MIPS: Remove unused R6000 support

The kernel contains a small amount of incomplete code aimed at
supporting old R6000 CPUs. This is:

  - Unused, as no machine selects CONFIG_SYS_HAS_CPU_R6000.

  - Broken, since there are glaring errors such as r6000_fpu.S moving
    the FCSR register to t1, then ignoring it & instead saving t0 into
    struct sigcontext...

  - A maintenance headache, since it's code that nobody can test which
    nevertheless imposes constraints on code which it shares with other
    machines.

Remove this incomplete & broken R6000 CPU support in order to clean up
and in preparation for changes which will no longer need to consider
dragging the pretense of R6000 support along with them.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16236/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 48d91d5..a2f6b19 100644 (file)
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1627,14 +1627,6 @@ config CPU_R5500
          NEC VR5500 and VR5500A series processors implement 64-bit MIPS IV
          instruction set.
 
-config CPU_R6000
-       bool "R6000"
-       depends on SYS_HAS_CPU_R6000
-       select CPU_SUPPORTS_32BIT_KERNEL
-       help
-         MIPS Technologies R6000 and R6000A series processors.  Note these
-         processors are extremely rare and the support for them is incomplete.
-
 config CPU_NEVADA
        bool "RM52xx"
        depends on SYS_HAS_CPU_NEVADA
@@ -1950,9 +1942,6 @@ config SYS_HAS_CPU_R5432
 config SYS_HAS_CPU_R5500
        bool
 
-config SYS_HAS_CPU_R6000
-       bool
-
 config SYS_HAS_CPU_NEVADA
        bool
 
@@ -2180,7 +2169,7 @@ config PAGE_SIZE_32KB
 
 config PAGE_SIZE_64KB
        bool "64kB"
-       depends on !CPU_R3000 && !CPU_TX39XX && !CPU_R6000
+       depends on !CPU_R3000 && !CPU_TX39XX
        help
          Using 64kB page size will result in higher performance kernel at
          the price of higher memory consumption.  This option is available on
@@ -2248,11 +2237,11 @@ config CPU_HAS_PREFETCH
 
 config CPU_GENERIC_DUMP_TLB
        bool
-       default y if !(CPU_R3000 || CPU_R6000 || CPU_R8000 || CPU_TX39XX)
+       default y if !(CPU_R3000 || CPU_R8000 || CPU_TX39XX)
 
 config CPU_R4K_FPU
        bool
-       default y if !(CPU_R3000 || CPU_R6000 || CPU_TX39XX || CPU_CAVIUM_OCTEON)
+       default y if !(CPU_R3000 || CPU_TX39XX || CPU_CAVIUM_OCTEON)
 
 config CPU_R4K_CACHE_TLB
        bool

diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index bc2708c..d78d615 100644 (file)
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -151,7 +151,6 @@ cflags-y += -fno-stack-check
 #
 cflags-$(CONFIG_CPU_R3000)     += -march=r3000
 cflags-$(CONFIG_CPU_TX39XX)    += -march=r3900
-cflags-$(CONFIG_CPU_R6000)     += -march=r6000 -Wa,--trap
 cflags-$(CONFIG_CPU_R4300)     += -march=r4300 -Wa,--trap
 cflags-$(CONFIG_CPU_VR41XX)    += -march=r4100 -Wa,--trap
 cflags-$(CONFIG_CPU_R4X00)     += -march=r4600 -Wa,--trap

diff --git a/arch/mips/include/asm/cpu-type.h b/arch/mips/include/asm/cpu-type.h
index 175fe56..a45af3d 100644 (file)
--- a/arch/mips/include/asm/cpu-type.h
+++ b/arch/mips/include/asm/cpu-type.h
@@ -151,11 +151,6 @@ static inline int __pure __get_cpu_type(const int cpu_type)
        case CPU_R5500:
 #endif
 
