Unverified Commit e2ff8423 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!15816 perf: Configure BRBE correctly on VHE host 

Merge Pull Request from: @zhangqizhi3 
 
The BRBE support backported of v18 didn't configure the BRBCR_EL1
correctly which will miss some key functions like FZP during sampling.

In VHE mode with MDCR_EL2.HPMN set to PMCR_EL0.N, the counters are
controlled by BRBCR_EL1 rather than BRBCR_EL2 (which writes to
BRBCR_EL1 are redirected to). Use the same value for both register
except keep EL1 and EL0 recording disabled in guests. 
 
Link:https://gitee.com/openeuler/kernel/pulls/15816

 

Signed-off-by: default avatarLi Nan <linan122@huawei.com>
parents ffee973a 7d863177

drivers/perf/arm_brbe.c

+15 −0
Original line number Diff line number Diff line
@@ -476,6 +476,16 @@ void armv8pmu_branch_enable(struct perf_event *event) 
	brbcr &= ~BRBCR_ELx_CONFIG_MASK;

	brbcr |= branch_type_to_brbcr(cpuc->brbe_sample_type);

	write_sysreg_s(brbcr, SYS_BRBCR_EL1);



	/*

	 * In VHE mode with MDCR_EL2.HPMN set to PMCR_EL0.N, the counters are

	 * controlled by BRBCR_EL1 rather than BRBCR_EL2 (which writes to

	 * BRBCR_EL1 are redirected to). Use the same value for both register

	 * except keep EL1 and EL0 recording disabled in guests.

	 */

	if (is_kernel_in_hyp_mode())

		write_sysreg_s(brbcr & ~(BRBCR_ELx_ExBRE | BRBCR_ELx_E0BRE), SYS_BRBCR_EL12);



	isb();

}
@@ -494,6 +504,11 @@ void armv8pmu_branch_disable(struct perf_event *event) 
	brbcr &= ~(BRBCR_ELx_E0BRE | BRBCR_ELx_ExBRE);

	brbfcr |= BRBFCR_EL1_PAUSED;

	write_sysreg_s(brbcr, SYS_BRBCR_EL1);



	/* See the comment in armv8pmu_branch_enable() */

	if (is_kernel_in_hyp_mode())

		write_sysreg_s(brbcr, SYS_BRBCR_EL12);



	write_sysreg_s(brbfcr, SYS_BRBFCR_EL1);

	isb();

}