netdev - [PATCH v4 13/26] cxl: prepare memdev creation for type2

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Message-ID: <20241017165225.21206-14-alejandro.lucero-palau@amd.com>
Date: Thu, 17 Oct 2024 17:52:12 +0100
From: <alejandro.lucero-palau@....com>
To: <linux-cxl@...r.kernel.org>, <netdev@...r.kernel.org>,
	<dan.j.williams@...el.com>, <martin.habets@...inx.com>,
	<edward.cree@....com>, <davem@...emloft.net>, <kuba@...nel.org>,
	<pabeni@...hat.com>, <edumazet@...gle.com>
CC: Alejandro Lucero <alucerop@....com>
Subject: [PATCH v4 13/26] cxl: prepare memdev creation for type2

From: Alejandro Lucero <alucerop@....com>

Current cxl core is relying on a CXL_DEVTYPE_CLASSMEM type device when
creating a memdev leading to problems when obtaining cxl_memdev_state
references from a CXL_DEVTYPE_DEVMEM type. This last device type is
managed by a specific vendor driver and does not need same sysfs files
since not userspace intervention is expected.

Create a new cxl_mem device type with no attributes for Type2.

Avoid debugfs files relying on existence of clx_memdev_state.

Make devm_cxl_add_memdev accesible from a accel driver.

Signed-off-by: Alejandro Lucero <alucerop@....com>
---
 drivers/cxl/core/memdev.c | 15 +++++++++++++--
 drivers/cxl/core/region.c |  3 ++-
 drivers/cxl/mem.c         | 25 +++++++++++++++++++------
 include/linux/cxl/cxl.h   |  2 ++
 4 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
index 56fddb0d6a85..f168cd42f8a5 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -546,9 +546,17 @@ static const struct device_type cxl_memdev_type = {
 	.groups = cxl_memdev_attribute_groups,
 };
 
+static const struct device_type cxl_accel_memdev_type = {
+	.name = "cxl_memdev",
+	.release = cxl_memdev_release,
+	.devnode = cxl_memdev_devnode,
+};
+
 bool is_cxl_memdev(const struct device *dev)
 {
-	return dev->type == &cxl_memdev_type;
+	return (dev->type == &cxl_memdev_type ||
+		dev->type == &cxl_accel_memdev_type);
+
 }
 EXPORT_SYMBOL_NS_GPL(is_cxl_memdev, CXL);
 
@@ -659,7 +667,10 @@ static struct cxl_memdev *cxl_memdev_alloc(struct cxl_dev_state *cxlds,
 	dev->parent = cxlds->dev;
 	dev->bus = &cxl_bus_type;
 	dev->devt = MKDEV(cxl_mem_major, cxlmd->id);
-	dev->type = &cxl_memdev_type;
+	if (cxlds->type == CXL_DEVTYPE_DEVMEM)
+		dev->type = &cxl_accel_memdev_type;
+	else
+		dev->type = &cxl_memdev_type;
 	device_set_pm_not_required(dev);
 	INIT_WORK(&cxlmd->detach_work, detach_memdev);
 
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 21ad5f242875..7e7761ff9fc4 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1941,7 +1941,8 @@ static int cxl_region_attach(struct cxl_region *cxlr,
 		return -EINVAL;
 	}
 
-	cxl_region_perf_data_calculate(cxlr, cxled);
+	if (cxlr->type == CXL_DECODER_HOSTONLYMEM)
+		cxl_region_perf_data_calculate(cxlr, cxled);
 
 	if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) {
 		int i;
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 7de232eaeb17..3a250ddeef35 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -131,12 +131,18 @@ static int cxl_mem_probe(struct device *dev)
 	dentry = cxl_debugfs_create_dir(dev_name(dev));
 	debugfs_create_devm_seqfile(dev, "dpamem", dentry, cxl_mem_dpa_show);
 
-	if (test_bit(CXL_POISON_ENABLED_INJECT, mds->poison.enabled_cmds))
-		debugfs_create_file("inject_poison", 0200, dentry, cxlmd,
-				    &cxl_poison_inject_fops);
-	if (test_bit(CXL_POISON_ENABLED_CLEAR, mds->poison.enabled_cmds))
-		debugfs_create_file("clear_poison", 0200, dentry, cxlmd,
-				    &cxl_poison_clear_fops);
+	/*
+	 * Avoid poison debugfs files for Type2 devices as they rely on
+	 * cxl_memdev_state.
+	 */
+	if (mds) {
+		if (test_bit(CXL_POISON_ENABLED_INJECT, mds->poison.enabled_cmds))
+			debugfs_create_file("inject_poison", 0200, dentry, cxlmd,
+					    &cxl_poison_inject_fops);
+		if (test_bit(CXL_POISON_ENABLED_CLEAR, mds->poison.enabled_cmds))
+			debugfs_create_file("clear_poison", 0200, dentry, cxlmd,
+					    &cxl_poison_clear_fops);
+	}
 
 	rc = devm_add_action_or_reset(dev, remove_debugfs, dentry);
 	if (rc)
@@ -222,6 +228,13 @@ static umode_t cxl_mem_visible(struct kobject *kobj, struct attribute *a, int n)
 	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
 	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds);
 
+	/*
+	 * Avoid poison sysfs files for Type2 devices as they rely on
+	 * cxl_memdev_state.
+	 */
+	if (!mds)
+		return 0;
+
 	if (a == &dev_attr_trigger_poison_list.attr)
 		if (!test_bit(CXL_POISON_ENABLED_LIST,
 			      mds->poison.enabled_cmds))
diff --git a/include/linux/cxl/cxl.h b/include/linux/cxl/cxl.h
index b8ee42b38f68..bbbcf6574246 100644
--- a/include/linux/cxl/cxl.h
+++ b/include/linux/cxl/cxl.h
@@ -57,4 +57,6 @@ int cxl_pci_accel_setup_regs(struct pci_dev *pdev, struct cxl_dev_state *cxlds);
 int cxl_request_resource(struct cxl_dev_state *cxlds, enum cxl_resource type);
 int cxl_release_resource(struct cxl_dev_state *cxlds, enum cxl_resource type);
 void cxl_set_media_ready(struct cxl_dev_state *cxlds);
+struct cxl_memdev *devm_cxl_add_memdev(struct device *host,
+				       struct cxl_dev_state *cxlds);
 #endif
-- 
2.17.1