-#ifdef CONFIG_SYS_HAS_CPU_R6000
-       case CPU_R6000:
-       case CPU_R6000A:
-#endif
-
 #ifdef CONFIG_SYS_HAS_CPU_NEVADA
        case CPU_NEVADA:
 #endif

diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index d0c152b..ece9b84 100644 (file)
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -286,11 +286,6 @@ enum cpu_type_enum {
        CPU_R3081, CPU_R3081E,
 
        /*
-        * R6000 class processors
-        */
-       CPU_R6000, CPU_R6000A,
-
-       /*
         * R4000 class processors
         */
        CPU_R4000PC, CPU_R4000SC, CPU_R4000MC, CPU_R4200, CPU_R4300, CPU_R4310,

diff --git a/arch/mips/include/asm/module.h b/arch/mips/include/asm/module.h
index e51add1..06552a9 100644 (file)
--- a/arch/mips/include/asm/module.h
+++ b/arch/mips/include/asm/module.h
@@ -114,8 +114,6 @@ search_module_dbetables(unsigned long addr)
 #define MODULE_PROC_FAMILY "R5432 "
 #elif defined CONFIG_CPU_R5500
 #define MODULE_PROC_FAMILY "R5500 "
-#elif defined CONFIG_CPU_R6000
-#define MODULE_PROC_FAMILY "R6000 "
 #elif defined CONFIG_CPU_NEVADA
 #define MODULE_PROC_FAMILY "NEVADA "
 #elif defined CONFIG_CPU_R8000

diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index 46c0581..afd66b2 100644 (file)
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -37,7 +37,6 @@ obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o
 
 obj-$(CONFIG_CPU_R4K_FPU)      += r4k_fpu.o r4k_switch.o
 obj-$(CONFIG_CPU_R3000)                += r2300_fpu.o r2300_switch.o
-obj-$(CONFIG_CPU_R6000)                += r6000_fpu.o r4k_switch.o
 obj-$(CONFIG_CPU_TX39XX)       += r2300_fpu.o r2300_switch.o
 obj-$(CONFIG_CPU_CAVIUM_OCTEON)        += r4k_fpu.o octeon_switch.o
 

diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index d08afc7..19ae0e2 100644 (file)
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -1394,24 +1394,6 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
                             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
                c->tlbsize = 48;
                break;
-       case PRID_IMP_R6000:
-               c->cputype = CPU_R6000;
-               __cpu_name[cpu] = "R6000";
-               set_isa(c, MIPS_CPU_ISA_II);
-               c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
-               c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
-                            MIPS_CPU_LLSC;
-               c->tlbsize = 32;
-               break;
-       case PRID_IMP_R6000A:
-               c->cputype = CPU_R6000A;
-               __cpu_name[cpu] = "R6000A";
-               set_isa(c, MIPS_CPU_ISA_II);
-               c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
-               c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
-                            MIPS_CPU_LLSC;
-               c->tlbsize = 32;
-               break;
        case PRID_IMP_RM7000:
                c->cputype = CPU_RM7000;
                __cpu_name[cpu] = "RM7000";

