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From:   Atish Patra <atishp@rivosinc.com>
To:     linux-kernel@vger.kernel.org
Cc:     Atish Patra <atishp@rivosinc.com>,
        Alexandre Ghiti <alexghiti@rivosinc.com>,
        Andrew Jones <ajones@ventanamicro.com>,
        Anup Patel <anup@brainfault.org>,
        Atish Patra <atishp@atishpatra.org>,
        Conor Dooley <conor.dooley@microchip.com>,
        Guo Ren <guoren@kernel.org>, Icenowy Zheng <uwu@icenowy.me>,
        kvm-riscv@lists.infradead.org, kvm@vger.kernel.org,
        linux-riscv@lists.infradead.org,
        Mark Rutland <mark.rutland@arm.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Will Deacon <will@kernel.org>
Subject: [RFC 2/9] drivers/perf: riscv: Add a flag to indicate SBI v2.0 support
Date:   Mon,  4 Dec 2023 18:43:03 -0800
Message-Id: <20231205024310.1593100-3-atishp@rivosinc.com>
In-Reply-To: <20231205024310.1593100-1-atishp@rivosinc.com>
References: <20231205024310.1593100-1-atishp@rivosinc.com>
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SBI v2.0 added few functions to improve SBI PMU extension. In order
to be backward compatible, the driver must use these functions only
if SBI v2.0 is available.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 drivers/perf/riscv_pmu_sbi.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index 16acd4dcdb96..40a335350d08 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -35,6 +35,8 @@
 PMU_FORMAT_ATTR(event, "config:0-47");
 PMU_FORMAT_ATTR(firmware, "config:63");
 
+static bool sbi_v2_available;
+
 static struct attribute *riscv_arch_formats_attr[] = {
 	&format_attr_event.attr,
 	&format_attr_firmware.attr,
@@ -1108,6 +1110,9 @@ static int __init pmu_sbi_devinit(void)
 		return 0;
 	}
 
+	if (sbi_spec_version >= sbi_mk_version(2, 0))
+		sbi_v2_available = true;
+
 	ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_RISCV_STARTING,
 				      "perf/riscv/pmu:starting",
 				      pmu_sbi_starting_cpu, pmu_sbi_dying_cpu);
-- 
2.34.1