Re: [PATCH v2 3/3] PCI/MSI: Remove arch_msi_check_device()
From: Bjorn Helgaas <bhelgaas@google.com>
Date: 2014-09-23 20:58:25
Also in:
linux-pci, lkml
Subsystem:
pci subsystem, the rest · Maintainers:
Bjorn Helgaas, Linus Torvalds
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@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-pci@vger.kernel.org Signed-off-by: Alexander Gordeev <redacted> --- 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 [off-list ref] 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 [off-list ref] Signed-off-by: Bjorn Helgaas [off-list ref]
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 [off-list ref]
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 [off-list ref]
Signed-off-by: Bjorn Helgaas [off-list ref]
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 [off-list ref]
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 [off-list ref]
Signed-off-by: Bjorn Helgaas [off-list ref]
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 [off-list ref]
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 [off-list ref]
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);