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authorYazen Ghannam <yazen.ghannam@amd.com>2026-09-03 10:43:25 -0500
committerBorislav Petkov (AMD) <bp@alien8.de>2026-09-10 18:05:43 -0700
commit27600805e62f800bacf990354632eae4e487d34c (patch)
treee8aec0ddfaa0bc264d79af632e3de3f1b75ae4c8 /arch/alpha/boot/head.S
downloadlinux-stable-27600805e62f800bacf990354632eae4e487d34c.tar.gz
linux-stable-27600805e62f800bacf990354632eae4e487d34c.zip
x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted
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 <sashiko-bot@kernel.org> Assisted-by: LLM Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org> Cc: <stable@kernel.org> Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com
Diffstat (limited to 'arch/alpha/boot/head.S')
-rw-r--r--arch/alpha/boot/head.S124
1 files changed, 124 insertions, 0 deletions
diff --git a/arch/alpha/boot/head.S b/arch/alpha/boot/head.S
new file mode 100644
index 000000000..06a7c95fe
--- /dev/null
+++ b/arch/alpha/boot/head.S
@@ -0,0 +1,124 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * arch/alpha/boot/head.S
+ *
+ * initial bootloader stuff..
+ */
+
+#include <asm/pal.h>
+
+ .set noreorder
+ .globl __start
+ .ent __start
+__start:
+ br $29,2f
+2: ldgp $29,0($29)
+ jsr $26,start_kernel
+ call_pal PAL_halt
+ .end __start
+
+ .align 5
+ .globl wrent
+ .ent wrent
+wrent:
+ .prologue 0
+ call_pal PAL_wrent
+ ret ($26)
+ .end wrent
+
+ .align 5
+ .globl wrkgp
+ .ent wrkgp
+wrkgp:
+ .prologue 0
+ call_pal PAL_wrkgp
+ ret ($26)
+ .end wrkgp
+
+ .align 5
+ .globl switch_to_osf_pal
+ .ent switch_to_osf_pal
+switch_to_osf_pal:
+ subq $30,128,$30
+ .frame $30,128,$26
+ stq $26,0($30)
+ stq $1,8($30)
+ stq $2,16($30)
+ stq $3,24($30)
+ stq $4,32($30)
+ stq $5,40($30)
+ stq $6,48($30)
+ stq $7,56($30)
+ stq $8,64($30)
+ stq $9,72($30)
+ stq $10,80($30)
+ stq $11,88($30)
+ stq $12,96($30)
+ stq $13,104($30)
+ stq $14,112($30)
+ stq $15,120($30)
+ .prologue 0
+
+ stq $30,0($17) /* save KSP in PCB */
+
+ bis $30,$30,$20 /* a4 = KSP */
+ br $17,1f
+
+ ldq $26,0($30)
+ ldq $1,8($30)
+ ldq $2,16($30)
+ ldq $3,24($30)
+ ldq $4,32($30)
+ ldq $5,40($30)
+ ldq $6,48($30)
+ ldq $7,56($30)
+ ldq $8,64($30)
+ ldq $9,72($30)
+ ldq $10,80($30)
+ ldq $11,88($30)
+ ldq $12,96($30)
+ ldq $13,104($30)
+ ldq $14,112($30)
+ ldq $15,120($30)
+ addq $30,128,$30
+ ret ($26)
+1: call_pal PAL_swppal
+ .end switch_to_osf_pal
+
+ .align 3
+ .globl tbi
+ .ent tbi
+tbi:
+ .prologue 0
+ call_pal PAL_tbi
+ ret ($26)
+ .end tbi
+
+ .align 3
+ .globl halt
+ .ent halt
+halt:
+ .prologue 0
+ call_pal PAL_halt
+ .end halt
+
+/* $16 - new stack page */
+ .align 3
+ .globl move_stack
+ .ent move_stack
+move_stack:
+ .prologue 0
+ lda $0, 0x1fff($31)
+ and $0, $30, $1 /* Stack offset */
+ or $1, $16, $16 /* New stack pointer */
+ mov $30, $1
+ mov $16, $2
+1: ldq $3, 0($1) /* Move the stack */
+ addq $1, 8, $1
+ stq $3, 0($2)
+ and $0, $1, $4
+ addq $2, 8, $2
+ bne $4, 1b
+ mov $16, $30
+ ret ($26)
+ .end move_stack