| Message ID | 20240816-dcd-type2-upstream-v3-22-7c9b96cba6d7@intel.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Ira Weiny |
| Headers | show |
| Series | DCD: Add support for Dynamic Capacity Devices (DCD) | expand |
On 8/16/24 7:44 AM, ira.weiny@intel.com wrote: > From: Navneet Singh <navneet.singh@intel.com> > > Dynamic capacity device extents may be left in an accepted state on a > device due to an unexpected host crash. In this case it is expected > that the creation of a new region on top of a DC partition can read > those extents and surface them for continued use. > > Once all endpoint decoders are part of a region and the region is being > realized a read of the devices extent list can reveal these previously > accepted extents. Once all endpoint decoders are part of a region and the region is being realized, a read of the 'devices extend list' can reveal these previously accepted extents. > > CXL r3.1 specifies the mailbox call Get Dynamic Capacity Extent List for > this purpose. The call returns all the extents for all dynamic capacity > partitions. If the fabric manager is adding extents to any DCD > partition, the extent list for the recovered region may change. In this > case the query must retry. Upon retry the query could encounter extents > which were accepted on a previous list query. Adding such extents is > ignored without error because they are entirely within a previous > accepted extent. > > The scan for existing extents races with the dax_cxl driver. This is > synchronized through the region device lock. Extents which are found > after the driver has loaded will surface through the normal notification > path while extents seen prior to the driver are read during driver load. > > 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: > [iweiny: Leverage the new add path from the event processing code such > that the adding and surfacing of extents flows through the same > code path for both event processing and existing extents. > While this does validate existing extents again on start up > this is an error recovery case / new boot scenario and should > not cause any major issues while making the code more > straight forward and maintainable.] > > [iweiny: use %par] > [iweiny: rebase] > [iweiny: Move this patch later in the series such that the realization > of extents can go through the same path as an add event] > [Fan: Issue a retry if the gen number changes] > [djiang: s/uint64_t/u64/] > [djiang: update function names] > [Jørgen/djbw: read the generation and total count on first iteration of > the Get Extent List call] > [djbw: s/cxl_mbox_get_dc_extent_in/cxl_mbox_get_extent_in/] > [djbw: s/cxl_mbox_get_dc_extent_out/cxl_mbox_get_extent_out/] > [djbw/iweiny: s/cxl_read_dc_extents/cxl_read_extent_list] > --- > drivers/cxl/core/core.h | 2 + > drivers/cxl/core/mbox.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++ > drivers/cxl/core/region.c | 12 ++++++ > drivers/cxl/cxlmem.h | 21 ++++++++++ > 4 files changed, 135 insertions(+) > > diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h > index 8dfc97b2e0a4..9e54064a6f48 100644 > --- a/drivers/cxl/core/core.h > +++ b/drivers/cxl/core/core.h > @@ -21,6 +21,8 @@ cxled_to_mds(struct cxl_endpoint_decoder *cxled) > return container_of(cxlds, struct cxl_memdev_state, cxlds); > } > > +void cxl_read_extent_list(struct cxl_endpoint_decoder *cxled); > + > #ifdef CONFIG_CXL_REGION > extern struct device_attribute dev_attr_create_pmem_region; > extern struct device_attribute dev_attr_create_ram_region; > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c > index f629ad7488ac..d43ac8eabf56 100644 > --- a/drivers/cxl/core/mbox.c > +++ b/drivers/cxl/core/mbox.c > @@ -1670,6 +1670,106 @@ int