diff options
| -rw-r--r-- | drivers/cxl/core/region.c | 99 |
1 files changed, 70 insertions, 29 deletions
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 6e5e1460068d..3a77aec2c447 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -349,30 +349,42 @@ err: return rc; } -static ssize_t commit_store(struct device *dev, struct device_attribute *attr, - const char *buf, size_t len) +static int queue_reset(struct cxl_region *cxlr) { - struct cxl_region *cxlr = to_cxl_region(dev); struct cxl_region_params *p = &cxlr->params; - bool commit; - ssize_t rc; + int rc; - rc = kstrtobool(buf, &commit); + rc = down_write_killable(&cxl_region_rwsem); if (rc) return rc; + /* Already in the requested state? */ + if (p->state < CXL_CONFIG_COMMIT) + goto out; + + p->state = CXL_CONFIG_RESET_PENDING; + +out: + up_write(&cxl_region_rwsem); + + return rc; +} + +static int __commit(struct cxl_region *cxlr) +{ + struct cxl_region_params *p = &cxlr->params; + int rc; + rc = down_write_killable(&cxl_region_rwsem); if (rc) return rc; /* Already in the requested state? */ - if (commit && p->state >= CXL_CONFIG_COMMIT) - goto out; - if (!commit && p->state < CXL_CONFIG_COMMIT) + if (p->state >= CXL_CONFIG_COMMIT) goto out; /* Not ready to commit? */ - if (commit && p->state < CXL_CONFIG_ACTIVE) { + if (p->state < CXL_CONFIG_ACTIVE) { rc = -ENXIO; goto out; } @@ -385,31 +397,60 @@ static ssize_t commit_store(struct device *dev, struct device_attribute *attr, if (rc) goto out; - if (commit) { - rc = cxl_region_decode_commit(cxlr); - if (rc == 0) - p->state = CXL_CONFIG_COMMIT; - } else { - p->state = CXL_CONFIG_RESET_PENDING; - up_write(&cxl_region_rwsem); - device_release_driver(&cxlr->dev); - down_write(&cxl_region_rwsem); - - /* - * The lock was dropped, so need to revalidate that the reset is - * still pending. - */ - if (p->state == CXL_CONFIG_RESET_PENDING) { - cxl_region_decode_reset(cxlr, p->interleave_ways); - p->state = CXL_CONFIG_ACTIVE; - } - } + rc = cxl_region_decode_commit(cxlr); + if (rc == 0) + p->state = CXL_CONFIG_COMMIT; out: up_write(&cxl_region_rwsem); + return rc; +} + +static ssize_t commit_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) +{ + struct cxl_region *cxlr = to_cxl_region(dev); + struct cxl_region_params *p = &cxlr->params; + bool commit; + ssize_t rc; + + rc = kstrtobool(buf, &commit); if (rc) return rc; + + if (commit) { + rc = __commit(cxlr); + if (rc) + return rc; + return len; + } + + rc = queue_reset(cxlr); + if (rc) + return rc; + + /* + * Unmap the region and depend the reset-pending state to ensure + * it does not go active again until post reset + */ + device_release_driver(&cxlr->dev); + + /* + * With the reset pending take cxl_region_rwsem unconditionally + * to ensure the reset gets handled before returning. + */ + guard(rwsem_write)(&cxl_region_rwsem); + + /* + * Revalidate that the reset is still pending in case another + * thread already handled this reset. + */ + if (p->state == CXL_CONFIG_RESET_PENDING) { + cxl_region_decode_reset(cxlr, p->interleave_ways); + p->state = CXL_CONFIG_ACTIVE; + } + return len; } |