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From: konrad.wilk@oracle•com (Konrad Rzeszutek Wilk)
To: linux-arm-kernel@lists•infradead.org
Subject: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls
Date: Thu, 26 Jul 2012 12:33:52 -0400	[thread overview]
Message-ID: <20120726163352.GC9222@phenom.dumpdata.com> (raw)
In-Reply-To: <1343316846-25860-2-git-send-email-stefano.stabellini@eu.citrix.com>

On Thu, Jul 26, 2012 at 04:33:44PM +0100, Stefano Stabellini wrote:
> Use r12 to pass the hypercall number to the hypervisor.
> 
> We need a register to pass the hypercall number because we might not
> know it at compile time and HVC only takes an immediate argument.
> 
> Among the available registers r12 seems to be the best choice because it
> is defined as "intra-procedure call scratch register".
> 
> Use the ISS to pass an hypervisor specific tag.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu•citrix.com>
> ---
>  arch/arm/include/asm/xen/hypercall.h |   50 ++++++++++++++++++++++++++
>  arch/arm/xen/Makefile                |    2 +-
>  arch/arm/xen/hypercall.S             |   65 ++++++++++++++++++++++++++++++++++
>  3 files changed, 116 insertions(+), 1 deletions(-)
>  create mode 100644 arch/arm/include/asm/xen/hypercall.h
>  create mode 100644 arch/arm/xen/hypercall.S
> 
> diff --git a/arch/arm/include/asm/xen/hypercall.h b/arch/arm/include/asm/xen/hypercall.h
> new file mode 100644
> index 0000000..4ac0624
> --- /dev/null
> +++ b/arch/arm/include/asm/xen/hypercall.h
> @@ -0,0 +1,50 @@
> +/******************************************************************************
> + * hypercall.h
> + *
> + * Linux-specific hypervisor handling.
> + *
> + * Stefano Stabellini <stefano.stabellini@eu•citrix.com>, Citrix, 2012
> + *
> + * 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; or, when distributed
> + * separately from the Linux kernel or incorporated into other
> + * software packages, subject to the following license:
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this source file (the "Software"), to deal in the Software without
> + * restriction, including without limitation the rights to use, copy, modify,
> + * merge, publish, distribute, sublicense, and/or sell copies of the Software,
> + * and to permit persons to whom the Software is furnished to do so, subject to
> + * the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
> + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#ifndef _ASM_ARM_XEN_HYPERCALL_H
> +#define _ASM_ARM_XEN_HYPERCALL_H
> +
> +#include <xen/interface/xen.h>
> +
> +long privcmd_call(unsigned call, unsigned long a1,
> +		unsigned long a2, unsigned long a3,
> +		unsigned long a4, unsigned long a5);
> +int HYPERVISOR_xen_version(int cmd, void *arg);
> +int HYPERVISOR_console_io(int cmd, int count, char *str);
> +int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count);
> +int HYPERVISOR_sched_op(int cmd, void *arg);
> +int HYPERVISOR_event_channel_op(int cmd, void *arg);
> +unsigned long HYPERVISOR_hvm_op(int op, void *arg);
> +int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
> +int HYPERVISOR_physdev_op(int cmd, void *arg);
> +
> +#endif /* _ASM_ARM_XEN_HYPERCALL_H */
> diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
> index 0bad594..b9d6acc 100644
> --- a/arch/arm/xen/Makefile
> +++ b/arch/arm/xen/Makefile
> @@ -1 +1 @@
> -obj-y		:= enlighten.o
> +obj-y		:= enlighten.o hypercall.o
> diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S
> new file mode 100644
> index 0000000..038cc5b
> --- /dev/null
> +++ b/arch/arm/xen/hypercall.S
> @@ -0,0 +1,65 @@
> +/******************************************************************************
> + * hypercall.S
> + *
> + * Xen hypercall wrappers
> + *
> + * The Xen hypercall calling convention is very similar to the ARM
> + * procedure calling convention: the first paramter is passed in r0, the
> + * second in r1, the third in r2 and the third in r3. Considering that

I think you meant 'and the fourth in r3'.

So where does the similarity end?  Just in that we use r12?

