| Message ID | 20250217144828.30651-8-ming.li@zohomail.com |
|---|---|
| State | New |
| Headers | show |
| Series | Use guard() instead of rwsem locking | expand |
On Mon, 17 Feb 2025 22:48:28 +0800 Li Ming <ming.li@zohomail.com> wrote: > Some operations need to be protected by the cxl_region_rwsem in > construct_region(). Currently, construct_region() uses down_write() and > up_write() for the cxl_region_rwsem locking, so there is a goto pattern > after down_write() invoked to release cxl_region_rwsem. > > construct region() can be optimized to remove the goto pattern. The > changes are creating a new function called construct_auto_region() which > will include all checking and operations protected by the > cxl_region_rwsem, and using guard(rwsem_write) to replace down_write() > and up_write() in construct_auto_region(). > > Signed-off-by: Li Ming <ming.li@zohomail.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
On 2/17/25 7:48 AM, Li Ming wrote: > Some operations need to be protected by the cxl_region_rwsem in > construct_region(). Currently, construct_region() uses down_write() and > up_write() for the cxl_region_rwsem locking, so there is a goto pattern > after down_write() invoked to release cxl_region_rwsem. > > construct region() can be optimized to remove the goto pattern. The > changes are creating a new function called construct_auto_region() which > will include all checking and operations protected by the > cxl_region_rwsem, and using guard(rwsem_write) to replace down_write() > and up_write() in construct_auto_region(). > > Signed-off-by: Li Ming <ming.li@zohomail.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> > --- > v2: > - Rename __construct_region() to construct_auto_region(). (Jonathan and Dave) > --- > drivers/cxl/core/region.c | 71 +++++++++++++++++++++------------------ > 1 file changed, 39 insertions(+), 32 deletions(-) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index 320a3f218131..7a9e51aba9f4 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -3216,49 +3216,31 @@ static int match_region_by_range(struct device *dev, const void *data) > return 0; > } > > -/* Establish an empty region covering the given HPA range */ > -static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, > - struct cxl_endpoint_decoder *cxled) > +static int construct_auto_region(struct cxl_region *cxlr, > + struct cxl_root_decoder *cxlrd, > + struct cxl_endpoint_decoder *cxled) > { > struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); > - struct cxl_port *port = cxlrd_to_port(cxlrd); > struct range *hpa = &cxled->cxld.hpa_range; > struct cxl_region_params *p; > - struct cxl_region *cxlr; > struct resource *res; > int rc; > > - do { > - cxlr = __create_region(cxlrd, cxled->mode, > - atomic_read(&cxlrd->region_id)); > - } while (IS_ERR(cxlr) && PTR_ERR(cxlr) == -EBUSY); > - > - if (IS_ERR(cxlr)) { > - dev_err(cxlmd->dev.parent, > - "%s:%s: %s failed assign region: %ld\n", > - dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), > - __func__, PTR_ERR(cxlr)); > - return cxlr; > - } > - > - down_write(&cxl_region_rwsem); > + guard(rwsem_write)(&cxl_region_rwsem); > p = &cxlr->params; > if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE) { > dev_err(cxlmd->dev.parent, > "%s:%s: %s autodiscovery interrupted\n", > dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), > __func__); > - rc = -EBUSY; > - goto err; > + return -EBUSY; > } > > set_bit(CXL_REGION_F_AUTO, &cxlr->flags); > > res = kmalloc(sizeof(*res), GFP_KERNEL); > - if (!res) { > - rc = -ENOMEM; > - goto err; > - } > + if (!res) > + return -ENOMEM; > > *res = DEFINE_RES_MEM_NAMED(hpa->start, range_len(hpa), > dev_name(&cxlr->dev)); > @@ -3281,7 +3263,7 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, > > rc = sysfs_update_group(&cxlr->dev.kobj, get_cxl_region_target_group()); > if (rc) > - goto err; > + return rc; > > dev_dbg(cxlmd->dev.parent, "%s:%s: %s %s res: %pr iw: %d ig: %d\n", > dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), __func__, > @@ -3290,14 +3272,39 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, > > /* ...to match put_device() in cxl_add_to_region() */ > get_device(&cxlr->dev); > - up_write(&cxl_region_rwsem); > > - return cxlr; > + return 0; > +} > > -err: > - up_write(&cxl_region_rwsem); > - devm_release_action(port->uport_dev, unregister_region, cxlr); > - return ERR_PTR(rc); > +/* Establish an empty region covering the given HPA range */ > +static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, > + struct