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/firmware/efi/fdtparams.c | 133 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) create mode 100644 drivers/firmware/efi/fdtparams.c (limited to 'drivers/firmware/efi/fdtparams.c') diff --git a/drivers/firmware/efi/fdtparams.c b/drivers/firmware/efi/fdtparams.c new file mode 100644 index 000000000..b815d2a75 --- /dev/null +++ b/drivers/firmware/efi/fdtparams.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#define pr_fmt(fmt) "efi: " fmt + +#include +#include +#include +#include +#include + +#include + +enum { + SYSTAB, + MMBASE, + MMSIZE, + DCSIZE, + DCVERS, + + PARAMCOUNT +}; + +static __initconst const char name[][22] = { + [SYSTAB] = "System Table ", + [MMBASE] = "MemMap Address ", + [MMSIZE] = "MemMap Size ", + [DCSIZE] = "MemMap Desc. Size ", + [DCVERS] = "MemMap Desc. Version ", +}; + +static __initconst const struct { + const char path[17]; + u8 paravirt; + const char params[PARAMCOUNT][26]; +} dt_params[] = { + { +#ifdef CONFIG_XEN // <-------17------> + .path = "/hypervisor/uefi", + .paravirt = 1, + .params = { + [SYSTAB] = "xen,uefi-system-table", + [MMBASE] = "xen,uefi-mmap-start", + [MMSIZE] = "xen,uefi-mmap-size", + [DCSIZE] = "xen,uefi-mmap-desc-size", + [DCVERS] = "xen,uefi-mmap-desc-ver", + } + }, { +#endif + .path = "/chosen", + .params = { // <-----------26-----------> + [SYSTAB] = "linux,uefi-system-table", + [MMBASE] = "linux,uefi-mmap-start", + [MMSIZE] = "linux,uefi-mmap-size", + [DCSIZE] = "linux,uefi-mmap-desc-size", + [DCVERS] = "linux,uefi-mmap-desc-ver", + } + } +}; + +static int __init efi_get_fdt_prop(const void *fdt, int node, const char *pname, + const char *rname, void *var, int size) +{ + const void *prop; + int len; + u64 val; + + prop = fdt_getprop(fdt, node, pname, &len); + if (!prop) + return 1; + + val = (len == 4) ? (u64)be32_to_cpup(prop) : get_unaligned_be64(prop); + + if (size == 8) + *(u64 *)var = val; + else + *(u32 *)var = (val < U32_MAX) ? val : U32_MAX; // saturate + + if (efi_enabled(EFI_DBG)) + pr_info(" %s: 0x%0*llx\n", rname, size * 2, val); + + return 0; +} + +u64 __init efi_get_fdt_params(struct efi_memory_map_data *mm) +{ + const void *fdt = initial_boot_params; + unsigned long systab; + int i, j, node; + struct { + void *var; + int size; + } target[] = { + [SYSTAB] = { &systab, sizeof(systab) }, + [MMBASE] = { &mm->phys_map, sizeof(mm->phys_map) }, + [MMSIZE] = { &mm->size, sizeof(mm->size) }, + [DCSIZE] = { &mm->desc_size, sizeof(mm->desc_size) }, + [DCVERS] = { &mm->desc_version, sizeof(mm->desc_version) }, + }; + + BUILD_BUG_ON(ARRAY_SIZE(target) != ARRAY_SIZE(name)); + BUILD_BUG_ON(ARRAY_SIZE(target) != ARRAY_SIZE(dt_params[0].params)); + + if (!fdt) + return 0; + + for (i = 0; i < ARRAY_SIZE(dt_params); i++) { + node = fdt_path_offset(fdt, dt_params[i].path); + if (node < 0) + continue; + + if (efi_enabled(EFI_DBG)) + pr_info("Getting UEFI parameters from %s in DT:\n", + dt_params[i].path); + + for (j = 0; j < ARRAY_SIZE(target); j++) { + const char *pname = dt_params[i].params[j]; + + if (!efi_get_fdt_prop(fdt, node, pname, name[j], + target[j].var, target[j].size)) + continue; + if (!j) + goto notfound; + pr_err("Can't find property '%s' in DT!\n", pname); + return 0; + } + if (dt_params[i].paravirt) + set_bit(EFI_PARAVIRT, &efi.flags); + return systab; + } +notfound: + pr_info("UEFI not found.\n"); + return 0; +} -- cgit v1.3.1