| Message ID | 92a8eab0aadde1c65f57e03d1ae0160929b23921.1681159309.git.alison.schofield@intel.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | CXL Poison List Retrieval & Tracing | expand |
alison.schofield@ wrote: > From: Alison Schofield <alison.schofield@intel.com> > > User space may need to know which region, if any, maps the poison > address(es) logged in a cxl_poison trace event. Since the mapping > of DPAs (device physical addresses) to a region can change, the > kernel must provide this information at the time the poison list > is read. The event informs user space that at event <timestamp> > this <region> mapped to this <DPA>, which is poisoned. > > The cxl_poison trace event is already wired up to log the region > name and uuid if it receives param 'struct cxl_region'. > > In order to provide that cxl_region, add another method for gathering > poison - by committed endpoint decoder mappings. This method is only > available with CONFIG_CXL_REGION and is only used if a region actually > maps the memdev where poison is being read. After the region driver > reads the poison list for all the mapped resources, control returns > to the memdev driver, where poison is read for any remaining unmapped > resources. > > Mixed mode decoders are not currently supported in Linux. Add a debug > message to the poison request path. That will serve as an alert that > poison list retrieval needs to add support for mixed mode. > > The default method remains: read the poison by memdev resource. > > Signed-off-by: Alison Schofield <alison.schofield@intel.com> > Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Reviewed-by: Ira Weiny <ira.weiny@intel.com> > Reviewed-by: Dave Jiang <dave.jiang@intel.com> > --- > drivers/cxl/core/core.h | 11 +++++++ > drivers/cxl/core/memdev.c | 62 +++++++++++++++++++++++++++++++++++++- > drivers/cxl/core/region.c | 63 +++++++++++++++++++++++++++++++++++++++ > 3 files changed, 135 insertions(+), 1 deletion(-) > > diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h > index e888e293943e..57bd22e01a0b 100644 > --- a/drivers/cxl/core/core.h > +++ b/drivers/cxl/core/core.h > @@ -25,7 +25,12 @@ void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled); > #define CXL_DAX_REGION_TYPE(x) (&cxl_dax_region_type) > int cxl_region_init(void); > void cxl_region_exit(void); > +int cxl_get_poison_by_endpoint(struct device *dev, void *data); > #else > +static inline int cxl_get_poison_by_endpoint(struct device *dev, void *data) > +{ > + return 0; > +} For a public function the lack of type safety jumps out at me... more below: > static inline void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled) > { > } > @@ -68,4 +73,10 @@ enum cxl_poison_trace_type { > CXL_POISON_TRACE_LIST, > }; > > +struct cxl_trigger_poison_context { > + struct cxl_port *port; > + enum cxl_decoder_mode mode; > + u64 offset; > +}; > + > #endif /* __CXL_CORE_H__ */ > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > index 297d87ebaca6..f26b5b6cda10 100644 > --- a/drivers/cxl/core/memdev.c > +++ b/drivers/cxl/core/memdev.c > @@ -106,6 +106,47 @@ static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr, > } > static DEVICE_ATTR_RO(numa_node); > > +static int cxl_get_poison_unmapped(struct cxl_memdev *cxlmd, > + struct cxl_trigger_poison_context *ctx) > +{ > + struct cxl_dev_state *cxlds = cxlmd->cxlds; > + u64 offset, length; > + int rc = 0; > + > + /* > + * Collect poison for the remaining unmapped resources > + * after poison is collected by committed endpoints. > + * > + * Knowing that PMEM must always follow RAM, get poison > + * for unmapped resources based on the last decoder's mode: > + * ram: scan remains of ram range, then any pmem range > + * pmem: scan remains of pmem range > + */ > + > + if (ctx->mode == CXL_DECODER_RAM) { > + offset = ctx->offset; > + length = resource_size(&cxlds->ram_res) - offset; > + rc = cxl_mem_get_poison(cxlmd, offset, length, NULL); > + if (rc == -EFAULT) > + rc = 0; > + if (rc) > + return rc; > + } > + if (ctx->mode == CXL_DECODER_PMEM) { > + offset = ctx->offset; > + length = resource_size(&cxlds->dpa_res) - offset; > + if (!length) > + return 0; > + } else if (resource_size(&cxlds->pmem_res)) { > + offset = cxlds->pmem_res.start; > + length = resource_size(&cxlds->pmem_res); > + } else { > + return 0; > + } > + > + return cxl_mem_get_poison(cxlmd, offset, length, NULL); > +} > + > static int cxl_get_poison_by_memdev(struct cxl_memdev *cxlmd) > { > struct cxl_dev_state *cxlds = cxlmd->cxlds; > @@ -139,14 +180,33 @@ ssize_t cxl_trigger_poison_list(struct device *dev, > const char *buf, size_t len) > { > struct cxl_memdev *cxlmd = to_cxl_memdev(dev); > + struct cxl_trigger_poison_context ctx; > + struct cxl_port *port; > bool trigger; > ssize_t rc; > > if (kstrtobool(buf, &trigger) || !trigger) > return -EINVAL; > > + port = dev_get_drvdata(&cxlmd->dev); > + if (!port || !is_cxl_endpoint(port)) > + return -EINVAL; > + > down_read(&cxl_dpa_rwsem); > - rc = cxl_get_poison_by_memdev(cxlmd); > + if (port->commit_end == -1) { > + /* No regions mapped to this memdev */ > + rc = cxl_get_poison_by_memdev(cxlmd); > + } else { > + /* Regions mapped, collect poison by endpoint */ > + ctx = (struct cxl_trigger_poison_context) { > + .port = port, > + }; > + rc = device_for_each_child(&port->dev, &ctx, > + cxl_get_poison_by_endpoint); > + if (rc == 1) > + rc = cxl_get_poison_unmapped(cxlmd, &ctx); Ah, cxl_get_poison_by_endpoint() is a function pointer to device_for_each_child(), that really feels like a detail that's private to the implementation. I would reorganize this to something like: if (port->commit_end == -1) { /* No regions mapped to this memdev */ rc = cxl_get_poison_by_memdev(cxlmd); } else { /* Regions mapped, collect poison by endpoint */ rc = cxl_get_poison_by_endpoint(endpoint); } ...and then internal to cxl_get_poison_by_endpoint() do: ctx = (struct cxl_trigger_poison_context) { .port = endpoint, }; rc = device_for_each_child(&port->dev, &ctx, poison_by_decoder); if (rc == 1) rc = cxl_get_poison_unmapped(cxlmd, &ctx); ...then the header file reads more calmly with the added type-safety. > + } > + > up_read(&cxl_dpa_rwsem); > > return rc ? rc : len; > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index f29028148806..4c4d3a6d631d 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -2213,6 +2213,69 @@ struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev) > } > EXPORT_SYMBOL_NS_GPL(to_cxl_pmem_region, CXL); > > +int cxl_get_poison_by_endpoint(struct device *dev, void *arg) > +{ > + struct cxl_trigger_poison_context *ctx = arg; > + struct cxl_endpoint_decoder *cxled; > + struct cxl_port *port = ctx->port; > + struct cxl_memdev *cxlmd; > + u64 offset, length; > + int rc = 0; > + > + down_read(&cxl_region_rwsem); > + > + if (!is_endpoint_decoder(dev)) > + goto out; > + > + cxled = to_cxl_endpoint_decoder(dev); > + if (!cxled->dpa_res || !resource_size(cxled->dpa_res)) > + goto out; > + > + /* > + * Regions are only created with single mode decoders: pmem or ram. > + * Linux does not currently support mixed mode decoders. This means > + * that reading poison per endpoint decoder adheres to the spec > + * requirement that poison reads of pmem and ram must be separated. > + * CXL 3.0 Spec 8.2.9.8.4.1 > + * > + * Watch for future support of mixed with a dev_dbg() msg. This sentence can go, mixed will never* be supported. * at least until the vendor that manages to ship such a thing comes and explains why the kernel needs to work around that awkwardness. > + */ > + if (cxled->mode == CXL_DECODER_MIXED) { > + dev_dbg(dev, "poison list read unsupported in mixed mode\n"); > + goto out; > + } > + > + cxlmd = cxled_to_memdev(cxled); > + if (cxled->skip) { > + offset = cxled->dpa_res->start - cxled->skip; > + length = cxled->skip; > + rc = cxl_mem_get_poison(cxlmd, offset, length, NULL); > + if (rc == -EFAULT && cxled->mode == CXL_DECODER_RAM) > + rc = 0; > + if (rc) > + goto out; > + } > + > + offset = cxled->dpa_res->start; > + length = cxled->dpa_res->end - offset + 1; > + rc = cxl_mem_get_poison(cxlmd, offset, length, cxled->cxld.region); > + if (rc == -EFAULT && cxled->mode == CXL_DECODER_RAM) > + rc = 0; > + if (rc) > + goto out; > + > + /* Iterate until commit_end is reached */ > + if (cxled->cxld.id == port->commit_end) > + rc = 1; > + > + /* ctx informs the memdev driver of last read poison */ > + ctx->mode = cxled->mode; > + ctx->offset = cxled->dpa_res->end + 1; > +out: > + up_read(&cxl_region_rwsem); > + return rc; > +} > + > static struct lock_class_key cxl_pmem_region_key; > > static struct cxl_pmem_region *cxl_pmem_region_alloc(struct cxl_region *cxlr) > -- > 2.37.3 >
On Tue, Apr 11, 2023 at 10:55:49PM -0700, Dan Williams wrote: > alison.schofield@ wrote: > > From: Alison Schofield <alison.schofield@intel.com> > > > > User space may need to know which region, if any, maps the poison > > address(es) logged in a cxl_poison trace event. Since the mapping > > of DPAs (device physical addresses) to a region can change, the > > kernel must provide this information at the time the poison list > > is read. The event informs user space that at event <timestamp> > > this <region> mapped to this <DPA>, which is poisoned. > > > > The cxl_poison trace event is already wired up to log the region > > name and uuid if it receives param 'struct cxl_region'. > > > > In order to provide that cxl_region, add another method for gathering > > poison - by committed endpoint decoder mappings. This method is only > > available with CONFIG_CXL_REGION and is only used if a region actually > > maps the memdev where poison is being read. After the region driver > > reads the poison list for all the mapped resources, control returns > > to the memdev driver, where poison is read for any remaining unmapped > > resources. > > > > Mixed mode decoders are not currently supported in Linux. Add a debug > > message to the poison request path. That will serve as an alert that > > poison list retrieval needs to add support for mixed mode. > > > > The default method remains: read the poison by memdev resource. > > > > Signed-off-by: Alison Schofield <alison.schofield@intel.com> > > Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > Reviewed-by: Ira Weiny <ira.weiny@intel.com> > > Reviewed-by: Dave Jiang <dave.jiang@intel.com> > > --- > > drivers/cxl/core/core.h | 11 +++++++ > > drivers/cxl/core/memdev.c | 62 +++++++++++++++++++++++++++++++++++++- > > drivers/cxl/core/region.c | 63 +++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 135 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h > > index e888e293943e..57bd22e01a0b 100644 > > --- a/drivers/cxl/core/core.h > > +++ b/drivers/cxl/core/core.h > > @@ -25,7 +25,12 @@ void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled); > > #define CXL_DAX_REGION_TYPE(x) (&cxl_dax_region_type) > > int cxl_region_init(void); > > void cxl_region_exit(void); > > +int cxl_get_poison_by_endpoint(struct device *dev, void *data); > > #else > > +static inline int cxl_get_poison_by_endpoint(struct device *dev, void *data) > > +{ > > + return 0; > > +} > > For a public function the lack of type safety jumps out at me... more > below: > > > static inline void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled) > > { > > } > > @@ -68,4 +73,10 @@ enum cxl_poison_trace_type { > > CXL_POISON_TRACE_LIST, > > }; > > > > +struct cxl_trigger_poison_context { > > + struct cxl_port *port; > > + enum cxl_decoder_mode mode; > > + u64 offset; > > +}; > > + > > #endif /* __CXL_CORE_H__ */ > > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > > index 297d87ebaca6..f26b5b6cda10 100644 > > --- a/drivers/cxl/core/memdev.c > > +++ b/drivers/cxl/core/memdev.c > > @@ -106,6 +106,47 @@ static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr, > > } > > static DEVICE_ATTR_RO(numa_node); > > > > +static int cxl_get_poison_unmapped(struct cxl_memdev *cxlmd, > > + struct cxl_trigger_poison_context *ctx) > > +{ > > + struct cxl_dev_state *cxlds = cxlmd->cxlds; > > + u64 offset, length; > > + int rc = 0; > > + > > + /* > > + * Collect poison for the remaining unmapped resources > > + * after poison is collected by committed endpoints. > > + * > > + * Knowing that PMEM must always follow RAM, get poison > > + * for unmapped resources based on the last decoder's mode: > > + * ram: scan remains of ram range, then any pmem range > > + * pmem: scan remains of pmem range > > + */ > > + > > + if (ctx->mode == CXL_DECODER_RAM) { > > + offset = ctx->offset; > > + length = resource_size(&cxlds->ram_res) - offset; > > + rc = cxl_mem_get_poison(cxlmd, offset, length, NULL); > > + if (rc == -EFAULT) > > + rc = 0; > > + if (rc) > > + return rc; > > + } > > + if (ctx->mode == CXL_DECODER_PMEM) { > > + offset = ctx->offset; > > + length = resource_size(&cxlds->dpa_res) - offset; > > + if (!length) > > + return 0; > > + } else if (resource_size(&cxlds->pmem_res)) { > > + offset = cxlds->pmem_res.start; > > + length = resource_size(&cxlds->pmem_res); > > + } else { > > + return 0; > > + } > > + > > + return cxl_mem_get_poison(cxlmd, offset, length, NULL); > > +} > > + > > static int cxl_get_poison_by_memdev(struct cxl_memdev *cxlmd) > > { > > struct cxl_dev_state *cxlds = cxlmd->cxlds; > > @@ -139,14 +180,33 @@ ssize_t cxl_trigger_poison_list(struct device *dev, > > const char *buf, size_t len) > > { > > struct cxl_memdev *cxlmd = to_cxl_memdev(dev); > > + struct cxl_trigger_poison_context ctx; > > + struct cxl_port *port; > > bool trigger; > > ssize_t rc; > > > > if (kstrtobool(buf, &trigger) || !trigger) > > return -EINVAL; > > > > + port = dev_get_drvdata(&cxlmd->dev); > > + if (!port || !is_cxl_endpoint(port)) > > + return -EINVAL; > > + > > down_read(&cxl_dpa_rwsem); > > - rc = cxl_get_poison_by_memdev(cxlmd); > > + if (port->commit_end == -1) { > > + /* No regions mapped to this memdev */ > > + rc = cxl_get_poison_by_memdev(cxlmd); > > + } else { > > + /* Regions mapped, collect poison by endpoint */ > > + ctx = (struct cxl_trigger_poison_context) { > > + .port = port, > > + }; > > + rc = device_for_each_child(&port->dev, &ctx, > > + cxl_get_poison_by_endpoint); > > + if (rc == 1) > > + rc = cxl_get_poison_unmapped(cxlmd, &ctx); > > Ah, cxl_get_poison_by_endpoint() is a function pointer to > device_for_each_child(), that really feels like a detail that's private > to the implementation. > > I would reorganize this to something like: > > if (port->commit_end == -1) { > /* No regions mapped to this memdev */ > rc = cxl_get_poison_by_memdev(cxlmd); > } else { > /* Regions mapped, collect poison by endpoint */ > rc = cxl_get_poison_by_endpoint(endpoint); > } > > ...and then internal to cxl_get_poison_by_endpoint() do: > > ctx = (struct cxl_trigger_poison_context) { > .port = endpoint, > }; > rc = device_for_each_child(&port->dev, &ctx, > poison_by_decoder); > if (rc == 1) > rc = cxl_get_poison_unmapped(cxlmd, &ctx); > > ...then the header file reads more calmly with the added type-safety. I'll take another stab at this. A couple of versions back, I pulled cxl_get_poison_unmapped() out of cxl_get_poison_by_endpoint() since it was not really work of the region driver. (Ira called that out in a review) Thanks, Alison > > > + } > > + > > up_read(&cxl_dpa_rwsem); > > > > return rc ? rc : len; > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > > index f29028148806..4c4d3a6d631d 100644 > > --- a/drivers/cxl/core/region.c > > +++ b/drivers/cxl/core/region.c > > @@ -2213,6 +2213,69 @@ struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev) > > } > > EXPORT_SYMBOL_NS_GPL(to_cxl_pmem_region, CXL); > > > > +int cxl_get_poison_by_endpoint(struct device *dev, void *arg) > > +{ > > + struct