diff --git a/drivers/base/core.c b/drivers/base/core.c index a4c853411a6b2..e42f1ad730780 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -4037,6 +4037,41 @@ int device_for_each_child_reverse(struct device *parent, void *data, } EXPORT_SYMBOL_GPL(device_for_each_child_reverse); +/** + * device_for_each_child_reverse_from - device child iterator in reversed order. + * @parent: parent struct device. + * @from: optional starting point in child list + * @fn: function to be called for each device. + * @data: data for the callback. + * + * Iterate over @parent's child devices, starting at @from, and call @fn + * for each, passing it @data. This helper is identical to + * device_for_each_child_reverse() when @from is NULL. + * + * @fn is checked each iteration. If it returns anything other than 0, + * iteration stop and that value is returned to the caller of + * device_for_each_child_reverse_from(); + */ +int device_for_each_child_reverse_from(struct device *parent, + struct device *from, const void *data, + int (*fn)(struct device *, const void *)) +{ + struct klist_iter i; + struct device *child; + int error = 0; + + if (!parent->p) + return 0; + + klist_iter_init_node(&parent->p->klist_children, &i, + (from ? &from->p->knode_parent : NULL)); + while ((child = prev_device(&i)) && !error) + error = fn(child, data); + klist_iter_exit(&i); + return error; +} +EXPORT_SYMBOL_GPL(device_for_each_child_reverse_from); + /** * device_find_child - device iterator for locating a particular device. * @parent: parent struct device diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index 3df10517a3278..223c273c0cd17 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -712,7 +712,44 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld) return 0; } -static int cxl_decoder_reset(struct cxl_decoder *cxld) +static int commit_reap(struct device *dev, const void *data) +{ + struct cxl_port *port = to_cxl_port(dev->parent); + struct cxl_decoder *cxld; + + if (!is_switch_decoder(dev) && !is_endpoint_decoder(dev)) + return 0; + + cxld = to_cxl_decoder(dev); + if (port->commit_end == cxld->id && + ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)) { + port->commit_end--; + dev_dbg(&port->dev, "reap: %s commit_end: %d\n", + dev_name(&cxld->dev), port->commit_end); + } + + return 0; +} + +void cxl_port_commit_reap(struct cxl_decoder *cxld) +{ + struct cxl_port *port = to_cxl_port(cxld->dev.parent); + + lockdep_assert_held_write(&cxl_region_rwsem); + + /* + * Once the highest committed decoder is disabled, free any other + * decoders that were pinned allocated by out-of-order release. + */ + port->commit_end--; + dev_dbg(&port->dev, "reap: %s commit_end: %d\n", dev_name(&cxld->dev), + port->commit_end); + device_for_each_child_reverse_from(&port->dev, &cxld->dev, NULL, + commit_reap); +} +EXPORT_SYMBOL_NS_GPL(cxl_port_commit_reap, CXL); + +static void cxl_decoder_reset(struct cxl_decoder *cxld) { struct cxl_port *port = to_cxl_port(cxld->dev.parent); struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev); @@ -721,14 +758,14 @@ static int cxl_decoder_reset(struct cxl_decoder *cxld) u32 ctrl; if ((cxld->flags & CXL_DECODER_F_ENABLE) == 0) - return 0; + return; - if (port->commit_end != id) { + if (port->commit_end == id) + cxl_port_commit_reap(cxld); + else dev_dbg(&port->dev, "%s: out of order reset, expected decoder%d.%d\n", dev_name(&cxld->dev), port->id, port->commit_end); - return -EBUSY; - } down_read(&cxl_dpa_rwsem); ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id)); @@ -741,7 +778,6 @@ static int cxl_decoder_reset(struct cxl_decoder *cxld) writel(0, hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id)); up_read(&cxl_dpa_rwsem); - port->commit_end--; cxld->flags &= ~CXL_DECODER_F_ENABLE; /* Userspace is now responsible for reconfiguring this decoder */ @@ -751,8 +787,6 @@ static int cxl_decoder_reset(struct cxl_decoder *cxld) cxled = to_cxl_endpoint_decoder(&cxld->dev); cxled->state = CXL_DECODER_STATE_MANUAL; } - - return 0; } static int cxl_setup_hdm_decoder_from_dvsec( diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index e701e4b040328..3478d20583035 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -232,8 +232,8 @@ static int cxl_region_invalidate_memregion(struct cxl_region *cxlr) "Bypassing cpu_cache_invalidate_memregion() for testing!