[tip: irq/core] PCI/MSI: Move pci_disable_msi() to api.c

tip-bot2 for Ahmed S. Darwish
2022-11-17T15:10:28Z

The following commit has been merged into the irq/core branch of tip:

Commit-ID: b12d0bec385b7a58b9e83751e6cd9f04ec3b23a4
Gitweb: https://git.kernel.org/tip/b12d0bec385b7a58b9e83751e6cd9f04ec3b23a4
Author: Ahmed S. Darwish <darwi@linutronix.de>
AuthorDate: Fri, 11 Nov 2022 14:54:45 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 17 Nov 2022 15:15:20 +01:00

PCI/MSI: Move pci_disable_msi() to api.c

msi.c is a maze of randomly sorted functions which makes the code
unreadable. As a first step split the driver visible API and the internal
implementation which also allows proper API documentation via one file.

Create drivers/pci/msi/api.c to group all exported device-driver PCI/MSI
APIs in one C file.

Begin by moving pci_disable_msi() there and add kernel-doc for the function
as appropriate.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20221111122014.696798036@linutronix.de

---
drivers/pci/msi/Makefile | 3 +--
drivers/pci/msi/api.c | 37 +++++++++++++++++++++++++++++++++++++
drivers/pci/msi/msi.c | 22 +++++-----------------
drivers/pci/msi/msi.h | 4 ++++
4 files changed, 47 insertions(+), 19 deletions(-)
create mode 100644 drivers/pci/msi/api.c

diff --git a/drivers/pci/msi/Makefile b/drivers/pci/msi/Makefile
index 4e0a7e0..839ff72 100644
--- a/drivers/pci/msi/Makefile
+++ b/drivers/pci/msi/Makefile
@@ -2,6 +2,5 @@
#
# Makefile for the PCI/MSI
obj-$(CONFIG_PCI) += pcidev_msi.o
-obj-$(CONFIG_PCI_MSI) += msi.o
-obj-$(CONFIG_PCI_MSI) += irqdomain.o
+obj-$(CONFIG_PCI_MSI) += api.o msi.o irqdomain.o
obj-$(CONFIG_PCI_MSI_ARCH_FALLBACKS) += legacy.o
diff --git a/drivers/pci/msi/api.c b/drivers/pci/msi/api.c
new file mode 100644
index 0000000..7485942
--- /dev/null
+++ b/drivers/pci/msi/api.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI MSI/MSI-X — Exported APIs for device drivers
+ *
+ * Copyright (C) 2003-2004 Intel
+ * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
+ * Copyright (C) 2016 Christoph Hellwig.
+ * Copyright (C) 2022 Linutronix GmbH
+ */
+
+#include <linux/export.h>
+
+#include "msi.h"
+
+/**
+ * pci_disable_msi() - Disable MSI interrupt mode on device
+ * @dev: the PCI device to operate on
+ *
+ * Legacy device driver API to disable MSI interrupt mode on device,
+ * free earlier allocated interrupt vectors, and restore INTx emulation.
+ * The PCI device Linux IRQ (@dev->irq) is restored to its default
+ * pin-assertion IRQ. This is the cleanup pair of pci_enable_msi().
+ *
+ * NOTE: The newer pci_alloc_irq_vectors() / pci_free_irq_vectors() API
+ * pair should, in general, be used instead.
+ */
+void pci_disable_msi(struct pci_dev *dev)
+{
+ if (!pci_msi_enabled() || !dev || !dev->msi_enabled)
+ return;
+
+ msi_lock_descs(&dev->dev);
+ pci_msi_shutdown(dev);
+ pci_free_msi_irqs(dev);
+ msi_unlock_descs(&dev->dev);
+}
+EXPORT_SYMBOL(pci_disable_msi);
diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index 5c310df..4a1300b 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -163,7 +163,7 @@ void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg)
}
EXPORT_SYMBOL_GPL(pci_write_msi_msg);

-static void free_msi_irqs(struct pci_dev *dev)
+void pci_free_msi_irqs(struct pci_dev *dev)
{
pci_msi_teardown_msi_irqs(dev);

@@ -413,7 +413,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,

err:
pci_msi_unmask(entry, msi_multi_mask(entry));
- free_msi_irqs(dev);
+ pci_free_msi_irqs(dev);
fail:
dev->msi_enabled = 0;
unlock:
@@ -531,7 +531,7 @@ static int msix_setup_interrupts(struct pci_dev *dev, void __iomem *base,
goto out_unlock;

out_free:
- free_msi_irqs(dev);
+ pci_free_msi_irqs(dev);
out_unlock:
msi_unlock_descs(&dev->dev);
kfree(masks);
@@ -680,7 +680,7 @@ int pci_msi_vec_count(struct pci_dev *dev)
}
EXPORT_SYMBOL(pci_msi_vec_count);

-static void pci_msi_shutdown(struct pci_dev *dev)
+void pci_msi_shutdown(struct pci_dev *dev)
{
struct msi_desc *desc;

@@ -701,18 +701,6 @@ static void pci_msi_shutdown(struct pci_dev *dev)
pcibios_alloc_irq(dev);
}

-void pci_disable_msi(struct pci_dev *dev)
-{
- if (!pci_msi_enable || !dev || !dev->msi_enabled)
- return;
-
- msi_lock_descs(&dev->dev);
- pci_msi_shutdown(dev);
- free_msi_irqs(dev);
- msi_unlock_descs(&dev->dev);
-}
-EXPORT_SYMBOL(pci_disable_msi);
-
/**
* pci_msix_vec_count - return the number of device's MSI-X table entries
* @dev: pointer to the pci_dev data structure of MSI-X device function
@@ -797,7 +785,7 @@ void pci_disable_msix(struct pci_dev *dev)

msi_lock_descs(&dev->dev);
pci_msix_shutdown(dev);
- free_msi_irqs(dev);
+ pci_free_msi_irqs(dev);
msi_unlock_descs(&dev->dev);
}
EXPORT_SYMBOL(pci_disable_msix);
diff --git a/drivers/pci/msi/msi.h b/drivers/pci/msi/msi.h
index d8f62d9..6348792 100644
--- a/drivers/pci/msi/msi.h
+++ b/drivers/pci/msi/msi.h
@@ -84,6 +84,10 @@ static inline __attribute_const__ u32 msi_multi_mask(struct msi_desc *desc)
return (1 << (1 << desc->pci.msi_attrib.multi_cap)) - 1;
}

+/* MSI internal functions invoked from the public APIs */
+void pci_msi_shutdown(struct pci_dev *dev);
+void pci_free_msi_irqs(struct pci_dev *dev);
+
/* Legacy (!IRQDOMAIN) fallbacks */
#ifdef CONFIG_PCI_MSI_ARCH_FALLBACKS
int pci_msi_legacy_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);