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, 74 insertions, 0 deletions

diff --git a/lib/crypto/mips/sha512.h b/lib/crypto/mips/sha512.h
new file mode 100644
index 000000000..b3ffbc1e8
--- /dev/null
+++ b/lib/crypto/mips/sha512.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Cryptographic API.
+ *
+ * SHA-512 and SHA-384 Secure Hash Algorithm.
+ *
+ * Adapted for OCTEON by Aaro Koskinen <aaro.koskinen@iki.fi>.
+ *
+ * Based on crypto/sha512_generic.c, which is:
+ *
+ * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
+ * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
+ * Copyright (c) 2003 Kyle McMartin <kyle@debian.org>
+ */
+
+#include <asm/octeon/crypto.h>
+#include <asm/octeon/octeon.h>
+
+/*
+ * We pass everything as 64-bit. OCTEON can handle misaligned data.
+ */
+
+static void sha512_blocks(struct sha512_block_state *state,
+			  const u8 *data, size_t nblocks)
+{
+	struct octeon_cop2_state cop2_state;
+	unsigned long flags;
+
+	if (!octeon_has_crypto())
+		return sha512_blocks_generic(state, data, nblocks);
+
+	flags = octeon_crypto_enable(&cop2_state);
+	write_octeon_64bit_hash_sha512(state->h[0], 0);
+	write_octeon_64bit_hash_sha512(state->h[1], 1);
+	write_octeon_64bit_hash_sha512(state->h[2], 2);
+	write_octeon_64bit_hash_sha512(state->h[3], 3);
+	write_octeon_64bit_hash_sha512(state->h[4], 4);
+	write_octeon_64bit_hash_sha512(state->h[5], 5);
+	write_octeon_64bit_hash_sha512(state->h[6], 6);
+	write_octeon_64bit_hash_sha512(state->h[7], 7);
+
+	do {
+		const u64 *block = (const u64 *)data;
+
+		write_octeon_64bit_block_sha512(block[0], 0);
+		write_octeon_64bit_block_sha512(block[1], 1);
+		write_octeon_64bit_block_sha512(block[2], 2);
+		write_octeon_64bit_block_sha512(block[3], 3);
+		write_octeon_64bit_block_sha512(block[4], 4);
+		write_octeon_64bit_block_sha512(block[5], 5);
+		write_octeon_64bit_block_sha512(block[6], 6);
+		write_octeon_64bit_block_sha512(block[7], 7);
+		write_octeon_64bit_block_sha512(block[8], 8);
+		write_octeon_64bit_block_sha512(block[9], 9);
+		write_octeon_64bit_block_sha512(block[10], 10);
+		write_octeon_64bit_block_sha512(block[11], 11);
+		write_octeon_64bit_block_sha512(block[12], 12);
+		write_octeon_64bit_block_sha512(block[13], 13);
+		write_octeon_64bit_block_sha512(block[14], 14);
+		octeon_sha512_start(block[15]);
+
+		data += SHA512_BLOCK_SIZE;
+	} while (--nblocks);
+
+	state->h[0] = read_octeon_64bit_hash_sha512(0);
+	state->h[1] = read_octeon_64bit_hash_sha512(1);
+	state->h[2] = read_octeon_64bit_hash_sha512(2);
+	state->h[3] = read_octeon_64bit_hash_sha512(3);
+	state->h[4] = read_octeon_64bit_hash_sha512(4);
+	state->h[5] = read_octeon_64bit_hash_sha512(5);
+	state->h[6] = read_octeon_64bit_hash_sha512(6);
+	state->h[7] = read_octeon_64bit_hash_sha512(7);
+	octeon_crypto_disable(&cop2_state, flags);
+}