| Message ID | 20240324-dcd-type2-upstream-v1-7-b7b00d623625@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | DCD: Add support for Dynamic Capacity Devices (DCD) | expand |
On Sun, 24 Mar 2024 16:18:10 -0700 ira.weiny@intel.com wrote: > From: Navneet Singh <navneet.singh@intel.com> > > To support Dynamic Capacity Devices (DCD) endpoint decoders will need to > map DC partitions (regions). In addition to assigning the size of the > DC partition, the decoder must assign any skip value from the previous > decoder. This must be done within a contiguous DPA space. > > Two complications arise with Dynamic Capacity regions which did not > exist with Ram and PMEM partitions. First, gaps in the DPA space can > exist between and around the DC Regions. Second, the Linux resource > tree does not allow a resource to be marked across existing nodes within > a tree. > > For clarity, below is an example of an 60GB device with 10GB of RAM, > 10GB of PMEM and 10GB for each of 2 DC Regions. The desired CXL mapping > is 5GB of RAM, 5GB of PMEM, and all 10GB of DC1. > > DPA RANGE > (dpa_res) > 0GB 10GB 20GB 30GB 40GB 50GB 60GB > |----------|----------|----------|----------|----------|----------| > > RAM PMEM DC0 DC1 > (ram_res) (pmem_res) (dc_res[0]) (dc_res[1]) > |----------|----------| <gap> |----------| <gap> |----------| > > RAM PMEM DC1 > |XXXXX|----|XXXXX|----|----------|----------|----------|XXXXXXXXXX| > 0GB 5GB 10GB 15GB 20GB 30GB 40GB 50GB 60GB To add another corner to the example, maybe map only part of DC1? > > The previous skip resource between RAM and PMEM was always a child of > the RAM resource and fit nicely [see (S) below]. Because of this > simplicity this skip resource reference was not stored in any CXL state. > On release the skip range could be calculated based on the endpoint > decoders stored values. > > Now when DC1 is being mapped 4 skip resources must be created as > children. One for the PMEM resource (A), two of the parent DPA resource > (B,D), and one more child of the DC0 resource (C). > > 0GB 10GB 20GB 30GB 40GB 50GB 60GB > |----------|----------|----------|----------|----------|----------| > | | > |----------|----------| | |----------| | |----------| > | | | | | > (S) (A) (B) (C) (D) > v v v v v > |XXXXX|----|XXXXX|----|----------|----------|----------|XXXXXXXXXX| > skip skip skip skip skip > > Expand the calculation of DPA freespace and enhance the logic to support > mapping/unmapping DC DPA space. To track the potential of multiple skip > resources an xarray is attached to the endpoint decoder. The existing > algorithm between RAM and PMEM is consolidated within the new one to > streamline the code even though the result is the storage of a single > skip resource in the xarray. > > 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: > [iweiny: Update cover letter] > --- > drivers/cxl/core/hdm.c | 192 +++++++++++++++++++++++++++++++++++++++++++----- > drivers/cxl/core/port.c | 2 + > drivers/cxl/cxl.h | 2 + > 3 files changed, 179 insertions(+), 17 deletions(-) > > diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c > index e22b6f4f7145..da7d58184490 100644 > --- a/drivers/cxl/core/hdm.c > +++ b/drivers/cxl/core/hdm.c > @@ -210,6 +210,25 @@ void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds) > } > EXPORT_SYMBOL_NS_GPL(cxl_dpa_debug, CXL); > > +static void cxl_skip_release(struct cxl_endpoint_decoder *cxled) > +{ > + struct cxl_dev_state *cxlds = cxled_to_memdev(cxled)->cxlds; > + struct cxl_port *port = cxled_to_port(cxled); > + struct device *dev = &port->dev; > + unsigned long index; > + void *entry; > + > + xa_for_each(&cxled->skip_res, index, entry) { > + struct resource *res = entry; > + > + dev_dbg(dev, "decoder%d.