diff options
Diffstat (limited to 'lib/el3_runtime/aarch64/context.S')
| -rw-r--r-- | lib/el3_runtime/aarch64/context.S | 65 |
1 files changed, 59 insertions, 6 deletions
diff --git a/lib/el3_runtime/aarch64/context.S b/lib/el3_runtime/aarch64/context.S index e6ab19bc..53dc02e6 100644 --- a/lib/el3_runtime/aarch64/context.S +++ b/lib/el3_runtime/aarch64/context.S @@ -24,9 +24,45 @@ .global save_gp_registers .global restore_gp_registers .global restore_gp_registers_eret + .global save_pmcr_disable_pmu .global el3_exit /* ----------------------------------------------------- + * If ARMv8.5-PMU is implemented, cycle counting is + * disabled by seting MDCR_EL3.SCCD to 1. + * ----------------------------------------------------- + */ +func save_pmcr_disable_pmu + /* ----------------------------------------------------- + * Check if earlier initialization MDCR_EL3.SCCD to 1 + * failed, meaning that ARMv8-PMU is not implemented and + * PMCR_EL0 should be saved in non-secure context. + * ----------------------------------------------------- + */ + mrs x9, mdcr_el3 + tst x9, #MDCR_SCCD_BIT + bne 1f + + /* Secure Cycle Counter is not disabled */ + mrs x9, pmcr_el0 + + /* Check caller's security state */ + mrs x10, scr_el3 + tst x10, #SCR_NS_BIT + beq 2f + + /* Save PMCR_EL0 if called from Non-secure state */ + str x9, [sp, #CTX_EL3STATE_OFFSET + CTX_PMCR_EL0] + + /* Disable cycle counter when event counting is prohibited */ +2: orr x9, x9, #PMCR_EL0_DP_BIT + msr pmcr_el0, x9 + + isb +1: ret +endfunc save_pmcr_disable_pmu + +/* ----------------------------------------------------- * The following function strictly follows the AArch64 * PCS to use x9-x17 (temporary caller-saved registers) * to save EL1 system register context. It assumes that @@ -80,9 +116,6 @@ func el1_sysregs_context_save mrs x9, vbar_el1 stp x17, x9, [x0, #CTX_CONTEXTIDR_EL1] - mrs x10, pmcr_el0 - str x10, [x0, #CTX_PMCR_EL0] - /* Save AArch32 system registers if the build has instructed so */ #if CTX_INCLUDE_AARCH32_REGS mrs x11, spsr_abt @@ -169,9 +202,6 @@ func el1_sysregs_context_restore msr contextidr_el1, x17 msr vbar_el1, x9 - ldr x10, [x0, #CTX_PMCR_EL0] - msr pmcr_el0, x10 - /* Restore AArch32 system registers if the build has instructed so */ #if CTX_INCLUDE_AARCH32_REGS ldp x11, x12, [x0, #CTX_SPSR_ABT] @@ -503,6 +533,29 @@ func el3_exit msr spsr_el3, x16 msr elr_el3, x17 + /* ----------------------------------------------------- + * Restore PMCR_EL0 when returning to Non-secure state + * if Secure Cycle Counter is not disabled in MDCR_EL3 + * when ARMv8.5-PMU is implemented + * ----------------------------------------------------- + */ + tst x18, #SCR_NS_BIT + beq 2f + + /* ----------------------------------------------------- + * Back to Non-secure state. + * Check if earlier initialization MDCR_EL3.SCCD to 1 + * failed, meaning that ARMv8-PMU is not implemented and + * PMCR_EL0 should be restored from non-secure context. + * ----------------------------------------------------- + */ + mrs x17, mdcr_el3 + tst x17, #MDCR_SCCD_BIT + bne 2f + ldr x17, [sp, #CTX_EL3STATE_OFFSET + CTX_PMCR_EL0] + msr pmcr_el0, x17 +2: + #if IMAGE_BL31 && DYNAMIC_WORKAROUND_CVE_2018_3639 /* Restore mitigation state as it was on entry to EL3 */ ldr x17, [sp, #CTX_CVE_2018_3639_OFFSET + CTX_CVE_2018_3639_DISABLE] |