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From: geoff@infradead.org (Geoff Levand)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v12 05/16] arm64: Add back cpu_reset routines
Date: Tue, 24 Nov 2015 22:25:33 +0000	[thread overview]
Message-ID: <3279584774ba40f088b79f4df864d69a5b57b516.1448403503.git.geoff@infradead.org> (raw)
In-Reply-To: <cover.1448403503.git.geoff@infradead.org>

Commit 68234df4ea7939f98431aa81113fbdce10c4a84b (arm64: kill flush_cache_all())
removed the global arm64 routines cpu_reset() and cpu_soft_restart() needed by
the arm64 kexec and kdump support.  Add simplified versions of those two
routines back with some changes needed for kexec in the new files cpu_reset.S,
and cpu_reset.h.

When a CPU is reset it needs to be put into the exception level it had
when it entered the kernel. Update cpu_reset() to accept an argument
which signals if the reset address needs to be entered at EL1 or EL2.

Signed-off-by: Geoff Levand <geoff@infradead.org>
---
 arch/arm64/kernel/cpu-reset.S | 84 +++++++++++++++++++++++++++++++++++++++++++
 arch/arm64/kernel/cpu-reset.h | 22 ++++++++++++
 2 files changed, 106 insertions(+)
 create mode 100644 arch/arm64/kernel/cpu-reset.S
 create mode 100644 arch/arm64/kernel/cpu-reset.h

diff --git a/arch/arm64/kernel/cpu-reset.S b/arch/arm64/kernel/cpu-reset.S
new file mode 100644
index 0000000..0423f27
--- /dev/null
+++ b/arch/arm64/kernel/cpu-reset.S
@@ -0,0 +1,84 @@
+/*
+ * cpu reset routines
+ *
+ * Copyright (C) 2001 Deep Blue Solutions Ltd.
+ * Copyright (C) 2012 ARM Ltd.
+ * Copyright (C) 2015 Huawei Futurewei Technologies.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/virt.h>
+
+#define SCTLR_ELx_I	(1 << 12)
+#define SCTLR_ELx_SA	(1 << 3)
+#define SCTLR_ELx_C	(1 << 2)
+#define SCTLR_ELx_A	(1 << 1)
+#define SCTLR_ELx_M	1
+#define SCTLR_ELx_FLAGS	(SCTLR_ELx_M | SCTLR_ELx_A | SCTLR_ELx_C |	\
+			 SCTLR_ELx_SA | SCTLR_ELx_I)
+
+.text
+.pushsection    .idmap.text, "ax"
+
+.align 5
+
+/*
+ * cpu_soft_restart(cpu_reset, el2_switch, entry, arg0, arg1) - Perform a cpu
+ * soft reset.
+ *
+ * @cpu_reset: Physical address of the cpu_reset routine.
+ * @el2_switch: Flag to indicate a swich to EL2 is needed, passed to cpu_reset.
+ * @entry: Location to jump to for soft reset, passed to cpu_reset.
+ * arg0: First argument passed to @entry.
+ * arg1: Second argument passed to @entry.
+ */
+
+ENTRY(cpu_soft_restart)
+	mov	x18, x0				// cpu_reset
+	mov	x0, x1				// el2_switch
+	mov	x1, x2				// entry
+	mov	x2, x3				// arg0
+	mov	x3, x4				// arg1
+	ret	x18
+ENDPROC(cpu_soft_restart)
+
+/*
+ * cpu_reset(el2_switch, entry, arg0, arg1) - Helper for cpu_soft_restart.
+ *
+ * @el2_switch: Flag to indicate a swich to EL2 is needed.
+ * @entry: Location to jump to for soft reset.
+ * arg0: First argument passed to @entry.
+ * arg1: Second argument passed to @entry.
+ *
+ * Put the CPU into the same state as it would be if it had been reset, and
+ * branch to what would be the reset vector. It must be executed with the
+ * flat identity mapping.
+ */
+
+ENTRY(cpu_reset)
+	/* Clear sctlr_el1 flags. */
+	mrs	x12, sctlr_el1
+	ldr	x13, =SCTLR_ELx_FLAGS
+	bic	x12, x12, x13
+	msr	sctlr_el1, x12
+	isb
+
+	cbz	x0, 1f				// el2_switch?
+
+	mov	x0, x1				// entry
+	mov	x1, x2				// arg0
+	mov	x2, x3				// arg1
+	hvc	#HVC_CALL_FUNC			// no return
+
+1:	mov	x18, x1				// entry
+	mov	x0, x2				// arg0
+	mov	x1, x3				// arg1
+	ret	x18
+ENDPROC(cpu_reset)
+
+.popsection
diff --git a/arch/arm64/kernel/cpu-reset.h b/arch/arm64/kernel/cpu-reset.h
new file mode 100644
index 0000000..79816b6
--- /dev/null
+++ b/arch/arm64/kernel/cpu-reset.h
@@ -0,0 +1,22 @@
+/*
+ * cpu reset routines
+ *
+ * Copyright (C) 2015 Huawei Futurewei Technologies.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#if !defined(_ARM64_CPU_RESET_H)
+#define _ARM64_CPU_RESET_H
+
+#include <asm/virt.h>
+
+void __attribute__((noreturn)) cpu_reset(unsigned long el2_switch,
+	unsigned long entry, unsigned long arg0, unsigned long arg1);
+void __attribute__((noreturn)) cpu_soft_restart(phys_addr_t cpu_reset,
+	unsigned long el2_switch, unsigned long entry, unsigned long arg0,
+	unsigned long arg1);
+
+#endif
-- 
2.5.0