cxl_dev_dynamic_capacity_identify(struct cxl_memdev_state *mds) > } > EXPORT_SYMBOL_NS_GPL(cxl_dev_dynamic_capacity_identify, CXL); > > +/* Return -EAGAIN if the extent list changes while reading */ > +static int __cxl_read_extent_list(struct cxl_endpoint_decoder *cxled) > +{ > + u32 current_index, total_read, total_expected, initial_gen_num; > + struct cxl_memdev_state *mds = cxled_to_mds(cxled); > + struct device *dev = mds->cxlds.dev; > + struct cxl_mbox_cmd mbox_cmd; > + u32 max_extent_count; > + bool first = true; > + > + struct cxl_mbox_get_extent_out *extents __free(kfree) = > + kvmalloc(mds->payload_size, GFP_KERNEL); > + if (!extents) > + return -ENOMEM; > + > + total_read = 0; > + current_index = 0; > + total_expected = 0; > + max_extent_count = (mds->payload_size - sizeof(*extents)) / > + sizeof(struct cxl_extent); > + do { > + struct cxl_mbox_get_extent_in get_extent; > + u32 nr_returned, current_total, current_gen_num; > + int rc; > + > + get_extent = (struct cxl_mbox_get_extent_in) { > + .extent_cnt = max(max_extent_count, > + total_expected - current_index), > + .start_extent_index = cpu_to_le32(current_index), > + }; > + > + mbox_cmd = (struct cxl_mbox_cmd) { > + .opcode = CXL_MBOX_OP_GET_DC_EXTENT_LIST, > + .payload_in = &get_extent, > + .size_in = sizeof(get_extent), > + .size_out = mds->payload_size, > + .payload_out = extents, > + .min_out = 1, > + }; > + > + rc = cxl_internal_send_cmd(mds, &mbox_cmd); > + if (rc < 0) > + return rc; > + > + /* Save initial data */ > + if (first) { > + total_expected = le32_to_cpu(extents->total_extent_count); > + initial_gen_num = le32_to_cpu(extents->generation_num); > + first = false; > + } > + > + nr_returned = le32_to_cpu(extents->returned_extent_count); > + total_read += nr_returned; > + current_total = le32_to_cpu(extents->total_extent_count); > + current_gen_num = le32_to_cpu(extents->generation_num); > + > + dev_dbg(dev, "Got extent list %d-%d of %d generation Num:%d\n", > + current_index, total_read - 1, current_total, current_gen_num); > + > + if (current_gen_num != initial_gen_num || total_expected != current_total) { > + dev_dbg(dev, "Extent list change detected; gen %u != %u : cnt %u != %u\n", > + current_gen_num, initial_gen_num, > + total_expected, current_total); > + return -EAGAIN; > + } > + > + for (int i = 0; i < nr_returned ; i++) { > + struct cxl_extent *extent = &extents->extent[i]; > + > + dev_dbg(dev, "Processing extent %d/%d\n", > + current_index + i, total_expected); > + > + rc = validate_add_extent(mds, extent); > + if (rc) > + continue; > + } > + > + current_index += nr_returned; > + } while (total_expected > total_read); > + > + return 0; > +} > + > +/** > + * cxl_read_extent_list() - Read existing extents > + * @cxled: Endpoint decoder which is part of a region > + * > + * Issue the Get Dynamic Capacity Extent List command to the device > + * and add existing extents if found. > + */ > +void cxl_read_extent_list(struct cxl_endpoint_decoder *cxled) cxl_process_extend_list()? It seems to do read+validate+add. > +{ > + int retry = 10; arbitrary retry number? maybe define it? DJ > + int rc; > + > + do { > + rc = __cxl_read_extent_list(cxled); > + } while (rc == -EAGAIN && retry--); > +} > + > static int add_dpa_res(struct device *dev, struct resource *parent, > struct resource *res, resource_size_t start, > resource_size_t size, const char *type) > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index 8c9171f914fb..885fb3004784 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -3190,6 +3190,15 @@ static int devm_cxl_add_pmem_region(struct cxl_region *cxlr) > return rc; > } > > +static void cxlr_add_existing_extents(struct cxl_region *cxlr) > +{ > + struct cxl_region_params *p = &cxlr->params; > + int