s390/maccess: fix absolute lowcore virtual vs physical address confusion

Due to historical reasons memcpy_absolute() and friend functions
misuse the notion of physical vs virtual addresses difference.

Note: this does not fix a bug currently, since virtual and physical
addresses are identical.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index c1ed1f51c25d8d8439e356e8250aeb320226e0b5..d4d311cb2bb5e8c105d47d78f1cd1de347b056e7 100644 (file)
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -199,15 +199,15 @@ out:
 /*
  * Check if physical address is within prefix or zero page
  */
-static int is_swapped(unsigned long addr)
+static int is_swapped(phys_addr_t addr)
 {
-       unsigned long lc;
+       phys_addr_t lc;
        int cpu;
 
        if (addr < sizeof(struct lowcore))
                return 1;
        for_each_online_cpu(cpu) {
-               lc = (unsigned long) lowcore_ptr[cpu];
+               lc = virt_to_phys(lowcore_ptr[cpu]);
                if (addr > lc + sizeof(struct lowcore) - 1 || addr < lc)
                        continue;
                return 1;
@@ -223,7 +223,8 @@ static int is_swapped(unsigned long addr)
  */
 void *xlate_dev_mem_ptr(phys_addr_t addr)
 {
-       void *bounce = (void *) addr;
+       void *ptr = phys_to_virt(addr);
+       void *bounce = ptr;
        unsigned long size;
 
        cpus_read_lock();
@@ -232,7 +233,7 @@ void *xlate_dev_mem_ptr(phys_addr_t addr)
                size = PAGE_SIZE - (addr & ~PAGE_MASK);
                bounce = (void *) __get_free_page(GFP_ATOMIC);
                if (bounce)
-                       memcpy_absolute(bounce, (void *) addr, size);
+                       memcpy_absolute(bounce, ptr, size);
        }
        preempt_enable();
        cpus_read_unlock();
@@ -242,8 +243,8 @@ void *xlate_dev_mem_ptr(phys_addr_t addr)
 /*
  * Free converted buffer for /dev/mem access (if necessary)
  */
-void unxlate_dev_mem_ptr(phys_addr_t addr, void *buf)
+void unxlate_dev_mem_ptr(phys_addr_t addr, void *ptr)
 {
-       if ((void *) addr != buf)
-               free_page((unsigned long) buf);
+       if (addr != virt_to_phys(ptr))
+               free_page((unsigned long)ptr);
 }