Re: [PATCH v2 3/3] PCI/MSI: Remove arch_msi_check_device()
From: Bjorn Helgaas
Date: Tue Sep 23 2014 - 16:58:28 EST
On Sun, Sep 07, 2014 at 08:57:55PM +0200, Alexander Gordeev wrote:
> There are no archs that override arch_msi_check_device()
> hook. Remove it as it is completely redundant.
>
> If an arch would need to check MSI/MSI-X possibility for a
> device it should make it within arch_setup_msi_irqs() hook.
>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
> Cc: linux-pci@xxxxxxxxxxxxxxx
> Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
> ---
> drivers/pci/msi.c | 49 +++++++++++++------------------------------------
> include/linux/msi.h | 3 ---
> 2 files changed, 13 insertions(+), 39 deletions(-)
I like this patch a lot, but it's doing several things at once, so I split
it into several patches as follows. I think it is equivalent, but I did
not add Thomas' tested-by.
I also reversed the sense of pci_msi_supported() so it returns true (1)
when MSI/MSI-X is supported and false (0) otherwise.
The whole thing is on my pci/msi branch at
https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/log/?h=pci/msi
Let me know if you see any issues.
Bjorn
commit 28a3ec3f672d42a877d8770a33305dfe82c2cc90
Author: Alexander Gordeev <agordeev@xxxxxxxxxx>
Date: Tue Sep 23 12:39:54 2014 -0600
PCI/MSI: Remove arch_msi_check_device()
No architectures implement arch_msi_check_device() or the struct msi_chip
.check_device() method, so remove them.
Remove the "type" parameter to pci_msi_check_device() because it was only
used to call arch_msi_check_device() and is no longer needed.
[bhelgaas: changelog, split to separate patch]
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index aff384aea639..a0b623d97ad8 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -56,16 +56,6 @@ void __weak arch_teardown_msi_irq(unsigned int irq)
chip->teardown_irq(chip, irq);
}
-int __weak arch_msi_check_device(struct pci_dev *dev, int nvec, int type)
-{
- struct msi_chip *chip = dev->bus->msi;
-
- if (!chip || !chip->check_device)
- return 0;
-
- return chip->check_device(chip, dev, nvec, type);
-}
-
int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
{
struct msi_desc *entry;
@@ -788,10 +778,9 @@ out_free:
* to determine if MSI/-X are supported for the device. If MSI/-X is
* supported return 0, else return an error code.
**/
-static int pci_msi_check_device(struct pci_dev *dev, int nvec, int type)
+static int pci_msi_check_device(struct pci_dev *dev, int nvec)
{
struct pci_bus *bus;
- int ret;
/* MSI must be globally enabled and supported by the device */
if (!pci_msi_enable || !dev || dev->no_msi)
@@ -816,10 +805,6 @@ static int pci_msi_check_device(struct pci_dev *dev, int nvec, int type)
if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
return -EINVAL;
- ret = arch_msi_check_device(dev, nvec, type);
- if (ret)
- return ret;
-
return 0;
}
@@ -925,7 +910,7 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
if (!entries || !dev->msix_cap || dev->current_state != PCI_D0)
return -EINVAL;
- status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX);
+ status = pci_msi_check_device(dev, nvec);
if (status)
return status;
@@ -1059,7 +1044,7 @@ int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec)
nvec = maxvec;
do {
- rc = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI);
+ rc = pci_msi_check_device(dev, nvec);
if (rc < 0) {
return rc;
} else if (rc > 0) {
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 6be66f48b026..36c63cfccf5b 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -55,7 +55,6 @@ int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc);
void arch_teardown_msi_irq(unsigned int irq);
int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
void arch_teardown_msi_irqs(struct pci_dev *dev);
-int arch_msi_check_device(struct pci_dev* dev, int nvec, int type);
void arch_restore_msi_irqs(struct pci_dev *dev);
void default_teardown_msi_irqs(struct pci_dev *dev);
@@ -72,8 +71,6 @@ struct msi_chip {
int (*setup_irq)(struct msi_chip *chip, struct pci_dev *dev,
struct msi_desc *desc);
void (*teardown_irq)(struct msi_chip *chip, unsigned int irq);
- int (*check_device)(struct msi_chip *chip, struct pci_dev *dev,
- int nvec, int type);
};
#endif /* LINUX_MSI_H */
commit 9d686dd5bbf62a249d0e4f54bffd848d573d2380
Author: Alexander Gordeev <agordeev@xxxxxxxxxx>
Date: Tue Sep 23 14:25:11 2014 -0600
PCI/MSI: Move D0 check into pci_msi_check_device()
Both callers of pci_msi_check_device() check that the device is in D0
state, so move the check from the callers into pci_msi_check_device()
itself.
In pci_enable_msi_range(), note that pci_msi_check_device() never returns a
positive value any more, so the loop that called it until it returns zero
or negative is no longer necessary.