i; > + > + for (i = 0; i < p->nr_targets; i++) > + cxl_read_extent_list(p->targets[i]); > +} > + > static void cxlr_dax_unregister(void *_cxlr_dax) > { > struct cxl_dax_region *cxlr_dax = _cxlr_dax; > @@ -3227,6 +3236,9 @@ static int devm_cxl_add_dax_region(struct cxl_region *cxlr) > dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent), > dev_name(dev)); > > + if (cxlr->mode == CXL_REGION_DC) > + cxlr_add_existing_extents(cxlr); > + > return devm_add_action_or_reset(&cxlr->dev, cxlr_dax_unregister, > cxlr_dax); > err: > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > index 3a40fe1f0be7..11c03637488d 100644 > --- a/drivers/cxl/cxlmem.h > +++ b/drivers/cxl/cxlmem.h > @@ -624,6 +624,27 @@ struct cxl_mbox_dc_response { > } __packed extent_list[]; > } __packed; > > +/* > + * Get Dynamic Capacity Extent List; Input Payload > + * CXL rev 3.1 section 8.2.9.9.9.2; Table 8-166 > + */ > +struct cxl_mbox_get_extent_in { > + __le32 extent_cnt; > + __le32 start_extent_index; > +} __packed; > + > +/* > + * Get Dynamic Capacity Extent List; Output Payload > + * CXL rev 3.1 section 8.2.9.9.9.2; Table 8-167 > + */ > +struct cxl_mbox_get_extent_out { > + __le32 returned_extent_count; > + __le32 total_extent_count; > + __le32 generation_num; > + u8 rsvd[4]; > + struct cxl_extent extent[]; > +} __packed; > + > struct cxl_mbox_get_supported_logs { > __le16 entries; > u8 rsvd[6]; >
Dave Jiang wrote: > > > On 8/16/24 7:44 AM, ira.weiny@intel.com wrote: > > From: Navneet Singh <navneet.singh@intel.com> > > > > Dynamic capacity device extents may be left in an accepted state on a > > device due to an unexpected host crash. In this case it is expected > > that the creation of a new region on top of a DC partition can read > > those extents and surface them for continued use. > > > > Once all endpoint decoders are part of a region and the region is being > > realized a read of the devices extent list can reveal these previously > > accepted extents. > > Once all endpoint decoders are part of a region and the region is being > realized, a read of the 'devices extend list' can reveal these previously > accepted extents. > Thanks, done. [snip] > > + > > +/** > > + * cxl_read_extent_list() - Read existing extents > > + * @cxled: Endpoint decoder which is part of a region > > + * > > + * Issue the Get Dynamic Capacity Extent List command to the device > > + * and add existing extents if found. > > + */ > > +void cxl_read_extent_list(struct cxl_endpoint_decoder *cxled) > > cxl_process_extend_list()? It seems to do read+validate+add. yea maybe. The name of this function actually changed in my mind many times. In the end I went for the higher level meaning which was to read the existing extent list. I'll change it because I'm not convinced of any particular name. > > > +{ > > + int retry = 10; > > arbitrary retry number? maybe define it? Sure. But it is still an arbitrary value of 10. I'll document my justification thusly. /* ... * A retry of 10 is somewhat arbitrary, however, extent changes should be * relatively rare while bringing up a region. So 10 should be plenty. */ #define CXL_READ_EXTENT_LIST_RETRY 10 Ira [snip]
On Fri, 16 Aug 2024 09:44:30 -0500 ira.weiny@intel.com wrote: > From: Navneet Singh <navneet.singh@intel.com> > > Dynamic capacity device extents may be left in an accepted state on a > device due to an unexpected host crash. In this case it is expected > that the creation of a new region on top of a DC partition can read > those extents and surface them for continued use. > > Once all endpoint decoders are part of a region and the region is being > realized a read of the devices extent list can reveal these previously > accepted extents. > > CXL r3.1 specifies the