[PATCH v9 10/13] PCI: Give pci_intx() its own devres callback
Philipp Stanner
pstanner at redhat.com
Thu Jun 13 11:50:23 UTC 2024
pci_intx() is one of the functions that have "hybrid mode" (i.e.,
sometimes managed, sometimes not). Providing a separate pcim_intx()
function with its own device resource and cleanup callback allows for
removing further large parts of the legacy PCI devres implementation.
As in the region-request-functions, pci_intx() has to call into its
managed counterpart for backwards compatibility.
As pci_intx() is an outdated function, pcim_intx() shall not be made
visible to drivers via a public API.
Implement pcim_intx() with its own device resource.
Make pci_intx() call pcim_intx() in the managed case.
Remove the now surplus function find_pci_dr().
Signed-off-by: Philipp Stanner <pstanner at redhat.com>
---
drivers/pci/devres.c | 76 ++++++++++++++++++++++++++++++++++++--------
drivers/pci/pci.c | 21 ++++++------
drivers/pci/pci.h | 13 ++++----
3 files changed, 80 insertions(+), 30 deletions(-)
diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
index e8de93e95eb6..7b72c952a9e5 100644
--- a/drivers/pci/devres.c
+++ b/drivers/pci/devres.c
@@ -42,6 +42,11 @@ struct pcim_iomap_devres {
void __iomem *table[PCI_STD_NUM_BARS];
};
+/* Used to restore the old intx state on driver detach. */
+struct pcim_intx_devres {
+ int orig_intx;
+};
+
enum pcim_addr_devres_type {
/* Default initializer. */
PCIM_ADDR_DEVRES_TYPE_INVALID,
@@ -397,32 +402,75 @@ int pcim_set_mwi(struct pci_dev *pdev)
}
EXPORT_SYMBOL(pcim_set_mwi);
+
static inline bool mask_contains_bar(int mask, int bar)
{
return mask & BIT(bar);
}
-static void pcim_release(struct device *gendev, void *res)
+static void pcim_intx_restore(struct device *dev, void *data)
{
- struct pci_dev *dev = to_pci_dev(gendev);
- struct pci_devres *this = res;
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct pcim_intx_devres *res = data;
- if (this->restore_intx)
- pci_intx(dev, this->orig_intx);
+ pci_intx(pdev, res->orig_intx);
+}
- if (pci_is_enabled(dev) && !dev->pinned)
- pci_disable_device(dev);
+static struct pcim_intx_devres *get_or_create_intx_devres(struct device *dev)
+{
+ struct pcim_intx_devres *res;
+
+ res = devres_find(dev, pcim_intx_restore, NULL, NULL);
+ if (res)
+ return res;
+
+ res = devres_alloc(pcim_intx_restore, sizeof(*res), GFP_KERNEL);
+ if (res)
+ devres_add(dev, res);
+
+ return res;
}
-/*
- * TODO: After the last four callers in pci.c are ported, find_pci_dr()
- * needs to be made static again.
+/**
+ * pcim_intx - managed pci_intx()
+ * @pdev: the PCI device to operate on
+ * @enable: boolean: whether to enable or disable PCI INTx
+ *
+ * Returns: 0 on success, -ENOMEM on error.
+ *
+ * Enables/disables PCI INTx for device @pdev.
+ * Restores the original state on driver detach.
*/
-struct pci_devres *find_pci_dr(struct pci_dev *pdev)
+int pcim_intx(struct pci_dev *pdev, int enable)
{
- if (pci_is_managed(pdev))
- return devres_find(&pdev->dev, pcim_release, NULL, NULL);
- return NULL;
+ u16 pci_command, new;
+ struct pcim_intx_devres *res;
+
+ res = get_or_create_intx_devres(&pdev->dev);
+ if (!res)
+ return -ENOMEM;
+
+ res->orig_intx = !enable;
+
+ pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
+
+ if (enable)
+ new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
+ else
+ new = pci_command | PCI_COMMAND_INTX_DISABLE;
+
+ if (new != pci_command)
+ pci_write_config_word(pdev, PCI_COMMAND, new);
+
+ return 0;
+}
+
+static void pcim_release(struct device *gendev, void *res)
+{
+ 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)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index db2cc48f3d63..1b4832a60047 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4443,6 +4443,16 @@ void pci_intx(struct pci_dev *pdev, int enable)
{
u16 pci_command, new;
+ /*
+ * This is done for backwards compatibility, because the old PCI devres
+ * API had a mode in which this function became managed if the dev had
+ * been enabled with pcim_enable_device() instead of pci_enable_device().
+ */
+ if (pci_is_managed(pdev)) {
+ WARN_ON_ONCE(pcim_intx(pdev, enable) != 0);
+ return;
+ }
+
pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
if (enable)
@@ -4450,17 +4460,8 @@ void pci_intx(struct pci_dev *pdev, int enable)
else
new = pci_command | PCI_COMMAND_INTX_DISABLE;
- if (new != pci_command) {
- struct pci_devres *dr;
-
+ if (new != pci_command)
pci_write_config_word(pdev, PCI_COMMAND, new);
-
- dr = find_pci_dr(pdev);
- if (dr && !dr->restore_intx) {
- dr->restore_intx = 1;
- dr->orig_intx = !enable;
- }
- }
}
EXPORT_SYMBOL_GPL(pci_intx);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index c355bb6a698d..9e87528f1157 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -816,16 +816,17 @@ static inline pci_power_t mid_pci_get_power_state(struct pci_dev *pdev)
* 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 and find_pci_dr() only need to be here because
- * they're used in pci.c. Port or move these functions to devres.c and
- * then remove them from here.
+ * 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 {
- unsigned int orig_intx:1;
- unsigned int restore_intx:1;
+ /*
+ * TODO:
+ * This struct is now surplus. Remove it by refactoring pci/devres.c
+ */
};
-struct pci_devres *find_pci_dr(struct pci_dev *pdev);
+int pcim_intx(struct pci_dev *dev, int enable);
int pcim_request_region(struct pci_dev *pdev, int bar, const char *name);
int pcim_request_region_exclusive(struct pci_dev *pdev, int bar, const char *name);
--
2.45.0
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