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/hppb.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 105 insertions(+) create mode 100644 drivers/parisc/hppb.c (limited to 'drivers/parisc/hppb.c') diff --git a/drivers/parisc/hppb.c b/drivers/parisc/hppb.c new file mode 100644 index 000000000..33709eafe --- /dev/null +++ b/drivers/parisc/hppb.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* +** hppb.c: +** HP-PB bus driver for the NOVA and K-Class systems. +** +** (c) Copyright 2002 Ryan Bradetich +** (c) Copyright 2002 Hewlett-Packard Company +** +** +*/ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include "iommu.h" + +struct hppb_card { + unsigned long hpa; + struct resource mmio_region; + struct hppb_card *next; +}; + +static struct hppb_card hppb_card_head = { + .hpa = 0, + .next = NULL, +}; + +#define IO_IO_LOW offsetof(struct bc_module, io_io_low) +#define IO_IO_HIGH offsetof(struct bc_module, io_io_high) + +/** + * hppb_probe - Determine if the hppb driver should claim this device. + * @dev: The device which has been found + * + * Determine if hppb driver should claim this chip (return 0) or not + * (return 1). If so, initialize the chip and tell other partners in crime + * they have work to do. + */ +static int __init hppb_probe(struct parisc_device *dev) +{ + int status; + struct hppb_card *card = &hppb_card_head; + + while(card->next) { + card = card->next; + } + + if(card->hpa) { + card->next = kzalloc_obj(struct hppb_card); + if(!card->next) { + printk(KERN_ERR "HP-PB: Unable to allocate memory.\n"); + return 1; + } + card = card->next; + } + + card->hpa = dev->hpa.start; + card->mmio_region.name = "HP-PB Bus"; + card->mmio_region.flags = IORESOURCE_MEM; + + card->mmio_region.start = gsc_readl(dev->hpa.start + IO_IO_LOW); + card->mmio_region.end = gsc_readl(dev->hpa.start + IO_IO_HIGH) - 1; + + status = ccio_request_resource(dev, &card->mmio_region); + + pr_info("Found GeckoBoa at %pap, bus space %pR,%s claimed.\n", + &dev->hpa.start, + &card->mmio_region, + (status < 0) ? " not":"" ); + + return 0; +} + +static const struct parisc_device_id hppb_tbl[] __initconst = { + { HPHW_BCPORT, HVERSION_REV_ANY_ID, 0x500, 0xc }, /* E25 and K */ + { HPHW_BCPORT, 0x0, 0x501, 0xc }, /* E35 */ + { HPHW_BCPORT, 0x0, 0x502, 0xc }, /* E45 */ + { HPHW_BCPORT, 0x0, 0x503, 0xc }, /* E55 */ + { 0, } +}; + +static struct parisc_driver hppb_driver __refdata = { + .name = "gecko_boa", + .id_table = hppb_tbl, + .probe = hppb_probe, +}; + +/** + * hppb_init - HP-PB bus initialization procedure. + * + * Register this driver. + */ +static int __init hppb_init(void) +{ + return register_parisc_driver(&hppb_driver); +} +arch_initcall(hppb_init); -- cgit v1.3.1