| Message ID | 20230604-dcd-type2-upstream-v2-5-f740c47e7916@intel.com |
|---|---|
| State | New, archived |
| Headers | show |
| Series | DCD: Add support for Dynamic Capacity Devices (DCD) | expand |
On Mon, 28 Aug 2023 22:20:56 -0700 Ira Weiny <ira.weiny@intel.com> wrote: > Endpoint decoders used to map Dynamic Capacity must be configured to > point to the correct Dynamic Capacity (DC) Region. The decoder mode > currently represents the partition the decoder points to such as ram or > pmem. > > Expand the mode to include DC Regions. > > Co-developed-by: Navneet Singh <navneet.singh@intel.com> > Signed-off-by: Navneet Singh <navneet.singh@intel.com> > Signed-off-by: Ira Weiny <ira.weiny@intel.com> I'm reading this in a linear fashion for now (and ideally that should always make sense) so I don't currently see the reason for the loops in here. If they are needed for a future patch, add something to the description to indicate that. > > --- > Changes for v2: > [iweiny: split from region creation patch] > --- > Documentation/ABI/testing/sysfs-bus-cxl | 19 ++++++++++--------- > drivers/cxl/core/hdm.c | 24 ++++++++++++++++++++++++ > drivers/cxl/core/port.c | 16 ++++++++++++++++ > 3 files changed, 50 insertions(+), 9 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl > index 6350dd82b9a9..2268ffcdb604 100644 > --- a/Documentation/ABI/testing/sysfs-bus-cxl > +++ b/Documentation/ABI/testing/sysfs-bus-cxl > @@ -257,22 +257,23 @@ Description: > > What: /sys/bus/cxl/devices/decoderX.Y/mode > Date: May, 2022 > -KernelVersion: v6.0 > +KernelVersion: v6.0, v6.6 (dcY) > Contact: linux-cxl@vger.kernel.org > Description: > (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it > translates from a host physical address range, to a device local > address range. Device-local address ranges are further split > - into a 'ram' (volatile memory) range and 'pmem' (persistent > - memory) range. The 'mode' attribute emits one of 'ram', 'pmem', > - 'mixed', or 'none'. The 'mixed' indication is for error cases > - when a decoder straddles the volatile/persistent partition > - boundary, and 'none' indicates the decoder is not actively > - decoding, or no DPA allocation policy has been set. > + into a 'ram' (volatile memory) range, 'pmem' (persistent > + memory) range, or Dynamic Capacity (DC) range. The 'mode' > + attribute emits one of 'ram', 'pmem', 'dcY', 'mixed', or > + 'none'. The 'mixed' indication is for error cases when a > + decoder straddles the volatile/persistent partition boundary, > + and 'none' indicates the decoder is not actively decoding, or > + no DPA allocation policy has been set. > > 'mode' can be written, when the decoder is in the 'disabled' > - state, with either 'ram' or 'pmem' to set the boundaries for the > - next allocation. > + state, with 'ram', 'pmem', or 'dcY' to set the boundaries for > + the next allocation. > > > What: /sys/bus/cxl/devices/decoderX.Y/dpa_resource > diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c > index a254f79dd4e8..3f4af1f5fac8 100644 > --- a/drivers/cxl/core/hdm.c > +++ b/drivers/cxl/core/hdm.c > @@ -267,6 +267,19 @@ static void devm_cxl_dpa_release(struct cxl_endpoint_decoder *cxled) > __cxl_dpa_release(cxled); > } > > +static int dc_mode_to_region_index(enum cxl_decoder_mode mode) > +{ > + int index = 0; > + > + for (int i = CXL_DECODER_DC0; i <= CXL_DECODER_DC7; i++) { As you are relying on them being in order and adjacent for the loop, why is if (mode < CXL_DECODER_DC0 || mode > CXL_DECODER_DC7) return -EINVAL; return mode - CXL_DECODER_DC0; Not sufficient? > + if (mode == i) > + return index; > + index++; > + } > + > + return -EINVAL; > +} > + > static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, > resource_size_t base, resource_size_t len, > resource_size_t skipped) > @@ -429,6 +442,7 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, > switch (mode) { > case CXL_DECODER_RAM: > case CXL_DECODER_PMEM: > + case CXL_DECODER_DC0 ... CXL_DECODER_DC7: > break; > default: > dev_dbg(dev, "unsupported mode: %d\n", mode); > @@ -456,6 +470,16 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, > goto out; > } > > + for (int i = CXL_DECODER_DC0; i <= CXL_DECODER_DC7; i++) { > + int index = dc_mode_to_region_index(i); > + > + if (mode == i && !resource_size(&cxlds->dc_res[index])) { Not obvious why we have the loop in this patch - perhaps it makes sense later. If this is to enable later changes, then good to say that in the patch description. otherwise, something like. int index; rc = dc_mode_to_region_index(i); if (rc < 0) goto out; index = rc; if (!resource_size(&cxlds->dc_res[index]) { .... > + dev_dbg(dev, "no available dynamic capacity\n"); > + rc = -ENXIO; > + goto out; > + } > + } > + > cxled->mode = mode; > rc = 0; > out: > diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c > index f58cf01f8d2c..ce4a66865db3 100644 > --- a/drivers/cxl/core/port.c > +++ b/drivers/cxl/core/port.c > @@ -197,6 +197,22 @@ static ssize_t mode_store(struct device *dev, struct device_attribute *attr, > mode = CXL_DECODER_PMEM; > else if (sysfs_streq(buf, "ram")) > mode = CXL_DECODER_RAM; > + else if (sysfs_streq(buf, "dc0")) > + mode = CXL_DECODER_DC0; > + else if (sysfs_streq(buf, "dc1")) > + mode = CXL_DECODER_DC1; > + else if (sysfs_streq(buf, "dc2")) > + mode = CXL_DECODER_DC2; > + else if (sysfs_streq(buf, "dc3")) > + mode = CXL_DECODER_DC3; > + else if (sysfs_streq(buf, "dc4")) > + mode = CXL_DECODER_DC4; > + else if (sysfs_streq(buf, "dc5")) > + mode = CXL_DECODER_DC5; > + else if (sysfs_streq(buf, "dc6")) > + mode = CXL_DECODER_DC6; > + else if (sysfs_streq(buf, "dc7")) > + mode = CXL_DECODER_DC7; > else > return -EINVAL; > >
On Mon, Aug 28, 2023 at 10:20:56PM -0700, Ira Weiny wrote: > Endpoint decoders used to map Dynamic Capacity must be configured to > point to the correct Dynamic Capacity (DC) Region. The decoder mode > currently represents the partition the decoder points to such as ram or > pmem. > > Expand the mode to include DC Regions. > > Co-developed-by: Navneet Singh <navneet.singh@intel.com> > Signed-off-by: Navneet Singh <navneet.singh@intel.com> > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > I have the same question about how dc_mode_to_region_index is implemented and used as Jonathan. Nice to see the code spit out, it is easier to review now. Fan > --- > Changes for v2: > [iweiny: split from region creation patch] > --- > Documentation/ABI/testing/sysfs-bus-cxl | 19 ++++++++++--------- > drivers/cxl/core/hdm.c | 24 ++++++++++++++++++++++++ > drivers/cxl/core/port.c | 16 ++++++++++++++++ > 3 files changed, 50 insertions(+), 9 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl > index 6350dd82b9a9..2268ffcdb604 100644 > --- a/Documentation/ABI/testing/sysfs-bus-cxl > +++ b/Documentation/ABI/testing/sysfs-bus-cxl > @@ -257,22 +257,23 @@ Description: > > What: /sys/bus/cxl/devices/decoderX.Y/mode > Date: May, 2022 > -KernelVersion: v6.0 > +KernelVersion: v6.0, v6.6 (dcY) > Contact: linux-cxl@vger.kernel.org > Description: > (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it > translates from a host physical address range, to a device local > address range. Device-local address ranges are further split > - into a 'ram' (volatile memory) range and 'pmem' (persistent > - memory) range. The 'mode' attribute emits one of 'ram', 'pmem', > - 'mixed', or 'none'. The 'mixed' indication is for error cases > - when a decoder straddles the volatile/persistent partition > - boundary, and 'none' indicates the decoder is not actively > - decoding, or no DPA allocation policy has been set. > + into a 'ram' (volatile memory) range, 'pmem' (persistent > + memory) range, or Dynamic Capacity (DC) range. The 'mode' > + attribute emits one of 'ram', 'pmem', 'dcY', 'mixed', or > + 'none'. The 'mixed' indication is for error cases when a > + decoder straddles the volatile/persistent partition boundary, > + and 'none' indicates the decoder is not actively decoding, or > + no DPA allocation policy has been set. > > 'mode' can be written, when the decoder is in the 'disabled' > - state, with either 'ram' or 'pmem' to set the boundaries for the > - next allocation. > + state, with 'ram', 'pmem', or 'dcY' to set the boundaries for > + the next allocation. > > > What: /sys/bus/cxl/devices/decoderX.Y/dpa_resource > diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c > index a254f79dd4e8..3f4af1f5fac8 100644 > --- a/drivers/cxl/core/hdm.c > +++ b/drivers/cxl/core/hdm.c > @@ -267,6 +267,19 @@ static void devm_cxl_dpa_release(struct cxl_endpoint_decoder *cxled) > __cxl_dpa_release(cxled); > } > > +static int dc_mode_to_region_index(enum cxl_decoder_mode mode) > +{ > + int index = 0; > + > + for (int i = CXL_DECODER_DC0; i <= CXL_DECODER_DC7; i++) { > + if (mode == i) > + return index; > + index++; > + } > + > + return -EINVAL; > +} > + > static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, > resource_size_t base, resource_size_t len, > resource_size_t skipped) > @@ -429,6 +442,7 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, > switch (mode) { > case CXL_DECODER_RAM: > case CXL_DECODER_PMEM: > + case CXL_DECODER_DC0 ... CXL_DECODER_DC7: > break; > default: > dev_dbg(dev, "unsupported mode: %d\n", mode); > @@ -456,6 +470,16 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, > goto out; > } > > + for (int i = CXL_DECODER_DC0; i <= CXL_DECODER_DC7; i++) { > + int index = dc_mode_to_region_index(i); > + > + if (mode == i && !resource_size(&cxlds->dc_res[index])) { > + dev_dbg(dev, "no available dynamic capacity\n"); > + rc = -ENXIO; > + goto out; > + } > + } > + > cxled->mode = mode; > rc = 0; > out: > diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c > index f58cf01f8d2c..ce4a66865db3 100644 > --- a/drivers/cxl/core/port.c > +++ b/drivers/cxl/core/port.c > @@ -197,6 +197,22 @@ static ssize_t mode_store(struct device *dev, struct device_attribute *attr, > mode = CXL_DECODER_PMEM; > else if (sysfs_streq(buf, "ram")) > mode = CXL_DECODER_RAM; > + else if (sysfs_streq(buf, "dc0")) > + mode = CXL_DECODER_DC0; > + else if (sysfs_streq(buf, "dc1")) > + mode = CXL_DECODER_DC1; > + else if (sysfs_streq(buf, "dc2")) > + mode = CXL_DECODER_DC2; > + else if (sysfs_streq(buf, "dc3")) > + mode = CXL_DECODER_DC3; > + else if (sysfs_streq(buf, "dc4")) > + mode = CXL_DECODER_DC4; > + else if (sysfs_streq(buf, "dc5")) > + mode = CXL_DECODER_DC5; > + else if (sysfs_streq(buf, "dc6")) > + mode = CXL_DECODER_DC6; > + else if (sysfs_streq(buf, "dc7")) > + mode = CXL_DECODER_DC7; > else > return -EINVAL; > > > -- > 2.41.0 >
Jonathan Cameron wrote: > On Mon, 28 Aug 2023 22:20:56 -0700 > Ira Weiny <ira.weiny@intel.com> wrote: > > > Endpoint decoders used to map Dynamic Capacity must be configured to > > point to the correct Dynamic Capacity (DC) Region. The decoder mode > > currently represents the partition the decoder points to such as ram or > > pmem. > > > > Expand the mode to include DC Regions. > > > > Co-developed-by: Navneet Singh <navneet.singh@intel.com> > > Signed-off-by: Navneet Singh <navneet.singh@intel.com> > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > I'm reading this in a linear fashion for now (and ideally that should > always make sense) so I don't currently see the reason for the loops > in here. If they are needed for a future patch, add something to the > description to indicate that. > > > > > --- > > Changes for v2: > > [iweiny: split from region creation patch] > > --- > > Documentation/ABI/testing/sysfs-bus-cxl | 19 ++++++++++--------- > > drivers/cxl/core/hdm.c | 24 ++++++++++++++++++++++++ > > drivers/cxl/core/port.c | 16 ++++++++++++++++ > > 3 files changed, 50 insertions(+), 9 deletions(-) > > > > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl > > index 6350dd82b9a9..2268ffcdb604 100644 > > --- a/Documentation/ABI/testing/sysfs-bus-cxl > > +++ b/Documentation/ABI/testing/sysfs-bus-cxl > > @@ -257,22 +257,23 @@ Description: > > > > What: /sys/bus/cxl/devices/decoderX.Y/mode > > Date: May, 2022 > > -KernelVersion: v6.0 > > +KernelVersion: v6.0, v6.6 (dcY) > > Contact: linux-cxl@vger.kernel.org > > Description: > > (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it > > translates from a host physical address range, to a device local > > address range. Device-local address ranges are further split > > - into a 'ram' (volatile memory) range and 'pmem' (persistent > > - memory) range. The 'mode' attribute emits one of 'ram', 'pmem', > > - 'mixed', or 'none'. The 'mixed' indication is for