From f0a267885e4d99325c92af27f972c018479b5f81 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 29 May 2024 14:49:01 +0300 Subject: PCI: Make PCI cfg_access_lock lockdep key a singleton The new lockdep annotation for cfg_access_lock naively registered a new key per device. This is overkill and leads to warnings on hash collisions at dynamic registration time: WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:1226 lockdep_register_key+0xb0/0x240 RIP: 0010:lockdep_register_key+0xb0/0x240 [..] Call Trace: ? __warn+0x8c/0x190 ? lockdep_register_key+0xb0/0x240 ? report_bug+0x1f8/0x200 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? lockdep_register_key+0xb0/0x240 pci_device_add+0x14b/0x560 ? pci_setup_device+0x42e/0x6a0 pci_scan_single_device+0xa7/0xd0 p2sb_scan_and_cache_devfn+0xc/0x90 p2sb_fs_init+0x15f/0x170 Switch to a shared static key for all instances. Fixes: 7e89efc6e9e4 ("PCI: Lock upstream bridge for pci_reset_function()") Reported-by: Jani Saarinen Closes: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_14834/bat-apl-1/boot0.txt Cc: Dave Jiang Cc: Bjorn Helgaas Signed-off-by: Dan Williams References: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/11223 Acked-by: Jani Nikula Signed-off-by: Imre Deak Link: https://patchwork.freedesktop.org/patch/msgid/20240529114901.344655-1-imre.deak@intel.com --- drivers/pci/probe.c | 7 ++++--- include/linux/pci.h | 1 - 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 8e696e547565..15168881ec94 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2533,6 +2533,8 @@ static void pci_set_msi_domain(struct pci_dev *dev) dev_set_msi_domain(&dev->dev, d); } +static struct lock_class_key cfg_access_key; + void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) { int ret; @@ -2546,9 +2548,8 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) dev->dev.dma_mask = &dev->dma_mask; dev->dev.dma_parms = &dev->dma_parms; dev->dev.coherent_dma_mask = 0xffffffffull; - lockdep_register_key(&dev->cfg_access_key); - lockdep_init_map(&dev->cfg_access_lock, dev_name(&dev->dev), - &dev->cfg_access_key, 0); + lockdep_init_map(&dev->cfg_access_lock, "&dev->cfg_access_lock", + &cfg_access_key, 0); dma_set_max_seg_size(&dev->dev, 65536); dma_set_seg_boundary(&dev->dev, 0xffffffff); diff --git a/include/linux/pci.h b/include/linux/pci.h index fb004fd4e889..5bece7fd11f8 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -413,7 +413,6 @@ struct pci_dev { struct resource driver_exclusive_resource; /* driver exclusive resource ranges */ bool match_driver; /* Skip attaching driver */ - struct lock_class_key cfg_access_key; struct lockdep_map cfg_access_lock; unsigned int transparent:1; /* Subtractive decode bridge */ -- cgit v1.2.3