1 /******************************************************************************
4 * Xen hypercall wrappers
6 * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2012
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34 * The Xen hypercall calling convention is very similar to the procedure
35 * call standard for the ARM 64-bit architecture: the first parameter is
36 * passed in x0, the second in x1, the third in x2, the fourth in x3 and
39 * The hypercall number is passed in x16.
41 * The return value is in x0.
43 * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
46 * Parameter structs passed to hypercalls are laid out according to
47 * the ARM 64-bit EABI standard.
50 #include <linux/linkage.h>
51 #include <asm/assembler.h>
52 #include <asm/asm-uaccess.h>
53 #include <xen/interface/xen.h>
58 #define HYPERCALL_SIMPLE(hypercall) \
59 ENTRY(HYPERVISOR_##hypercall) \
60 mov x16, #__HYPERVISOR_##hypercall; \
63 ENDPROC(HYPERVISOR_##hypercall)
65 #define HYPERCALL0 HYPERCALL_SIMPLE
66 #define HYPERCALL1 HYPERCALL_SIMPLE
67 #define HYPERCALL2 HYPERCALL_SIMPLE
68 #define HYPERCALL3 HYPERCALL_SIMPLE
69 #define HYPERCALL4 HYPERCALL_SIMPLE
70 #define HYPERCALL5 HYPERCALL_SIMPLE
74 HYPERCALL2(xen_version);
75 HYPERCALL3(console_io);
76 HYPERCALL3(grant_table_op);
78 HYPERCALL2(event_channel_op);
80 HYPERCALL2(memory_op);
81 HYPERCALL2(physdev_op);
84 HYPERCALL1(platform_op_raw);
85 HYPERCALL2(multicall);
86 HYPERCALL2(vm_assist);
97 * Privcmd calls are issued by the userspace. The kernel needs to
98 * enable access to TTBR0_EL1 as the hypervisor would issue stage 1
99 * translations to user memory via AT instructions. Since AT
100 * instructions are not affected by the PAN bit (ARMv8.1), we only
101 * need the explicit uaccess_enable/disable if the TTBR0 PAN emulation
102 * is enabled (it implies that hardware UAO and PAN disabled).
104 uaccess_ttbr0_enable x6, x7, x8
108 * Disable userspace access from kernel once the hyp call completed.
110 uaccess_ttbr0_disable x6, x7
112 ENDPROC(privcmd_call);