124 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			124 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| /******************************************************************************
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|  * hypercall.S
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|  *
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|  * Xen hypercall wrappers
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|  *
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|  * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2012
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|  *
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|  * This program is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU General Public License version 2
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|  * as published by the Free Software Foundation; or, when distributed
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|  * separately from the Linux kernel or incorporated into other
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|  * software packages, subject to the following license:
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|  *
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|  * Permission is hereby granted, free of charge, to any person obtaining a copy
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|  * of this source file (the "Software"), to deal in the Software without
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|  * restriction, including without limitation the rights to use, copy, modify,
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|  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
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|  * and to permit persons to whom the Software is furnished to do so, subject to
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|  * the following conditions:
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|  *
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|  * The above copyright notice and this permission notice shall be included in
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|  * all copies or substantial portions of the Software.
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|  *
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|  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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|  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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|  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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|  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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|  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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|  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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|  * IN THE SOFTWARE.
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|  */
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| 
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| /*
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|  * The Xen hypercall calling convention is very similar to the ARM
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|  * procedure calling convention: the first paramter is passed in r0, the
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|  * second in r1, the third in r2 and the fourth in r3. Considering that
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|  * Xen hypercalls have 5 arguments at most, the fifth paramter is passed
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|  * in r4, differently from the procedure calling convention of using the
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|  * stack for that case.
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|  *
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|  * The hypercall number is passed in r12.
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|  *
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|  * The return value is in r0.
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|  *
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|  * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
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|  * hypercall tag.
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|  */
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| 
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| #include <linux/linkage.h>
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| #include <asm/assembler.h>
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| #include <asm/opcodes-virt.h>
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| #include <xen/interface/xen.h>
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| 
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| 
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| #define XEN_IMM 0xEA1
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| 
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| #define HYPERCALL_SIMPLE(hypercall)		\
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| ENTRY(HYPERVISOR_##hypercall)			\
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| 	mov r12, #__HYPERVISOR_##hypercall;	\
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| 	__HVC(XEN_IMM);						\
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| 	ret lr;					\
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| ENDPROC(HYPERVISOR_##hypercall)
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| 
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| #define HYPERCALL0 HYPERCALL_SIMPLE
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| #define HYPERCALL1 HYPERCALL_SIMPLE
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| #define HYPERCALL2 HYPERCALL_SIMPLE
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| #define HYPERCALL3 HYPERCALL_SIMPLE
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| #define HYPERCALL4 HYPERCALL_SIMPLE
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| 
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| #define HYPERCALL5(hypercall)			\
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| ENTRY(HYPERVISOR_##hypercall)			\
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| 	stmdb sp!, {r4}						\
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| 	ldr r4, [sp, #4]					\
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| 	mov r12, #__HYPERVISOR_##hypercall;	\
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| 	__HVC(XEN_IMM);						\
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| 	ldm sp!, {r4}						\
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| 	ret lr					\
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| ENDPROC(HYPERVISOR_##hypercall)
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| 
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|                 .text
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| 
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| HYPERCALL2(xen_version);
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| HYPERCALL3(console_io);
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| HYPERCALL3(grant_table_op);
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| HYPERCALL2(sched_op);
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| HYPERCALL2(event_channel_op);
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| HYPERCALL2(hvm_op);
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| HYPERCALL2(memory_op);
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| HYPERCALL2(physdev_op);
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| HYPERCALL3(vcpu_op);
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| HYPERCALL1(tmem_op);
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| HYPERCALL1(platform_op_raw);
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| HYPERCALL2(multicall);
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| HYPERCALL2(vm_assist);
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| HYPERCALL3(dm_op);
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| 
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| ENTRY(privcmd_call)
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| 	stmdb sp!, {r4}
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| 	mov r12, r0
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| 	mov r0, r1
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| 	mov r1, r2
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| 	mov r2, r3
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| 	ldr r3, [sp, #8]
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| 	/*
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| 	 * Privcmd calls are issued by the userspace. We need to allow the
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| 	 * kernel to access the userspace memory before issuing the hypercall.
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| 	 */
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| 	uaccess_enable r4
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| 
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| 	/* r4 is loaded now as we use it as scratch register before */
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| 	ldr r4, [sp, #4]
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| 	__HVC(XEN_IMM)
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| 
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| 	/*
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| 	 * Disable userspace access from kernel. This is fine to do it
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| 	 * unconditionally as no set_fs(KERNEL_DS)/set_fs(get_ds()) is
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| 	 * called before.
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| 	 */
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| 	uaccess_disable r4
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| 
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| 	ldm sp!, {r4}
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| 	ret lr
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| ENDPROC(privcmd_call);
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