5 files changed, 34 insertions, 35 deletions

diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index 8f2cada4f7c9..8e83da66df0d 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 dcfdcb3ea163..2f6cfd460cb6 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 f2fe18f3f01f..95fa5ac6c4ce 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 06264ae8ccd9..489d1d8d96b0 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 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();