%d: releasing skipped space; %pr\n", > + port->id, cxled->cxld.id, res); > + __release_region(&cxlds->dpa_res, res->start, > + resource_size(res)); > + xa_erase(&cxled->skip_res, index); > + } > +} > + > /* > * Must be called in a context that synchronizes against this decoder's > * port ->remove() callback (like an endpoint decoder sysfs attribute) > @@ -220,15 +239,11 @@ static void __cxl_dpa_release(struct cxl_endpoint_decoder *cxled) > struct cxl_port *port = cxled_to_port(cxled); > struct cxl_dev_state *cxlds = cxlmd->cxlds; > struct resource *res = cxled->dpa_res; > - resource_size_t skip_start; > > lockdep_assert_held_write(&cxl_dpa_rwsem); > > - /* save @skip_start, before @res is released */ > - skip_start = res->start - cxled->skip; > __release_region(&cxlds->dpa_res, res->start, resource_size(res)); > - if (cxled->skip) > - __release_region(&cxlds->dpa_res, skip_start, cxled->skip); > + cxl_skip_release(cxled); > cxled->skip = 0; > cxled->dpa_res = NULL; > put_device(&cxled->cxld.dev); > @@ -263,6 +278,100 @@ static int dc_mode_to_region_index(enum cxl_decoder_mode mode) > return mode - CXL_DECODER_DC0; > } > > +static int cxl_request_skip(struct cxl_endpoint_decoder *cxled, > + resource_size_t skip_base, resource_size_t skip_len) > +{ > + struct cxl_dev_state *cxlds = cxled_to_memdev(cxled)->cxlds; > + const char *name = dev_name(&cxled->cxld.dev); > + struct cxl_port *port = cxled_to_port(cxled); > + struct resource *dpa_res = &cxlds->dpa_res; > + struct device *dev = &port->dev; > + struct resource *res; > + int rc; > + > + res = __request_region(dpa_res, skip_base, skip_len, name, 0); > + if (!res) > + return -EBUSY; > + > + rc = xa_insert(&cxled->skip_res, skip_base, res, GFP_KERNEL); > + if (rc) { > + __release_region(dpa_res, skip_base, skip_len); > + return rc; > + } > + > + dev_dbg(dev, "decoder%d.%d: skipped space; %pr\n", > + port->id, cxled->cxld.id, res); > + return 0; > +} > + > +static int cxl_reserve_dpa_skip(struct cxl_endpoint_decoder *cxled, > + resource_size_t base, resource_size_t skipped) > +{ > + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); > + struct cxl_port *port = cxled_to_port(cxled); > + struct cxl_dev_state *cxlds = cxlmd->cxlds; > + resource_size_t skip_base = base - skipped; > + struct device *dev = &port->dev; > + resource_size_t skip_len = 0; > + int rc, index; > + > + if (resource_size(&cxlds->ram_res) && skip_base <= cxlds->ram_res.end) { > + skip_len = cxlds->ram_res.end - skip_base + 1; > + rc = cxl_request_skip(cxled, skip_base, skip_len); > + if (rc) > + return rc; > + skip_base += skip_len; > + } > + > + if (skip_base == base) { > + dev_dbg(dev, "skip done ram!\n"); > + return 0; > + } > + > + if (resource_size(&cxlds->pmem_res) && > + skip_base <= cxlds->pmem_res.end) { > + skip_len = cxlds->pmem_res.end - skip_base + 1; > + rc = cxl_request_skip(cxled, skip_base, skip_len); > + if (rc) > + return rc; > + skip_base += skip_len; > + } > + > + index = dc_mode_to_region_index(cxled->mode); > + for (int i = 0; i <= index; i++) { > + struct resource *dcr = &cxlds->dc_res[i]; > + > + if (skip_base < dcr->start) { > + skip_len = dcr->start - skip_base; > + rc = cxl_request_skip(cxled, skip_base, skip_len); > + if (rc) > + return rc; > + skip_base += skip_len; > + } > + > + if (skip_base == base) { > + dev_dbg(dev, "skip done DC region %d!\n", i); > + break; > + } > + > + if (resource_size(dcr) && skip_base <= dcr->end) { > + if (skip_base > base) { > + dev_err(dev, "Skip error DC region %d; skip_base %pa; base %pa\n", > + i, &skip_base, &base); > + return -ENXIO; > + } > + > + skip_len = dcr->end - skip_base + 1; > + rc = cxl_request_skip(cxled, skip_base, skip_len); > + if (rc) > + return rc; > + skip_base += skip_len; > + } > + } > + > + return 0; > +} > + > static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, > resource_size_t base, resource_size_t len, > resource_size_t skipped) > @@ -300,13 +409,12 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, > } > > if (skipped) { > - res = __request_region(&cxlds->dpa_res, base - skipped, skipped, > - dev_name(&cxled->cxld.dev), 0); > - if (!res) { > - dev_dbg(dev, > - "decoder%d.%d: failed to reserve skipped space\n", > - port->id, cxled->cxld.id); > - return -EBUSY; > + int rc = cxl_reserve_dpa_skip(cxled, base, skipped); > + > + if (rc) { > + dev_dbg(dev, "decoder%d.