diff --git a/arch/mips/kernel/r6000_fpu.S b/arch/mips/kernel/r6000_fpu.S
deleted file mode 100644 (file)
index 9cc7bfa..0000000
--- a/arch/mips/kernel/r6000_fpu.S
+++ /dev/null
@@ -1,99 +0,0 @@
-/*
- * r6000_fpu.S: Save/restore floating point context for signal handlers.
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Copyright (C) 1996 by Ralf Baechle
- *
- * Multi-arch abstraction and asm macros for easier reading:
- * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
- */
-#include <asm/asm.h>
-#include <asm/fpregdef.h>
-#include <asm/mipsregs.h>
-#include <asm/asm-offsets.h>
-#include <asm/regdef.h>
-
-       .set    noreorder
-       .set    mips2
-       .set    push
-       SET_HARDFLOAT
-
-/**
- * _save_fp_context() - save FP context from the FPU
- * @a0 - pointer to fpregs field of sigcontext
- * @a1 - pointer to fpc_csr field of sigcontext
- *
- * Save FP context, including the 32 FP data registers and the FP
- * control & status register, from the FPU to signal context.
- */
-       LEAF(_save_fp_context)
-       mfc0    t0,CP0_STATUS
-       sll     t0,t0,2
-       bgez    t0,1f
-        nop
-
-       cfc1    t1,fcr31
-       /* Store the 16 double precision registers */
-       sdc1    $f0,0(a0)
-       sdc1    $f2,16(a0)
-       sdc1    $f4,32(a0)
-       sdc1    $f6,48(a0)
-       sdc1    $f8,64(a0)
-       sdc1    $f10,80(a0)
-       sdc1    $f12,96(a0)
-       sdc1    $f14,112(a0)
-       sdc1    $f16,128(a0)
-       sdc1    $f18,144(a0)
-       sdc1    $f20,160(a0)
-       sdc1    $f22,176(a0)
-       sdc1    $f24,192(a0)
-       sdc1    $f26,208(a0)
-       sdc1    $f28,224(a0)
-       sdc1    $f30,240(a0)
-       jr      ra
-        sw     t0,(a1)
-1:     jr      ra
-        nop
-       END(_save_fp_context)
-
-/**
- * _restore_fp_context() - restore FP context to the FPU
- * @a0 - pointer to fpregs field of sigcontext
- * @a1 - pointer to fpc_csr field of sigcontext
- *
- * Restore FP context, including the 32 FP data registers and the FP
- * control & status register, from signal context to the FPU.
- */
-       LEAF(_restore_fp_context)
-       mfc0    t0,CP0_STATUS
-       sll     t0,t0,2
-
-       bgez    t0,1f
-        lw     t0,(a1)
-       /* Restore the 16 double precision registers */
-       ldc1    $f0,0(a0)
-       ldc1    $f2,16(a0)
-       ldc1    $f4,32(a0)
-       ldc1    $f6,48(a0)
-       ldc1    $f8,64(a0)
-       ldc1    $f10,80(a0)
-       ldc1    $f12,96(a0)
-       ldc1    $f14,112(a0)
-       ldc1    $f16,128(a0)
-       ldc1    $f18,144(a0)
-       ldc1    $f20,160(a0)
-       ldc1    $f22,176(a0)
-       ldc1    $f24,192(a0)
-       ldc1    $f26,208(a0)
-       ldc1    $f28,224(a0)
-       ldc1    $f30,240(a0)
-       jr      ra
-        ctc1   t0,fcr31
-1:     jr      ra
-        nop
-       END(_restore_fp_context)
-
-       .set pop        /* SET_HARDFLOAT */

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index b68b4d0..b52a785 100644 (file)
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -2428,21 +2428,6 @@ void __init trap_init(void)
        set_except_vector(EXCCODE_TR, handle_tr);
        set_except_vector(EXCCODE_MSAFPE, handle_msa_fpe);
 
-       if (current_cpu_type() == CPU_R6000 ||
-           current_cpu_type() == CPU_R6000A) {
-               /*
-                * The R6000 is the only R-series CPU that features a machine
-                * check exception (similar to the R4000 cache error) and
-                * unaligned ldc1/sdc1 exception.  The handlers have not been
-                * written yet.  Well, anyway there is no R6000 machine on the
-                * current list of targets for Linux/MIPS.
-                * (Duh, crap, there is someone with a triple R6k machine)
-                */
-               //set_except_vector(14, handle_mc);
-               //set_except_vector(15, handle_ndc);
-       }
-
-
        if (board_nmi_handler_setup)
                board_nmi_handler_setup();
 

diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 5aadc69..79b9f2a 100644 (file)
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -2634,11 +2634,6 @@ void build_tlb_refill_handler(void)
 #endif
                break;
 
-       case CPU_R6000:
-       case CPU_R6000A:
-               panic("No R6000 TLB refill handler yet");
-               break;
-
        case CPU_R8000:
                panic("No R8000 TLB refill handler yet");
                break;