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PCI: vmd: Make vmd_dev::cfg_lock a raw_spinlock_t type

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[ Upstream commit 18056a48669a040bef491e63b25896561ee14d90 ]

The access to the PCI config space via pci_ops::read and pci_ops::write is
a low-level hardware access. The functions can be accessed with disabled
interrupts even on PREEMPT_RT. The pci_lock is a raw_spinlock_t for this
purpose.

A spinlock_t becomes a sleeping lock on PREEMPT_RT, so it cannot be
acquired with disabled interrupts. The vmd_dev::cfg_lock is accessed in
the same context as the pci_lock.

Make vmd_dev::cfg_lock a raw_spinlock_t type so it can be used with
interrupts disabled.

This was reported as:

  BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
  Call Trace:
   rt_spin_lock+0x4e/0x130
   vmd_pci_read+0x8d/0x100 [vmd]
   pci_user_read_config_byte+0x6f/0xe0
   pci_read_config+0xfe/0x290
   sysfs_kf_bin_read+0x68/0x90

Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Acked-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
[bigeasy: reword commit message]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Link: https://lore.kernel.org/r/20250218080830.ufw3IgyX@linutronix.de
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: add back report info from
https://lore.kernel.org/lkml/20241218115951.83062-1-ryotkkr98@gmail.com/]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Ryo Takakura
2025-02-18 09:08:30 +01:00
committed by Greg Kroah-Hartman
parent 73d2b96250
commit 5c3cfcf0b4
1 changed files with 6 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/pci/controller/vmd.c
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@@ -125,7 +125,7 @@ struct vmd_irq_list {
struct vmd_dev {
struct pci_dev *dev;
spinlock_t cfg_lock;
raw_spinlock_t cfg_lock;
void __iomem *cfgbar;
int msix_count;
@@ -391,7 +391,7 @@ static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
if (!addr)
return -EFAULT;
spin_lock_irqsave(&vmd->cfg_lock, flags);
raw_spin_lock_irqsave(&vmd->cfg_lock, flags);
switch (len) {
case 1:
*value = readb(addr);
@@ -406,7 +406,7 @@ static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
ret = -EINVAL;
break;
}
spin_unlock_irqrestore(&vmd->cfg_lock, flags);
raw_spin_unlock_irqrestore(&vmd->cfg_lock, flags);
return ret;
}
@@ -426,7 +426,7 @@ static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg,
if (!addr)
return -EFAULT;
spin_lock_irqsave(&vmd->cfg_lock, flags);
raw_spin_lock_irqsave(&vmd->cfg_lock, flags);
switch (len) {
case 1:
writeb(value, addr);
@@ -444,7 +444,7 @@ static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg,
ret = -EINVAL;
break;
}
spin_unlock_irqrestore(&vmd->cfg_lock, flags);
raw_spin_unlock_irqrestore(&vmd->cfg_lock, flags);
return ret;
}
@@ -1009,7 +1009,7 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
if (features & VMD_FEAT_OFFSET_FIRST_VECTOR)
vmd->first_vec = 1;
spin_lock_init(&vmd->cfg_lock);
raw_spin_lock_init(&vmd->cfg_lock);
pci_set_drvdata(dev, vmd);
err = vmd_enable_domain(vmd, features);
if (err)