| Message ID | 438b01ccaa70592539e8eda4eb2b1d617ba03160.1681838292.git.alison.schofield@intel.com |
|---|---|
| State | Accepted |
| Commit | f0832a58639691af575fa28ffaeb657c51f3ca06 |
| 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, poison is read for > any remaining unmapped resources. > > 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 | 5 ++ > drivers/cxl/core/memdev.c | 13 +++- > drivers/cxl/core/region.c | 124 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 141 insertions(+), 1 deletion(-) > > diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h > index e888e293943e..deb5f87d6d0a 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 cxl_port *port); > #else > +static inline int cxl_get_poison_by_endpoint(struct cxl_port *port) > +{ > + return 0; > +} > static inline void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled) > { > } > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > index 71f5ec6ba6c1..8db7f220f182 100644 > --- a/drivers/cxl/core/memdev.c > +++ b/drivers/cxl/core/memdev.c > @@ -136,13 +136,24 @@ static int cxl_get_poison_by_memdev(struct cxl_memdev *cxlmd) > > int cxl_trigger_poison_list(struct cxl_memdev *cxlmd) > { > + struct cxl_port *port; > int rc; > > + port = dev_get_drvdata(&cxlmd->dev); > + if (!port || !is_cxl_endpoint(port)) > + return -EINVAL; > + > rc = down_read_interruptible(&cxl_dpa_rwsem); > if (rc) > return rc; > > - 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 */ > + rc = cxl_get_poison_by_endpoint(port); > + } > up_read(&cxl_dpa_rwsem); > > return rc; > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index f29028148806..5f1c8ce9d956 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -2213,6 +2213,130 @@ struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev) > } > EXPORT_SYMBOL_NS_GPL(to_cxl_pmem_region, CXL); > > +struct cxl_poison_context { > + struct cxl_port *port; > + enum cxl_decoder_mode mode; > + u64 offset; > +}; > + > +static int cxl_get_poison_unmapped(struct cxl_memdev *cxlmd, > + struct cxl_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 poison_by_decoder(struct device *dev, void *arg) Looks like an extra space snuck in there, I can fix that up on applying. > +{ > + struct cxl_poison_context *ctx = arg; > + struct cxl_endpoint_decoder *cxled; > + struct cxl_memdev *cxlmd; > + u64 offset, length; > + int rc = 0; > + > + if (!is_endpoint_decoder(dev)) > + return rc; > + > + cxled = to_cxl_endpoint_decoder(dev); > + if (!cxled->dpa_res || !resource_size(cxled->dpa_res)) > + return rc; > + > + /* > + * Regions are only created with single mode decoders: pmem or ram. > + * Linux does not support mixed mode decoders. This means that > + * reading poison per endpoint decoder adheres to the requirement > + * that poison reads of pmem and ram must be separated. > + * CXL 3.0 Spec 8.2.9.8.4.1 > + */ > + if (cxled->mode == CXL_DECODER_MIXED) { > + dev_dbg(dev, "poison list read unsupported in mixed mode\n"); > + return rc; > + } > + > + 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) > + return rc; > + } > + > + 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) > + return rc; > + > + /* Iterate until commit_end is reached */ > + if (cxled->cxld.id == ctx->port->commit_end) { > + ctx->offset = cxled->dpa_res->end + 1; > + ctx->mode = cxled->mode; > + rc = 1; I think a "return 1" is appropriate here with a "return 0" below, I can also fix that up on applying. > + } > + > + return rc; > +} > + > +int cxl_get_poison_by_endpoint(struct cxl_port *port) > +{ > + struct cxl_poison_context ctx; > + int rc = 0; > + > + rc = down_read_interruptible(&cxl_region_rwsem); > + if (rc) > + return rc; > + > + ctx = (struct cxl_poison_context) { > + .port = port > + }; > + > + rc = device_for_each_child(&port->dev, &ctx, poison_by_decoder); > + if (rc == 1) > + rc = cxl_get_poison_unmapped(to_cxl_memdev(port->uport), &ctx); > + > + 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 >
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h index e888e293943e..deb5f87d6d0a 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 cxl_port *port); #else +static inline int cxl_get_poison_by_endpoint(struct cxl_port *port) +{ + return 0; +} static inline void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled) { } diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c index 71f5ec6ba6c1..8db7f220f182 100644 --- a/drivers/cxl/core/memdev.c +++ b/drivers/cxl/core/memdev.c @@ -136,13 +136,24 @@ static int cxl_get_poison_by_memdev(struct cxl_memdev *cxlmd) int cxl_trigger_poison_list(struct cxl_memdev *cxlmd) { + struct cxl_port *port; int rc; + port = dev_get_drvdata(&cxlmd->dev); + if (!port || !is_cxl_endpoint(port)) + return -EINVAL; + rc = down_read_interruptible(&cxl_dpa_rwsem); if (rc) return rc; - 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 */ + rc = cxl_get_poison_by_endpoint(port); + } up_read(&cxl_dpa_rwsem); return rc; diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index f29028148806..5f1c8ce9d956 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -2213,6 +2213,130 @@ struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev) } EXPORT_SYMBOL_NS_GPL(to_cxl_pmem_region, CXL); +struct cxl_poison_context { + struct cxl_port *port; + enum cxl_decoder_mode mode; + u64 offset; +}; + +static int cxl_get_poison_unmapped(struct cxl_memdev *cxlmd, + struct cxl_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 poison_by_decoder(struct device *dev, void *arg) +{ + struct cxl_poison_context *ctx = arg; + struct cxl_endpoint_decoder *cxled; + struct cxl_memdev *cxlmd; + u64 offset, length; + int rc = 0; + + if (!is_endpoint_decoder(dev)) + return rc; + + cxled = to_cxl_endpoint_decoder(dev); + if (!cxled->dpa_res || !resource_size(cxled->dpa_res)) + return rc; + + /* + * Regions are only created with single mode decoders: pmem or ram. + * Linux does not support mixed mode decoders. This means that + * reading poison per endpoint decoder adheres to the requirement + * that poison reads of pmem and ram must be separated. + * CXL 3.0 Spec 8.2.9.8.4.1 + */ + if (cxled->mode == CXL_DECODER_MIXED) { + dev_dbg(dev, "poison list read unsupported in mixed mode\n"); + return rc; + } + + 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) + return rc; + } + + 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) + return rc; + + /* Iterate until commit_end is reached */ + if (cxled->cxld.id == ctx->port->commit_end) { + ctx->offset = cxled->dpa_res->end + 1; + ctx->mode = cxled->mode; + rc = 1; + } + + return rc; +} + +int cxl_get_poison_by_endpoint(struct cxl_port *port) +{ + struct cxl_poison_context ctx; + int rc = 0; + + rc = down_read_interruptible(&cxl_region_rwsem); + if (rc) + return rc; + + ctx = (struct cxl_poison_context) { + .port = port + }; + + rc = device_for_each_child(&port->dev, &ctx, poison_by_decoder); + if (rc == 1) + rc = cxl_get_poison_unmapped(to_cxl_memdev(port->uport), &ctx); + + 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)