cxl_endpoint_decoder *cxled) > +{ > + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); > + struct cxl_port *port = cxlrd_to_port(cxlrd); > + struct cxl_region *cxlr; > + int rc; > + > + do { > + cxlr = __create_region(cxlrd, cxled->mode, > + atomic_read(&cxlrd->region_id)); > + } while (IS_ERR(cxlr) && PTR_ERR(cxlr) == -EBUSY); > + > + if (IS_ERR(cxlr)) { > + dev_err(cxlmd->dev.parent, > + "%s:%s: %s failed assign region: %ld\n", > + dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), > + __func__, PTR_ERR(cxlr)); > + return cxlr; > + } > + > + rc = construct_auto_region(cxlr, cxlrd, cxled); > + if (rc) { > + devm_release_action(port->uport_dev, unregister_region, cxlr); > + return ERR_PTR(rc); > + } > + > + return cxlr; > } > > int cxl_add_to_region(struct cxl_port *root, struct cxl_endpoint_decoder *cxled)
On Mon, Feb 17, 2025 at 10:48:28PM +0800, Li Ming wrote: > Some operations need to be protected by the cxl_region_rwsem in > construct_region(). Currently, construct_region() uses down_write() and > up_write() for the cxl_region_rwsem locking, so there is a goto pattern > after down_write() invoked to release cxl_region_rwsem. > > construct region() can be optimized to remove the goto pattern. The > changes are creating a new function called construct_auto_region() which > will include all checking and operations protected by the > cxl_region_rwsem, and using guard(rwsem_write) to replace down_write() > and up_write() in construct_auto_region(). > > Signed-off-by: Li Ming <ming.li@zohomail.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> snip
Li Ming wrote: > Some operations need to be protected by the cxl_region_rwsem in > construct_region(). Currently, construct_region() uses down_write() and > up_write() for the cxl_region_rwsem locking, so there is a goto pattern > after down_write() invoked to release cxl_region_rwsem. > > construct region() can be optimized to remove the goto pattern. The > changes are creating a new function called construct_auto_region() which > will include all checking and operations protected by the > cxl_region_rwsem, and using guard(rwsem_write) to replace down_write() > and up_write() in construct_auto_region(). > > Signed-off-by: Li Ming <ming.li@zohomail.com> > --- > v2: > - Rename __construct_region() to construct_auto_region(). (Jonathan and Dave) > --- > drivers/cxl/core/region.c | 71 +++++++++++++++++++++------------------ > 1 file changed, 39 insertions(+), 32 deletions(-) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index 320a3f218131..7a9e51aba9f4 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -3216,49 +3216,31 @@ static int match_region_by_range(struct device *dev, const void *data) > return 0; > } > > -/* Establish an empty region covering the given HPA range */ > -static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, > - struct cxl_endpoint_decoder *cxled) > +static int construct_auto_region(struct cxl_region *cxlr, ...probably would have called this __construct_region() since there is little distinction that merits adding the "auto" qualifier. Other than that, for this and the others you can add: Reviewed-by: Dan Williams <dan.j.williams@intel.com>
On 2/20/2025 9:04 AM, Dan Williams wrote: > Li Ming wrote: >> Some operations need to be protected by the cxl_region_rwsem in >> construct_region(). Currently, construct_region() uses down_write() and >> up_write() for the cxl_region_rwsem locking, so there is a goto pattern >> after down_write() invoked to release cxl_region_rwsem. >> >> construct region() can be optimized to remove the goto pattern. The >> changes are creating a new function called construct_auto_region() which >> will include all checking and operations protected by the >> cxl_region_rwsem, and using guard(rwsem_write) to replace down_write() >> and up_write() in construct_auto_region(). >> >> Signed-off-by: Li Ming <ming.li@zohomail.com> >> --- >> v2: >> - Rename __construct_region() to construct_auto_region(). (Jonathan and Dave) >> --- >> drivers/cxl/core/region.c | 71 +++++++++++++++++++++------------------ >> 1 file changed, 39 insertions(+), 32 deletions(-) >> >> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c >> index 320a3f218131..7a9e51aba9f4 100644 >> --- a/drivers/cxl/core/region.c >> +++ b/drivers/cxl/core/region.c >> @@ -3216,49 +3216,31 @@ static int match_region_by_range(struct device *dev, const void *data) >> return 0; >> } >> >> -/* Establish an empty region covering the given HPA range */ >> -static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, >> - struct cxl_endpoint_decoder *cxled) >> +static int construct_auto_region(struct cxl_region *cxlr, > ...probably would have called this __construct_region() since there is > little distinction that merits adding the "auto" qualifier. Sure, will revert this renaming, continue to use __construct_region(), thanks for review. Ming > > Other than that, for this and the others you can add: > > Reviewed-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 320a3f218131..7a9e51aba9f4 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -3216,49 +3216,31 @@ static int match_region_by_range(struct device *dev, const void *data) return 0; } -/* Establish an empty region covering the given HPA range */ -static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, - struct cxl_endpoint_decoder *cxled) +static int construct_auto_region(struct cxl_region *cxlr, + struct cxl_root_decoder *cxlrd, + struct cxl_endpoint_decoder *cxled) { struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); - struct cxl_port *port = cxlrd_to_port(cxlrd); struct range *hpa = &cxled->cxld.hpa_range; struct cxl_region_params *p; - struct cxl_region *cxlr; struct resource *res; int rc; - do { - cxlr = __create_region(cxlrd, cxled->mode, - atomic_read(&cxlrd->region_id)); - } while (IS_ERR(cxlr) && PTR_ERR(cxlr) == -EBUSY); - - if (IS_ERR(cxlr)) { - dev_err(cxlmd->dev.parent, - "%s:%s: %s failed assign region: %ld\n", - dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), - __func__, PTR_ERR(cxlr)); - return cxlr; - } - - down_write(&cxl_region_rwsem); + guard(rwsem_write)(&cxl_region_rwsem); p = &cxlr->params; if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE) { dev_err(cxlmd->dev.parent, "%s:%s: %s autodiscovery interrupted\n", dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), __func__); - rc = -EBUSY; - goto err; + return -EBUSY; } set_bit(CXL_REGION_F_AUTO, &cxlr->flags); res = kmalloc(sizeof(*res), GFP_KERNEL); - if (!res) { - rc = -ENOMEM; - goto err; - } + if (!res) + return -ENOMEM; *res = DEFINE_RES_MEM_NAMED(hpa->start, range_len(hpa), dev_name(&cxlr->dev)); @@ -3281,7 +3263,7 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, rc = sysfs_update_group(&cxlr->dev.kobj, get_cxl_region_target_group()); if (rc) - goto err; + return rc; dev_dbg(cxlmd->dev.parent, "%s:%s: %s %s res: %pr iw: %d ig: %d\n", dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), __func__, @@ -3290,14 +3272,39 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, /* ...to match put_device() in cxl_add_to_region() */ get_device(&cxlr->dev); - up_write(&cxl_region_rwsem); - return cxlr; + return 0; +} -err: - up_write(&cxl_region_rwsem); - devm_release_action(port->uport_dev, unregister_region, cxlr); - return ERR_PTR(rc); +/* Establish an empty region covering the given HPA range */ +static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, + struct cxl_endpoint_decoder *cxled) +{ + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); + struct cxl_port *port = cxlrd_to_port(cxlrd); + struct cxl_region *cxlr; + int rc; + + do { + cxlr = __create_region(cxlrd, cxled->mode, + atomic_read(&cxlrd->region_id)); + } while (IS_ERR(cxlr) && PTR_ERR(cxlr) == -EBUSY); + + if (IS_ERR(cxlr)) { + dev_err(cxlmd->dev.parent, + "%s:%s: %s failed assign region: %ld\n", + dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), + __func__, PTR_ERR(cxlr)); + return cxlr; + } + + rc = construct_auto_region(cxlr, cxlrd, cxled); + if (rc) { + devm_release_action(port->uport_dev, unregister_region, cxlr); + return ERR_PTR(rc); + } + + return cxlr; } int cxl_add_to_region(struct cxl_port *root, struct cxl_endpoint_decoder *cxled)
Some operations need to be protected by the cxl_region_rwsem in construct_region(). Currently, construct_region() uses down_write() and up_write() for the cxl_region_rwsem locking, so there is a goto pattern after down_write() invoked to release cxl_region_rwsem. construct region() can be optimized to remove the goto pattern. The changes are creating a new function called construct_auto_region() which will include all checking and operations protected by the cxl_region_rwsem, and using guard(rwsem_write) to replace down_write() and up_write() in construct_auto_region(). Signed-off-by: Li Ming <ming.li@zohomail.com> --- v2: - Rename __construct_region() to construct_auto_region(). (Jonathan and Dave) --- drivers/cxl/core/region.c | 71 +++++++++++++++++++++------------------ 1 file changed, 39 insertions(+), 32 deletions(-)