%d: failed to reserve skipped space; %pa - %pa\n", > + port->id, cxled->cxld.id, &base, &skipped); > + return rc; > } > } > res = __request_region(&cxlds->dpa_res, base, len, > @@ -314,14 +422,20 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, > if (!res) { > dev_dbg(dev, "decoder%d.%d: failed to reserve allocation\n", > port->id, cxled->cxld.id); > - if (skipped) > - __release_region(&cxlds->dpa_res, base - skipped, > - skipped); > + cxl_skip_release(cxled); > return -EBUSY; > } > cxled->dpa_res = res; > cxled->skip = skipped; > > + for (int mode = CXL_DECODER_DC0; mode <= CXL_DECODER_DC7; mode++) { > + int index = dc_mode_to_region_index(mode); > + > + if (resource_contains(&cxlds->dc_res[index], res)) { > + cxled->mode = mode; > + goto success; > + } > + } > if (resource_contains(&cxlds->pmem_res, res)) > cxled->mode = CXL_DECODER_PMEM; > else if (resource_contains(&cxlds->ram_res, res)) > @@ -332,6 +446,9 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, > cxled->mode = CXL_DECODER_MIXED; > } > > +success: > + dev_dbg(dev, "decoder%d.%d: %pr mode: %d\n", port->id, cxled->cxld.id, > + cxled->dpa_res, cxled->mode); > port->hdm_end++; > get_device(&cxled->cxld.dev); > return 0; > @@ -463,14 +580,14 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, > > int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size) > { > + resource_size_t free_ram_start, free_pmem_start, free_dc_start; > struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); > - resource_size_t free_ram_start, free_pmem_start; > struct cxl_port *port = cxled_to_port(cxled); > struct cxl_dev_state *cxlds = cxlmd->cxlds; > struct device *dev = &cxled->cxld.dev; > resource_size_t start, avail, skip; > struct resource *p, *last; > - int rc; > + int rc, dc_index; > > down_write(&cxl_dpa_rwsem); Obviously not related to this patch as such, but maybe a good place for scoped_guard() to avoid the dance around unlocking the rwsem and allow some early returns on the error paths. > if (cxled->cxld.region) { > @@ -500,6 +617,21 @@ int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size) > else > free_pmem_start = cxlds->pmem_res.start; > > + /* > + * Limit each decoder to a single DC region to map memory with > + * different DSMAS entry. > + */ > + dc_index = dc_mode_to_region_index(cxled->mode); > + if (dc_index >= 0) { > + if (cxlds->dc_res[dc_index].child) { > + dev_err(dev, "Cannot allocate DPA from DC Region: %d\n", > + dc_index); > + rc = -EINVAL; > + goto out; > + } > + free_dc_start = cxlds->dc_res[dc_index].start; > + } > + > if (cxled->mode == CXL_DECODER_RAM) { > start = free_ram_start; > avail = cxlds->ram_res.end - start + 1; > @@ -521,12 +653,38 @@ int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size) > else > skip_end = start - 1; > skip = skip_end - skip_start + 1; > + } else if (cxl_decoder_mode_is_dc(cxled->mode)) { > + resource_size_t skip_start, skip_end; > + > + start = free_dc_start; > + avail = cxlds->dc_res[dc_index].end - start + 1; > + if ((resource_size(&cxlds->pmem_res) == 0) || !cxlds->pmem_res.child) > + skip_start = free_ram_start; > + else > + skip_start = free_pmem_start; > + /* > + * If any dc region is already mapped, then that allocation > + * already handled the RAM and PMEM skip. Check for DC region > + * skip. > + */ > + for (int i = dc_index - 1; i >= 0 ; i--) { > + if (cxlds->dc_res[i].child) { > + skip_start = cxlds->dc_res[i].child->end + 1; > + break; > + } > + } > + > + skip_end = start - 1; > + skip = skip_end - skip_start + 1; I notice in the pmem equivalent there is a case for part of the region already mapped. Can that not happen for a DC region as well? > } else { > dev_dbg(dev, "mode not set\n"); > rc = -EINVAL; > goto out; > } > > + dev_dbg(dev, "DPA Allocation start: %pa len: %#llx Skip: %pa\n", > + &start, size, &skip); > + > if (size > avail) { > dev_dbg(dev, "%pa exceeds available %s capacity: %pa\n", &size, > cxled->mode == CXL_DECODER_RAM ? "ram" : "pmem",
