RISC-V: Fix some RV32 bugs and build failures

This patch set fixes up various failures in the RV32I port.  The fixes
are all nominally independent, but are really only testable together
because the RV32I port fails to build without all of them.  The patch
set includes:

* The removal of tishift on RV32I targets, as 128-bit integers are not
  supported by the toolchain.
* The removal of swiotlb from RV32I targets, since all physical
  addresses can be mapped by all hardware on all existing RV32I targets.
* The addition of ummodi3 and udivmoddi4 from an old version of GCC that
  was licensed under GPLv2 as generic code, along with their use on
  RV32I targets.
* A fix to our page alignment logic within ioremap for RV32I targets.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

4 files changed, 7 insertions, 2 deletions

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 4198759f6798..fe451348ae57 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -109,6 +109,7 @@ config ARCH_RV32I
 	select GENERIC_LIB_ASHRDI3
 	select GENERIC_LIB_LSHRDI3
 	select GENERIC_LIB_UCMPDI2
+	select GENERIC_LIB_UMODDI3
 
 config ARCH_RV64I
 	bool "RV64I"
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index b2d26d9d8489..c9461985db7e 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -227,7 +227,10 @@ void __init setup_arch(char **cmdline_p)
 	setup_bootmem();
 	paging_init();
 	unflatten_device_tree();
+
+#ifdef CONFIG_SWIOTLB
 	swiotlb_init(1);
+#endif
 
 #ifdef CONFIG_SMP
 	setup_smp();
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index 445ec84f9a47..5739bd05d289 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -2,6 +2,7 @@ lib-y	+= delay.o
 lib-y	+= memcpy.o
 lib-y	+= memset.o
 lib-y	+= uaccess.o
-lib-y	+= tishift.o
+
+lib-(CONFIG_64BIT) += tishift.o
 
 lib-$(CONFIG_32BIT) += udivdi3.o
diff --git a/arch/riscv/mm/ioremap.c b/arch/riscv/mm/ioremap.c
index 70ef2724cdf6..bd2f2db557cc 100644
--- a/arch/riscv/mm/ioremap.c
+++ b/arch/riscv/mm/ioremap.c
@@ -42,7 +42,7 @@ static void __iomem *__ioremap_caller(phys_addr_t addr, size_t size,
 
 	/* Page-align mappings */
 	offset = addr & (~PAGE_MASK);
-	addr &= PAGE_MASK;
+	addr -= offset;
 	size = PAGE_ALIGN(size + offset);
 
 	area = get_vm_area_caller(size, VM_IOREMAP, caller);