MIPS: Use generic checksum functions for MIPS R6

The following instructions have been removed from MIPS R6

ulw, ulh, swl, lwr, lwl, swr.

However, all of them are used in the MIPS specific checksum implementation.
As a result of which, we will use the generic checksum on MIPS R6
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

arch/mips/Kconfig

@@ -1034,6 +1034,9 @@ config MIPS_MACHINE
 config NO_IOPORT_MAP
 	def_bool n
 
+config GENERIC_CSUM
+	bool
+
 config GENERIC_ISA_DMA
 	bool
 	select ZONE_DMA if GENERIC_ISA_DMA_SUPPORT_BROKEN=n
@@ -1312,6 +1315,7 @@ config CPU_MIPS32_R6
 	select CPU_SUPPORTS_32BIT_KERNEL
 	select CPU_SUPPORTS_HIGHMEM
 	select CPU_SUPPORTS_MSA
+	select GENERIC_CSUM
 	select HAVE_KVM
 	select MIPS_O32_FP64_SUPPORT
 	help
@@ -1363,6 +1367,7 @@ config CPU_MIPS64_R6
 	select CPU_SUPPORTS_64BIT_KERNEL
 	select CPU_SUPPORTS_HIGHMEM
 	select CPU_SUPPORTS_MSA
+	select GENERIC_CSUM
 	help
 	  Choose this option to build a kernel for release 6 or later of the
 	  MIPS64 architecture.  New MIPS processors, starting with the Warrior

arch/mips/include/asm/Kbuild

 # MIPS headers
+generic-(CONFIG_GENERIC_CSUM) += checksum.h
 generic-y += cputime.h
 generic-y += current.h
 generic-y += dma-contiguous.h

arch/mips/include/asm/checksum.h

@@ -12,6 +12,10 @@
 #ifndef _ASM_CHECKSUM_H
 #define _ASM_CHECKSUM_H
 
+#ifdef CONFIG_GENERIC_CSUM
+#include <asm-generic/checksum.h>
+#else
+
 #include <linux/in6.h>
 
 #include <asm/uaccess.h>
@@ -274,5 +278,6 @@ static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 }
 
 #include <asm-generic/checksum.h>
+#endif /* CONFIG_GENERIC_CSUM */
 
 #endif /* _ASM_CHECKSUM_H */

arch/mips/kernel/mips_ksyms.c

@@ -67,11 +67,13 @@ EXPORT_SYMBOL(__strnlen_kernel_asm);
 EXPORT_SYMBOL(__strnlen_user_nocheck_asm);
 EXPORT_SYMBOL(__strnlen_user_asm);
 
+#ifndef CONFIG_CPU_MIPSR6
 EXPORT_SYMBOL(csum_partial);
 EXPORT_SYMBOL(csum_partial_copy_nocheck);
 EXPORT_SYMBOL(__csum_partial_copy_kernel);
 EXPORT_SYMBOL(__csum_partial_copy_to_user);
 EXPORT_SYMBOL(__csum_partial_copy_from_user);
+#endif
 
 EXPORT_SYMBOL(invalid_pte_table);
 #ifdef CONFIG_FUNCTION_TRACER

arch/mips/lib/Makefile

@@ -8,6 +8,7 @@ lib-y	+= bitops.o csum_partial.o delay.o memcpy.o memset.o \
 
 obj-y			+= iomap.o
 obj-$(CONFIG_PCI)	+= iomap-pci.o
+lib-$(CONFIG_GENERIC_CSUM)	:= $(filter-out csum_partial.o, $(lib-y))
 
 obj-$(CONFIG_CPU_GENERIC_DUMP_TLB) += dump_tlb.o
 obj-$(CONFIG_CPU_R3000)		+= r3k_dump_tlb.o