Re: [RFC PATCH 2/2] arm64: Use SYSTEM_OFF2 PSCI call to power off for hibernate

From: David Woodhouse <dwmw2@infradead.org>
To: Sudeep Holla <sudeep.holla@arm.com>
Cc: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org,
	Paolo Bonzini <pbonzini@redhat.com>,
	Jonathan Corbet <corbet@lwn.net>, Marc Zyngier <maz@kernel.org>,
	Oliver Upton <oliver.upton@linux.dev>,
	James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Zenghui Yu <yuzenghui@huawei.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Lorenzo Pieralisi <lpieralisi@kernel.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>,
	Mostafa Saleh <smostafa@google.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	 linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	kvmarm@lists.linux.dev,  linux-pm@vger.kernel.org
Subject: Re: [RFC PATCH 2/2] arm64: Use SYSTEM_OFF2 PSCI call to power off for hibernate
Date: Tue, 12 Mar 2024 16:36:05 +0000	[thread overview]
Message-ID: <520ce28050c29cca754493f0595d4a64d45796ee.camel@infradead.org> (raw)
In-Reply-To: <ZfB7c9ifUiZR6gy1@bogus>

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On Tue, 2024-03-12 at 15:57 +0000, Sudeep Holla wrote:
> Looked briefly at register_sys_off_handler and it should be OK to call
> it from psci_init_system_off2() below. Any particular reason for having
> separate initcall to do this ? We can even eliminate the need for
> psci_init_system_off2 if it can be called from there. What am I missing ?

My first attempt did that. I don't think we can kmalloc that early:

[    0.000000] psci: SMC Calling Convention v1.1
[    0.000000] Unable to handle kernel read from unreadable memory at virtual address 0000000000000018
[    0.000000] Mem abort info:
[    0.000000]   ESR = 0x0000000096000004
[    0.000000]   EC = 0x25: DABT (current EL), IL = 32 bits
[    0.000000]   SET = 0, FnV = 0
[    0.000000]   EA = 0, S1PTW = 0
[    0.000000]   FSC = 0x04: level 0 translation fault
[    0.000000] Data abort info:
[    0.000000]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[    0.000000]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[    0.000000]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[    0.000000] [0000000000000018] user address but active_mm is swapper
[    0.000000] Internal error: Oops: 0000000096000004 [#1] SMP
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.8.0-rc3+ #30
[    0.000000] pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    0.000000] pc : kmalloc_trace+0x138/0x340
[    0.000000] lr : register_sys_off_handler+0x60/0x258
[    0.000000] sp : ffff8000827d3d10
[    0.000000] x29: ffff8000827d3d20 x28: 000000005cd7e0ac x27: 0000000000001f3f
[    0.000000] x26: 0000000000000000 x25: ffff8000802bd890 x24: ffff8000802bd890
[    0.000000] x23: 0000000000000040 x22: 0000000000000dc0 x21: 0000000000000001
[    0.000000] x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000006
[    0.000000] x17: 000000000036fd40 x16: 000000005ec902c0 x15: ffff8000827d37c0
[    0.000000] x14: 0000000000000000 x13: 312e3176206e6f69 x12: 746e65766e6f4320
[    0.000000] x11: 00000000ffffdfff x10: ffff8000828cebe0 x9 : ffff80008281ea10
[    0.000000] x8 : ffff8000827d3d78 x7 : 0000000000000000 x6 : 0000000000000000
[    0.000000] x5 : 0000000000000000 x4 : ffff8000827e0000 x3 : ffff8000827f41c0
[    0.000000] x2 : 0000000000000040 x1 : 0000000000000dc0 x0 : 0000000000000000
[    0.000000] Call trace:
[    0.000000]  kmalloc_trace+0x138/0x340
[    0.000000]  register_sys_off_handler+0x60/0x258
[    0.000000]  psci_probe+0x2cc/0x350
[    0.000000]  psci_acpi_init+0x50/0x88
[    0.000000]  setup_arch+0x194/0x278
[    0.000000]  start_kernel+0x7c/0x410
[    0.000000]  __primary_switched+0xb8/0xc8
[    0.000000] Code: b5000f7a f94003f4 aa1803fe d50320ff (b9401a64) 
[    0.000000] ---[ end trace 0000000000000000 ]---
[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
[    0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---

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