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Message-ID: <20240123094317.15958-9-pstanner@redhat.com>
Date: Tue, 23 Jan 2024 10:43:05 +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 08/10] PCI: give pci(m)_intx its own devres callback
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As pci_intx() is an outdated function, pcim_intx() shall not be made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 other 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 struct pci_devres from pci.h.
Signed-off-by: Philipp Stanner <pstanner@...hat.com>
---
drivers/pci/devres.c | 76 ++++++++++++++++++++++++++++++++++----------
drivers/pci/pci.c | 24 +++++++-------
drivers/pci/pci.h | 21 +++---------
3 files changed, 77 insertions(+), 44 deletions(-)
diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
index d396d672a6f4..4314d0863282 100644
--- a/drivers/pci/devres.c
+++ b/drivers/pci/devres.c
@@ -40,6 +40,11 @@ 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,
@@ -401,31 +406,70 @@ int pcim_set_mwi(struct pci_dev *pdev)
}
EXPORT_SYMBOL(pcim_set_mwi);
+static void pcim_intx_restore(struct device *dev, void *data)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct pcim_intx_devres *res = data;
-static void pcim_release(struct device *gendev, void *res)
+ pci_intx(pdev, res->orig_intx);
+}
+
+static struct pcim_intx_devres *get_or_create_intx_devres(struct device *dev)
{
- struct pci_dev *dev = to_pci_dev(gendev);
- struct pci_devres *this = res;
+ struct pcim_intx_devres *res;
- if (this->restore_intx)
- pci_intx(dev, this->orig_intx);
+ res = devres_find(dev, pcim_intx_restore, NULL, NULL);
+ if (res)
+ return res;
- if (!dev->pinned)
- pci_disable_device(dev);
+ res = devres_alloc(pcim_intx_restore, sizeof(*res), GFP_KERNEL);
+ if (res)
+ devres_add(dev, res);
+
+ return res;
}
-/*
- * TODO:
- * Once the last four callers in pci.c are ported, this function here 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 (!dev->pinned)
+ pci_disable_device(dev);
}
-EXPORT_SYMBOL(find_pci_dr);
static struct pci_devres *get_pci_dr(struct pci_dev *pdev)
{
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ab8d66e05662..323d5b52f669 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3877,7 +3877,7 @@ EXPORT_SYMBOL_GPL(pci_common_swizzle);
void pci_release_region(struct pci_dev *pdev, int bar)
{
/*
- * This is done for backwards compatibility, because the old pci-devres
+ * This is done for backwards compatibility, because the old PCI devres
* API had a mode in which the function became managed if it had been
* enabled with pcim_enable_device() instead of pci_enable_device().
*/
@@ -4465,11 +4465,22 @@ void pci_disable_parity(struct pci_dev *dev)
* This is a "hybrid" function: Its normally unmanaged, but becomes managed
* when pcim_enable_device() has been called in advance.
* This hybrid feature is DEPRECATED!
+ * Use pcim_intx() if you need a managed version.
*/
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)
@@ -4477,17 +4488,8 @@ 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 667bfdd61d5e..e6d4b81ff09e 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -796,24 +796,11 @@ static inline pci_power_t mid_pci_get_power_state(struct pci_dev *pdev)
#endif
/*
- * TODO:
- * The following two components wouldn't need to be here if they weren't used at
- * four last places in pci.c
- * Port or move these functions to devres.c and then remove the
- * pci_devres-components from this header file here.
+ * This is a helper that shall only ever be called by pci_intx(). It helps
+ * cleaning up the PCI devres API in which pci_intx() became a managed function
+ * under certain conditions.
*/
-/*
- * 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.
- */
-struct pci_devres {
- unsigned int orig_intx:1;
- unsigned int restore_intx:1;
-};
-
-struct pci_devres *find_pci_dr(struct pci_dev *pdev);
+int pcim_intx(struct pci_dev *dev, int enable);
/*
* Config Address for PCI Configuration Mechanism #1
--
2.43.0
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