MIPS: features: Add initial support for Segmentation Control registers

MIPS32R3 introduced a new set of Segmentation Control registers which
increase the flexibility of the segmented-based memory scheme.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Acked-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6131/

diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 296606b191863e182cead10d72a23c87bc1d5b3e..6e70b03b6aab8dbcad47703bc9d3a325adec859b 100644 (file)
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -23,6 +23,10 @@
 #ifndef cpu_has_tlbinv
 #define cpu_has_tlbinv         (cpu_data[0].options & MIPS_CPU_TLBINV)
 #endif
+#ifndef cpu_has_segments
+#define cpu_has_segments       (cpu_data[0].options & MIPS_CPU_SEGMENTS)
+#endif
+
 
 /*
  * For the moment we don't consider R6000 and R8000 so we can assume that

diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index e0a215f33d4521d17063e14f122da02f0e5c76b4..1ac232564aec09edd9e8eb34bcc7842b7e4483d5 100644 (file)
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -352,6 +352,7 @@ enum cpu_type_enum {
 #define MIPS_CPU_RIXI          0x00800000 /* CPU has TLB Read/eXec Inhibit */
 #define MIPS_CPU_MICROMIPS     0x01000000 /* CPU has microMIPS capability */
 #define MIPS_CPU_TLBINV                0x02000000 /* CPU supports TLBINV/F */
+#define MIPS_CPU_SEGMENTS      0x04000000 /* CPU supports Segmentation Control registers */
 
 /*
  * CPU ASE encodings

diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index 412fe9970781f92d98326b0e829b42c8064564f9..0558f9b429aece4e02e4630f2bc80da461c259ae 100644 (file)
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -664,6 +664,26 @@
 #define MIPS_FPIR_L            (_ULCAST_(1) << 21)
 #define MIPS_FPIR_F64          (_ULCAST_(1) << 22)
 
+/*
+ * Bits in the MIPS32 Memory Segmentation registers.
+ */
+#define MIPS_SEGCFG_PA_SHIFT   9
+#define MIPS_SEGCFG_PA         (_ULCAST_(127) << MIPS_SEGCFG_PA_SHIFT)
+#define MIPS_SEGCFG_AM_SHIFT   4
+#define MIPS_SEGCFG_AM         (_ULCAST_(7) << MIPS_SEGCFG_AM_SHIFT)
+#define MIPS_SEGCFG_EU_SHIFT   3
+#define MIPS_SEGCFG_EU         (_ULCAST_(1) << MIPS_SEGCFG_EU_SHIFT)
+#define MIPS_SEGCFG_C_SHIFT    0
+#define MIPS_SEGCFG_C          (_ULCAST_(7) << MIPS_SEGCFG_C_SHIFT)
+
+#define MIPS_SEGCFG_UUSK       _ULCAST_(7)
+#define MIPS_SEGCFG_USK                _ULCAST_(5)
+#define MIPS_SEGCFG_MUSUK      _ULCAST_(4)
+#define MIPS_SEGCFG_MUSK       _ULCAST_(3)
+#define MIPS_SEGCFG_MSK                _ULCAST_(2)
+#define MIPS_SEGCFG_MK         _ULCAST_(1)
+#define MIPS_SEGCFG_UK         _ULCAST_(0)
+
 #ifndef __ASSEMBLY__
 
 /*
@@ -1138,6 +1158,15 @@ do {                                                                     \
 #define read_c0_ebase()                __read_32bit_c0_register($15, 1)
 #define write_c0_ebase(val)    __write_32bit_c0_register($15, 1, val)
 
+/* MIPSR3 */
+#define read_c0_segctl0()      __read_32bit_c0_register($5, 2)
+#define write_c0_segctl0(val)  __write_32bit_c0_register($5, 2, val)
+
+#define read_c0_segctl1()      __read_32bit_c0_register($5, 3)
+#define write_c0_segctl1(val)  __write_32bit_c0_register($5, 3, val)
+
+#define read_c0_segctl2()      __read_32bit_c0_register($5, 4)
+#define write_c0_segctl2(val)  __write_32bit_c0_register($5, 4, val)
 
 /* Cavium OCTEON (cnMIPS) */
 #define read_c0_cvmcount()     __read_ulong_c0_register($9, 6)

diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 5dac95a728444430cdf021f6c51abbf7107f1282..b534d33699f1a36ee8180eda16ea9fded686f71a 100644 (file)
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -272,6 +272,8 @@ static inline unsigned int decode_config3(struct cpuinfo_mips *c)
                c->options |= MIPS_CPU_MICROMIPS;
        if (config3 & MIPS_CONF3_VZ)
                c->ases |= MIPS_ASE_VZ;
+       if (config3 & MIPS_CONF3_SC)
+               c->options |= MIPS_CPU_SEGMENTS;
 
        return config3 & MIPS_CONF_M;
 }