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

1 files changed, 183 insertions, 0 deletions

diff --git a/arch/alpha/lib/memmove.S b/arch/alpha/lib/memmove.S
new file mode 100644
index 000000000..3a27689e3
--- /dev/null
+++ b/arch/alpha/lib/memmove.S
@@ -0,0 +1,183 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * arch/alpha/lib/memmove.S
+ *
+ * Barely optimized memmove routine for Alpha EV5.
+ *
+ * This is hand-massaged output from the original memcpy.c.  We defer to
+ * memcpy whenever possible; the backwards copy loops are not unrolled.
+ */
+#include <linux/export.h>
+	.set noat
+	.set noreorder
+	.text
+
+	.align 4
+	.globl memmove
+	.ent memmove
+memmove:
+	ldgp $29, 0($27)
+	unop
+	nop
+	.prologue 1
+
+	addq $16,$18,$4
+	addq $17,$18,$5
+	cmpule $4,$17,$1		/*  dest + n <= src  */
+	cmpule $5,$16,$2		/*  dest >= src + n  */
+
+	bis $1,$2,$1
+	mov $16,$0
+	xor $16,$17,$2
+	bne $1,memcpy			!samegp
+
+	and $2,7,$2			/* Test for src/dest co-alignment.  */
+	and $16,7,$1
+	cmpule $16,$17,$3
+	bne $3,$memmove_up		/* dest < src */
+
+	and $4,7,$1
+	bne $2,$misaligned_dn
+	unop
+	beq $1,$skip_aligned_byte_loop_head_dn
+
+$aligned_byte_loop_head_dn:
+	lda $4,-1($4)
+	lda $5,-1($5)
+	unop
+	ble $18,$egress
+
+	ldq_u $3,0($5)
+	ldq_u $2,0($4)
+	lda $18,-1($18)
+	extbl $3,$5,$1
+
+	insbl $1,$4,$1
+	mskbl $2,$4,$2
+	bis $1,$2,$1
+	and $4,7,$6
+
+	stq_u $1,0($4)
+	bne $6,$aligned_byte_loop_head_dn
+
+$skip_aligned_byte_loop_head_dn:
+	lda $18,-8($18)
+	blt $18,$skip_aligned_word_loop_dn
+
+$aligned_word_loop_dn:
+	ldq $1,-8($5)
+	nop
+	lda $5,-8($5)
+	lda $18,-8($18)
+
+	stq $1,-8($4)
+	nop
+	lda $4,-8($4)
+	bge $18,$aligned_word_loop_dn
+
+$skip_aligned_word_loop_dn:
+	lda $18,8($18)
+	bgt $18,$byte_loop_tail_dn
+	unop
+	ret $31,($26),1
+
+	.align 4
+$misaligned_dn:
+	nop
+	fnop
+	unop
+	beq $18,$egress
+
+$byte_loop_tail_dn:
+	ldq_u $3,-1($5)
+	ldq_u $2,-1($4)
+	lda $5,-1($5)
+	lda $4,-1($4)
+
+	lda $18,-1($18)
+	extbl $3,$5,$1
+	insbl $1,$4,$1
+	mskbl $2,$4,$2
+
+	bis $1,$2,$1
+	stq_u $1,0($4)
+	bgt $18,$byte_loop_tail_dn
+	br $egress
+
+$memmove_up:
+	mov $16,$4
+	mov $17,$5
+	bne $2,$misaligned_up
+	beq $1,$skip_aligned_byte_loop_head_up
+
+$aligned_byte_loop_head_up:
+	unop
+	ble $18,$egress
+	ldq_u $3,0($5)
+	ldq_u $2,0($4)
+
+	lda $18,-1($18)
+	extbl $3,$5,$1
+	insbl $1,$4,$1
+	mskbl $2,$4,$2
+
+	bis $1,$2,$1
+	lda $5,1($5)
+	stq_u $1,0($4)
+	lda $4,1($4)
+
+	and $4,7,$6
+	bne $6,$aligned_byte_loop_head_up
+
+$skip_aligned_byte_loop_head_up:
+	lda $18,-8($18)
+	blt $18,$skip_aligned_word_loop_up
+
+$aligned_word_loop_up:
+	ldq $1,0($5)
+	nop
+	lda $5,8($5)
+	lda $18,-8($18)
+
+	stq $1,0($4)
+	nop
+	lda $4,8($4)
+	bge $18,$aligned_word_loop_up
+
+$skip_aligned_word_loop_up:
+	lda $18,8($18)
+	bgt $18,$byte_loop_tail_up
+	unop
+	ret $31,($26),1
+
+	.align 4
+$misaligned_up:
+	nop
+	fnop
+	unop
+	beq $18,$egress
+
+$byte_loop_tail_up:
+	ldq_u $3,0($5)
+	ldq_u $2,0($4)
+	lda $18,-1($18)
+	extbl $3,$5,$1
+
+	insbl $1,$4,$1
+	mskbl $2,$4,$2
+	bis $1,$2,$1
+	stq_u $1,0($4)
+
+	lda $5,1($5)
+	lda $4,1($4)
+	nop
+	bgt $18,$byte_loop_tail_up
+
+$egress:
+	ret $31,($26),1
+	nop
+	nop
+	nop
+
+	.end memmove
+	EXPORT_SYMBOL(memmove)