From: geoff@infradead.org (Geoff Levand) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v12 03/16] arm64: Add new hcall HVC_CALL_FUNC Date: Tue, 24 Nov 2015 22:25:33 +0000 [thread overview] Message-ID: <1ce2d414ff42cccf0995a3a94a1efc9211abb01b.1448403503.git.geoff@infradead.org> (raw) In-Reply-To: <cover.1448403503.git.geoff@infradead.org> Add the new hcall HVC_CALL_FUNC that allows execution of a function at EL2. During CPU reset the CPU must be brought to the exception level it had on entry to the kernel. The HVC_CALL_FUNC hcall will provide the mechanism needed for this exception level switch. To allow the HVC_CALL_FUNC exception vector to work without a stack, which is needed to support an hcall at CPU reset, this implementation uses register x18 to store the link register across the caller provided function. This dictates that the caller provided function must preserve the contents of register x18. Signed-off-by: Geoff Levand <geoff@infradead.org> --- arch/arm64/include/asm/virt.h | 13 +++++++++++++ arch/arm64/kernel/hyp-stub.S | 13 ++++++++++++- 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index eb10368..3070096 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -45,6 +45,19 @@ #define HVC_SET_VECTORS 2 +/* + * HVC_CALL_FUNC - Execute a function at EL2. + * + * @x0: Physical address of the function to be executed. + * @x1: Passed as the first argument to the function. + * @x2: Passed as the second argument to the function. + * @x3: Passed as the third argument to the function. + * + * The called function must preserve the contents of register x18. + */ + +#define HVC_CALL_FUNC 3 + #define BOOT_CPU_MODE_EL1 (0xe11) #define BOOT_CPU_MODE_EL2 (0xe12) diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index 017ab519..e8febe9 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -67,8 +67,19 @@ el1_sync: b 2f 1: cmp x18, #HVC_SET_VECTORS - b.ne 2f + b.ne 1f msr vbar_el2, x0 + b 2f + +1: cmp x18, #HVC_CALL_FUNC + b.ne 2f + mov x18, lr + mov lr, x0 + mov x0, x1 + mov x1, x2 + mov x2, x3 + blr lr + mov lr, x18 2: eret ENDPROC(el1_sync) -- 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 03/16] arm64: Add new hcall HVC_CALL_FUNC Date: Tue, 24 Nov 2015 22:25:33 +0000 [thread overview] Message-ID: <1ce2d414ff42cccf0995a3a94a1efc9211abb01b.1448403503.git.geoff@infradead.org> (raw) In-Reply-To: <cover.1448403503.git.geoff@infradead.org> Add the new hcall HVC_CALL_FUNC that allows execution of a function at EL2. During CPU reset the CPU must be brought to the exception level it had on entry to the kernel. The HVC_CALL_FUNC hcall will provide the mechanism needed for this exception level switch. To allow the HVC_CALL_FUNC exception vector to work without a stack, which is needed to support an hcall at CPU reset, this implementation uses register x18 to store the link register across the caller provided function. This dictates that the caller provided function must preserve the contents of register x18. Signed-off-by: Geoff Levand <geoff@infradead.org> --- arch/arm64/include/asm/virt.h | 13 +++++++++++++ arch/arm64/kernel/hyp-stub.S | 13 ++++++++++++- 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index eb10368..3070096 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -45,6 +45,19 @@ #define HVC_SET_VECTORS 2 +/* + * HVC_CALL_FUNC - Execute a function at EL2. + * + * @x0: Physical address of the function to be executed. + * @x1: Passed as the first argument to the function. + * @x2: Passed as the second argument to the function. + * @x3: Passed as the third argument to the function. + * + * The called function must preserve the contents of register x18. + */ + +#define HVC_CALL_FUNC 3 + #define BOOT_CPU_MODE_EL1 (0xe11) #define BOOT_CPU_MODE_EL2 (0xe12) diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index 017ab519..e8febe9 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -67,8 +67,19 @@ el1_sync: b 2f 1: cmp x18, #HVC_SET_VECTORS - b.ne 2f + b.ne 1f msr vbar_el2, x0 + b 2f + +1: cmp x18, #HVC_CALL_FUNC + b.ne 2f + mov x18, lr + mov lr, x0 + mov x0, x1 + mov x1, x2 + mov x2, x3 + blr lr + mov lr, x18 2: eret ENDPROC(el1_sync) -- 2.5.0 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev 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 ` Geoff Levand [this message] 2015-11-24 22:25 ` [PATCH v12 03/16] arm64: Add new hcall HVC_CALL_FUNC 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 ` [PATCH v12 05/16] arm64: Add back cpu_reset routines Geoff Levand 2015-11-24 22:25 ` 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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