diff options
| author | Ryo Takakura <ryotkkr98@gmail.com> | 2025-02-18 09:08:30 +0100 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2025-03-18 20:05:06 -0500 |
| commit | 18056a48669a040bef491e63b25896561ee14d90 (patch) | |
| tree | fc38650e70a1aac99076dee544f9283afa88685c /drivers/pci/controller/vmd.c | |
| parent | 2014c95afecee3e76ca4a56956a936e23283f05b (diff) | |
PCI: vmd: Make vmd_dev::cfg_lock a raw_spinlock_t type
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>
Diffstat (limited to 'drivers/pci/controller/vmd.c')
| -rw-r--r-- | drivers/pci/controller/vmd.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index 9d9596947350..94ceec50a2b9 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -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) |