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PCI/MSI: Move non-mask check back into low level accessors 

The recent rework of PCI/MSI[X] masking moved the non-mask checks from the
low level accessors into the higher level mask/unmask functions.

This missed the fact that these accessors can be invoked from other places
as well. The missing checks break XEN-PV which sets pci_msi_ignore_mask and
also violates the virtual MSIX and the msi_attrib.maskbit protections.

Instead of sprinkling checks all over the place, lift them back into the
low level accessor functions. To avoid checking three different conditions
combine them into one property of msi_desc::msi_attrib.

[ josef: Fixed the missed conversion in the core code ]

Fixes: fcacdfbef5 ("PCI/MSI: Provide a new set of mask and unmask functions")
Reported-by: Josef Johansson <josef@oderland.se>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Josef Johansson <josef@oderland.se>
Cc: Bjorn Helgaas <helgaas@kernel.org>
Cc: stable@vger.kernel.org
This commit is contained in:
Thomas Gleixner 2021-11-04 00:27:29 +01:00
parent debe436e77
commit 9c8e9c9681
3 changed files with 17 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
drivers/pci/msi.c
View File

@ -148,6 +148,9 @@ static noinline void pci_msi_update_mask(struct msi_desc *desc, u32 clear, u32 s
raw_spinlock_t *lock = &desc->dev->msi_lock;
unsigned long flags;
if (!desc->msi_attrib.can_mask)
return;
raw_spin_lock_irqsave(lock, flags);
desc->msi_mask &= ~clear;
desc->msi_mask |= set;
@ -181,7 +184,8 @@ static void pci_msix_write_vector_ctrl(struct msi_desc *desc, u32 ctrl)
{
void __iomem *desc_addr = pci_msix_desc_addr(desc);
writel(ctrl, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
if (desc->msi_attrib.can_mask)
writel(ctrl, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
}
static inline void pci_msix_mask(struct msi_desc *desc)
@ -200,23 +204,17 @@ static inline void pci_msix_unmask(struct msi_desc *desc)
static void __pci_msi_mask_desc(struct msi_desc *desc, u32 mask)
{
if (pci_msi_ignore_mask || desc->msi_attrib.is_virtual)
return;
if (desc->msi_attrib.is_msix)
pci_msix_mask(desc);
else if (desc->msi_attrib.maskbit)
else
pci_msi_mask(desc, mask);
}
static void __pci_msi_unmask_desc(struct msi_desc *desc, u32 mask)
{
if (pci_msi_ignore_mask || desc->msi_attrib.is_virtual)
return;
if (desc->msi_attrib.is_msix)
pci_msix_unmask(desc);
else if (desc->msi_attrib.maskbit)
else
pci_msi_unmask(desc, mask);
}
@ -484,7 +482,8 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
entry->msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT);
entry->msi_attrib.is_virtual = 0;
entry->msi_attrib.entry_nr = 0;
entry->msi_attrib.maskbit = !!(control & PCI_MSI_FLAGS_MASKBIT);
entry->msi_attrib.can_mask = !pci_msi_ignore_mask &&
!!(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));
@ -495,7 +494,7 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
/* Save the initial mask status */
if (entry->msi_attrib.maskbit)
if (entry->msi_attrib.can_mask)
pci_read_config_dword(dev, entry->mask_pos, &entry->msi_mask);
out:
@ -639,10 +638,13 @@ 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.can_mask = !pci_msi_ignore_mask &&
!entry->msi_attrib.is_virtual;
entry->msi_attrib.default_irq = dev->irq;
entry->mask_base = base;
if (!entry->msi_attrib.is_virtual) {
if (entry->msi_attrib.can_mask) {
addr = pci_msix_desc_addr(entry);
entry->msix_ctrl = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
}

2
include/linux/msi.h
View File

@ -148,7 +148,7 @@ struct msi_desc {
u8 is_msix : 1;
u8 multiple : 3;
u8 multi_cap : 3;
u8 maskbit : 1;
u8 can_mask : 1;
u8 is_64 : 1;
u8 is_virtual : 1;
u16 entry_nr;

4
kernel/irq/msi.c
View File

@ -529,10 +529,10 @@ static bool msi_check_reservation_mode(struct irq_domain *domain,
/*
* Checking the first MSI descriptor is sufficient. MSIX supports
* masking and MSI does so when the maskbit is set.
* masking and MSI does so when the can_mask attribute is set.
*/
desc = first_msi_entry(dev);
return desc->msi_attrib.is_msix || desc->msi_attrib.maskbit;
return desc->msi_attrib.is_msix || desc->msi_attrib.can_mask;
}
int __msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,