projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| a66086b8 AB |
1 | /* |
| 2 | * This program is free software; you can redistribute it and/or modify | |
| 3 | * it under the terms of the GNU General Public License as published by | |
| 4 | * the Free Software Foundation; either version 2 of the License, or | |
| 5 | * (at your option) any later version. | |
| 6 | * | |
| 7 | * This program is distributed in the hope that it will be useful, | |
| 8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 10 | * GNU General Public License for more details. | |
| 11 | * | |
| 12 | * You should have received a copy of the GNU General Public License | |
| 13 | * along with this program; if not, write to the Free Software | |
| 14 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
| 15 | * | |
| 16 | * Copyright (C) IBM Corporation, 2011 | |
| 17 | * | |
| 18 | * Authors: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> | |
| 19 | * Anton Blanchard <anton@au.ibm.com> | |
| 20 | */ | |
| 21 | #include <linux/uaccess.h> | |
| 22 | #include <linux/hardirq.h> | |
| ae3a197e | 23 | #include <asm/switch_to.h> |
| a66086b8 | 24 | |
| 6f7839e5 | 25 | int enter_vmx_usercopy(void) |
| a66086b8 AB |
26 | { |
| 27 | if (in_interrupt()) | |
| 28 | return 0; | |
| 29 | ||
| 5f76eea8 DH |
30 | preempt_disable(); |
| 31 | /* | |
| 32 | * We need to disable page faults as they can call schedule and | |
| 33 | * thus make us lose the VMX context. So on page faults, we just | |
| 34 | * fail which will cause a fallback to the normal non-vmx copy. | |
| a66086b8 AB |
35 | */ |
| 36 | pagefault_disable(); | |
| 37 | ||
| 38 | enable_kernel_altivec(); | |
| 39 | ||
| 40 | return 1; | |
| 41 | } | |
| 42 | ||
| 43 | /* | |
| 44 | * This function must return 0 because we tail call optimise when calling | |
| 45 | * from __copy_tofrom_user_power7 which returns 0 on success. | |
| 46 | */ | |
| 6f7839e5 | 47 | int exit_vmx_usercopy(void) |
| a66086b8 | 48 | { |
| dc4fbba1 | 49 | disable_kernel_altivec(); |
| a66086b8 | 50 | pagefault_enable(); |
| 5f76eea8 | 51 | preempt_enable(); |
| a66086b8 AB |
52 | return 0; |
| 53 | } | |
| fde69282 AB |
54 | |
| 55 | int enter_vmx_copy(void) | |
| 56 | { | |
| 57 | if (in_interrupt()) | |
| 58 | return 0; | |
| 59 | ||
| 60 | preempt_disable(); | |
| 61 | ||
| 62 | enable_kernel_altivec(); | |
| 63 | ||
| 64 | return 1; | |
| 65 | } | |
| 66 | ||
| 67 | /* | |
| 68 | * All calls to this function will be optimised into tail calls. We are | |
| 69 | * passed a pointer to the destination which we return as required by a | |
| 70 | * memcpy implementation. | |
| 71 | */ | |
| 72 | void *exit_vmx_copy(void *dest) | |
| 73 | { | |
| dc4fbba1 | 74 | disable_kernel_altivec(); |
| fde69282 AB |
75 | preempt_enable(); |
| 76 | return dest; | |
| 77 | } |