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author | Jiri Kosina <jkosina@suse.cz> | 2011-09-15 15:08:05 +0200 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2011-09-15 15:08:18 +0200 |
commit | e060c38434b2caa78efe7cedaff4191040b65a15 (patch) | |
tree | 407361230bf6733f63d8e788e4b5e6566ee04818 /arch/s390/mm/maccess.c | |
parent | viacam: Don't explode if pci_find_bus() returns NULL (diff) | |
parent | mm: account skipped entries to avoid looping in find_get_pages (diff) | |
download | linux-e060c38434b2caa78efe7cedaff4191040b65a15.tar.xz linux-e060c38434b2caa78efe7cedaff4191040b65a15.zip |
Merge branch 'master' into for-next
Fast-forward merge with Linus to be able to merge patches
based on more recent version of the tree.
Diffstat (limited to 'arch/s390/mm/maccess.c')
-rw-r--r-- | arch/s390/mm/maccess.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c index 51e5cd9b906a..5dbbaa6e594c 100644 --- a/arch/s390/mm/maccess.c +++ b/arch/s390/mm/maccess.c @@ -85,3 +85,19 @@ int memcpy_real(void *dest, void *src, size_t count) arch_local_irq_restore(flags); return rc; } + +/* + * Copy memory to absolute zero + */ +void copy_to_absolute_zero(void *dest, void *src, size_t count) +{ + unsigned long cr0; + + BUG_ON((unsigned long) dest + count >= sizeof(struct _lowcore)); + preempt_disable(); + __ctl_store(cr0, 0, 0); + __ctl_clear_bit(0, 28); /* disable lowcore protection */ + memcpy_real(dest + store_prefix(), src, count); + __ctl_load(cr0, 0, 0); + preempt_enable(); +} |