[v4,19/40] cxl/port: Up-level cxl_add_dport() locking requirements to the caller

Commit Message

Dan Williams Feb. 1, 2022, 1:07 a.m. UTC

In preparation for moving dport enumeration into the core, require the
port device lock to be acquired by the caller.

Signed-off-by: Dan Williams <[e-mail]>
---
Changes since v3:
- Fix a rebase oversight that left device_lock() instead of
  cxl_device_lock(). (Jonathan and Ben)

 drivers/cxl/acpi.c            |    2 ++
 drivers/cxl/core/port.c       |    3 +--
 tools/testing/cxl/mock_acpi.c |    4 ++++
 3 files changed, 7 insertions(+), 2 deletions(-)

Comments

Jonathan Cameron Feb. 1, 2022, 11 a.m. UTC | #1

On Mon, 31 Jan 2022 17:07:38 -0800
Dan Williams <[e-mail]> wrote:

> In preparation for moving dport enumeration into the core, require the
> port device lock to be acquired by the caller.
> 
> Signed-off-by: Dan Williams <[e-mail]>
Reviewed-by: Jonathan Cameron <[e-mail]>

Patch

diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index ab2b76532272..5d848b77d8e8 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -342,7 +342,9 @@  static int add_host_bridge_dport(struct device *match, void *arg)
 		return 0;
 	}
 
+	cxl_device_lock(&root_port->dev);
 	rc = cxl_add_dport(root_port, match, uid, ctx.chbcr);
+	cxl_device_unlock(&root_port->dev);
 	if (rc) {
 		dev_err(host, "failed to add downstream port: %s\n",
 			dev_name(match));
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index af7a515e4572..369cc52e0837 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -519,7 +519,7 @@  static int add_dport(struct cxl_port *port, struct cxl_dport *new)
 {
 	struct cxl_dport *dup;
 
-	cxl_device_lock(&port->dev);
+	device_lock_assert(&port->dev);
 	dup = find_dport(port, new->port_id);
 	if (dup)
 		dev_err(&port->dev,
@@ -528,7 +528,6 @@  static int add_dport(struct cxl_port *port, struct cxl_dport *new)
 			dev_name(dup->dport));
 	else
 		list_add_tail(&new->list, &port->dports);
-	cxl_device_unlock(&port->dev);
 
 	return dup ? -EEXIST : 0;
 }
diff --git a/tools/testing/cxl/mock_acpi.c b/tools/testing/cxl/mock_acpi.c
index 4c8a493ace56..c953e3ab6494 100644
--- a/tools/testing/cxl/mock_acpi.c
+++ b/tools/testing/cxl/mock_acpi.c
@@ -57,7 +57,9 @@  static int match_add_root_port(struct pci_dev *pdev, void *data)
 
 	/* TODO walk DVSEC to find component register base */
 	port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap);
+	cxl_device_lock(&port->dev);
 	rc = cxl_add_dport(port, &pdev->dev, port_num, CXL_RESOURCE_NONE);
+	cxl_device_unlock(&port->dev);
 	if (rc) {
 		dev_err(dev, "failed to add dport: %s (%d)\n",
 			dev_name(&pdev->dev), rc);
@@ -78,7 +80,9 @@  static int mock_add_root_port(struct platform_device *pdev, void *data)
 	struct device *dev = ctx->dev;
 	int rc;
 
+	cxl_device_lock(&port->dev);
 	rc = cxl_add_dport(port, &pdev->dev, pdev->id, CXL_RESOURCE_NONE);
+	cxl_device_unlock(&port->dev);
 	if (rc) {
 		dev_err(dev, "failed to add dport: %s (%d)\n",
 			dev_name(&pdev->dev), rc);