From: Koichiro Den Date: Wed, 4 Mar 2026 08:30:28 +0000 (+0900) Subject: NTB: epf: Avoid calling pci_irq_vector() from hardirq context X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4dcddc1c794d1c65eda68f1f8dd04a0fecc0870f;p=thirdparty%2Flinux.git NTB: epf: Avoid calling pci_irq_vector() from hardirq context ntb_epf_vec_isr() calls pci_irq_vector() in hardirq context to derive the vector number. pci_irq_vector() calls msi_get_virq() that takes a mutex and can therefore trigger "scheduling while atomic" splats: BUG: scheduling while atomic: kworker/u33:0/55/0x00010001 ... Call trace: ... schedule+0x38/0x110 schedule_preempt_disabled+0x28/0x50 __mutex_lock.constprop.0+0x848/0x908 __mutex_lock_slowpath+0x18/0x30 mutex_lock+0x4c/0x60 msi_domain_get_virq+0xe8/0x138 pci_irq_vector+0x2c/0x60 ntb_epf_vec_isr+0x28/0x120 [ntb_hw_epf] __handle_irq_event_percpu+0x70/0x3a8 handle_irq_event+0x48/0x100 handle_edge_irq+0x100/0x1c8 ... Cache the Linux IRQ number for vector 0 when vectors are allocated and use it as a base in the ISR. Running the ISR in a threaded IRQ handler would also avoid the problem, but that would be unnecessary here. Fixes: 812ce2f8d14e ("NTB: Add support for EPF PCI Non-Transparent Bridge") Signed-off-by: Koichiro Den Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Reviewed-by: Dave Jiang Cc: stable@vger.kernel.org # v5.12+ Link: https://patch.msgid.link/20260304083028.1391068-3-den@valinux.co.jp --- diff --git a/drivers/ntb/hw/epf/ntb_hw_epf.c b/drivers/ntb/hw/epf/ntb_hw_epf.c index 5a35f341f821..8925c688930c 100644 --- a/drivers/ntb/hw/epf/ntb_hw_epf.c +++ b/drivers/ntb/hw/epf/ntb_hw_epf.c @@ -92,6 +92,7 @@ struct ntb_epf_dev { int db_val; u64 db_valid_mask; + int irq_base; }; #define ntb_ndev(__ntb) container_of(__ntb, struct ntb_epf_dev, ntb) @@ -318,7 +319,7 @@ static irqreturn_t ntb_epf_vec_isr(int irq, void *dev) struct ntb_epf_dev *ndev = dev; int irq_no; - irq_no = irq - pci_irq_vector(ndev->ntb.pdev, 0); + irq_no = irq - ndev->irq_base; ndev->db_val = irq_no + 1; if (irq_no == 0) @@ -350,6 +351,7 @@ static int ntb_epf_init_isr(struct ntb_epf_dev *ndev, int msi_min, int msi_max) argument &= ~MSIX_ENABLE; } + ndev->irq_base = pci_irq_vector(pdev, 0); for (i = 0; i < irq; i++) { ret = request_irq(pci_irq_vector(pdev, i), ntb_epf_vec_isr, 0, "ntb_epf", ndev);