Commit | Line | Data |
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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
a66086b8 | 2 | /* |
a66086b8 AB |
3 | * |
4 | * Copyright (C) IBM Corporation, 2011 | |
5 | * | |
6 | * Authors: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> | |
7 | * Anton Blanchard <anton@au.ibm.com> | |
8 | */ | |
9 | #include <linux/uaccess.h> | |
10 | #include <linux/hardirq.h> | |
ae3a197e | 11 | #include <asm/switch_to.h> |
42f5b4ca | 12 | #include <asm/asm-prototypes.h> |
a66086b8 | 13 | |
6f7839e5 | 14 | int enter_vmx_usercopy(void) |
a66086b8 AB |
15 | { |
16 | if (in_interrupt()) | |
17 | return 0; | |
18 | ||
5f76eea8 DH |
19 | preempt_disable(); |
20 | /* | |
21 | * We need to disable page faults as they can call schedule and | |
22 | * thus make us lose the VMX context. So on page faults, we just | |
23 | * fail which will cause a fallback to the normal non-vmx copy. | |
a66086b8 AB |
24 | */ |
25 | pagefault_disable(); | |
26 | ||
27 | enable_kernel_altivec(); | |
28 | ||
29 | return 1; | |
30 | } | |
31 | ||
32 | /* | |
33 | * This function must return 0 because we tail call optimise when calling | |
34 | * from __copy_tofrom_user_power7 which returns 0 on success. | |
35 | */ | |
6f7839e5 | 36 | int exit_vmx_usercopy(void) |
a66086b8 | 37 | { |
dc4fbba1 | 38 | disable_kernel_altivec(); |
a66086b8 | 39 | pagefault_enable(); |
5f76eea8 | 40 | preempt_enable(); |
a66086b8 AB |
41 | return 0; |
42 | } | |
fde69282 | 43 | |
d58badfb | 44 | int enter_vmx_ops(void) |
fde69282 AB |
45 | { |
46 | if (in_interrupt()) | |
47 | return 0; | |
48 | ||
49 | preempt_disable(); | |
50 | ||
51 | enable_kernel_altivec(); | |
52 | ||
53 | return 1; | |
54 | } | |
55 | ||
56 | /* | |
57 | * All calls to this function will be optimised into tail calls. We are | |
58 | * passed a pointer to the destination which we return as required by a | |
59 | * memcpy implementation. | |
60 | */ | |
d58badfb | 61 | void *exit_vmx_ops(void *dest) |
fde69282 | 62 | { |
dc4fbba1 | 63 | disable_kernel_altivec(); |
fde69282 AB |
64 | preempt_enable(); |
65 | return dest; | |
66 | } |