error cases > > - when a decoder straddles the volatile/persistent partition > > - boundary, and 'none' indicates the decoder is not actively > > - decoding, or no DPA allocation policy has been set. > > + into a 'ram' (volatile memory) range, 'pmem' (persistent > > + memory) range, or Dynamic Capacity (DC) range. The 'mode' > > + attribute emits one of 'ram', 'pmem', 'dcY', 'mixed', or > > + 'none'. The 'mixed' indication is for error cases when a > > + decoder straddles the volatile/persistent partition boundary, > > + and 'none' indicates the decoder is not actively decoding, or > > + no DPA allocation policy has been set. > > > > 'mode' can be written, when the decoder is in the 'disabled' > > - state, with either 'ram' or 'pmem' to set the boundaries for the > > - next allocation. > > + state, with 'ram', 'pmem', or 'dcY' to set the boundaries for > > + the next allocation. > > > > > > What: /sys/bus/cxl/devices/decoderX.Y/dpa_resource > > diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c > > index a254f79dd4e8..3f4af1f5fac8 100644 > > --- a/drivers/cxl/core/hdm.c > > +++ b/drivers/cxl/core/hdm.c > > @@ -267,6 +267,19 @@ static void devm_cxl_dpa_release(struct cxl_endpoint_decoder *cxled) > > __cxl_dpa_release(cxled); > > } > > > > +static int dc_mode_to_region_index(enum cxl_decoder_mode mode) > > +{ > > + int index = 0; > > + > > + for (int i = CXL_DECODER_DC0; i <= CXL_DECODER_DC7; i++) { > As you are relying on them being in order and adjacent for the loop, why is > > if (mode < CXL_DECODER_DC0 || mode > CXL_DECODER_DC7) > return -EINVAL; > > return mode - CXL_DECODER_DC0; > > Not sufficient? That would work yes. There is no future need for a loop. It was just implemented this way early on and I did not really think about it too much. Done. > > > + if (mode == i) > > + return index; > > + index++; > > + } > > + > > + return -EINVAL; > > +} > > + > > static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, > > resource_size_t base, resource_size_t len, > > resource_size_t skipped) > > @@ -429,6 +442,7 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, > > switch (mode) { > > case CXL_DECODER_RAM: > > case CXL_DECODER_PMEM: > > + case CXL_DECODER_DC0 ... CXL_DECODER_DC7: > > break; > > default: > > dev_dbg(dev, "unsupported mode: %d\n", mode); > > @@ -456,6 +470,16 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, > > goto out; > > } > > > > + for (int i = CXL_DECODER_DC0; i <= CXL_DECODER_DC7; i++) { > > + int index = dc_mode_to_region_index(i); > > + > > + if (mode == i && !resource_size(&cxlds->dc_res[index])) { > > Not obvious why we have the loop in this patch - perhaps it makes sense later. I think it was just walking through the DC regions like the previous code was walking through the PMEM/RAM 'regions'. > If this is to enable later changes, then good to say that in the patch description. ... nope... > otherwise, something like. > > int index; > > rc = dc_mode_to_region_index(i); > if (rc < 0) > goto out; > > index = rc; > if (!resource_size(&cxlds->dc_res[index]) { > .... > Yea... but that won't exactly work. Something like this: diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index cf5d656c271b..f250d1566682 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -463,10 +463,12 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, goto out; } - for (int i = CXL_DECODER_DC0; i <= CXL_DECODER_DC7; i++) { - int index = dc_mode_to_region_index(i); + if (cxl_decoder_mode_is_dc(mode)) { + rc = dc_mode_to_region_index(mode); + if (rc < 0) + goto out; - if (mode == i && !resource_size(&cxlds->dc_res[index])) { + if (!resource_size(&cxlds->dc_res[rc])) { dev_dbg(dev, "no available dynamic capacity\n"); rc = -ENXIO; goto out; But looking at the function I think there could be a clean up patch before this. I don't see the need to check the mode twice. ... Yes I think that looks cleaner. Thanks for the review! Ira
