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authorMichael Holzheu <holzheu@linux.vnet.ibm.com>2012-05-24 14:35:16 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-05-30 09:04:49 +0200
commit73bf463efaba6a1efe69349c6d7275d03468adf4 (patch)
tree66a5c2eb6cc72bd8e627ba88931a23e1fdb25248 /arch
parentf4815ac6c935b8e441fe12504d62e0e8ff7f7ce5 (diff)
downloadlinux-73bf463efaba6a1efe69349c6d7275d03468adf4.tar.gz
s390/kernel: Introduce memcpy_absolute() function
This patch introduces the new function memcpy_absolute() that allows to copy memory using absolute addressing. This means that the prefix swap does not apply when this function is used. With this patch also all s390 kernel code that accesses absolute zero now uses the new memcpy_absolute() function. The old and less generic copy_to_absolute_zero() function is removed. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/include/asm/uaccess.h2
-rw-r--r--arch/s390/kernel/ipl.c15
-rw-r--r--arch/s390/kernel/os_info.c2
-rw-r--r--arch/s390/kernel/setup.c12
-rw-r--r--arch/s390/mm/maccess.c38
5 files changed, 34 insertions, 35 deletions
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index 8f2cada4f7c..8e83da66df0 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -377,7 +377,7 @@ clear_user(void __user *to, unsigned long n)
}
extern int memcpy_real(void *, void *, size_t);
-extern void copy_to_absolute_zero(void *dest, void *src, size_t count);
+extern void memcpy_absolute(void *, void *, size_t);
extern int copy_to_user_real(void __user *dest, void *src, size_t count);
extern int copy_from_user_real(void *dest, void __user *src, size_t count);
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index dcfdcb3ea16..2f6cfd460cb 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -1528,12 +1528,15 @@ static struct shutdown_action __refdata dump_action = {
static void dump_reipl_run(struct shutdown_trigger *trigger)
{
- u32 csum;
-
- csum = csum_partial(reipl_block_actual, reipl_block_actual->hdr.len, 0);
- copy_to_absolute_zero(&S390_lowcore.ipib_checksum, &csum, sizeof(csum));
- copy_to_absolute_zero(&S390_lowcore.ipib, &reipl_block_actual,
- sizeof(reipl_block_actual));
+ struct {
+ void *addr;
+ __u32 csum;
+ } __packed ipib;
+
+ ipib.csum = csum_partial(reipl_block_actual,
+ reipl_block_actual->hdr.len, 0);
+ ipib.addr = reipl_block_actual;
+ memcpy_absolute(&S390_lowcore.ipib, &ipib, sizeof(ipib));
dump_run(trigger);
}
diff --git a/arch/s390/kernel/os_info.c b/arch/s390/kernel/os_info.c
index f2fe18f3f01..95fa5ac6c4c 100644
--- a/arch/s390/kernel/os_info.c
+++ b/arch/s390/kernel/os_info.c
@@ -60,7 +60,7 @@ void __init os_info_init(void)
os_info.version_minor = OS_INFO_VERSION_MINOR;
os_info.magic = OS_INFO_MAGIC;
os_info.csum = os_info_csum(&os_info);
- copy_to_absolute_zero(&S390_lowcore.os_info, &ptr, sizeof(ptr));
+ memcpy_absolute(&S390_lowcore.os_info, &ptr, sizeof(ptr));
}
#ifdef CONFIG_CRASH_DUMP
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 06264ae8ccd..489d1d8d96b 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -428,10 +428,12 @@ static void __init setup_lowcore(void)
lc->restart_fn = (unsigned long) do_restart;
lc->restart_data = 0;
lc->restart_source = -1UL;
- memcpy(&S390_lowcore.restart_stack, &lc->restart_stack,
- 4*sizeof(unsigned long));
- copy_to_absolute_zero(&S390_lowcore.restart_psw,
- &lc->restart_psw, sizeof(psw_t));
+
+ /* Setup absolute zero lowcore */
+ memcpy_absolute(&S390_lowcore.restart_stack, &lc->restart_stack,
+ 4 * sizeof(unsigned long));
+ memcpy_absolute(&S390_lowcore.restart_psw, &lc->restart_psw,
+ sizeof(lc->restart_psw));
set_prefix((u32)(unsigned long) lc);
lowcore_ptr[0] = lc;
@@ -598,7 +600,7 @@ static void __init setup_vmcoreinfo(void)
#ifdef CONFIG_KEXEC
unsigned long ptr = paddr_vmcoreinfo_note();
- copy_to_absolute_zero(&S390_lowcore.vmcore_info, &ptr, sizeof(ptr));
+ memcpy_absolute(&S390_lowcore.vmcore_info, &ptr, sizeof(ptr));
#endif
}
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index 795a0a9bb2e..921fa541dc0 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();