mailbox call Get Dynamic Capacity Extent List for > this purpose. The call returns all the extents for all dynamic capacity > partitions. If the fabric manager is adding extents to any DCD > partition, the extent list for the recovered region may change. In this > case the query must retry. Upon retry the query could encounter extents > which were accepted on a previous list query. Adding such extents is > ignored without error because they are entirely within a previous > accepted extent. > > The scan for existing extents races with the dax_cxl driver. This is > synchronized through the region device lock. Extents which are found > after the driver has loaded will surface through the normal notification > path while extents seen prior to the driver are read during driver load. Ah. So the earlier code to just eat duplicates was to handle this race. Add a comment there perhaps so people like me get less confused :) Jonathan > > 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> LGTM Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
On Fri, Aug 16, 2024 at 09:44:30AM -0500, ira.weiny@intel.com wrote: > From: Navneet Singh <navneet.singh@intel.com> > > Dynamic capacity device extents may be left in an accepted state on a > device due to an unexpected host crash. In this case it is expected > that the creation of a new region on top of a DC partition can read > those extents and surface them for continued use. > > Once all endpoint decoders are part of a region and the region is being > realized a read of the devices extent list can reveal these previously > accepted extents. > > CXL r3.1 specifies the mailbox call Get Dynamic Capacity Extent List for > this purpose. The call returns all the extents for all dynamic capacity > partitions. If the fabric manager is adding extents to any DCD > partition, the extent list for the recovered region may change. In this > case the query must retry. Upon retry the query could encounter extents > which were accepted on a previous list query. Adding such extents is > ignored without error because they are entirely within a previous > accepted extent. > > The scan for existing extents races with the dax_cxl driver. This is > synchronized through the region device lock. Extents which are found > after the driver has loaded will surface through the normal notification > path while extents seen prior to the driver are read during driver load. > > 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> With the minor things fixed mentioned by Jonathan and Dave, Reviewed-by: Fan Ni <fan.ni@samsung.com> > > --- > Changes: > [iweiny: Leverage the new add path from the event processing code such > that the adding and surfacing of extents flows through the same > code path for both event processing and existing extents. > While this does validate existing extents again on start up > this is an error recovery case / new boot scenario and should > not cause any major issues while making the code more > straight forward and maintainable.] > > [iweiny: use %par] > [iweiny: rebase] > [iweiny: Move this patch later in the series such that the realization > of extents can go through the same path as an add event] > [Fan: Issue a retry if the gen number changes] > [djiang: s/uint64_t/u64/] > [djiang: update function names] > [Jørgen/djbw: read the generation and total count on first iteration of > the Get Extent List call] > [djbw: s/cxl_mbox_get_dc_extent_in/cxl_mbox_get_extent_in/] > [djbw: s/cxl_mbox_get_dc_extent_out/cxl_mbox_get_extent_out/] > [djbw/iweiny: s/cxl_read_dc_extents/cxl_read_extent_list] > --- > drivers/cxl/core/core.h | 2 + > drivers/cxl/core/mbox.