arm64: errata: Add KRYO 2XX/3XX/4XX silver cores to Spectre BHB safe list

JIRA: https://issues.redhat.com/browse/RHEL-119900

commit 0c9fc6e
Author: Douglas Anderson <dianders@chromium.org>
Date:   Tue, 7 Jan 2025 12:06:00 -0800

    arm64: errata: Add KRYO 2XX/3XX/4XX silver cores to Spectre BHB safe list

    Qualcomm has confirmed that, much like Cortex A53 and A55, KRYO
    2XX/3XX/4XX silver cores are unaffected by Spectre BHB. Add them to
    the safe list.

    Fixes: 558c303 ("arm64: Mitigate spectre style branch history side channels")
    Cc: stable@vger.kernel.org
    Cc: Scott Bauer <sbauer@quicinc.com>
    Signed-off-by: Douglas Anderson <dianders@chromium.org>
    Acked-by: Trilok Soni <quic_tsoni@quicinc.com>
    Link: https://lore.kernel.org/r/20250107120555.v4.3.Iab8dbfb5c9b1e143e7a29f410bce5f9525a0ba32@changeid
    Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Signed-off-by: Waiman Long <longman@redhat.com>

Author: Waiman-Long

arch/arm64/kernel/proton-pack.c

@@ -854,6 +854,9 @@ static bool is_spectre_bhb_safe(int scope)
 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A510),
 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A520),
 		MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53),
+		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_SILVER),
+		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER),
+		MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER),
 		{},
 	};
 	static bool all_safe = true;