> + * Xen hypercalls have 5 arguments at most, the fifth paramter is passed
> + * in r4, differently from the procedure calling convention of using the

> + * stack for that case.
> + *
> + * The hypercall number is passed in r12.
> + *
> + * The return value is in r0.
> + *
> + * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
> + * hypercall tag.
> + *
> + * Stefano Stabellini <stefano.stabellini@eu•citrix.com>, Citrix, 2012
> + */
> +
> +#include <linux/linkage.h>
> +#include <asm/assembler.h>
> +#include <xen/interface/xen.h>
> +
> +
> +/* HVC 0xEA1 */
> +#ifdef CONFIG_THUMB2_KERNEL
> +#define xen_hvc .word 0xf7e08ea1
> +#else
> +#define xen_hvc .word 0xe140ea71
> +#endif
> +
> +/* We need to save and restore r4, because Xen clobbers it. */

Hmm, the comment says r4, but right below I see r12?
Should this comment be by 'privcmd_call'?

> +#define HYPERCALL(hypercall)			\
> +ENTRY(HYPERVISOR_##hypercall)			\
> +	mov r12, #__HYPERVISOR_##hypercall;	\
> +	xen_hvc;							\
> +	mov pc, lr;							\
> +ENDPROC(HYPERVISOR_##hypercall)
> +
> +                .text
> +
> +HYPERCALL(xen_version);
> +HYPERCALL(console_io);
> +HYPERCALL(grant_table_op);
> +HYPERCALL(sched_op);
> +HYPERCALL(event_channel_op);
> +HYPERCALL(hvm_op);
> +HYPERCALL(memory_op);
> +HYPERCALL(physdev_op);
> +
> +ENTRY(privcmd_call)
> +	stmdb	sp!, {r4}
> +	mov r12, r0
> +	mov r0, r1
> +	mov r1, r2
> +	mov r2, r3
> +	ldr r3, [sp, #8]
> +	ldr r4, [sp, #4]
> +	xen_hvc
> +	pop {r4}
> +	mov pc, lr
> +ENDPROC(privcmd_call);
> -- 
> 1.7.2.5
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel at lists.xen.org
> http://lists.xen.org/xen-devel

  reply	other threads:[~2012-07-26 16:33 UTC|newest]