[bhelgaas: changelog, split to separate patch]
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index a0b623d97ad8..416a4917a64a 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -783,7 +783,10 @@ static int pci_msi_check_device(struct pci_dev *dev, int nvec)
struct pci_bus *bus;
/* MSI must be globally enabled and supported by the device */
- if (!pci_msi_enable || !dev || dev->no_msi)
+ if (!pci_msi_enable)
+ return -EINVAL;
+
+ if (!dev || dev->no_msi || dev->current_state != PCI_D0)
return -EINVAL;
/*
@@ -907,13 +910,13 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
int status, nr_entries;
int i, j;
- if (!entries || !dev->msix_cap || dev->current_state != PCI_D0)
- return -EINVAL;
-
status = pci_msi_check_device(dev, nvec);
if (status)
return status;
+ if (!entries)
+ return -EINVAL;
+
nr_entries = pci_msix_vec_count(dev);
if (nr_entries < 0)
return nr_entries;
@@ -1020,8 +1023,9 @@ int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec)
int nvec;
int rc;
- if (dev->current_state != PCI_D0)
- return -EINVAL;
+ rc = pci_msi_check_device(dev, minvec);
+ if (rc)
+ return rc;
WARN_ON(!!dev->msi_enabled);
@@ -1044,17 +1048,6 @@ int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec)
nvec = maxvec;
do {
- rc = pci_msi_check_device(dev, nvec);
- if (rc < 0) {
- return rc;
- } else if (rc > 0) {
- if (rc < minvec)
- return -ENOSPC;
- nvec = rc;
- }
- } while (rc);
-
- do {
rc = msi_capability_init(dev, nvec);
if (rc < 0) {
return rc;
commit 99b4b82ffbc665cfa363a89144c8cc29eb46ce3d
Author: Alexander Gordeev <agordeev@xxxxxxxxxx>
Date: Tue Sep 23 12:45:58 2014 -0600
PCI/MSI: Rename pci_msi_check_device() to pci_msi_supported()
Rename pci_msi_check_device() to pci_msi_supported() for clarity. Note
that pci_msi_supported() returns true if MSI/MSI-X is supported, so code
like:
if (pci_msi_supported(...))
reads naturally.
[bhelgaas: changelog, split to separate patch, reverse sense]
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 416a4917a64a..d40323f0ed44 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -769,16 +769,15 @@ out_free:
}
/**
- * pci_msi_check_device - check whether MSI may be enabled on a device
+ * pci_msi_supported - check whether MSI may be enabled on a device
* @dev: pointer to the pci_dev data structure of MSI device function
* @nvec: how many MSIs have been requested ?
- * @type: are we checking for MSI or MSI-X ?
*
* Look at global flags, the device itself, and its parent buses
* to determine if MSI/-X are supported for the device. If MSI/-X is
- * supported return 0, else return an error code.
+ * supported return 1, else return 0.
**/
-static int pci_msi_check_device(struct pci_dev *dev, int nvec)
+static int pci_msi_supported(struct pci_dev *dev, int nvec)
{
struct pci_bus *bus;
@@ -795,7 +794,7 @@ static int pci_msi_check_device(struct pci_dev *dev, int nvec)
* b) the list manipulation code assumes nvec >= 1.
*/
if (nvec < 1)
- return -ERANGE;
+ return 0;
/*
* Any bridge which does NOT route MSI transactions from its
@@ -806,9 +805,9 @@ static int pci_msi_check_device(struct pci_dev *dev, int nvec)
*/
for (bus = dev->bus; bus; bus = bus->parent)
if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
- return -EINVAL;
+ return 0;
- return 0;
+ return 1;
}
/**
@@ -910,9 +909,8 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
int status, nr_entries;
int i, j;
- status = pci_msi_check_device(dev, nvec);
- if (status)
- return status;
+ if (!pci_msi_supported(dev, nvec))
+ return -EINVAL;
if (!entries)
return -EINVAL;
@@ -1023,9 +1021,8 @@ int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec)
int nvec;
int rc;
- rc = pci_msi_check_device(dev, minvec);
- if (rc)
- return rc;
+ if (!pci_msi_supported(dev, minvec))
+ return -EINVAL;
WARN_ON(!!dev->msi_enabled);
commit 83be7664f8492b8e4b72cd9375433909d40c018b
Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Date: Tue Sep 23 14:38:28 2014 -0600
PCI/MSI: Remove unnecessary temporary variable
The only use of "status" is to hold a value which is immediately returned,
so just return and remove the variable directly.
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index d40323f0ed44..aae2fc80692b 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -906,7 +906,7 @@ EXPORT_SYMBOL(pci_msix_vec_count);
**/
int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
{
- int status, nr_entries;
+ int nr_entries;
int i, j;
if (!pci_msi_supported(dev, nvec))
@@ -937,8 +937,7 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
dev_info(&dev->dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
return -EINVAL;
}
- status = msix_capability_init(dev, entries, nvec);
- return status;
+ return msix_capability_init(dev, entries, nvec);
}
EXPORT_SYMBOL(pci_enable_msix);
--
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