From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- drivers/parisc/wax.c | 140 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 140 insertions(+) create mode 100644 drivers/parisc/wax.c (limited to 'drivers/parisc/wax.c') diff --git a/drivers/parisc/wax.c b/drivers/parisc/wax.c new file mode 100644 index 000000000..a82a5e88e --- /dev/null +++ b/drivers/parisc/wax.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * WAX Device Driver + * + * (c) Copyright 2000 The Puffin Group Inc. + * + * (c) 2000-2023 by Helge Deller + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "gsc.h" + +#define WAX_GSC_IRQ 7 /* Hardcoded Interrupt for GSC */ + +static void wax_choose_irq(struct parisc_device *dev, void *ctrl) +{ + int irq; + + switch (dev->id.sversion) { + case 0x73: irq = 1; break; /* i8042 General */ + case 0x8c: irq = 6; break; /* Serial */ + case 0x90: irq = 10; break; /* EISA */ + default: return; /* Unknown */ + } + + gsc_asic_assign_irq(ctrl, irq, &dev->irq); + + switch (dev->id.sversion) { + case 0x73: irq = 2; break; /* i8042 High-priority */ + case 0x90: irq = 0; break; /* EISA NMI */ + default: return; /* No secondary IRQ */ + } + + gsc_asic_assign_irq(ctrl, irq, &dev->aux_irq); +} + +static void __init +wax_init_irq(struct gsc_asic *wax) +{ + unsigned long base = wax->hpa; + + /* Wax-off */ + gsc_writel(0x00000000, base+OFFSET_IMR); + + /* clear pending interrupts */ + gsc_readl(base+OFFSET_IRR); + + /* We're not really convinced we want to reset the onboard + * devices. Firmware does it for us... + */ + + /* Resets */ +// gsc_writel(0xFFFFFFFF, base+0x1000); /* HIL */ +// gsc_writel(0xFFFFFFFF, base+0x2000); /* RS232-B on Wax */ +} + +static int __init wax_init_chip(struct parisc_device *dev) +{ + struct gsc_asic *wax; + struct parisc_device *parent; + int ret; + + wax = kzalloc_obj(*wax); + if (!wax) + return -ENOMEM; + + wax->name = "wax"; + wax->hpa = dev->hpa.start; + + wax->version = 0; /* gsc_readb(wax->hpa+WAX_VER); */ + printk(KERN_INFO "%s at 0x%lx found.\n", wax->name, wax->hpa); + + /* Stop wax hissing for a bit */ + wax_init_irq(wax); + + /* the IRQ wax should use */ + dev->irq = gsc_claim_irq(&wax->gsc_irq, WAX_GSC_IRQ); + if (dev->irq < 0) { + printk(KERN_ERR "%s(): cannot get GSC irq\n", + __func__); + kfree(wax); + return -EBUSY; + } + + wax->eim = ((u32) wax->gsc_irq.txn_addr) | wax->gsc_irq.txn_data; + + ret = request_irq(wax->gsc_irq.irq, gsc_asic_intr, 0, "wax", wax); + if (ret < 0) { + kfree(wax); + return ret; + } + + /* enable IRQ's for devices below WAX */ + gsc_writel(wax->eim, wax->hpa + OFFSET_IAR); + + /* Done init'ing, register this driver */ + ret = gsc_common_setup(dev, wax); + if (ret) { + kfree(wax); + return ret; + } + + gsc_fixup_irqs(dev, wax, wax_choose_irq); + /* On 715-class machines, Wax EISA is a sibling of Wax, not a child. */ + parent = parisc_parent(dev); + if (parent->id.hw_type != HPHW_IOA) { + gsc_fixup_irqs(parent, wax, wax_choose_irq); + } + + return ret; +} + +static const struct parisc_device_id wax_tbl[] __initconst = { + { HPHW_BA, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0008e }, + { 0, } +}; + +MODULE_DEVICE_TABLE(parisc, wax_tbl); + +static struct parisc_driver wax_driver __refdata = { + .name = "wax", + .id_table = wax_tbl, + .probe = wax_init_chip, +}; + +static int __init wax_init(void) +{ + return register_parisc_driver(&wax_driver); +} +arch_initcall(wax_init); -- cgit v1.3.1