WARNING: multiple messages have this Message-ID (diff)
From: Geoff Levand <geoff@infradead.org>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	marc.zyngier@arm.com, kexec@lists.infradead.org,
	AKASHI Takahiro <takahiro.akashi@linaro.org>,
	christoffer.dall@linaro.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v12 05/16] arm64: Add back cpu_reset routines
Date: Tue, 24 Nov 2015 22:25:33 +0000	[thread overview]
Message-ID: <3279584774ba40f088b79f4df864d69a5b57b516.1448403503.git.geoff@infradead.org> (raw)
In-Reply-To: <cover.1448403503.git.geoff@infradead.org>

Commit 68234df4ea7939f98431aa81113fbdce10c4a84b (arm64: kill flush_cache_all())
removed the global arm64 routines cpu_reset() and cpu_soft_restart() needed by
the arm64 kexec and kdump support.  Add simplified versions of those two
routines back with some changes needed for kexec in the new files cpu_reset.S,
and cpu_reset.h.

When a CPU is reset it needs to be put into the exception level it had
when it entered the kernel. Update cpu_reset() to accept an argument
which signals if the reset address needs to be entered at EL1 or EL2.

Signed-off-by: Geoff Levand <geoff@infradead.org>
---
 arch/arm64/kernel/cpu-reset.S | 84 +++++++++++++++++++++++++++++++++++++++++++
 arch/arm64/kernel/cpu-reset.h | 22 ++++++++++++
 2 files changed, 106 insertions(+)
 create mode 100644 arch/arm64/kernel/cpu-reset.S
 create mode 100644 arch/arm64/kernel/cpu-reset.h

