Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Wed, 10 Apr 2024 11:49:11 -0700 | From | Alison Schofield <> | Subject | Re: [PATCH 02/26] cxl/core: Separate region mode from decoder mode |
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On Sun, Mar 24, 2024 at 04:18:05PM -0700, Ira Weiny wrote: > From: Navneet Singh <navneet.singh@intel.com> > > Until now region modes and decoder modes were equivalent in that they > were either PMEM or RAM. With the upcoming addition of Dynamic Capacity > regions (which will represent an array of device regions [better named > partitions] the index of which could be different on different > interleaved devices), the mode of an endpoint decoder and a region will > no longer be equivalent. > > Define a new region mode enumeration and adjust the code for it. > > Suggested-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com> > Signed-off-by: Navneet Singh <navneet.singh@intel.com> > Co-developed-by: Ira Weiny <ira.weiny@intel.com> > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > --- > Changes for v1 > <none> > --- > drivers/cxl/core/region.c | 77 +++++++++++++++++++++++++++++++++++------------ > drivers/cxl/cxl.h | 26 ++++++++++++++-- > 2 files changed, 81 insertions(+), 22 deletions(-) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index 4c7fd2d5cccb..1723d17f121e 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -40,7 +40,7 @@ static ssize_t uuid_show(struct device *dev, struct device_attribute *attr, > rc = down_read_interruptible(&cxl_region_rwsem); > if (rc) > return rc; > - if (cxlr->mode != CXL_DECODER_PMEM) > + if (cxlr->mode != CXL_REGION_PMEM) > rc = sysfs_emit(buf, "\n"); > else > rc = sysfs_emit(buf, "%pUb\n", &p->uuid); > @@ -353,7 +353,7 @@ static umode_t cxl_region_visible(struct kobject *kobj, struct attribute *a, > * Support tooling that expects to find a 'uuid' attribute for all > * regions regardless of mode. > */ > - if (a == &dev_attr_uuid.attr && cxlr->mode != CXL_DECODER_PMEM) > + if (a == &dev_attr_uuid.attr && cxlr->mode != CXL_REGION_PMEM) > return 0444; > return a->mode; > } > @@ -516,7 +516,7 @@ static ssize_t mode_show(struct device *dev, struct device_attribute *attr, > { > struct cxl_region *cxlr = to_cxl_region(dev); > > - return sysfs_emit(buf, "%s\n", cxl_decoder_mode_name(cxlr->mode)); > + return sysfs_emit(buf, "%s\n", cxl_region_mode_name(cxlr->mode)); > } > static DEVICE_ATTR_RO(mode); > > @@ -542,7 +542,7 @@ static int alloc_hpa(struct cxl_region *cxlr, resource_size_t size) > > /* ways, granularity and uuid (if PMEM) need to be set before HPA */ > if (!p->interleave_ways || !p->interleave_granularity || > - (cxlr->mode == CXL_DECODER_PMEM && uuid_is_null(&p->uuid))) > + (cxlr->mode == CXL_REGION_PMEM && uuid_is_null(&p->uuid))) > return -ENXIO; > > div64_u64_rem(size, (u64)SZ_256M * p->interleave_ways, &remainder); > @@ -1683,6 +1683,17 @@ static int cxl_region_sort_targets(struct cxl_region *cxlr) > return rc; > } > > +static bool cxl_modes_compatible(enum cxl_region_mode rmode, > + enum cxl_decoder_mode dmode) > +{
Perhaps is_region_mode_compatible() ?
Seems we have precedence for asking these questions that have boolean responses. I picked 'region' because it is the region we are trying to construct.
> + if (rmode == CXL_REGION_RAM && dmode == CXL_DECODER_RAM) > + return true; > + if (rmode == CXL_REGION_PMEM && dmode == CXL_DECODER_PMEM) > + return true; > + > + return false; > +} > + > static int cxl_region_attach(struct cxl_region *cxlr, > struct cxl_endpoint_decoder *cxled, int pos) > { > @@ -1693,9 +1704,11 @@ static int cxl_region_attach(struct cxl_region *cxlr, > struct cxl_dport *dport; > int rc = -ENXIO; > > - if (cxled->mode != cxlr->mode) { > - dev_dbg(&cxlr->dev, "%s region mode: %d mismatch: %d\n", > - dev_name(&cxled->cxld.dev), cxlr->mode, cxled->mode); > + if (!cxl_modes_compatible(cxlr->mode, cxled->mode)) { > + dev_dbg(&cxlr->dev, "%s region mode: %s mismatch decoder: %s\n", > + dev_name(&cxled->cxld.dev), > + cxl_region_mode_name(cxlr->mode), > + cxl_decoder_mode_name(cxled->mode)); > return -EINVAL; > }
Does the above return bypass this next code segment (not in your diff):
if (cxled->mode == CXL_DECODER_DEAD) { dev_dbg(&cxlr->dev, "%s dead\n", dev_name(&cxled->cxld.dev)); return -ENODEV; }
It seems we are changing the return value on DEAD.
More below where a new check for DEAD is added ...
snip
> /* Establish an empty region covering the given HPA range */ > static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, > struct cxl_endpoint_decoder *cxled) > @@ -2808,12 +2840,17 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, > struct cxl_port *port = cxlrd_to_port(cxlrd); > struct range *hpa = &cxled->cxld.hpa_range; > struct cxl_region_params *p; > + enum cxl_region_mode mode; > struct cxl_region *cxlr; > struct resource *res; > int rc; > > + if (cxled->mode == CXL_DECODER_DEAD) > + return ERR_PTR(-EINVAL);
I see this addition, but it is in a different place and with a different return value. Help me understand that this is no change in behavior.
> + > + mode = cxl_decoder_to_region_mode(cxled->mode); > do { > - cxlr = __create_region(cxlrd, cxled->mode, > + cxlr = __create_region(cxlrd, mode, > atomic_read(&cxlrd->region_id)); > } while (IS_ERR(cxlr) && PTR_ERR(cxlr) == -EBUSY); >
snip
> /* > * Track whether this decoder is reserved for region autodiscovery, or > * free for userspace provisioning. > @@ -511,7 +532,8 @@ struct cxl_region_params { > * struct cxl_region - CXL region > * @dev: This region's device > * @id: This region's id. Id is globally unique across all regions > - * @mode: Endpoint decoder allocation / access mode > + * @mode: Region mode which defines which endpoint decoder mode the region is > + * compatible with
Maybe... @mode: Region mode used for decoder compatibility check
snip to end
--Alison
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