[PATCH v3 3/3] PCI/MSI: remove msi_attrib.default_irq in msi_desc

From: Barry Song
Date: Wed Aug 25 2021 - 06:28:00 EST


From: Marc Zyngier <maz@xxxxxxxxxx>

default_irq is hideous as it should be per-device but not per-desc.
On the other hand, MSI-X case doesn't use it at all. Since sysfs
IRQ has moved to use the msi_entry instead of pci_dev.irq, now it
seems it is safe to remove msi_attrib.default_irq.

Cc: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx>
Cc: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
[Barry: Updated pci_irq_vector and __pci_restore_msi_state]
Signed-off-by: Barry Song <song.bao.hua@xxxxxxxxxxxxx>
---
drivers/pci/msi.c | 12 +++++-------
include/linux/msi.h | 2 --
2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index e5e7533..9434afa 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -422,7 +422,7 @@ static void __pci_restore_msi_state(struct pci_dev *dev)
if (!dev->msi_enabled)
return;

- entry = irq_get_msi_desc(dev->irq);
+ entry = first_pci_msi_entry(dev);

pci_intx_for_msi(dev, 0);
pci_msi_set_enable(dev, 0);
@@ -591,7 +591,6 @@ static int populate_msi_sysfs(struct pci_dev *pdev)
entry->msi_attrib.is_virtual = 0;
entry->msi_attrib.entry_nr = 0;
entry->msi_attrib.maskbit = !!(control & PCI_MSI_FLAGS_MASKBIT);
- entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */
entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
entry->msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));

@@ -682,7 +681,6 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,
dev->msi_enabled = 1;

pcibios_free_irq(dev);
- dev->irq = entry->irq;
return 0;
}

@@ -742,7 +740,6 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
entry->msi_attrib.is_virtual =
entry->msi_attrib.entry_nr >= vec_count;

- entry->msi_attrib.default_irq = dev->irq;
entry->mask_base = base;

addr = pci_msix_desc_addr(entry);
@@ -964,8 +961,6 @@ static void pci_msi_shutdown(struct pci_dev *dev)
mask = msi_mask(desc->msi_attrib.multi_cap);
msi_mask_irq(desc, mask, 0);

- /* Restore dev->irq to its default pin-assertion IRQ */
- dev->irq = desc->msi_attrib.default_irq;
pcibios_alloc_irq(dev);
}

@@ -1301,12 +1296,15 @@ int pci_irq_vector(struct pci_dev *dev, unsigned int nr)

if (WARN_ON_ONCE(nr >= entry->nvec_used))
return -EINVAL;
+
+ return entry->irq + nr;
} else {
if (WARN_ON_ONCE(nr > 0))
return -EINVAL;
}

- return dev->irq + nr;
+ /* legacy INTx */
+ return dev->irq;
}
EXPORT_SYMBOL(pci_irq_vector);

diff --git a/include/linux/msi.h b/include/linux/msi.h
index e8bdcb8..a631664 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -114,7 +114,6 @@ struct ti_sci_inta_msi_desc {
* @maskbit: [PCI MSI/X] Mask-Pending bit supported?
* @is_64: [PCI MSI/X] Address size: 0=32bit 1=64bit
* @entry_nr: [PCI MSI/X] Entry which is described by this descriptor
- * @default_irq:[PCI MSI/X] The default pre-assigned non-MSI irq
* @mask_pos: [PCI MSI] Mask register position
* @mask_base: [PCI MSI-X] Mask register base address
* @platform: [platform] Platform device specific msi descriptor data
@@ -148,7 +147,6 @@ struct msi_desc {
u8 is_64 : 1;
u8 is_virtual : 1;
u16 entry_nr;
- unsigned default_irq;
} msi_attrib;
union {
u8 mask_pos;
--
1.8.3.1