diff --git a/arch/arm64/kernel/cpu-reset.S b/arch/arm64/kernel/cpu-reset.S
new file mode 100644
index 0000000..0423f27
--- /dev/null
+++ b/arch/arm64/kernel/cpu-reset.S
@@ -0,0 +1,84 @@
+/*
+ * cpu reset routines
+ *
+ * Copyright (C) 2001 Deep Blue Solutions Ltd.
+ * Copyright (C) 2012 ARM Ltd.
+ * Copyright (C) 2015 Huawei Futurewei Technologies.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/virt.h>
+
+#define SCTLR_ELx_I	(1 << 12)
+#define SCTLR_ELx_SA	(1 << 3)
+#define SCTLR_ELx_C	(1 << 2)
+#define SCTLR_ELx_A	(1 << 1)
+#define SCTLR_ELx_M	1
+#define SCTLR_ELx_FLAGS	(SCTLR_ELx_M | SCTLR_ELx_A | SCTLR_ELx_C |	\
+			 SCTLR_ELx_SA | SCTLR_ELx_I)
+
+.text
+.pushsection    .idmap.text, "ax"
+
+.align 5
+
+/*
+ * cpu_soft_restart(cpu_reset, el2_switch, entry, arg0, arg1) - Perform a cpu
+ * soft reset.
+ *
+ * @cpu_reset: Physical address of the cpu_reset routine.
+ * @el2_switch: Flag to indicate a swich to EL2 is needed, passed to cpu_reset.
+ * @entry: Location to jump to for soft reset, passed to cpu_reset.
+ * arg0: First argument passed to @entry.
+ * arg1: Second argument passed to @entry.
+ */
+
+ENTRY(cpu_soft_restart)
+	mov	x18, x0				// cpu_reset
+	mov	x0, x1				// el2_switch
+	mov	x1, x2				// entry
+	mov	x2, x3				// arg0
+	mov	x3, x4				// arg1
+	ret	x18
+ENDPROC(cpu_soft_restart)
+
+/*
+ * cpu_reset(el2_switch, entry, arg0, arg1) - Helper for cpu_soft_restart.
+ *
+ * @el2_switch: Flag to indicate a swich to EL2 is needed.
+ * @entry: Location to jump to for soft reset.
+ * arg0: First argument passed to @entry.
+ * arg1: Second argument passed to @entry.
+ *
+ * Put the CPU into the same state as it would be if it had been reset, and
+ * branch to what would be the reset vector. It must be executed with the
+ * flat identity mapping.
+ */
+
+ENTRY(cpu_reset)
+	/* Clear sctlr_el1 flags. */
+	mrs	x12, sctlr_el1
+	ldr	x13, =SCTLR_ELx_FLAGS
+	bic	x12, x12, x13
+	msr	sctlr_el1, x12
+	isb
+
+	cbz	x0, 1f				// el2_switch?
+
+	mov	x0, x1				// entry
+	mov	x1, x2				// arg0
+	mov	x2, x3				// arg1
+	hvc	#HVC_CALL_FUNC			// no return
+
+1:	mov	x18, x1				// entry
+	mov	x0, x2				// arg0
+	mov	x1, x3				// arg1
+	ret	x18
+ENDPROC(cpu_reset)
+
+.popsection
diff --git a/arch/arm64/kernel/cpu-reset.h b/arch/arm64/kernel/cpu-reset.h
new file mode 100644
index 0000000..79816b6
--- /dev/null
+++ b/arch/arm64/kernel/cpu-reset.h
@@ -0,0 +1,22 @@
+/*
+ * cpu reset routines
+ *
+ * Copyright (C) 2015 Huawei Futurewei Technologies.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#if !defined(_ARM64_CPU_RESET_H)
+#define _ARM64_CPU_RESET_H
+
+#include <asm/virt.h>
+
+void __attribute__((noreturn)) cpu_reset(unsigned long el2_switch,
+	unsigned long entry, unsigned long arg0, unsigned long arg1);
+void __attribute__((noreturn)) cpu_soft_restart(phys_addr_t cpu_reset,
+	unsigned long el2_switch, unsigned long entry, unsigned long arg0,
+	unsigned long arg1);
+
+#endif
-- 
2.5.0



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  parent reply	other threads:[~2015-11-24 22:25 UTC|newest]