On Sun, Mar 24, 2024 at 04:18:10PM -0700, Ira Weiny wrote: > From: Navneet Singh <navneet.singh@intel.com> > > To support Dynamic Capacity Devices (DCD) endpoint decoders will need to > map DC partitions (regions). In addition to assigning the size of the > DC partition, the decoder must assign any skip value from the previous > decoder. This must be done within a contiguous DPA space. > > Two complications arise with Dynamic Capacity regions which did not > exist with Ram and PMEM partitions. First, gaps in the DPA space can RAM > exist between and around the DC Regions. Second, the Linux resource > tree does not allow a resource to be marked across existing nodes within > a tree. > > For clarity, below is an example of an 60GB device with 10GB of RAM, > 10GB of PMEM and 10GB for each of 2 DC Regions. The desired CXL mapping > is 5GB of RAM, 5GB of PMEM, and all 10GB of DC1. > > DPA RANGE > (dpa_res) > 0GB 10GB 20GB 30GB 40GB 50GB 60GB > |----------|----------|----------|----------|----------|----------| > > RAM PMEM DC0 DC1 > (ram_res) (pmem_res) (dc_res[0]) (dc_res[1]) > |----------|----------| <gap> |----------| <gap> |----------| > > RAM PMEM DC1 > |XXXXX|----|XXXXX|----|----------|----------|----------|XXXXXXXXXX| > 0GB 5GB 10GB 15GB 20GB 30GB 40GB 50GB 60GB > > The previous skip resource between RAM and PMEM was always a child of > the RAM resource and fit nicely [see (S) below]. Because of this > simplicity this skip resource reference was not stored in any CXL state. > On release the skip range could be calculated based on the endpoint > decoders stored values. > > Now when DC1 is being mapped 4 skip resources must be created as > children. One for the PMEM resource (A), two of the parent DPA resource > (B,D), and one more child of the DC0 resource (C). > > 0GB 10GB 20GB 30GB 40GB 50GB 60GB > |----------|----------|----------|----------|----------|----------| > | | > |----------|----------| | |----------| | |----------| > | | | | | > (S) (A) (B) (C) (D) > v v v v v > |XXXXX|----|XXXXX|----|----------|----------|----------|XXXXXXXXXX| > skip skip skip skip skip > Nice art! > Expand the calculation of DPA freespace and enhance the logic to support > mapping/unmapping DC DPA space. To track the potential of multiple skip > resources an xarray is attached to the endpoint decoder. The existing > algorithm between RAM and PMEM is consolidated within the new one to > streamline the code even though the result is the storage of a single > skip resource in the xarray. This passed the unit test cxl-poison.sh that relies on you not totally breaking the cxled->skip here. Not exactly a tested by, but something! > > 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: > [iweiny: Update cover letter] > --- > drivers/cxl/core/hdm.c | 192 +++++++++++++++++++++++++++++++++++++++++++----- > drivers/cxl/core/port.c | 2 + > drivers/cxl/cxl.h | 2 + > 3 files changed, 179 insertions(+), 17 deletions(-) > > diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c > index e22b6f4f7145..da7d58184490 100644 > --- a/drivers/cxl/core/hdm.c > +++ b/drivers/cxl/core/hdm.c > @@ -210,6 +210,25 @@ void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds) > } > EXPORT_SYMBOL_NS_GPL(cxl_dpa_debug, CXL); > > +static void cxl_skip_release(struct cxl_endpoint_decoder *cxled) > +{ > + struct cxl_dev_state *cxlds = cxled_to_memdev(cxled)->cxlds; > + struct cxl_port *port = cxled_to_port(cxled); > + struct device *dev = &port->dev; Here and below it's probably needless to define dev. Just &port->dev in your single dev_dbg() This is something to check for across the patchset. > + unsigned long index; > + void *entry; > + > + xa_for_each(&cxled->skip_res, index, entry) { > + struct resource *res = entry; > + > + dev_dbg(dev, "decoder%d.