cxl_trigger_poison_context *ctx = arg; > > + struct cxl_endpoint_decoder *cxled; > > + struct cxl_port *port = ctx->port; > > + struct cxl_memdev *cxlmd; > > + u64 offset, length; > > + int rc = 0; > > + > > + down_read(&cxl_region_rwsem); > > + > > + if (!is_endpoint_decoder(dev)) > > + goto out; > > + > > + cxled = to_cxl_endpoint_decoder(dev); > > + if (!cxled->dpa_res || !resource_size(cxled->dpa_res)) > > + goto out; > > + > > + /* > > + * Regions are only created with single mode decoders: pmem or ram. > > + * Linux does not currently support mixed mode decoders. This means > > + * that reading poison per endpoint decoder adheres to the spec > > + * requirement that poison reads of pmem and ram must be separated. > > + * CXL 3.0 Spec 8.2.9.8.4.1 > > + * > > + * Watch for future support of mixed with a dev_dbg() msg. > > This sentence can go, mixed will never* be supported. > > * at least until the vendor that manages to ship such a thing comes and > explains why the kernel needs to work around that awkwardness. > Got it! > > + */ snip >
Alison Schofield wrote: [..] > > Ah, cxl_get_poison_by_endpoint() is a function pointer to > > device_for_each_child(), that really feels like a detail that's private > > to the implementation. > > > > I would reorganize this to something like: > > > > if (port->commit_end == -1) { > > /* No regions mapped to this memdev */ > > rc = cxl_get_poison_by_memdev(cxlmd); > > } else { > > /* Regions mapped, collect poison by endpoint */ > > rc = cxl_get_poison_by_endpoint(endpoint); > > } > > > > ...and then internal to cxl_get_poison_by_endpoint() do: > > > > ctx = (struct cxl_trigger_poison_context) { > > .port = endpoint, > > }; > > rc = device_for_each_child(&port->dev, &ctx, > > poison_by_decoder); > > if (rc == 1) > > rc = cxl_get_poison_unmapped(cxlmd, &ctx); > > > > ...then the header file reads more calmly with the added type-safety. > > I'll take another stab at this. > > A couple of versions back, I pulled cxl_get_poison_unmapped() out of > cxl_get_poison_by_endpoint() since it was not really work of the > region driver. (Ira called that out in a review) I think it's ok to have poison_by_decoder() and cxl_get_poison_unmapped() within cxl_get_poison_by_endpoint() because decoder-mapped and unmapped-capacity are both a part of the endpoint. Given that the region core and the region driver are both glommed into drivers/cxl/core/region.c I would not worry too much about the unmapped scanning being in that file if it keeps all the poison code better colocated.
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h index e888e293943e..57bd22e01a0b 100644 --- a/drivers/cxl/core/core.h +++ b/drivers/cxl/core/core.h @@ -25,7 +25,12 @@ void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled); #define CXL_DAX_REGION_TYPE(x) (&cxl_dax_region_type) int cxl_region_init(void); void cxl_region_exit(void); +int cxl_get_poison_by_endpoint(struct device *dev, void *data); #else +static inline int cxl_get_poison_by_endpoint(struct device *dev, void *data) +{ + return 0; +} static inline void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled) { } @@ -68,4 +73,10 @@ enum cxl_poison_trace_type { CXL_POISON_TRACE_LIST, }; +struct cxl_trigger_poison_context { + struct cxl_port *port; + enum cxl_decoder_mode mode; + u64 offset; +}; + #endif /* __CXL_CORE_H__ */ diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c index 297d87ebaca6..f26b5b6cda10 100644 --- a/drivers/cxl/core/memdev.c +++ b/drivers/cxl/core/memdev.c @@ -106,6 +106,47 @@ static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RO(numa_node); +static int cxl_get_poison_unmapped(struct cxl_memdev *cxlmd, + struct cxl_trigger_poison_context *ctx) +{ + struct cxl_dev_state *cxlds = cxlmd->cxlds; + u64 offset, length; + int rc = 0; + + /* + * Collect poison for the remaining unmapped resources + * after poison is collected by committed endpoints. + * + * Knowing that