diff mbox series

[1/3] arm64: proton-pack: Move the loop and firmware enable sequences into helpers

Message ID 20250122174736.1560714-2-james.morse@arm.com (mailing list archive)
State New
Headers show
Series arm64: proton-pack: Add Spectre-BSE mitigation for Cortex-A7{2,3,5} | expand

Commit Message

James Morse Jan. 22, 2025, 5:47 p.m. UTC 
A variant of Spectre-BHB needs to be able to tweak the way the BHB
mitigation is selected. Move the enable routines for the loop and firmware
vectors into helpers.

Signed-off-by: James Morse <james.morse@arm.com>
---
 arch/arm64/kernel/proton-pack.c | 80 +++++++++++++++++++--------------
 1 file changed, 47 insertions(+), 33 deletions(-)
diff mbox series

Patch

diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index da53722f95d4..193f141d4367 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -999,9 +999,53 @@  static int __init parse_spectre_bhb_param(char *str)
 }
 early_param("nospectre_bhb", parse_spectre_bhb_param);
 
-void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry)
+static void spectre_bhb_enable_fw_mitigation(void)
 {
 	bp_hardening_cb_t cpu_cb;
+	struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data);
+
+	/*
+	 * Ensure KVM uses one of the spectre bp_hardening
+	 * vectors. The indirect vector doesn't include the EL3
+	 * call, so needs upgrading to
+	 * HYP_VECTOR_SPECTRE_INDIRECT.
+	 */
+	if (!data->slot || data->slot == HYP_VECTOR_INDIRECT)
+		data->slot += 1;
+
+	this_cpu_set_vectors(EL1_VECTOR_BHB_FW);
+
+	/*
+	 * The WA3 call in the vectors supersedes the WA1 call
+	 * made during context-switch. Uninstall any firmware
+	 * bp_hardening callback.
+	 */
+	cpu_cb = spectre_v2_get_sw_mitigation_cb();
+	if (__this_cpu_read(bp_hardening_data.fn) != cpu_cb)
+		__this_cpu_write(bp_hardening_data.fn, NULL);
+
+	set_bit(BHB_FW, &system_bhb_mitigations);
+}
+
+static void spectre_bhb_enable_loop_mitigation(void)
+{
+	struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data);
+
+	/*
+	 * Ensure KVM uses the indirect vector which will have the
+	 * branchy-loop added. A57/A72-r0 will already have selected
+	 * the spectre-indirect vector, which is sufficient for BHB
+	 * too.
+	 */
+	if (!data->slot)
+		data->slot = HYP_VECTOR_INDIRECT;
+
+	this_cpu_set_vectors(EL1_VECTOR_BHB_LOOP);
+	set_bit(BHB_LOOP, &system_bhb_mitigations);
+}
+
+void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry)
+{
 	enum mitigation_state fw_state, state = SPECTRE_VULNERABLE;
 	struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data);
 
@@ -1029,43 +1073,13 @@  void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry)
 		state = SPECTRE_MITIGATED;
 		set_bit(BHB_INSN, &system_bhb_mitigations);
 	} else if (spectre_bhb_loop_affected(SCOPE_LOCAL_CPU)) {
-		/*
-		 * Ensure KVM uses the indirect vector which will have the
-		 * branchy-loop added. A57/A72-r0 will already have selected
-		 * the spectre-indirect vector, which is sufficient for BHB
-		 * too.
-		 */
-		if (!data->slot)
-			data->slot = HYP_VECTOR_INDIRECT;
-
-		this_cpu_set_vectors(EL1_VECTOR_BHB_LOOP);
+		spectre_bhb_enable_loop_mitigation();
 		state = SPECTRE_MITIGATED;
-		set_bit(BHB_LOOP, &system_bhb_mitigations);
 	} else if (is_spectre_bhb_fw_affected(SCOPE_LOCAL_CPU)) {
 		fw_state = spectre_bhb_get_cpu_fw_mitigation_state();
 		if (fw_state == SPECTRE_MITIGATED) {
-			/*
-			 * Ensure KVM uses one of the spectre bp_hardening
-			 * vectors. The indirect vector doesn't include the EL3
-			 * call, so needs upgrading to
-			 * HYP_VECTOR_SPECTRE_INDIRECT.
-			 */
-			if (!data->slot || data->slot == HYP_VECTOR_INDIRECT)
-				data->slot += 1;
-
-			this_cpu_set_vectors(EL1_VECTOR_BHB_FW);
-
-			/*
-			 * The WA3 call in the vectors supersedes the WA1 call
-			 * made during context-switch. Uninstall any firmware
-			 * bp_hardening callback.
-			 */
-			cpu_cb = spectre_v2_get_sw_mitigation_cb();
-			if (__this_cpu_read(bp_hardening_data.fn) != cpu_cb)
-				__this_cpu_write(bp_hardening_data.fn, NULL);
-
+			spectre_bhb_enable_fw_mitigation();
 			state = SPECTRE_MITIGATED;
-			set_bit(BHB_FW, &system_bhb_mitigations);
 		}
 	}