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++ > drivers/cxl/core/region.c | 12 ++++++ > drivers/cxl/cxlmem.h | 21 ++++++++++ > 4 files changed, 135 insertions(+) > > diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h > index 8dfc97b2e0a4..9e54064a6f48 100644 > --- a/drivers/cxl/core/core.h > +++ b/drivers/cxl/core/core.h > @@ -21,6 +21,8 @@ cxled_to_mds(struct cxl_endpoint_decoder *cxled) > return container_of(cxlds, struct cxl_memdev_state, cxlds); > } > > +void cxl_read_extent_list(struct cxl_endpoint_decoder *cxled); > + > #ifdef CONFIG_CXL_REGION > extern struct device_attribute dev_attr_create_pmem_region; > extern struct device_attribute dev_attr_create_ram_region; > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c > index f629ad7488ac..d43ac8eabf56 100644 > --- a/drivers/cxl/core/mbox.c > +++ b/drivers/cxl/core/mbox.c > @@ -1670,6 +1670,106 @@ int cxl_dev_dynamic_capacity_identify(struct cxl_memdev_state *mds) > } > EXPORT_SYMBOL_NS_GPL(cxl_dev_dynamic_capacity_identify, CXL); > > +/* Return -EAGAIN if the extent list changes while reading */ > +static int __cxl_read_extent_list(struct cxl_endpoint_decoder *cxled) > +{ > + u32 current_index, total_read, total_expected, initial_gen_num; > + struct cxl_memdev_state *mds = cxled_to_mds(cxled); > + struct device *dev = mds->cxlds.dev; > + struct cxl_mbox_cmd mbox_cmd; > + u32 max_extent_count; > + bool first = true; > + > + struct cxl_mbox_get_extent_out *extents __free(kfree) = > + kvmalloc(mds->payload_size, GFP_KERNEL); > + if (!extents) > + return -ENOMEM; > + > + total_read = 0; > + current_index = 0; > + total_expected = 0; > + max_extent_count = (mds->payload_size - sizeof(*extents)) / > + sizeof(struct cxl_extent); > + do { > + struct cxl_mbox_get_extent_in get_extent; > + u32 nr_returned, current_total, current_gen_num; > + int rc; > + > + get_extent = (struct cxl_mbox_get_extent_in) { > + .extent_cnt = max(max_extent_count, > + total_expected - current_index), > + .start_extent_index = cpu_to_le32(current_index), > + }; > + > + mbox_cmd = (struct cxl_mbox_cmd) { > + .opcode = CXL_MBOX_OP_GET_DC_EXTENT_LIST, > + .payload_in = &get_extent, > + .size_in = sizeof(get_extent), > + .size_out = mds->payload_size, > + .payload_out = extents, > + .min_out = 1, > + }; > + > + rc = cxl_internal_send_cmd(mds, &mbox_cmd); > + if (rc < 0) > + return rc; > + > + /* Save initial data */ > + if (first) { > + total_expected = le32_to_cpu(extents->total_extent_count); > + initial_gen_num = le32_to_cpu(extents->generation_num); > + first = false; > + } > + > + nr_returned = le32_to_cpu(extents->returned_extent_count); > + total_read += nr_returned; > + current_total = le32_to_cpu(extents->total_extent_count); > + current_gen_num = le32_to_cpu(extents->generation_num); > + > + dev_dbg(dev, "Got extent list %d-%d of %d generation Num:%d\n", > + current_index, total_read - 1, current_total, current_gen_num); > + > + if (current_gen_num != initial_gen_num || total_expected != current_total) { > + dev_dbg(dev, "Extent list change detected; gen %u != %u : cnt %u != %u\n", > + current_gen_num, initial_gen_num, > + total_expected, current_total); > + return -EAGAIN; > + } > + > + for (int i = 0; i < nr_returned ; i++) { > + struct cxl_extent *extent = &extents->extent[i]; > + > + dev_dbg(dev, "Processing extent %d/%d\n", > + current_index + i, total_expected); > + > + rc = validate_add_extent(mds, extent); > + if (rc) > + continue; > + } > + > + current_index += nr_returned; > + } while (total_expected > total_read); > + > + return 0; > +} > + > +/** > + * cxl_read_extent_list() - Read existing extents > + * @cxled: Endpoint decoder which is part of a region > + * > + * Issue the Get Dynamic Capacity Extent List command to the device > + * and add existing extents if found. > + */ > +void