\n"); return 0; } else { - dev_err(&cxlr->dev, - "Failed to synchronize CPU cache state\n"); + dev_WARN(&cxlr->dev, + "Failed to synchronize CPU cache state\n"); return -ENXIO; } } @@ -242,19 +242,17 @@ static int cxl_region_invalidate_memregion(struct cxl_region *cxlr) return 0; } -static int cxl_region_decode_reset(struct cxl_region *cxlr, int count) +static void cxl_region_decode_reset(struct cxl_region *cxlr, int count) { struct cxl_region_params *p = &cxlr->params; - int i, rc = 0; + int i; /* - * Before region teardown attempt to flush, and if the flush - * fails cancel the region teardown for data consistency - * concerns + * Before region teardown attempt to flush, evict any data cached for + * this region, or scream loudly about missing arch / platform support + * for CXL teardown. */ - rc = cxl_region_invalidate_memregion(cxlr); - if (rc) - return rc; + cxl_region_invalidate_memregion(cxlr); for (i = count - 1; i >= 0; i--) { struct cxl_endpoint_decoder *cxled = p->targets[i]; @@ -277,23 +275,17 @@ static int cxl_region_decode_reset(struct cxl_region *cxlr, int count) cxl_rr = cxl_rr_load(iter, cxlr); cxld = cxl_rr->decoder; if (cxld->reset) - rc = cxld->reset(cxld); - if (rc) - return rc; + cxld->reset(cxld); set_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags); } endpoint_reset: - rc = cxled->cxld.reset(&cxled->cxld); - if (rc) - return rc; + cxled->cxld.reset(&cxled->cxld); set_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags); } /* all decoders associated with this region have been torn down */ clear_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags); - - return 0; } static int commit_decoder(struct cxl_decoder *cxld) @@ -409,16 +401,8 @@ static ssize_t commit_store(struct device *dev, struct device_attribute *attr, * still pending. */ if (p->state == CXL_CONFIG_RESET_PENDING) { - rc = cxl_region_decode_reset(cxlr, p->interleave_ways); - /* - * Revert to committed since there may still be active - * decoders associated with this region, or move forward - * to active to mark the reset successful - */ - if (rc) - p->state = CXL_CONFIG_COMMIT; - else - p->state = CXL_CONFIG_ACTIVE; + cxl_region_decode_reset(cxlr, p->interleave_ways); + p->state = CXL_CONFIG_ACTIVE; } } @@ -2054,13 +2038,7 @@ static int cxl_region_detach(struct cxl_endpoint_decoder *cxled) get_device(&cxlr->dev); if (p->state > CXL_CONFIG_ACTIVE) { - /* - * TODO: tear down all impacted regions if a device is - * removed out of order - */ - rc = cxl_region_decode_reset(cxlr, p->interleave_ways); - if (rc) - goto out; + cxl_region_decode_reset(cxlr, p->interleave_ways); p->state = CXL_CONFIG_ACTIVE; } diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 0d8b810a51f04..5406e3ab3d4a4 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -359,7 +359,7 @@ struct cxl_decoder { struct cxl_region *region; unsigned long flags; int (*commit)(struct cxl_decoder *cxld); - int (*reset)(struct cxl_decoder *cxld); + void (*reset)(struct cxl_decoder *cxld); }; /* @@ -730,6 +730,7 @@ static inline bool is_cxl_root(struct cxl_port *port) int cxl_num_decoders_committed(struct cxl_port *port); bool is_cxl_port(const struct device *dev); struct cxl_port *to_cxl_port(const struct device *dev); +void cxl_port_commit_reap(struct cxl_decoder *cxld); struct pci_bus; int devm_cxl_register_pci_bus(struct device *host, struct device *uport_dev, struct pci_bus *bus); diff --git a/include/linux/device.h b/include/linux/device.h index b4bde8d226979..667cb6db90193 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1078,6 +1078,9 @@ int device_for_each_child(struct device *dev, void *data, int (*fn)(struct device *dev, void *data)); int device_for_each_child_reverse(struct device *dev, void *data, int (*fn)(struct device *dev, void *data)); +int device_for_each_child_reverse_from(struct device *parent, + struct device *from, const void *data, + int (*fn)(struct device *, const void *)); struct device *device_find_child(struct device *dev, void *data, int (*match)(struct device *dev, void *data)); struct device *device_find_child_by_name(struct device *parent, diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c index 90d5afd52dd06..c5bbd89b31920 100644 --- a/tools/testing/cxl/test/cxl.c +++ b/tools/testing/cxl/test/cxl.c @@ -693,26 +693,22 @@ static int mock_decoder_commit(struct cxl_decoder *cxld) return 0; } -static int mock_decoder_reset(struct cxl_decoder *cxld) +static void mock_decoder_reset(struct cxl_decoder *cxld) { struct cxl_port *port = to_cxl_port(cxld->dev.parent); int id = cxld->id; if ((cxld->flags & CXL_DECODER_F_ENABLE) == 0) - return 0; + return; dev_dbg(&port->dev, "%s reset\n", dev_name(&cxld->dev)); - if (port->commit_end != id) { + if (port->commit_end == id) + cxl_port_commit_reap(cxld); + else dev_dbg(&port->dev, "%s: out of order reset, expected decoder%d.%d\n", dev_name(&cxld->dev), port->id, port->commit_end); - return -EBUSY; - } - - port->commit_end--; cxld->flags &= ~CXL_DECODER_F_ENABLE; - - return 0; } static void default_mock_decoder(struct cxl_decoder *cxld)