From 25216afc9db53d85dc648aba8fb7f6d31f2c8731 Mon Sep 17 00:00:00 2001
From: Philipp Stanner <pstanner@redhat.com>
Date: Thu, 13 Jun 2024 13:50:23 +0200
Subject: [PATCH] PCI: Add managed pcim_intx()
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pci_intx() is a "hybrid" function, i.e., it is managed if
pcim_enable_device() has been called, but unmanaged otherwise.
Add pcim_intx(), which is always managed, and implement pci_intx() using
it.
Remove the now-unused struct pci_devres.orig_intx and .restore_intx and
find_pci_dr().
Link: https://lore.kernel.org/r/20240613115032.29098-11-pstanner@redhat.com
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
[kwilczynski: squashed in
https://lore.kernel.org/r/426645d40776198e0fcc942f4a6cac4433c7a9aa.camel@redhat.com
to fix problem reported and tested by Ashish Kalra <Ashish.Kalra@amd.com>:
https://lore.kernel.org/r/20240708214656.4721-1-Ashish.Kalra@amd.com
https://lore.kernel.org/r/8c4634e9-4f02-4c54-9c89-d75e2f4bf026@amd.com/]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/devres.c | 84 ++++++++++++++++++++++++++++++++++++--------
drivers/pci/pci.c | 19 +++++-----
drivers/pci/pci.h | 13 +++----
3 files changed, 85 insertions(+), 31 deletions(-)
diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
index d3c29ec30ad735..f7b7184384124c 100644
--- a/drivers/pci/devres.c
+++ b/drivers/pci/devres.c
@@ -43,6 +43,11 @@ 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,
@@ -406,27 +411,78 @@ static inline bool mask_contains_bar(int mask, int bar)
return mask & BIT(bar);
}
-static void pcim_release(struct device *gendev, void *res)
+/*
+ * This is a copy of pci_intx() used to bypass the problem of recursive
+ * function calls due to the hybrid nature of pci_intx().
+ */
+static void __pcim_intx(struct pci_dev *pdev, int enable)
{
- struct pci_dev *dev = to_pci_dev(gendev);
- struct pci_devres *this = res;
+ u16 pci_command, new;
- if (this->restore_intx)
- pci_intx(dev, this->orig_intx);
+ pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
- if (pci_is_enabled(dev) && !dev->pinned)
- pci_disable_device(dev);
+ 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);
}
-/*
- * TODO: After the last four callers in pci.c are ported, find_pci_dr()
- * needs to be made static again.
+static void pcim_intx_restore(struct device *dev, void *data)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct pcim_intx_devres *res = data;
+
+ __pcim_intx(pdev, res->orig_intx);
+}
+
+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;
+}
+
+/**
+ * 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.
+ *
+ * Enable/disable PCI INTx for device @pdev.
+ * Restore 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;
+ struct pcim_intx_devres *res;
+
+ res = get_or_create_intx_devres(&pdev->dev);
+ if (!res)
+ return -ENOMEM;
+
+ res->orig_intx = !enable;
+ __pcim_intx(pdev, enable);
+
+ 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 a0fad5990f03cf..807f8be043cd43 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4442,12 +4442,18 @@ void pci_disable_parity(struct pci_dev *dev)
* NOTE:
* This is a "hybrid" function: It's normally unmanaged, but becomes managed
* when pcim_enable_device() has been called in advance. This hybrid feature is
- * DEPRECATED!
+ * DEPRECATED! If you want managed cleanup, use pcim_intx() instead.
*/
void pci_intx(struct pci_dev *pdev, int enable)
{
u16 pci_command, new;
+ /* Preserve the "hybrid" behavior for backwards compatibility */
+ 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)
@@ -4455,17 +4461,8 @@ 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 9a12f6774431fe..21cb4417635081 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,