Revert "MIPS: SiByte: Enable swiotlb for SWARM, LittleSur and BigSur"

BugLink: https://bugs.launchpad.net/bugs/1845405

This reverts commit c890a458 which is
commit e4849aff upstream

Guenter writes:
	Upstream commit e4849aff ("MIPS: SiByte: Enable swiotlb for SWARM,
	LittleSur and BigSur") results in build failures in v4.4.y and v4.14.y.

	make bigsur_defconfig:

	warning: (SIBYTE_SWARM && SIBYTE_SENTOSA && SIBYTE_BIGSUR && SWIOTLB_XEN && AMD_IOMMU) selects SWIOTLB which has unmet direct dependencies (CAVIUM_OCTEON_SOC || MACH_LOONGSON64 && CPU_LOONGSON3 || NLM_XLP_BOARD || NLM_XLR_BOARD)
	warning: (SIBYTE_SWARM && SIBYTE_SENTOSA && SIBYTE_BIGSUR && SWIOTLB_XEN && AMD_IOMMU) selects SWIOTLB which has unmet direct dependencies (CAVIUM_OCTEON_SOC || MACH_LOONGSON64 && CPU_LOONGSON3 || NLM_XLP_BOARD || NLM_XLR_BOARD)

	and the actual build:

	lib/swiotlb.o: In function `swiotlb_tbl_map_single':
	(.text+0x1c0): undefined reference to `iommu_is_span_boundary'
	Makefile:1021: recipe for target 'vmlinux' failed
Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/mips/Kconfig

@@ -761,7 +761,6 @@ config SIBYTE_SWARM
 	select SYS_SUPPORTS_HIGHMEM
 	select SYS_SUPPORTS_LITTLE_ENDIAN
 	select ZONE_DMA32 if 64BIT
-	select SWIOTLB if ARCH_DMA_ADDR_T_64BIT && PCI
 
 config SIBYTE_LITTLESUR
 	bool "Sibyte BCM91250C2-LittleSur"
@@ -784,7 +783,6 @@ config SIBYTE_SENTOSA
 	select SYS_HAS_CPU_SB1
 	select SYS_SUPPORTS_BIG_ENDIAN
 	select SYS_SUPPORTS_LITTLE_ENDIAN
-	select SWIOTLB if ARCH_DMA_ADDR_T_64BIT && PCI
 
 config SIBYTE_BIGSUR
 	bool "Sibyte BCM91480B-BigSur"
@@ -798,7 +796,6 @@ config SIBYTE_BIGSUR
 	select SYS_SUPPORTS_HIGHMEM
 	select SYS_SUPPORTS_LITTLE_ENDIAN
 	select ZONE_DMA32 if 64BIT
-	select SWIOTLB if ARCH_DMA_ADDR_T_64BIT && PCI
 
 config SNI_RM
 	bool "SNI RM200/300/400"

arch/mips/sibyte/common/Makefile

 obj-y := cfe.o
-obj-$(CONFIG_SWIOTLB)			+= dma.o
 obj-$(CONFIG_SIBYTE_BUS_WATCHER)	+= bus_watcher.o
 obj-$(CONFIG_SIBYTE_CFE_CONSOLE)	+= cfe_console.o
 obj-$(CONFIG_SIBYTE_TBPROF)		+= sb_tbprof.o

arch/mips/sibyte/common/dma.c

-// SPDX-License-Identifier: GPL-2.0+
-/*
- *	DMA support for Broadcom SiByte platforms.
- *
- *	Copyright (c) 2018  Maciej W. Rozycki
- */
-
-#include <linux/swiotlb.h>
-#include <asm/bootinfo.h>
-
-void __init plat_swiotlb_setup(void)
-{
-	swiotlb_init(1);
-}