%d: releasing skipped space; %pr\n", > + port->id, cxled->cxld.id, res); > + __release_region(&cxlds->dpa_res, res->start, > + resource_size(res)); > + xa_erase(&cxled->skip_res, index); > + } > +} > + > /* > * Must be called in a context that synchronizes against this decoder's > * port ->remove() callback (like an endpoint decoder sysfs attribute) > @@ -220,15 +239,11 @@ static void __cxl_dpa_release(struct cxl_endpoint_decoder *cxled) > struct cxl_port *port = cxled_to_port(cxled); > struct cxl_dev_state *cxlds = cxlmd->cxlds; > struct resource *res = cxled->dpa_res; > - resource_size_t skip_start; > > lockdep_assert_held_write(&cxl_dpa_rwsem); > > - /* save @skip_start, before @res is released */ > - skip_start = res->start - cxled->skip; > __release_region(&cxlds->dpa_res, res->start, resource_size(res)); > - if (cxled->skip) > - __release_region(&cxlds->dpa_res, skip_start, cxled->skip); > + cxl_skip_release(cxled); > cxled->skip = 0; > cxled->dpa_res = NULL; > put_device(&cxled->cxld.dev); > @@ -263,6 +278,100 @@ static int dc_mode_to_region_index(enum cxl_decoder_mode mode) > return mode - CXL_DECODER_DC0; > } > > +static int cxl_request_skip(struct cxl_endpoint_decoder *cxled, > + resource_size_t skip_base, resource_size_t skip_len) > +{ > + struct cxl_dev_state *cxlds = cxled_to_memdev(cxled)->cxlds; > + const char *name = dev_name(&cxled->cxld.dev); > + struct cxl_port *port = cxled_to_port(cxled); > + struct resource *dpa_res = &cxlds->dpa_res; > + struct device *dev = &port->dev; again > + struct resource *res; > + int rc; > + > + res = __request_region(dpa_res, skip_base, skip_len, name, 0); > + if (!res) > + return -EBUSY; > + > + rc = xa_insert(&cxled->skip_res, skip_base, res, GFP_KERNEL); > + if (rc) { > + __release_region(dpa_res, skip_base, skip_len); > + return rc; > + } > + > + dev_dbg(dev, "decoder%d.%d: skipped space; %pr\n", > + port->id, cxled->cxld.id, res); > + return 0; > +} > + > +static int cxl_reserve_dpa_skip(struct cxl_endpoint_decoder *cxled, > + resource_size_t base, resource_size_t skipped) > +{ > + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); > + struct cxl_port *port = cxled_to_port(cxled); > + struct cxl_dev_state *cxlds = cxlmd->cxlds; > + resource_size_t skip_base = base - skipped; > + struct device *dev = &port->dev; > + resource_size_t skip_len = 0; > + int rc, index; > + > + if (resource_size(&cxlds->ram_res) && skip_base <= cxlds->ram_res.end) { > + skip_len = cxlds->ram_res.end - skip_base + 1; > + rc = cxl_request_skip(cxled, skip_base, skip_len); > + if (rc) > + return rc; > + skip_base += skip_len; > + } > + > + if (skip_base == base) { > + dev_dbg(dev, "skip done ram!\n"); > + return 0; > + } > + > + if (resource_size(&cxlds->pmem_res) && > + skip_base <= cxlds->pmem_res.end) { > + skip_len = cxlds->pmem_res.end - skip_base + 1; > + rc = cxl_request_skip(cxled, skip_base, skip_len); > + if (rc) > + return rc; > + skip_base += skip_len; > + } > + > + index = dc_mode_to_region_index(cxled->mode); > + for (int i = 0; i <= index; i++) { > + struct resource *dcr = &cxlds->dc_res[i]; > + > + if (skip_base < dcr->start) { > + skip_len = dcr->start - skip_base; > + rc = cxl_request_skip(cxled, skip_base, skip_len); > + if (rc) > + return rc; > + skip_base += skip_len; > + } > + > + if (skip_base == base) { > + dev_dbg(dev, "skip done DC region %d!\n", i); > + break; > + } > + > + if (resource_size(dcr) && skip_base <= dcr->end) { > + if (skip_base > base) { > + dev_err(dev, "Skip error DC region %d; skip_base %pa; base %pa\n", > + i, &skip_base, &base); > + return -ENXIO; > + } > + > + skip_len = dcr->end - skip_base + 1; > + rc = cxl_request_skip(cxled, skip_base, skip_len); > + if (rc) > + return rc; > + skip_base += skip_len; > + } > + } > + > + return 0; > +} > + > static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, > resource_size_t base, resource_size_t len, > resource_size_t skipped) > @@ -300,13 +409,12 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, > } > > if (skipped) { > - res = __request_region(&cxlds->dpa_res, base - skipped, skipped, > - dev_name(&cxled->cxld.dev), 0); > - if (!res) { > - dev_dbg(dev, > - "decoder%d.%d: failed to reserve skipped space\n", > - port->id, cxled->cxld.id); > - return -EBUSY; > + int rc = cxl_reserve_dpa_skip(cxled, base, skipped); > + > + if (rc) { > + dev_dbg(dev, "decoder%d.