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Diffstat (limited to 'arch/s390/mm')
-rw-r--r--arch/s390/mm/maccess.c38
1 files changed, 16 insertions, 22 deletions
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index 795a0a9bb2eb..921fa541dc04 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -101,19 +101,27 @@ int memcpy_real(void *dest, void *src, size_t count)
}
/*
- * Copy memory to absolute zero
+ * Copy memory in absolute mode (kernel to kernel)
*/
-void copy_to_absolute_zero(void *dest, void *src, size_t count)
+void memcpy_absolute(void *dest, void *src, size_t count)
{
- unsigned long cr0;
+ unsigned long cr0, flags, prefix;
- BUG_ON((unsigned long) dest + count >= sizeof(struct _lowcore));
- preempt_disable();
+ flags = arch_local_irq_save();
__ctl_store(cr0, 0, 0);
__ctl_clear_bit(0, 28); /* disable lowcore protection */
- memcpy_real(dest + store_prefix(), src, count);
+ prefix = store_prefix();
+ if (prefix) {
+ local_mcck_disable();
+ set_prefix(0);
+ memcpy(dest, src, count);
+ set_prefix(prefix);
+ local_mcck_enable();
+ } else {
+ memcpy(dest, src, count);
+ }
__ctl_load(cr0, 0, 0);
- preempt_enable();
+ arch_local_irq_restore(flags);
}
/*
@@ -188,20 +196,6 @@ static int is_swapped(unsigned long addr)
}
/*
- * Return swapped prefix or zero page address
- */
-static unsigned long get_swapped(unsigned long addr)
-{
- unsigned long prefix = store_prefix();
-
- if (addr < sizeof(struct _lowcore))
- return addr + prefix;
- if (addr >= prefix && addr < prefix + sizeof(struct _lowcore))
- return addr - prefix;
- return addr;
-}
-
-/*
* Convert a physical pointer for /dev/mem access
*
* For swapped prefix pages a new buffer is returned that contains a copy of
@@ -218,7 +212,7 @@ void *xlate_dev_mem_ptr(unsigned long addr)
size = PAGE_SIZE - (addr & ~PAGE_MASK);
bounce = (void *) __get_free_page(GFP_ATOMIC);
if (bounce)
- memcpy_real(bounce, (void *) get_swapped(addr), size);
+ memcpy_absolute(bounce, (void *) addr, size);
}
preempt_enable();
put_online_cpus();