[PATCH v9 11/13] PCI: Remove legacy pcim_release()

Philipp Stanner
2024-06-13T11:50:59Z

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 PCI devres implementation.

Replace pcim_release() with pcim_disable_device().
Remove the now surplus function get_pci_dr().
Remove the struct pci_devres from pci.h.

Signed-off-by: Philipp Stanner <pstanner@redhat.com>
---
drivers/pci/devres.c | 53 +++++++++++++++++++++-----------------------
drivers/pci/pci.h | 16 -------------
2 files changed, 25 insertions(+), 44 deletions(-)

diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
index 7b72c952a9e5..37ac8fd37291 100644
--- a/drivers/pci/devres.c
+++ b/drivers/pci/devres.c
@@ -465,48 +465,45 @@ 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 (pci_is_enabled(dev) && !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 ret;
+ }

- return rc;
+ pdev->is_managed = true;
+
+ return ret;
}
EXPORT_SYMBOL(pcim_enable_device);

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 9e87528f1157..e51e6fa79fcc 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -810,22 +810,6 @@ static inline pci_power_t mid_pci_get_power_state(struct pci_dev *pdev)
}
#endif

-/*
- * Managed PCI resources. This manages device on/off, INTx/MSI/MSI-X
- * on/off and BAR regions. pci_dev itself records MSI/MSI-X status, so
- * there's no need to track it separately. pci_devres is initialized
- * when a device is enabled using managed PCI device enable interface.
- *
- * TODO: Struct pci_devres only needs to be here because they're used in pci.c.
- * Port or move these functions to devres.c and then remove them from here.
- */
-struct pci_devres {
- /*
- * TODO:
- * This struct is now surplus. Remove it by refactoring pci/devres.c
- */
-};
-
int pcim_intx(struct pci_dev *dev, int enable);

int pcim_request_region(struct pci_dev *pdev, int bar, const char *name);
--
2.45.0