linux-kernel - [PATCH V5 18/21] RISC-V: time.c: Add ACPI support for time

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230508115237.216337-19-sunilvl@ventanamicro.com>
Date:   Mon,  8 May 2023 17:22:34 +0530
From:   Sunil V L <sunilvl@...tanamicro.com>
To:     linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-riscv@...ts.infradead.org, linux-acpi@...r.kernel.org,
        linux-crypto@...r.kernel.org, platform-driver-x86@...r.kernel.org,
        llvm@...ts.linux.dev
Cc:     Jonathan Corbet <corbet@....net>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        "Rafael J . Wysocki" <rafael@...nel.org>,
        Len Brown <lenb@...nel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Weili Qian <qianweili@...wei.com>,
        Zhou Wang <wangzhou1@...ilicon.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        "David S . Miller" <davem@...emloft.net>,
        Marc Zyngier <maz@...nel.org>,
        Maximilian Luz <luzmaximilian@...il.com>,
        Hans de Goede <hdegoede@...hat.com>,
        Mark Gross <markgross@...nel.org>,
        Nathan Chancellor <nathan@...nel.org>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Tom Rix <trix@...hat.com>,
        Sunil V L <sunilvl@...tanamicro.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        Andrew Jones <ajones@...tanamicro.com>,
        Conor Dooley <conor.dooley@...rochip.com>
Subject: [PATCH V5 18/21] RISC-V: time.c: Add ACPI support for time_init()

On ACPI based platforms, timer related information is
available in RHCT. Add ACPI based probe support to the
timer initialization.

Signed-off-by: Sunil V L <sunilvl@...tanamicro.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Reviewed-by: Andrew Jones <ajones@...tanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@...rochip.com>
---
 arch/riscv/kernel/time.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/arch/riscv/kernel/time.c b/arch/riscv/kernel/time.c
index babaf3b48ba8..23641e82a9df 100644
--- a/arch/riscv/kernel/time.c
+++ b/arch/riscv/kernel/time.c
@@ -4,6 +4,7 @@
  * Copyright (C) 2017 SiFive
  */
 
+#include <linux/acpi.h>
 #include <linux/of_clk.h>
 #include <linux/clockchips.h>
 #include <linux/clocksource.h>
@@ -18,17 +19,29 @@ EXPORT_SYMBOL_GPL(riscv_timebase);
 void __init time_init(void)
 {
 	struct device_node *cpu;
+	struct acpi_table_rhct *rhct;
+	acpi_status status;
 	u32 prop;
 
-	cpu = of_find_node_by_path("/cpus");
-	if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
-		panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
-	of_node_put(cpu);
-	riscv_timebase = prop;
+	if (acpi_disabled) {
+		cpu = of_find_node_by_path("/cpus");
+		if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
+			panic("RISC-V system with no 'timebase-frequency' in DTS\n");
+
+		of_node_put(cpu);
+		riscv_timebase = prop;
+		of_clk_init(NULL);
+	} else {
+		status = acpi_get_table(ACPI_SIG_RHCT, 0, (struct acpi_table_header **)&rhct);
+		if (ACPI_FAILURE(status))
+			panic("RISC-V ACPI system with no RHCT table\n");
+
+		riscv_timebase = rhct->time_base_freq;
+		acpi_put_table((struct acpi_table_header *)rhct);
+	}
 
 	lpj_fine = riscv_timebase / HZ;
 
-	of_clk_init(NULL);
 	timer_probe();
 
 	tick_setup_hrtimer_broadcast();
-- 
2.34.1