Thread overview: 178+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-24 22:25 [PATCH v12 00/16] arm64 kexec kernel patches v12 Geoff Levand
2015-11-24 22:25 ` Geoff Levand
2015-11-24 22:25 ` [PATCH v12 06/16] Revert "arm64: mm: remove unused cpu_set_idmap_tcr_t0sz function" Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-11-24 22:25 ` [PATCH v12 04/16] arm64: kvm: allows kvm cpu hotplug Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-11-27 13:54   ` Marc Zyngier
2015-11-27 13:54     ` Marc Zyngier
2015-12-02 22:40   ` Ashwin Chaugule
2015-12-02 22:40     ` Ashwin Chaugule
2015-12-03 13:55     ` Ashwin Chaugule
2015-12-03 13:55       ` Ashwin Chaugule
2015-12-03 13:58     ` Marc Zyngier
2015-12-03 13:58       ` Marc Zyngier
2015-12-10 18:31       ` Geoff Levand
2015-12-10 18:31         ` Geoff Levand
2015-12-11 16:31         ` Will Deacon
2015-12-11 16:31           ` Will Deacon
2015-12-15  8:48           ` AKASHI Takahiro
2015-12-15  8:48             ` AKASHI Takahiro
2015-12-10 18:44       ` Shi, Yang
2015-12-10 18:44         ` Shi, Yang
2015-12-11  8:09         ` AKASHI Takahiro
2015-12-11  8:09           ` AKASHI Takahiro
2015-12-14 18:00           ` Shi, Yang
2015-12-14 18:00             ` Shi, Yang
2015-12-11  8:06       ` AKASHI Takahiro
2015-12-11  8:06         ` AKASHI Takahiro
2015-12-11 13:00         ` Shanker Donthineni
2015-12-11 13:00           ` Shanker Donthineni
2015-12-11 16:28         ` Marc Zyngier
2015-12-11 16:28           ` Marc Zyngier
2015-12-11 18:00           ` Shanker Donthineni
2015-12-11 18:00             ` Shanker Donthineni
2015-12-11 18:11             ` Marc Zyngier
2015-12-11 18:11               ` Marc Zyngier
2015-12-11 19:11               ` Shanker Donthineni
2015-12-11 19:11                 ` Shanker Donthineni
2015-12-11 20:13           ` Ashwin Chaugule
2015-12-11 20:13             ` Ashwin Chaugule
2015-12-14  7:33           ` AKASHI Takahiro
2015-12-14  7:33             ` AKASHI Takahiro
2015-12-14 17:33             ` Marc Zyngier
2015-12-14 17:33               ` Marc Zyngier
2015-12-15  7:51               ` AKASHI Takahiro
2015-12-15  7:51                 ` AKASHI Takahiro
2015-12-15  8:45                 ` Marc Zyngier
2015-12-15  8:45                   ` Marc Zyngier
2015-12-15  9:51                   ` AKASHI Takahiro
2015-12-15  9:51                     ` AKASHI Takahiro
2015-12-15 10:13                     ` Marc Zyngier
2015-12-15 10:13                       ` Marc Zyngier
2015-11-24 22:25 ` [PATCH v12 02/16] arm64: Convert hcalls to use HVC immediate value Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-11-24 22:25 ` [PATCH v12 03/16] arm64: Add new hcall HVC_CALL_FUNC Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-11-24 22:25 ` [PATCH v12 01/16] arm64: Fold proc-macros.S into assembler.h Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-11-24 22:25 ` Geoff Levand [this message]
2015-11-24 22:25   ` [PATCH v12 05/16] arm64: Add back cpu_reset routines Geoff Levand
2015-11-27 14:19   ` Marc Zyngier
2015-11-27 14:19     ` Marc Zyngier
2015-11-30  5:28     ` Pratyush Anand
2015-11-30  5:28       ` Pratyush Anand
2015-11-30 10:40       ` Marc Zyngier
2015-11-30 10:40         ` Marc Zyngier
2015-12-02 22:57         ` Geoff Levand
2015-12-02 22:57           ` Geoff Levand
2015-12-03  9:32           ` Will Deacon
2015-12-03  9:32             ` Will Deacon
2015-12-10  0:49             ` Geoff Levand
2015-12-10  0:49               ` Geoff Levand
2015-12-10 10:17               ` Will Deacon
2015-12-10 10:17                 ` Will Deacon
2015-11-30 20:03     ` Geoff Levand
2015-11-30 20:03       ` Geoff Levand
2015-12-01  9:38       ` Marc Zyngier
2015-12-01  9:38         ` Marc Zyngier
2015-11-24 22:25 ` [PATCH v12 07/16] Revert "arm64: remove dead code" Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-11-24 22:25 ` [PATCH v12 16/16] arm64: kdump: relax BUG_ON() if more than one cpus are still active Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-12-15 17:05   ` Will Deacon
2015-12-15 17:05     ` Will Deacon
2015-12-16  5:51     ` AKASHI Takahiro
2015-12-16  5:51       ` AKASHI Takahiro
