1 files changed, 64 insertions, 69 deletions

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index e701e4b04032..d77899650798 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;
 		}
 	}
 
@@ -794,26 +778,50 @@ out:
 	return rc;
 }
 
+static int check_commit_order(struct device *dev, const void *data)
+{
+	struct cxl_decoder *cxld = to_cxl_decoder(dev);
+
+	/*
+	 * if port->commit_end is not the only free decoder, then out of
+	 * order shutdown has occurred, block further allocations until
+	 * that is resolved
+	 */
+	if (((cxld->flags & CXL_DECODER_F_ENABLE) == 0))
+		return -EBUSY;
+	return 0;
+}
+
 static int match_free_decoder(struct device *dev, void *data)
 {
+	struct cxl_port *port = to_cxl_port(dev->parent);
 	struct cxl_decoder *cxld;
-	int *id = data;
+	int rc;
 
 	if (!is_switch_decoder(dev))
 		return 0;
 
 	cxld = to_cxl_decoder(dev);
 
-	/* enforce ordered allocation */
-	if (cxld->id != *id)
+	if (cxld->id != port->commit_end + 1)
 		return 0;
 
-	if (!cxld->region)
-		return 1;
-
-	(*id)++;
+	if (cxld->region) {
+		dev_dbg(dev->parent,
+			"next decoder to commit (%s) is already reserved (%s)\n",
+			dev_name(dev), dev_name(&cxld->region->dev));
+		return 0;
+	}
 
-	return 0;
+	rc = device_for_each_child_reverse_from(dev->parent, dev, NULL,
+						check_commit_order);
+	if (rc) {
+		dev_dbg(dev->parent,
+			"unable to allocate %s due to out of order shutdown\n",
+			dev_name(dev));
+		return 0;
+	}
+	return 1;
 }
 
 static int match_auto_decoder(struct device *dev, void *data)
@@ -840,7 +848,6 @@ cxl_region_find_decoder(struct cxl_port *port,
 			struct cxl_region *cxlr)
 {
 	struct device *dev;
-	int id = 0;
 
 	if (port == cxled_to_port(cxled))
 		return &cxled->cxld;
@@ -849,7 +856,7 @@ cxl_region_find_decoder(struct cxl_port *port,
 		dev = device_find_child(&port->dev, &cxlr->params,
 					match_auto_decoder);
 	else
-		dev = device_find_child(&port->dev, &id, match_free_decoder);
+		dev = device_find_child(&port->dev, NULL, match_free_decoder);
 	if (!dev)
 		return NULL;
 	/*
@@ -2054,13 +2061,7 @@ 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;
 	}
 
@@ -2298,7 +2299,7 @@ bool is_cxl_region(struct device *dev)
 {
 	return dev->type == &cxl_region_type;
 }
-EXPORT_SYMBOL_NS_GPL(is_cxl_region, CXL);
+EXPORT_SYMBOL_NS_GPL(is_cxl_region, "CXL");
 
 static struct cxl_region *to_cxl_region(struct device *dev)
 {
@@ -2536,9 +2537,8 @@ static struct cxl_region *__create_region(struct cxl_root_decoder *cxlrd,
 	return devm_cxl_add_region(cxlrd, id, mode, CXL_DECODER_HOSTONLYMEM);
 }
 
-static ssize_t create_pmem_region_store(struct device *dev,
-					struct device_attribute *attr,
-					const char *buf, size_t len)
+static ssize_t create_region_store(struct device *dev, const char *buf,
+				   size_t len, enum cxl_decoder_mode mode)
 {
 	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);
 	struct cxl_region *cxlr;
@@ -2548,31 +2548,26 @@ static ssize_t create_pmem_region_store(struct device *dev,
 	if (rc != 1)
 		return -EINVAL;
 
-	cxlr = __create_region(cxlrd, CXL_DECODER_PMEM, id);
+	cxlr = __create_region(cxlrd, mode, id);
 	if (IS_ERR(cxlr))
 		return PTR_ERR(cxlr);
 
 	return len;
 }
+
+static ssize_t create_pmem_region_store(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t len)
+{
+	return create_region_store(dev, buf, len, CXL_DECODER_PMEM);
+}
 DEVICE_ATTR_RW(create_pmem_region);
 
 static ssize_t create_ram_region_store(struct device *dev,
 				       struct device_attribute *attr,
 				       const char *buf, size_t len)
 {
-	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);
-	struct cxl_region *cxlr;
-	int rc, id;
-
-	rc = sscanf(buf, "region%d\n", &id);
-	if (rc != 1)
-		return -EINVAL;
-
-	cxlr = __create_region(cxlrd, CXL_DECODER_RAM, id);
-	if (IS_ERR(cxlr))
-		return PTR_ERR(cxlr);
-
-	return len;
+	return create_region_store(dev, buf, len, CXL_DECODER_RAM);
 }
 DEVICE_ATTR_RW(create_ram_region);
 
@@ -2657,7 +2652,7 @@ bool is_cxl_pmem_region(struct device *dev)
 {
 	return dev->type == &cxl_pmem_region_type;
 }
-EXPORT_SYMBOL_NS_GPL(is_cxl_pmem_region, CXL);
+EXPORT_SYMBOL_NS_GPL(is_cxl_pmem_region, "CXL");
 
 struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
 {
@@ -2666,7 +2661,7 @@ struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
 		return NULL;
 	return container_of(dev, struct cxl_pmem_region, dev);
 }
-EXPORT_SYMBOL_NS_GPL(to_cxl_pmem_region, CXL);
+EXPORT_SYMBOL_NS_GPL(to_cxl_pmem_region, "CXL");
 
 struct cxl_poison_context {
 	struct cxl_port *port;
@@ -3020,7 +3015,7 @@ struct cxl_dax_region *to_cxl_dax_region(struct device *dev)
 		return NULL;
 	return container_of(dev, struct cxl_dax_region, dev);
 }
-EXPORT_SYMBOL_NS_GPL(to_cxl_dax_region, CXL);
+EXPORT_SYMBOL_NS_GPL(to_cxl_dax_region, "CXL");
 
 static struct lock_class_key cxl_dax_region_key;
 
@@ -3364,7 +3359,7 @@ out:
 	put_device(cxlrd_dev);
 	return rc;
 }
-EXPORT_SYMBOL_NS_GPL(cxl_add_to_region, CXL);
+EXPORT_SYMBOL_NS_GPL(cxl_add_to_region, "CXL");
 
 static int is_system_ram(struct resource *res, void *arg)
 {
@@ -3467,6 +3462,6 @@ void cxl_region_exit(void)
 	cxl_driver_unregister(&cxl_region_driver);
 }
 
-MODULE_IMPORT_NS(CXL);
-MODULE_IMPORT_NS(DEVMEM);
+MODULE_IMPORT_NS("CXL");
+MODULE_IMPORT_NS("DEVMEM");
 MODULE_ALIAS_CXL(CXL_DEVICE_REGION);