%d: failed to reserve skipped space; %pa - %pa\n", > + port->id, cxled->cxld.id, &base, &skipped); > + return rc; > } > } > res = __request_region(&cxlds->dpa_res, base, len, > @@ -314,14 +422,20 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, > if (!res) { > dev_dbg(dev, "decoder%d.%d: failed to reserve allocation\n", > port->id, cxled->cxld.id); > - if (skipped) > - __release_region(&cxlds->dpa_res, base - skipped, > - skipped); > + cxl_skip_release(cxled); > return -EBUSY; > } > cxled->dpa_res = res; > cxled->skip = skipped; > > + for (int mode = CXL_DECODER_DC0; mode <= CXL_DECODER_DC7; mode++) { > + int index = dc_mode_to_region_index(mode); > + > + if (resource_contains(&cxlds->dc_res[index], res)) { > + cxled->mode = mode; > + goto success; > + } > + } > if (resource_contains(&cxlds->pmem_res, res)) > cxled->mode = CXL_DECODER_PMEM; > else if (resource_contains(&cxlds->ram_res, res)) > @@ -332,6 +446,9 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, > cxled->mode = CXL_DECODER_MIXED; > } > > +success: > + dev_dbg(dev, "decoder%d.%d: %pr mode: %d\n", port->id, cxled->cxld.id, > + cxled->dpa_res, cxled->mode); > port->hdm_end++; > get_device(&cxled->cxld.dev); > return 0; > @@ -463,14 +580,14 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, > > int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size) > { > + resource_size_t free_ram_start, free_pmem_start, free_dc_start; > struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); > - resource_size_t free_ram_start, free_pmem_start; > struct cxl_port *port = cxled_to_port(cxled); > struct cxl_dev_state *cxlds = cxlmd->cxlds; > struct device *dev = &cxled->cxld.dev; > resource_size_t start, avail, skip; > struct resource *p, *last; > - int rc; > + int rc, dc_index; > > down_write(&cxl_dpa_rwsem); > if (cxled->cxld.region) { > @@ -500,6 +617,21 @@ int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size) > else > free_pmem_start = cxlds->pmem_res.start; > > + /* > + * Limit each decoder to a single DC region to map memory with > + * different DSMAS entry. > + */ > + dc_index = dc_mode_to_region_index(cxled->mode); > + if (dc_index >= 0) { > + if (cxlds->dc_res[dc_index].child) { > + dev_err(dev, "Cannot allocate DPA from DC Region: %d\n", > + dc_index); > + rc = -EINVAL; > + goto out; > + } > + free_dc_start = cxlds->dc_res[dc_index].start; > + } From the "Limit each decoder" comment to here please explain. I'm reading we cannot alloc dpa from this DC region because is has a child? And a child is a region? Maybe I got it ;) snip to end --Alison
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index e22b6f4f7145..da7d58184490 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -210,6 +210,25 @@ void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds) } EXPORT_SYMBOL_NS_GPL(cxl_dpa_debug, CXL); +static void cxl_skip_release(struct cxl_endpoint_decoder *cxled) +{ + struct cxl_dev_state *cxlds = cxled_to_memdev(cxled)->cxlds; + struct cxl_port *port = cxled_to_port(cxled); + struct device *dev = &port->dev; + unsigned long index; + void *entry; + + xa_for_each(&cxled->skip_res, index, entry) { + struct resource *res = entry; + + dev_dbg(dev, "decoder%d.%d: releasing skipped space; %pr\n", + port->id, cxled->cxld.id, res); + __release_region(&cxlds->dpa_res, res->start, + resource_size(res)); + xa_erase(&cxled->skip_res, index); + } +} + /* * Must be called in a context that synchronizes against this decoder's * port ->remove() callback (like an endpoint decoder sysfs attribute) @@ -220,15 +239,11 @@ static void __cxl_dpa_release(struct cxl_endpoint_decoder *cxled) struct cxl_port *port = cxled_to_port(cxled); struct cxl_dev_state *cxlds = cxlmd->cxlds; struct resource *res = cxled->dpa_res; - resource_size_t skip_start; lockdep_assert_held_write(&cxl_dpa_rwsem); - /* save @skip_start, before @res is released */ - skip_start = res->start - cxled->skip; __release_region(&cxlds->dpa_res, res->start, resource_size(res)); - if (cxled->skip) - __release_region(&cxlds->dpa_res, skip_start, cxled->skip); + cxl_skip_release(cxled); cxled->skip = 0; cxled->dpa_res = NULL; put_device(&cxled->cxld.dev); @@ -263,6 +278,100 @@ static int dc_mode_to_region_index(enum cxl_decoder_mode mode) return mode - CXL_DECODER_DC0; } +static int cxl_request_skip(struct cxl_endpoint_decoder *cxled, + resource_size_t skip_base, resource_size_t skip_len) +{ + struct cxl_dev_state *cxlds = cxled_to_memdev(cxled)->cxlds; + const char *name = dev_name(&cxled->cxld.dev); + struct cxl_port *port = cxled_to_port(cxled); + struct resource *dpa_res = &cxlds->dpa_res; + struct device *dev = &port->dev; + struct resource *res; + int rc; + + res = __request_region(dpa_res, skip_base, skip_len, name, 0); + if (!res) + return -EBUSY; + + rc = xa_insert(&cxled->skip_res, skip_base, res, GFP_KERNEL); + if (rc) { + __release_region(dpa_res, skip_base, skip_len); + return rc; + } + + dev_dbg(dev, "decoder%d.%d: skipped space; %pr\n", + port->id, cxled->cxld.id, res); + return 0; +} + +static int cxl_reserve_dpa_skip(struct cxl_endpoint_decoder *cxled, + resource_size_t base, resource_size_t skipped) +{ + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); + struct cxl_port *port = cxled_to_port(cxled); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + resource_size_t skip_base = base - skipped; + struct device *dev = &port->dev; + resource_size_t skip_len = 0; + int rc, index; + + if (resource_size(&cxlds->ram_res) && skip_base <= cxlds->ram_res.end) { + skip_len = cxlds->ram_res.end - skip_base + 1; + rc = cxl_request_skip(cxled, skip_base, skip_len); + if (rc) + return rc; + skip_base += skip_len; + } + + if (skip_base == base) { + dev_dbg(dev, "skip done ram!\n"); + return 0; + } + + if (resource_size(&cxlds->pmem_res) && + skip_base <= cxlds->pmem_res.end) { + skip_len = cxlds->pmem_res.end - skip_base + 1; + rc = cxl_request_skip(cxled, skip_base, skip_len); + if (rc) + return rc; + skip_base += skip_len; + } + + index = dc_mode_to_region_index(cxled->mode); + for (int i = 0; i <= index; i++) { + struct resource *dcr = &cxlds->dc_res[i]; + + if (skip_base < dcr->start) { + skip_len = dcr->start - skip_base; + rc = cxl_request_skip(cxled, skip_base, skip_len); + if (rc) + return rc; + skip_base += skip_len; + } + + if (skip_base == base) { + dev_dbg(dev, "skip done DC region %d!\n", i); + break; + } + + if (resource_size(dcr) && skip_base <= dcr->end) { + if (skip_base > base) { + dev_err(dev, "Skip error DC region %d; skip_base %pa; base %pa\n", + i, &skip_base, &base); + return -ENXIO; + } + + skip_len = dcr->end - skip_base + 1; + rc = cxl_request_skip(cxled, skip_base, skip_len); + if (rc) + return rc; + skip_base += skip_len; + } + } + + return 0; +} + static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, resource_size_t base, resource_size_t len, resource_size_t skipped) @@ -300,13 +409,12 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, } if (skipped) { - res = __request_region(&cxlds->dpa_res, base - skipped, skipped, - dev_name(&cxled->cxld.dev), 0); - if (!res) { - dev_dbg(dev, - "decoder%d.%d: failed to reserve skipped space\n", - port->id, cxled->cxld.id); - return -EBUSY; + int rc = cxl_reserve_dpa_skip(cxled, base, skipped); + + if (rc) { + dev_dbg(dev, "decoder%d.%d: failed to reserve skipped space; %pa - %pa\n", + port->id, cxled->cxld.id, &base, &skipped); + return rc; } } res = __request_region(&cxlds->dpa_res, base, len, @@ -314,14 +422,20 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, if (!res) { dev_dbg(dev, "decoder%d.%d: failed to reserve allocation\n", port->id, cxled->cxld.id); - if (skipped) - __release_region(&cxlds->dpa_res, base - skipped, - skipped); + cxl_skip_release(cxled); return -EBUSY; } cxled->dpa_res = res; cxled->skip = skipped; + for (int mode = CXL_DECODER_DC0; mode <= CXL_DECODER_DC7; mode++) { + int index = dc_mode_to_region_index(mode); + + if (resource_contains(&cxlds->dc_res[index], res)) { + cxled->mode = mode; + goto success; + } + } if (resource_contains(&cxlds->pmem_res, res)) cxled->mode = CXL_DECODER_PMEM; else if (resource_contains(&cxlds->ram_res, res)) @@ -332,6 +446,9 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, cxled->mode = CXL_DECODER_MIXED; } +success: + dev_dbg(dev, "decoder%d.