MIPS: loongson32: Switch to generic core

The generic MIPS core is fully compatible with Loongson-1 SoCs,
so migrate Loongson-1 to it.

Main changes are:
 - Merge CPU_LOONGSON1B and CPU_LOONGSON1C into a unified CPU_LOONGSON32,
   as both are based on the GS232 core.
 - Consolidate LOONGSON1_LS1B and LOONGSON1_LS1C Kconfig options into
   MACH_LOONGSON32.
 - Enable MACH_GENERIC_CORE and remove the legacy custom implementation.
 - Remove all Loongson-1 platform devices and associated code,
   which are now obsolete due to Device Tree support.
 - Misc cleanup.

Partially based on earlier work by Jiaxun Yang.

Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Keguang Zhang <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

Author: kelvincheung

MAINTAINERS

@@ -17017,7 +17017,6 @@ L:	[email protected]
 S:	Maintained
 F:	Documentation/devicetree/bindings/*/loongson,ls1*.yaml
 F:	arch/mips/boot/dts/loongson/loongson1*
-F:	arch/mips/include/asm/mach-loongson32/
 F:	arch/mips/loongson32/
 F:	drivers/*/*loongson1*
 F:	drivers/mtd/nand/raw/loongson1-nand-controller.c

arch/mips/Kconfig

@@ -480,6 +480,23 @@ config LANTIQ
 
 config MACH_LOONGSON32
 	bool "Loongson 32-bit family of machines"
+	select MACH_GENERIC_CORE
+	select USE_OF
+	select BUILTIN_DTB
+	select BOOT_ELF32
+	select CEVT_R4K
+	select CSRC_R4K
+	select COMMON_CLK
+	select DMA_NONCOHERENT
+	select GENERIC_IRQ_SHOW_LEVEL
+	select IRQ_MIPS_CPU
+	select LS1X_IRQ
+	select SYS_HAS_CPU_LOONGSON32
+	select SYS_HAS_EARLY_PRINTK
+	select USE_GENERIC_EARLY_PRINTK_8250
+	select SYS_SUPPORTS_32BIT_KERNEL
+	select SYS_SUPPORTS_LITTLE_ENDIAN
+	select SYS_SUPPORTS_HIGHMEM
 	select SYS_SUPPORTS_ZBOOT
 	help
 	  This enables support for the Loongson-1 family of machines.
@@ -1386,25 +1403,20 @@ config CPU_LOONGSON2F
 	  have a similar programming interface with FPGA northbridge used in
 	  Loongson2E.
 
-config CPU_LOONGSON1B
-	bool "Loongson 1B"
-	depends on SYS_HAS_CPU_LOONGSON1B
-	select CPU_LOONGSON32
-	select LEDS_GPIO_REGISTER
-	help
-	  The Loongson 1B is a 32-bit SoC, which implements the MIPS32
-	  Release 1 instruction set and part of the MIPS32 Release 2
-	  instruction set.
-
-config CPU_LOONGSON1C
-	bool "Loongson 1C"
-	depends on SYS_HAS_CPU_LOONGSON1C
-	select CPU_LOONGSON32
+config CPU_LOONGSON32
+	bool "Loongson 32-bit CPU"
+	depends on SYS_HAS_CPU_LOONGSON32
+	select CPU_MIPS32
+	select CPU_MIPSR2
+	select CPU_HAS_PREFETCH
+	select CPU_HAS_LOAD_STORE_LR
+	select CPU_SUPPORTS_32BIT_KERNEL
+	select CPU_SUPPORTS_HIGHMEM
+	select CPU_SUPPORTS_CPUFREQ
 	select LEDS_GPIO_REGISTER
 	help
-	  The Loongson 1C is a 32-bit SoC, which implements the MIPS32
-	  Release 1 instruction set and part of the MIPS32 Release 2
-	  instruction set.
+	  The Loongson GS232 microarchitecture implements the MIPS32 Release 1
+	  instruction set and part of the MIPS32 Release 2 instruction set.
 
 config CPU_MIPS32_R1
 	bool "MIPS32 Release 1"
@@ -1839,15 +1851,6 @@ config CPU_LOONGSON2EF
 	select CPU_SUPPORTS_HUGEPAGES
 	select RTC_MC146818_LIB
 
-config CPU_LOONGSON32
-	bool
-	select CPU_MIPS32
-	select CPU_MIPSR2
-	select CPU_HAS_PREFETCH
-	select CPU_SUPPORTS_32BIT_KERNEL
-	select CPU_SUPPORTS_HIGHMEM
-	select CPU_SUPPORTS_CPUFREQ
-
 config CPU_BMIPS32_3300
 	select SMP_UP if SMP
 	bool
@@ -1885,10 +1888,7 @@ config SYS_HAS_CPU_LOONGSON2F
 	select CPU_SUPPORTS_CPUFREQ
 	select CPU_SUPPORTS_ADDRWINCFG if 64BIT
 
-config SYS_HAS_CPU_LOONGSON1B
-	bool
-
-config SYS_HAS_CPU_LOONGSON1C
+config SYS_HAS_CPU_LOONGSON32
 	bool
 
 config SYS_HAS_CPU_MIPS32_R1
@@ -2999,8 +2999,8 @@ choice
 	prompt "Kernel command line type"
 	depends on !CMDLINE_OVERRIDE
 	default MIPS_CMDLINE_FROM_DTB if USE_OF && !ATH79 && !MACH_INGENIC && \
-					 !MACH_LOONGSON64 && !MIPS_MALTA && \
-					 !CAVIUM_OCTEON_SOC
+					 !MACH_LOONGSON64 && !MACH_LOONGSON32 && \
+					 !MIPS_MALTA && !CAVIUM_OCTEON_SOC
 	default MIPS_CMDLINE_FROM_BOOTLOADER
 
 	config MIPS_CMDLINE_FROM_DTB

arch/mips/include/asm/cpu-type.h

@@ -24,8 +24,7 @@ static inline int __pure __get_cpu_type(const int cpu_type)
 	case CPU_LOONGSON64:
 #endif
 
-#if defined(CONFIG_SYS_HAS_CPU_LOONGSON1B) || \
-    defined(CONFIG_SYS_HAS_CPU_LOONGSON1C)
+#ifdef CONFIG_SYS_HAS_CPU_LOONGSON32
 	case CPU_LOONGSON32:
 #endif