[PATCH 5/5] sparc64: Match the machine description's combined crypto names

[Stian Halseth]

crypto_hwcaps[] is indexed by CFR bit, and mdesc_cpu_hwcap_list() reuses
it to match hwcap-list strings. Those are two different namespaces. CFR
has a bit each for the Montgomery multiply and square, while the machine
description names the pair with one string, so "mont" and "xmont" match
nothing.

Nothing breaks today: any recognised crypto name sets HWCAP_SPARC_CRYPTO,
and a chip offering the Montgomery operations offers "aes" too. It is
still wrong, since a machine description listing only the Montgomery
names would leave HWCAP_SPARC_CRYPTO clear.

Match them from a list of their own rather than adding them to
crypto_hwcaps[], where they would claim a CFR bit that means something
else.

Signed-off-by: Stian Halseth <stian@xxxxxx>
---
 arch/sparc/kernel/setup_64.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/sparc/kernel/setup_64.c b/arch/sparc/kernel/setup_64.c
index 6f3b1d56a8c79..a53fe2d1eabba 100644
--- a/arch/sparc/kernel/setup_64.c
+++ b/arch/sparc/kernel/setup_64.c
@@ -396,6 +396,14 @@ static const char *crypto_hwcaps[] = {
 	"xmpmul", "xmontmul", "xmontsqr",
 };
 
+/* crypto_hwcaps[] is indexed by CFR bit.  The machine description names
+ * the Montgomery operations with one string each where CFR splits them
+ * into a multiply and a square, so those names need a list of their own.
+ */
+static const char * const crypto_mdesc_hwcaps[] __initconst = {
+	"mont", "xmont",
+};
+
 void cpucap_info(struct seq_file *m)
 {
 	unsigned long caps = sparc64_elf_hwcap;
@@ -506,6 +514,12 @@ static unsigned long __init mdesc_cpu_hwcap_list(void)
 				known = true;
 			}
 		}
+		for (i = 0; i < ARRAY_SIZE(crypto_mdesc_hwcaps); i++) {
+			if (!strcmp(prop, crypto_mdesc_hwcaps[i])) {
+				caps |= HWCAP_SPARC_CRYPTO;
+				known = true;
+			}
+		}
 
 		if (!known)
 			pr_info("CPU CAPS: unknown hwcap-list entry '%s'\n",
-- 
2.43.0