%d: %pr mode: %d\n", port->id, cxled->cxld.id, + cxled->dpa_res, cxled->mode); port->hdm_end++; get_device(&cxled->cxld.dev); return 0; @@ -463,14 +580,14 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size) { + resource_size_t free_ram_start, free_pmem_start, free_dc_start; struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); - resource_size_t free_ram_start, free_pmem_start; struct cxl_port *port = cxled_to_port(cxled); struct cxl_dev_state *cxlds = cxlmd->cxlds; struct device *dev = &cxled->cxld.dev; resource_size_t start, avail, skip; struct resource *p, *last; - int rc; + int rc, dc_index; down_write(&cxl_dpa_rwsem); if (cxled->cxld.region) { @@ -500,6 +617,21 @@ int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size) else free_pmem_start = cxlds->pmem_res.start; + /* + * Limit each decoder to a single DC region to map memory with + * different DSMAS entry. + */ + dc_index = dc_mode_to_region_index(cxled->mode); + if (dc_index >= 0) { + if (cxlds->dc_res[dc_index].child) { + dev_err(dev, "Cannot allocate DPA from DC Region: %d\n", + dc_index); + rc = -EINVAL; + goto out; + } + free_dc_start = cxlds->dc_res[dc_index].start; + } + if (cxled->mode == CXL_DECODER_RAM) { start = free_ram_start; avail = cxlds->ram_res.end - start + 1; @@ -521,12 +653,38 @@ int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size) else skip_end = start - 1; skip = skip_end - skip_start + 1; + } else if (cxl_decoder_mode_is_dc(cxled->mode)) { + resource_size_t skip_start, skip_end; + + start = free_dc_start; + avail = cxlds->dc_res[dc_index].end - start + 1; + if ((resource_size(&cxlds->pmem_res) == 0) || !cxlds->pmem_res.child) + skip_start = free_ram_start; + else + skip_start = free_pmem_start; + /* + * If any dc region is already mapped, then that allocation + * already handled the RAM and PMEM skip. Check for DC region + * skip. + */ + for (int i = dc_index - 1; i >= 0 ; i--) { + if (cxlds->dc_res[i].child) { + skip_start = cxlds->dc_res[i].child->end + 1; + break; + } + } + + skip_end = start - 1; + skip = skip_end - skip_start + 1; } else { dev_dbg(dev, "mode not set\n"); rc = -EINVAL; goto out; } + dev_dbg(dev, "DPA Allocation start: %pa len: %#llx Skip: %pa\n", + &start, size, &skip); + if (size > avail) { dev_dbg(dev, "%pa exceeds available %s capacity: %pa\n", &size, cxled->mode == CXL_DECODER_RAM ? "ram" : "pmem", diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 80c0651794eb..036b61cb3007 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -434,6 +434,7 @@ static void cxl_endpoint_decoder_release(struct device *dev) struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(dev); __cxl_decoder_release(&cxled->cxld); + xa_destroy(&cxled->skip_res); kfree(cxled); } @@ -1896,6 +1897,7 @@ struct cxl_endpoint_decoder *cxl_endpoint_decoder_alloc(struct cxl_port *port) return ERR_PTR(-ENOMEM); cxled->pos = -1; + xa_init(&cxled->skip_res); cxld = &cxled->cxld; rc = cxl_decoder_init(port, cxld); if (rc) { diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 3b8935089c0c..15d418b3bc9b 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -441,6 +441,7 @@ enum cxl_decoder_state { * @cxld: base cxl_decoder_object * @dpa_res: actively claimed DPA span of this decoder * @skip: offset into @dpa_res where @cxld.hpa_range maps + * @skip_res: array of skipped resources from the previous decoder end * @mode: which memory type / access-mode-partition this decoder targets * @state: autodiscovery state * @pos: interleave position in @cxld.region @@ -449,6 +450,7 @@ struct cxl_endpoint_decoder { struct cxl_decoder cxld; struct resource *dpa_res; resource_size_t skip; + struct xarray skip_res; enum cxl_decoder_mode mode; enum cxl_decoder_state state; int pos;