s390: Stop using weak symbols for __iowrite64_copy()

Complete switching the __iowriteXX_copy() routines over to use #define and
arch provided inline/macro functions instead of weak symbols.

S390 has an implementation that simply calls another memcpy
function. Inline this so the callers don't have to do two jumps.

Link: https://lore.kernel.org/r/3-v3-1893cd8b9369+1925-mlx5_arm_wc_jgg@nvidia.com
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

arch/s390/include/asm/io.h

@@ -81,6 +81,13 @@ static inline void __iowrite32_copy(void __iomem *to, const void *from,
 }
 #define __iowrite32_copy __iowrite32_copy
 
+static inline void __iowrite64_copy(void __iomem *to, const void *from,
+				    size_t count)
+{
+	zpci_memcpy_toio(to, from, count * 8);
+}
+#define __iowrite64_copy __iowrite64_copy
+
 #endif /* CONFIG_PCI */
 
 #include <asm-generic/io.h>

arch/s390/pci/pci.c

@@ -250,12 +250,6 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 	return 0;
 }
 
-/* combine single writes by using store-block insn */
-void __iowrite64_copy(void __iomem *to, const void *from, size_t count)
-{
-	zpci_memcpy_toio(to, from, count * 8);
-}
-
 void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 			   unsigned long prot)
 {

include/linux/io.h

@@ -21,7 +21,10 @@ void __iowrite32_copy(void __iomem *to, const void *from, size_t count);
 #endif
 
 void __ioread32_copy(void *to, const void __iomem *from, size_t count);
+
+#ifndef __iowrite64_copy
 void __iowrite64_copy(void __iomem *to, const void *from, size_t count);
+#endif
 
 #ifdef CONFIG_MMU
 int ioremap_page_range(unsigned long addr, unsigned long end,

lib/iomap_copy.c

@@ -60,9 +60,8 @@ EXPORT_SYMBOL_GPL(__ioread32_copy);
  * time.  Order of access is not guaranteed, nor is a memory barrier
  * performed afterwards.
  */
-void __attribute__((weak)) __iowrite64_copy(void __iomem *to,
-					    const void *from,
-					    size_t count)
+#ifndef __iowrite64_copy
+void __iowrite64_copy(void __iomem *to, const void *from, size_t count)
 {
 #ifdef CONFIG_64BIT
 	u64 __iomem *dst = to;
@@ -75,5 +74,5 @@ void __attribute__((weak)) __iowrite64_copy(void __iomem *to,
 	__iowrite32_copy(to, from, count * 2);
 #endif
 }
-
 EXPORT_SYMBOL_GPL(__iowrite64_copy);
+#endif