Fan Ni wrote: > On Mon, Aug 28, 2023 at 10:20:56PM -0700, Ira Weiny wrote: > > Endpoint decoders used to map Dynamic Capacity must be configured to > > point to the correct Dynamic Capacity (DC) Region. The decoder mode > > currently represents the partition the decoder points to such as ram or > > pmem. > > > > Expand the mode to include DC Regions. > > > > Co-developed-by: Navneet Singh <navneet.singh@intel.com> > > Signed-off-by: Navneet Singh <navneet.singh@intel.com> > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > > > I have the same question about how dc_mode_to_region_index is > implemented and used as Jonathan. I changed it per Jonathans recommendation. Was that satisfactory or were you looking for more information? > > Nice to see the code spit out, it is easier to review now. Thanks, Ira
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 6350dd82b9a9..2268ffcdb604 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -257,22 +257,23 @@ Description: What: /sys/bus/cxl/devices/decoderX.Y/mode Date: May, 2022 -KernelVersion: v6.0 +KernelVersion: v6.0, v6.6 (dcY) Contact: linux-cxl@vger.kernel.org Description: (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it translates from a host physical address range, to a device local address range. Device-local address ranges are further split - into a 'ram' (volatile memory) range and 'pmem' (persistent - memory) range. The 'mode' attribute emits one of 'ram', 'pmem', - 'mixed', or 'none'. The 'mixed' indication is for error cases - when a decoder straddles the volatile/persistent partition - boundary, and 'none' indicates the decoder is not actively - decoding, or no DPA allocation policy has been set. + into a 'ram' (volatile memory) range, 'pmem' (persistent + memory) range, or Dynamic Capacity (DC) range. The 'mode' + attribute emits one of 'ram', 'pmem', 'dcY', 'mixed', or + 'none'. The 'mixed' indication is for error cases when a + decoder straddles the volatile/persistent partition boundary, + and 'none' indicates the decoder is not actively decoding, or + no DPA allocation policy has been set. 'mode' can be written, when the decoder is in the 'disabled' - state, with either 'ram' or 'pmem' to set the boundaries for the - next allocation. + state, with 'ram', 'pmem', or 'dcY' to set the boundaries for + the next allocation. What: /sys/bus/cxl/devices/decoderX.Y/dpa_resource diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index a254f79dd4e8..3f4af1f5fac8 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -267,6 +267,19 @@ static void devm_cxl_dpa_release(struct cxl_endpoint_decoder *cxled) __cxl_dpa_release(cxled); } +static int dc_mode_to_region_index(enum cxl_decoder_mode mode) +{ + int index = 0; + + for (int i = CXL_DECODER_DC0; i <= CXL_DECODER_DC7; i++) { + if (mode == i) + return index; + index++; + } + + return -EINVAL; +} + static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, resource_size_t base, resource_size_t len, resource_size_t skipped) @@ -429,6 +442,7 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, switch (mode) { case CXL_DECODER_RAM: case CXL_DECODER_PMEM: + case CXL_DECODER_DC0 ... CXL_DECODER_DC7: break; default: dev_dbg(dev, "unsupported mode: %d\n", mode); @@ -456,6 +470,16 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, goto out; } + for (int i = CXL_DECODER_DC0; i <= CXL_DECODER_DC7; i++) { + int index = dc_mode_to_region_index(i); + + if (mode == i && !resource_size(&cxlds->dc_res[index])) { + dev_dbg(dev, "no available dynamic capacity\n"); + rc = -ENXIO; + goto out; + } + } + cxled->mode = mode; rc = 0; out: diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index f58cf01f8d2c..ce4a66865db3 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -197,6 +197,22 @@ static ssize_t mode_store(struct device *dev, struct device_attribute *attr, mode = CXL_DECODER_PMEM; else if (sysfs_streq(buf, "ram")) mode = CXL_DECODER_RAM; + else if (sysfs_streq(buf, "dc0")) + mode = CXL_DECODER_DC0; + else if (sysfs_streq(buf, "dc1")) + mode = CXL_DECODER_DC1; + else if (sysfs_streq(buf, "dc2")) + mode = CXL_DECODER_DC2; + else if (sysfs_streq(buf, "dc3")) + mode = CXL_DECODER_DC3; + else if (sysfs_streq(buf, "dc4")) + mode = CXL_DECODER_DC4; + else if (sysfs_streq(buf, "dc5")) + mode = CXL_DECODER_DC5; + else if (sysfs_streq(buf, "dc6")) + mode = CXL_DECODER_DC6; + else if (sysfs_streq(buf, "dc7")) + mode = CXL_DECODER_DC7; else return -EINVAL;