[PATCH] RISC-V: Disable IPMMU_VMSA on rv32

[Palmer Dabbelt]

Without this I get a Kconfig warning and then subsequent build failure
when building allmodconfig on rv32.

WARNING: unmet direct dependencies detected for IOMMU_IO_PGTABLE_LPAE
  Depends on [n]: IOMMU_SUPPORT [=y] && (ARM || ARM64 || COMPILE_TEST [=y] && !GENERIC_ATOMIC64 [=y])
  Selected by [y]:
  - IPMMU_VMSA [=y] && IOMMU_SUPPORT [=y] && (ARCH_RENESAS [=y] || COMPILE_TEST [=y] && !GENERIC_ATOMIC64 [=y])

linux/drivers/iommu/io-pgtable-arm.c: Assembler messages:
linux/drivers/iommu/io-pgtable-arm.c:330: Error: unrecognized opcode `lr.d s4,0(s1)'
linux/drivers/iommu/io-pgtable-arm.c:332: Error: unrecognized opcode `sc.d.rl a5,s6,0(s1)'
make[5]: *** [linux/scripts/Makefile.build:250: drivers/iommu/io-pgtable-arm.o] Error 1
make[4]: *** [linux/scripts/Makefile.build:502: drivers/iommu] Error 2
make[3]: *** [linux/scripts/Makefile.build:502: drivers] Error 2

Signed-off-by: Palmer Dabbelt <palmer at rivosinc.com>

---

This one seems pretty ugly, but I like to at least have a workaround for
the allmodconfig failures before sending up a PR.
---
 arch/riscv/configs/32-bit.config | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/riscv/configs/32-bit.config b/arch/riscv/configs/32-bit.config
index f6af0f708df4..7a2fa9b37b1c 100644
--- a/arch/riscv/configs/32-bit.config
+++ b/arch/riscv/configs/32-bit.config
@@ -2,3 +2,4 @@ CONFIG_ARCH_RV32I=y
 CONFIG_32BIT=y
 # CONFIG_PORTABLE is not set
 CONFIG_NONPORTABLE=y
+CONFIG_IPMMU_VMSA=n
-- 
2.38.1