[20/21] riscv: Switch over to GENERIC_CPU_DEVICES

Message ID	E1r5R4G-00Ct0M-PS@rmk-PC.armlinux.org.uk
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Headers	show Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="yzid5gv5" In-Reply-To: <ZVyz/Ve5pPu8AWoA@shell.armlinux.org.uk> References: <ZVyz/Ve5pPu8AWoA@shell.armlinux.org.uk> From: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> To: linux-pm@vger.kernel.org, loongarch@lists.linux.dev, linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, kvmarm@lists.linux.dev, x86@kernel.org, linux-csky@vger.kernel.org, linux-doc@vger.kernel.org, linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org Cc: Salil Mehta <salil.mehta@huawei.com>, Jean-Philippe Brucker <jean-philippe@linaro.org>, jianyong.wu@arm.com, justin.he@arm.com, James Morse <james.morse@arm.com>, Paul Walmsley <paul.walmsley@sifive.com>, Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu> Subject: [PATCH 20/21] riscv: Switch over to GENERIC_CPU_DEVICES Precedence: bulk MIME-Version: 1.0 Content-Disposition: inline Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="utf-8" Message-Id: <E1r5R4G-00Ct0M-PS@rmk-PC.armlinux.org.uk> Sender: Russell King <rmk@armlinux.org.uk> Date: Tue, 21 Nov 2023 13:45:32 +0000
Series	Initial cleanups for vCPU hotplug \| expand [00/21] Initial cleanups for vCPU hotplug [01/21] arch_topology: Make register_cpu_capacity_sysctl() tolerant to late CPUs [02/21] x86: intel_epb: Don't rely on link order [03/21] x86/topology: remove arch_register_cpu() exports [04/21] Loongarch: remove arch_register_cpu() exports [05/21] ACPI: Move ACPI_HOTPLUG_CPU to be disabled on arm64 and riscv [06/21] drivers: base: Use present CPUs in GENERIC_CPU_DEVICES [07/21] drivers: base: Allow parts of GENERIC_CPU_DEVICES to be overridden [08/21] drivers: base: Implement weak arch_unregister_cpu() [09/21] drivers: base: add arch_cpu_is_hotpluggable() [10/21] drivers: base: Move cpu_dev_init() after node_dev_init() [11/21] drivers: base: Print a warning instead of panic() when register_cpu() fails [12/21] arm64: setup: Switch over to GENERIC_CPU_DEVICES using arch_register_cpu() [13/21] arm64: convert to arch_cpu_is_hotpluggable() [14/21] x86/topology: Switch over to GENERIC_CPU_DEVICES [15/21] x86/topology: use weak version of arch_unregister_cpu() [16/21] x86/topology: convert to use arch_cpu_is_hotpluggable() [17/21] LoongArch: Switch over to GENERIC_CPU_DEVICES [18/21] LoongArch: Use the __weak version of arch_unregister_cpu() [19/21] LoongArch: convert to use arch_cpu_is_hotpluggable() [20/21] riscv: Switch over to GENERIC_CPU_DEVICES [21/21] riscv: convert to use arch_cpu_is_hotpluggable()

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E1r5R4G-00Ct0M-PS@rmk-PC.armlinux.org.uk

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In-Reply-To: <ZVyz/Ve5pPu8AWoA@shell.armlinux.org.uk>
References: <ZVyz/Ve5pPu8AWoA@shell.armlinux.org.uk>
From: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
To: linux-pm@vger.kernel.org,
	 loongarch@lists.linux.dev,
	 linux-acpi@vger.kernel.org,
	 linux-arch@vger.kernel.org,
	 linux-kernel@vger.kernel.org,
	 linux-arm-kernel@lists.infradead.org,
	 linux-riscv@lists.infradead.org,
	 kvmarm@lists.linux.dev,
	 x86@kernel.org,
	 linux-csky@vger.kernel.org,
	 linux-doc@vger.kernel.org,
	 linux-ia64@vger.kernel.org,
	 linux-parisc@vger.kernel.org
Cc: Salil Mehta <salil.mehta@huawei.com>,
	 Jean-Philippe Brucker <jean-philippe@linaro.org>,
	 jianyong.wu@arm.com,
	 justin.he@arm.com,
	 James Morse <james.morse@arm.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>
Subject: [PATCH 20/21] riscv: Switch over to GENERIC_CPU_DEVICES
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Sender: Russell King <rmk@armlinux.org.uk>
Date: Tue, 21 Nov 2023 13:45:32 +0000

