linux-kernel - [PATCH v2 09/10] PCI: remove legacy pcim

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Message-ID: <20240123094317.15958-10-pstanner@redhat.com>
Date: Tue, 23 Jan 2024 10:43:06 +0100
From: Philipp Stanner <pstanner@...hat.com>
To: Jonathan Corbet <corbet@....net>,
	Hans de Goede <hdegoede@...hat.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Daniel Vetter <daniel@...ll.ch>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Philipp Stanner <pstanner@...hat.com>,
	Sam Ravnborg <sam@...nborg.org>,
	dakr@...hat.com
Cc: linux-doc@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	dri-devel@...ts.freedesktop.org,
	linux-pci@...r.kernel.org
Subject: [PATCH v2 09/10] PCI: remove legacy pcim_release()

Thanks to preceding cleanup steps, pcim_release() is now not needed
anymore and can be replaced by pcim_disable_device(), which is the exact
counterpart to pcim_enable_device().

This permits removing further parts of the old devres API.

Replace pcim_release() with pcim_disable_device().
Remove the now surplus function get_pci_dr().

Signed-off-by: Philipp Stanner <pstanner@...hat.com>
---
 drivers/pci/devres.c | 49 +++++++++++++++++++-------------------------
 1 file changed, 21 insertions(+), 28 deletions(-)

diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
index 4314d0863282..f368181c6c92 100644
--- a/drivers/pci/devres.c
+++ b/drivers/pci/devres.c
@@ -463,48 +463,41 @@ int pcim_intx(struct pci_dev *pdev, int enable)
 	return 0;
 }
 
-static void pcim_release(struct device *gendev, void *res)
+static void pcim_disable_device(void *pdev_raw)
 {
-	struct pci_dev *dev = to_pci_dev(gendev);
-
-	if (!dev->pinned)
-		pci_disable_device(dev);
-}
-
-static struct pci_devres *get_pci_dr(struct pci_dev *pdev)
-{
-	struct pci_devres *dr, *new_dr;
-
-	dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
-	if (dr)
-		return dr;
+	struct pci_dev *pdev = pdev_raw;
 
-	new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
-	if (!new_dr)
-		return NULL;
-	return devres_get(&pdev->dev, new_dr, NULL, NULL);
+	if (!pdev->pinned)
+		pci_disable_device(pdev);
 }
 
 /**
  * pcim_enable_device - Managed pci_enable_device()
  * @pdev: PCI device to be initialized
  *
- * Managed pci_enable_device().
+ * Returns: 0 on success, negative error code on failure.
+ *
+ * Managed pci_enable_device(). Device will automatically be disabled on
+ * driver detach.
  */
 int pcim_enable_device(struct pci_dev *pdev)
 {
-	struct pci_devres *dr;
-	int rc;
+	int ret;
 
-	dr = get_pci_dr(pdev);
-	if (unlikely(!dr))
-		return -ENOMEM;
+	ret = devm_add_action(&pdev->dev, pcim_disable_device, pdev);
+	if (ret != 0)
+		return ret;
 
-	rc = pci_enable_device(pdev);
-	if (!rc)
-		pdev->is_managed = 1;
+	/*
+	 * We prefer removing the action in case of an error over
+	 * devm_add_action_or_reset() because the later could theoretically be
+	 * disturbed by users having pinned the device too soon.
+	 */
+	ret = pci_enable_device(pdev);
+	if (ret != 0)
+		devm_remove_action(&pdev->dev, pcim_disable_device, pdev);
 
-	return rc;
+	return ret;
 }
 EXPORT_SYMBOL(pcim_enable_device);
 
-- 
2.43.0