This is a note to let you know that I've just added the patch titled
PCI/MSI: Move non-mask check back into low level accessors
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-msi-move-non-mask-check-back-into-low-level-accessors.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9c8e9c9681a0f3f1ae90a90230d059c7a1dece5a Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Date: Thu, 4 Nov 2021 00:27:29 +0100
Subject: PCI/MSI: Move non-mask check back into low level accessors
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
commit 9c8e9c9681a0f3f1ae90a90230d059c7a1dece5a upstream.
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: fcacdfbef5a1 ("PCI/MSI: Provide a new set of mask and unmask functions")
Reported-by: Josef Johansson <josef@xxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Josef Johansson <josef@xxxxxxxxxxx>
Cc: Bjorn Helgaas <helgaas@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/msi.c | 26 ++++++++++++++------------
include/linux/msi.h | 2 +-
kernel/irq/msi.c | 4 ++--
3 files changed, 17 insertions(+), 15 deletions(-)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -148,6 +148,9 @@ static noinline void pci_msi_update_mask
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(s
{
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(struc
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
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
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:
@@ -638,10 +637,13 @@ static int msix_setup_entries(struct pci
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);
}
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -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;
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -529,10 +529,10 @@ static bool msi_check_reservation_mode(s
/*
* 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,
Patches currently in stable-queue which might be from tglx@xxxxxxxxxxxxx are
queue-5.15/pci-msi-move-non-mask-check-back-into-low-level-accessors.patch
queue-5.15/ia64-kprobes-fix-to-pass-correct-trampoline-address-to-the-handler.patch
queue-5.15/pci-msi-destroy-sysfs-before-freeing-entries.patch
queue-5.15/rcu-always-inline-rcu_dynticks_task-_-enter-exit.patch
queue-5.15/ftrace-do-cpu-checking-after-preemption-disabled.patch
queue-5.15/irq-mips-avoid-nested-irq_enter.patch
queue-5.15/rcu-fix-rcu_dynticks_curr_cpu_in_eqs-vs-noinstr.patch
queue-5.15/x86-iopl-fake-iopl-3-cli-sti-usage.patch
