rest > of the bits in the status register are reserved, and there is a warning > following the diagram that says: > > Note: The driver cannot assume the value of the RESERVED bits in the > status register are zero. These reserved bits need to be masked off, and > the driver must avoid checking the state of those bits. > > This change ensures that for hardware implementations that set these > reserved bits in the status register, the driver won't incorrectly fail the > block I/Os. > > Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> > Reviewed-by: Lee, Chun-Yi <jlee@suse.com> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: stable@vger.kernel.org # v4.2+ Ping on this patch - through which tree should we merge this for v4.8-rc2? Dan's nvdimm tree? > --- > > Changes from V1: > - Rebased onto the v4.8 merge tree. As Joey points out the ND BLK code > recently moved from drivers/acpi/nfit.c to drivers/acpi/nfit/core.c. > Since we were in the merge window for v4.8 I didn't know what to use as > a baseline, so I just used v4.7, which was apparently incorrect. Sorry > about that. > > - Added Joey's reviewed-by. > > For stable kernels v4.2 and beyond the v1 patch for drivers/acpi/nfit.c > applies cleanly and should be used. > > --- > drivers/acpi/nfit/core.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c > index 8c234dd..80cc7c0 100644 > --- a/drivers/acpi/nfit/core.c > +++ b/drivers/acpi/nfit/core.c > @@ -1527,11 +1527,12 @@ static u32 read_blk_stat(struct nfit_blk *nfit_blk, unsigned int bw) > { > struct nfit_blk_mmio *mmio = &nfit_blk->mmio[DCR]; > u64 offset = nfit_blk->stat_offset + mmio->size * bw; > + const u32 STATUS_MASK = 0x80000037; > > if (mmio->num_lines) > offset = to_interleave_offset(offset, mmio); > > - return readl(mmio->addr.base + offset); > + return readl(mmio->addr.base + offset) & STATUS_MASK; > } > > static void write_blk_ctl(struct nfit_blk *nfit_blk, unsigned int bw, > -- > 2.9.0 >
On Mon, Aug 8, 2016 at 12:10 PM, Ross Zwisler <ross.zwisler@linux.intel.com> wrote: > On Tue, Aug 02, 2016 at 12:26:53PM -0600, Ross Zwisler wrote: >> The "NVDIMM Block Window Driver Writer's Guide": >> >> http://pmem.io/documents/ >> http://pmem.io/documents/NVDIMM_DriverWritersGuide-July-2016.pdf >> >> defines the layout of the block window status register. For the July 2016 >> version of the spec linked to above, this happens in Figure 4 on page 26. >> >> The only bits defined in this spec are bits 31, 5, 4, 2, 1 and 0. The rest >> of the bits in the status register are reserved, and there is a warning >> following the diagram that says: >> >> Note: The driver cannot assume the value of the RESERVED bits in the >> status register are zero. These reserved bits need to be masked off, and >> the driver must avoid checking the state of those bits. >> >> This change ensures that for hardware implementations that set these >> reserved bits in the status register, the driver won't incorrectly fail the >> block I/Os. >> >> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> >> Reviewed-by: Lee, Chun-Yi <jlee@suse.com> >> Cc: Dan Williams <dan.j.williams@intel.com> >> Cc: stable@vger.kernel.org # v4.2+ > > Ping on this patch - through which tree should we merge this for v4.8-rc2? > Dan's nvdimm tree? It's getting 0-day coverage on my libnvdimm-pending branch and will go to Linus at the end of the week.
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 8c234dd..80cc7c0 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1527,11 +1527,12 @@ static u32 read_blk_stat(struct nfit_blk *nfit_blk, unsigned int bw) { struct nfit_blk_mmio *mmio = &nfit_blk->mmio[DCR]; u64 offset = nfit_blk->stat_offset + mmio->size * bw; + const u32 STATUS_MASK = 0x80000037; if (mmio->num_lines) offset = to_interleave_offset(offset, mmio); - return readl(mmio->addr.base + offset); + return readl(mmio->addr.base + offset) & STATUS_MASK; } static void write_blk_ctl(struct nfit_blk *nfit_blk, unsigned int bw,