Series

Initial cleanups for vCPU hotplug | expand

Commit Message

Russell King (Oracle) Nov. 21, 2023, 1:45 p.m. UTC

From: James Morse <james.morse@arm.com>

Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be
overridden by the arch code, switch over to this to allow common code
to choose when the register_cpu() call is made.

This allows topology_init() to be removed.

This is an intermediate step to the logic being moved to drivers/acpi,
where GENERIC_CPU_DEVICES will do the work when booting with acpi=off.

This patch also has the effect of moving the registration of CPUs from
subsys to driver core initialisation, prior to any initcalls running.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
Changes since RFC v2:
 * Add note about initialisation order change.
---
 arch/riscv/Kconfig        |  1 +
 arch/riscv/kernel/setup.c | 19 ++++---------------
 2 files changed, 5 insertions(+), 15 deletions(-)

Comments

Samuel Holland Nov. 22, 2023, 8:05 p.m. UTC | #1

On 2023-11-21 7:45 AM, Russell King (Oracle) wrote:
> From: James Morse <james.morse@arm.com>
> 
> Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be
> overridden by the arch code, switch over to this to allow common code
> to choose when the register_cpu() call is made.
> 
> This allows topology_init() to be removed.
> 
> This is an intermediate step to the logic being moved to drivers/acpi,
> where GENERIC_CPU_DEVICES will do the work when booting with acpi=off.
> 
> This patch also has the effect of moving the registration of CPUs from
> subsys to driver core initialisation, prior to any initcalls running.
> 
> Signed-off-by: James Morse <james.morse@arm.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
> Reviewed-by: Gavin Shan <gshan@redhat.com>
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> ---
> Changes since RFC v2:
>  * Add note about initialisation order change.
> ---
>  arch/riscv/Kconfig        |  1 +
>  arch/riscv/kernel/setup.c | 19 ++++---------------
>  2 files changed, 5 insertions(+), 15 deletions(-)

Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 95a2a06acc6a..162425cb9739 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -71,6 +71,7 @@  config RISCV
 	select GENERIC_ARCH_TOPOLOGY
 	select GENERIC_ATOMIC64 if !64BIT
 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
+	select GENERIC_CPU_DEVICES
 	select GENERIC_EARLY_IOREMAP
 	select GENERIC_ENTRY
 	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 535a837de55d..b3a0aa2b78d5 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -51,7 +51,6 @@  atomic_t hart_lottery __section(".sdata")
 #endif
 ;
 unsigned long boot_cpu_hartid;
-static DEFINE_PER_CPU(struct cpu, cpu_devices);
 
 /*
  * Place kernel memory regions on the resource tree so that
@@ -299,23 +298,13 @@  void __init setup_arch(char **cmdline_p)
 	riscv_user_isa_enable();
 }
 
-static int __init topology_init(void)
+int arch_register_cpu(int cpu)
 {
-	int i, ret;
+	struct cpu *c = &per_cpu(cpu_devices, cpu);
 
-	for_each_possible_cpu(i) {
-		struct cpu *cpu = &per_cpu(cpu_devices, i);
-
-		cpu->hotpluggable = cpu_has_hotplug(i);
-		ret = register_cpu(cpu, i);
-		if (unlikely(ret))
-			pr_warn("Warning: %s: register_cpu %d failed (%d)\n",
-			       __func__, i, ret);
-	}
-
-	return 0;
+	c->hotpluggable = cpu_has_hotplug(cpu);
+	return register_cpu(c, cpu);
 }
-subsys_initcall(topology_init);
 
 void free_initmem(void)
 {

[20/21] riscv: Switch over to GENERIC_CPU_DEVICES

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