2015-11-24 22:25 ` [PATCH v12 11/16] arm64: kdump: reserve memory for crash dump kernel Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-12-15 17:29   ` Will Deacon
2015-12-15 17:29     ` Will Deacon
2015-12-16  5:19     ` AKASHI Takahiro
2015-12-16  5:19       ` AKASHI Takahiro
2015-12-16  7:36       ` Pratyush Anand
2015-12-16  7:36         ` Pratyush Anand
2015-11-24 22:25 ` [PATCH v12 15/16] arm64: kdump: enable kdump in the arm64 defconfig Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-11-24 22:25 ` [PATCH v12 09/16] arm64/kexec: Add pr_devel output Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-12-15 17:15   ` Will Deacon
2015-12-15 17:15     ` Will Deacon
2015-12-16  0:45     ` Geoff Levand
2015-12-16  0:45       ` Geoff Levand
2015-12-16  0:46   ` [PATCH v12.4] arm64/kexec: Add pr_debug output Geoff Levand
2015-12-16  0:46     ` Geoff Levand
2015-11-24 22:25 ` [PATCH v12 12/16] arm64: kdump: implement machine_crash_shutdown() Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-11-27 14:39   ` Marc Zyngier
2015-11-27 14:39     ` Marc Zyngier
2015-12-10 11:34     ` AKASHI Takahiro
2015-12-10 11:34       ` AKASHI Takahiro
2015-12-10 11:44       ` Marc Zyngier
2015-12-10 11:44         ` Marc Zyngier
2015-12-10 12:55         ` AKASHI Takahiro
2015-12-10 12:55           ` AKASHI Takahiro
2015-12-10 13:43           ` Marc Zyngier
2015-12-10 13:43             ` Marc Zyngier
2015-12-03  4:15   ` Pratyush Anand
2015-12-03  4:15     ` Pratyush Anand
2015-12-10 11:42     ` AKASHI Takahiro
2015-12-10 11:42       ` AKASHI Takahiro
2015-12-10 11:50       ` Pratyush Anand
2015-12-10 11:50         ` Pratyush Anand
2015-11-24 22:25 ` [PATCH v12 14/16] arm64: kdump: update a kernel doc Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-12-15 17:17   ` Will Deacon
2015-12-15 17:17     ` Will Deacon
2015-12-16  5:48     ` AKASHI Takahiro
2015-12-16  5:48       ` AKASHI Takahiro
2015-11-24 22:25 ` [PATCH v12 10/16] arm64/kexec: Enable kexec in the arm64 defconfig Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-11-24 22:25 ` [PATCH v12 13/16] arm64: kdump: add kdump support Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-12-15 17:45   ` Will Deacon
2015-12-15 17:45     ` Will Deacon
2015-12-16  5:41     ` AKASHI Takahiro
2015-12-16  5:41       ` AKASHI Takahiro
2015-11-24 22:25 ` [PATCH v12 08/16] arm64/kexec: Add core kexec support Geoff Levand
2015-11-24 22:25   ` Geoff Levand
2015-11-27 13:13   ` Pratyush Anand
2015-11-27 13:13     ` Pratyush Anand
2015-11-30 18:51     ` Geoff Levand
2015-11-30 18:51       ` Geoff Levand
2015-12-01  2:16       ` Pratyush Anand
2015-12-01  2:16         ` Pratyush Anand
2015-12-01 18:32         ` Azriel Samson
2015-12-01 18:32           ` Azriel Samson
2015-12-02 22:49           ` Geoff Levand
2015-12-02 22:49             ` Geoff Levand
2015-12-03  4:37             ` Azriel Samson
2015-12-03  4:37               ` Azriel Samson
2015-12-03 19:56               ` Geoff Levand
2015-12-03 19:56                 ` Geoff Levand
2015-12-04  0:39                 ` Azriel Samson
2015-12-04  0:39                   ` Azriel Samson
2015-12-04  3:54                   ` Pratyush Anand
2015-12-04  3:54                     ` Pratyush Anand
2015-12-07 18:47                     ` Geoff Levand
2015-12-07 18:47                       ` Geoff Levand
2015-12-03  6:09             ` Pratyush Anand
2015-12-03  6:09               ` Pratyush Anand
2015-12-01 19:03         ` Mark Rutland
2015-12-01 19:03           ` Mark Rutland
2015-12-02 21:08           ` Geoff Levand
2015-12-02 21:08             ` Geoff Levand
2015-12-03 16:06             ` Mark Rutland
2015-12-03 16:06               ` Mark Rutland
2015-12-15 18:29   ` Will Deacon
2015-12-15 18:29     ` Will Deacon
2015-12-16  0:14     ` Geoff Levand
2015-12-16  0:14       ` Geoff Levand
2015-12-16  7:18       ` Pratyush Anand
2015-12-16  7:18         ` Pratyush Anand
2015-12-16  9:30         ` James Morse
2015-12-16  9:30           ` James Morse
2015-12-16 10:32           ` Pratyush Anand
2015-12-16 10:32             ` Pratyush Anand
2015-12-16  0:14   ` [PATCH v12.4] " Geoff Levand
2015-12-16  0:14     ` Geoff Levand

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