PMEM must always follow RAM, get poison + * for unmapped resources based on the last decoder's mode: + * ram: scan remains of ram range, then any pmem range + * pmem: scan remains of pmem range + */ + + if (ctx->mode == CXL_DECODER_RAM) { + offset = ctx->offset; + length = resource_size(&cxlds->ram_res) - offset; + rc = cxl_mem_get_poison(cxlmd, offset, length, NULL); + if (rc == -EFAULT) + rc = 0; + if (rc) + return rc; + } + if (ctx->mode == CXL_DECODER_PMEM) { + offset = ctx->offset; + length = resource_size(&cxlds->dpa_res) - offset; + if (!length) + return 0; + } else if (resource_size(&cxlds->pmem_res)) { + offset = cxlds->pmem_res.start; + length = resource_size(&cxlds->pmem_res); + } else { + return 0; + } + + return cxl_mem_get_poison(cxlmd, offset, length, NULL); +} + static int cxl_get_poison_by_memdev(struct cxl_memdev *cxlmd) { struct cxl_dev_state *cxlds = cxlmd->cxlds; @@ -139,14 +180,33 @@ ssize_t cxl_trigger_poison_list(struct device *dev, const char *buf, size_t len) { struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_trigger_poison_context ctx; + struct cxl_port *port; bool trigger; ssize_t rc; if (kstrtobool(buf, &trigger) || !trigger) return -EINVAL; + port = dev_get_drvdata(&cxlmd->dev); + if (!port || !is_cxl_endpoint(port)) + return -EINVAL; + down_read(&cxl_dpa_rwsem); - rc = cxl_get_poison_by_memdev(cxlmd); + if (port->commit_end == -1) { + /* No regions mapped to this memdev */ + rc = cxl_get_poison_by_memdev(cxlmd); + } else { + /* Regions mapped, collect poison by endpoint */ + ctx = (struct cxl_trigger_poison_context) { + .port = port, + }; + rc = device_for_each_child(&port->dev, &ctx, + cxl_get_poison_by_endpoint); + if (rc == 1) + rc = cxl_get_poison_unmapped(cxlmd, &ctx); + } + up_read(&cxl_dpa_rwsem); return rc ? rc : len; diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index f29028148806..4c4d3a6d631d 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -2213,6 +2213,69 @@ struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev) } EXPORT_SYMBOL_NS_GPL(to_cxl_pmem_region, CXL); +int cxl_get_poison_by_endpoint(struct device *dev, void *arg) +{ + struct cxl_trigger_poison_context *ctx = arg; + struct cxl_endpoint_decoder *cxled; + struct cxl_port *port = ctx->port; + struct cxl_memdev *cxlmd; + u64 offset, length; + int rc = 0; + + down_read(&cxl_region_rwsem); + + if (!is_endpoint_decoder(dev)) + goto out; + + cxled = to_cxl_endpoint_decoder(dev); + if (!cxled->dpa_res || !resource_size(cxled->dpa_res)) + goto out; + + /* + * Regions are only created with single mode decoders: pmem or ram. + * Linux does not currently support mixed mode decoders. This means + * that reading poison per endpoint decoder adheres to the spec + * requirement that poison reads of pmem and ram must be separated. + * CXL 3.0 Spec 8.2.9.8.4.1 + * + * Watch for future support of mixed with a dev_dbg() msg. + */ + if (cxled->mode == CXL_DECODER_MIXED) { + dev_dbg(dev, "poison list read unsupported in mixed mode\n"); + goto out; + } + + cxlmd = cxled_to_memdev(cxled); + if (cxled->skip) { + offset = cxled->dpa_res->start - cxled->skip; + length = cxled->skip; + rc = cxl_mem_get_poison(cxlmd, offset, length, NULL); + if (rc == -EFAULT && cxled->mode == CXL_DECODER_RAM) + rc = 0; + if (rc) + goto out; + } + + offset = cxled->dpa_res->start; + length = cxled->dpa_res->end - offset + 1; + rc = cxl_mem_get_poison(cxlmd, offset, length, cxled->cxld.region); + if (rc == -EFAULT && cxled->mode == CXL_DECODER_RAM) + rc = 0; + if (rc) + goto out; + + /* Iterate until commit_end is reached */ + if (cxled->cxld.id == port->commit_end) + rc = 1; + + /* ctx informs the memdev driver of last read poison */ + ctx->mode = cxled->mode; + ctx->offset = cxled->dpa_res->end + 1; +out: + up_read(&cxl_region_rwsem); + return rc; +} + static struct lock_class_key cxl_pmem_region_key; static struct cxl_pmem_region *cxl_pmem_region_alloc(struct cxl_region *cxlr)