cxl_read_extent_list(struct cxl_endpoint_decoder *cxled) > +{ > + int retry = 10; > + int rc; > + > + do { > + rc = __cxl_read_extent_list(cxled); > + } while (rc == -EAGAIN && retry--); > +} > + > static int add_dpa_res(struct device *dev, struct resource *parent, > struct resource *res, resource_size_t start, > resource_size_t size, const char *type) > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index 8c9171f914fb..885fb3004784 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -3190,6 +3190,15 @@ static int devm_cxl_add_pmem_region(struct cxl_region *cxlr) > return rc; > } > > +static void cxlr_add_existing_extents(struct cxl_region *cxlr) > +{ > + struct cxl_region_params *p = &cxlr->params; > + int i; > + > + for (i = 0; i < p->nr_targets; i++) > + cxl_read_extent_list(p->targets[i]); > +} > + > static void cxlr_dax_unregister(void *_cxlr_dax) > { > struct cxl_dax_region *cxlr_dax = _cxlr_dax; > @@ -3227,6 +3236,9 @@ static int devm_cxl_add_dax_region(struct cxl_region *cxlr) > dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent), > dev_name(dev)); > > + if (cxlr->mode == CXL_REGION_DC) > + cxlr_add_existing_extents(cxlr); > + > return devm_add_action_or_reset(&cxlr->dev, cxlr_dax_unregister, > cxlr_dax); > err: > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > index 3a40fe1f0be7..11c03637488d 100644 > --- a/drivers/cxl/cxlmem.h > +++ b/drivers/cxl/cxlmem.h > @@ -624,6 +624,27 @@ struct cxl_mbox_dc_response { > } __packed extent_list[]; > } __packed; > > +/* > + * Get Dynamic Capacity Extent List; Input Payload > + * CXL rev 3.1 section 8.2.9.9.9.2; Table 8-166 > + */ > +struct cxl_mbox_get_extent_in { > + __le32 extent_cnt; > + __le32 start_extent_index; > +} __packed; > + > +/* > + * Get Dynamic Capacity Extent List; Output Payload > + * CXL rev 3.1 section 8.2.9.9.9.2; Table 8-167 > + */ > +struct cxl_mbox_get_extent_out { > + __le32 returned_extent_count; > + __le32 total_extent_count; > + __le32 generation_num; > + u8 rsvd[4]; > + struct cxl_extent extent[]; > +} __packed; > + > struct cxl_mbox_get_supported_logs { > __le16 entries; > u8 rsvd[6]; > > -- > 2.45.2 >
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h index 8dfc97b2e0a4..9e54064a6f48 100644 --- a/drivers/cxl/core/core.h +++ b/drivers/cxl/core/core.h @@ -21,6 +21,8 @@ cxled_to_mds(struct cxl_endpoint_decoder *cxled) return container_of(cxlds, struct cxl_memdev_state, cxlds); } +void cxl_read_extent_list(struct cxl_endpoint_decoder *cxled); + #ifdef CONFIG_CXL_REGION extern struct device_attribute dev_attr_create_pmem_region; extern struct device_attribute dev_attr_create_ram_region; diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index f629ad7488ac..d43ac8eabf56 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -1670,6 +1670,106 @@ int cxl_dev_dynamic_capacity_identify(struct cxl_memdev_state *mds) } EXPORT_SYMBOL_NS_GPL(cxl_dev_dynamic_capacity_identify, CXL); +/* Return -EAGAIN if the extent list changes while reading */ +static int __cxl_read_extent_list(struct cxl_endpoint_decoder *cxled) +{ + u32 current_index, total_read, total_expected, initial_gen_num; + struct cxl_memdev_state *mds = cxled_to_mds(cxled); + struct device *dev = mds->cxlds.dev; + struct cxl_mbox_cmd mbox_cmd; + u32 max_extent_count; + bool first = true; + + struct cxl_mbox_get_extent_out *extents __free(kfree) = + kvmalloc(mds->payload_size, GFP_KERNEL); + if (!extents) + return -ENOMEM; + + total_read = 0; + current_index = 0; + total_expected = 0; + max_extent_count = (mds->payload_size - sizeof(*extents)) / + sizeof(struct cxl_extent); + do { + struct cxl_mbox_get_extent_in get_extent; + u32 nr_returned, current_total, current_gen_num; + int rc; + + get_extent = (struct cxl_mbox_get_extent_in) { + .extent_cnt = max(max_extent_count, + total_expected - current_index), + .start_extent_index = cpu_to_le32(current_index), + }; + + mbox_cmd = (struct cxl_mbox_cmd) { + .opcode = CXL_MBOX_OP_GET_DC_EXTENT_LIST, + .payload_in = &get_extent, + .size_in = sizeof(get_extent), + .size_out = mds->payload_size, + .payload_out = extents, + .min_out = 1, + }; + + rc = cxl_internal_send_cmd(mds, &mbox_cmd); + if (rc < 0) + return rc; + + /* Save initial data */ + if (first) { + total_expected = le32_to_cpu(extents->total_extent_count); + initial_gen_num = le32_to_cpu(extents->generation_num); + first = false; + } + + nr_returned = le32_to_cpu(extents->returned_extent_count); + total_read += nr_returned; + current_total = le32_to_cpu(extents->total_extent_count); + current_gen_num = le32_to_cpu(extents->generation_num); + + dev_dbg(dev, "Got extent list %d-%d of %d generation Num:%d\n", + current_index, total_read - 1, current_total, current_gen_num); + + if (current_gen_num != initial_gen_num || total_expected != current_total) { + dev_dbg(dev, "Extent list change detected; gen %u != %u : cnt %u != %u\n", + current_gen_num, initial_gen_num, + total_expected, current_total); + return -EAGAIN; + } + + for (int i = 0; i < nr_returned ; i++) { + struct cxl_extent *extent = &extents->extent[i]; + + dev_dbg(dev, "Processing extent %d/%d\n", + current_index + i, total_expected); + + rc = validate_add_extent(mds, extent); + if (rc) + continue; + } + + current_index += nr_returned; + } while (total_expected > total_read); + + return 0; +} + +/** + * cxl_read_extent_list() - Read existing extents + * @cxled: Endpoint decoder which is part of a region + * + * Issue the Get Dynamic Capacity Extent List command to the device + * and add existing extents if found. + */ +void cxl_read_extent_list(struct cxl_endpoint_decoder *cxled) +{ + int retry = 10; + int rc; + + do { + rc = __cxl_read_extent_list(cxled); + } while (rc == -EAGAIN && retry--); +} + static int add_dpa_res(struct device *dev, struct resource *parent, struct resource *res, resource_size_t start, resource_size_t size, const char *type) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 8c9171f914fb..885fb3004784 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -3190,6 +3190,15 @@ static int devm_cxl_add_pmem_region(struct cxl_region *cxlr) return rc; } +static void cxlr_add_existing_extents(struct cxl_region *cxlr) +{ + struct cxl_region_params *p = &cxlr->params; + int i; + + for (i = 0; i < p->nr_targets; i++) + cxl_read_extent_list(p->targets[i]); +} + static void cxlr_dax_unregister(void *_cxlr_dax) { struct cxl_dax_region *cxlr_dax = _cxlr_dax; @@ -3227,6 +3236,9 @@ static int devm_cxl_add_dax_region(struct cxl_region *cxlr) dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent), dev_name(dev)); + if (cxlr->mode == CXL_REGION_DC) + cxlr_add_existing_extents(cxlr); + return devm_add_action_or_reset(&cxlr->dev, cxlr_dax_unregister, cxlr_dax); err: diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index 3a40fe1f0be7..11c03637488d 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -624,6 +624,27 @@ struct cxl_mbox_dc_response { } __packed extent_list[]; } __packed; +/* + * Get Dynamic Capacity Extent List; Input Payload + * CXL rev 3.1 section 8.2.9.9.9.2; Table 8-166 + */ +struct cxl_mbox_get_extent_in { + __le32 extent_cnt; + __le32 start_extent_index; +} __packed; + +/* + * Get Dynamic Capacity Extent List; Output Payload + * CXL rev 3.1 section 8.2.9.9.9.2; Table 8-167 + */ +struct cxl_mbox_get_extent_out { + __le32 returned_extent_count; + __le32 total_extent_count; + __le32 generation_num; + u8 rsvd[4]; + struct cxl_extent extent[]; +} __packed; + struct cxl_mbox_get_supported_logs { __le16 entries; u8 rsvd[6];