Thread overview: 99+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-26 15:33 [PATCH 00/24] Introduce Xen support on ARM Stefano Stabellini
2012-07-26 15:33 ` [PATCH 01/24] arm: initial Xen support Stefano Stabellini
2012-07-26 16:30   ` [Xen-devel] " Konrad Rzeszutek Wilk
2012-07-27 11:56     ` Stefano Stabellini
2012-08-01 10:42       ` Konrad Rzeszutek Wilk
2012-08-06 10:55         ` Stefano Stabellini
2012-08-01 18:27   ` Rob Herring
2012-08-02  7:35     ` Ian Campbell
2012-08-02 14:13       ` [Xen-devel] " Konrad Rzeszutek Wilk
2012-08-06 10:46         ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 02/24] xen/arm: hypercalls Stefano Stabellini
2012-07-26 16:33   ` Konrad Rzeszutek Wilk [this message]
2012-07-27  9:17     ` [Xen-devel] " Ian Campbell
2012-07-27 13:02       ` Stefano Stabellini
2012-07-27 13:18         ` Ian Campbell
2012-07-27 13:41           ` Stefano Stabellini
2012-07-27 14:21         ` Russell King - ARM Linux
2012-07-27 14:36           ` Stefano Stabellini
2012-07-27 14:39           ` Ian Campbell
2012-07-27 14:59             ` Russell King - ARM Linux
2012-07-26 16:56   ` David Vrabel
2012-07-26 17:19     ` Stefano Stabellini
2012-07-27  9:00     ` Ian Campbell
2012-07-26 19:19   ` Christopher Covington
2012-07-27  9:19     ` Ian Campbell
2012-07-27 12:56       ` Christopher Covington
2012-07-27 13:57         ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 03/24] xen/arm: page.h definitions Stefano Stabellini
2012-07-26 16:36   ` [Xen-devel] " Konrad Rzeszutek Wilk
2012-07-27 13:47     ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 04/24] xen/arm: sync_bitops Stefano Stabellini
2012-07-26 16:37   ` [Xen-devel] " Konrad Rzeszutek Wilk
2012-07-27  9:28     ` Ian Campbell
2012-08-01 14:35       ` Konrad Rzeszutek Wilk
2012-08-01 16:07         ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 05/24] xen/arm: empty implementation of grant_table arch specific functions Stefano Stabellini
2012-08-01 14:16   ` Konrad Rzeszutek Wilk
2012-08-01 15:46     ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 06/24] xen: missing includes Stefano Stabellini
2012-07-27  6:57   ` [Xen-devel] " Jan Beulich
2012-07-27 16:47     ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 07/24] xen/arm: Xen detection and shared_info page mapping Stefano Stabellini
2012-07-27  9:36   ` Ian Campbell
2012-07-27 14:48     ` Stefano Stabellini
2012-07-27 14:51       ` Ian Campbell
2012-08-01 14:19   ` Konrad Rzeszutek Wilk
2012-08-01 15:45     ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 08/24] xen/arm: Introduce xen_pfn_t for pfn and mfn types Stefano Stabellini
2012-08-01 14:22   ` Konrad Rzeszutek Wilk
2012-08-01 15:50     ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 09/24] xen/arm: compile and run xenbus Stefano Stabellini
2012-08-01 14:28   ` Konrad Rzeszutek Wilk
2012-08-06 11:17     ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 10/24] xen: do not compile manage, balloon, pci, acpi and cpu_hotplug on ARM Stefano Stabellini
2012-07-27  7:01   ` [Xen-devel] " Jan Beulich
2012-07-27 16:51     ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 11/24] xen/arm: introduce CONFIG_XEN " Stefano Stabellini
2012-08-01 14:34   ` [Xen-devel] " Konrad Rzeszutek Wilk
2012-07-26 15:33 ` [PATCH 12/24] xen/arm: Introduce xen_guest_init Stefano Stabellini
2012-07-27  9:42   ` Ian Campbell
2012-07-27 15:54     ` Stefano Stabellini
2012-07-27 16:11       ` Ian Campbell
2012-08-01 14:38   ` Konrad Rzeszutek Wilk
2012-07-26 15:33 ` [PATCH 13/24] xen/arm: get privilege status Stefano Stabellini
2012-07-27  9:44   ` Ian Campbell
2012-07-27 14:25     ` Stefano Stabellini
2012-07-27 14:33       ` Ian Campbell
2012-08-01 14:39         ` Konrad Rzeszutek Wilk
2012-08-01 16:21           ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 14/24] xen/arm: initialize grant_table on ARM Stefano Stabellini
2012-08-01 14:40   ` Konrad Rzeszutek Wilk
2012-08-01 17:08     ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 15/24] xen/arm: receive Xen events " Stefano Stabellini
2012-08-01 14:44   ` Konrad Rzeszutek Wilk
2012-08-06 10:31     ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 16/24] xen/arm: implement alloc/free_xenballooned_pages with alloc_pages/kfree Stefano Stabellini
2012-07-26 15:33 ` [PATCH 17/24] xen: allow privcmd for HVM guests Stefano Stabellini
2012-07-27  7:04   ` [Xen-devel] " Jan Beulich
2012-07-27 14:10     ` Stefano Stabellini
2012-08-01 14:47       ` Konrad Rzeszutek Wilk
2012-07-26 15:34 ` [PATCH 18/24] xen/arm: compile blkfront and blkback Stefano Stabellini
2012-07-27  9:48   ` Ian Campbell
2012-07-27 16:25     ` Stefano Stabellini
2012-08-01 14:48   ` Konrad Rzeszutek Wilk
2012-08-01 16:19     ` Stefano Stabellini
2012-07-26 15:34 ` [PATCH 19/24] xen/arm: compile netback Stefano Stabellini
2012-07-26 15:34 ` [PATCH 20/24] xen: update xen_add_to_physmap interface Stefano Stabellini
2012-08-01 14:52   ` Konrad Rzeszutek Wilk
2012-08-01 16:18     ` Stefano Stabellini
2012-08-01 18:19     ` Mukesh Rathor
2012-07-26 15:34 ` [PATCH 21/24] arm/v2m: initialize arch_timers even if v2m_timer is not present Stefano Stabellini
2012-08-01 14:52   ` Konrad Rzeszutek Wilk
2012-08-01 16:06     ` Stefano Stabellini
2012-07-26 15:34 ` [PATCH 22/24] ARM: enable earlyprintk=xen Stefano Stabellini
2012-07-26 15:34 ` [PATCH 23/24] hvc_xen: allow dom0_write_console for HVM guests Stefano Stabellini
2012-08-01 14:54   ` Konrad Rzeszutek Wilk
2012-08-01 16:04     ` Stefano Stabellini
2012-07-26 15:34 ` [PATCH 24/24] [HACK] xen/arm: implement xen_remap_domain_mfn_range Stefano Stabellini
2012-08-01 14:56   ` Konrad Rzeszutek Wilk

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