MIPS: cpu-features: Add cpu_has_ftlb

Add cpu_has_ftlb, which specifies that an FTLB is present in addition to
the VTLB, probed based on whether Config.MT == 4 (rather than 1 for
standard JTLB).

This is necessary since MIPS release 6 removes Config4.MMUExtDef, so the
presence of the FTLB fields in Config4 must be determined from Config.MT
instead.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11159/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 9801ac9826554ca0d8ab2e27e21ad6305f18da67..fe67f12ac2393b23705b4a094bbf8c3b7cc77166 100644 (file)
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -20,6 +20,9 @@
 #ifndef cpu_has_tlb
 #define cpu_has_tlb            (cpu_data[0].options & MIPS_CPU_TLB)
 #endif
+#ifndef cpu_has_ftlb
+#define cpu_has_ftlb           (cpu_data[0].options & MIPS_CPU_FTLB)
+#endif
 #ifndef cpu_has_tlbinv
 #define cpu_has_tlbinv         (cpu_data[0].options & MIPS_CPU_TLBINV)
 #endif

diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index cd89e9855775276ea7c3a185d9e61b3702f06b6f..82ad15f11049284c2f347fc66b68ea5091fb810d 100644 (file)
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -385,6 +385,7 @@ enum cpu_type_enum {
 #define MIPS_CPU_CDMM          0x4000000000ull /* CPU has Common Device Memory Map */
 #define MIPS_CPU_BP_GHIST      0x8000000000ull /* R12K+ Branch Prediction Global History */
 #define MIPS_CPU_SP            0x10000000000ull /* Small (1KB) page support */
+#define MIPS_CPU_FTLB          0x20000000000ull /* CPU has Fixed-page-size TLB */
 
 /*
  * CPU ASE encodings

diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index d3cd8eac81e3a76baf455dd95e881cfd9c72eed9..c64781cf649f86b4ca4eec0fee38ba4c4da523e7 100644 (file)
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -487,6 +487,8 @@
 
 /* Bits specific to the MIPS32/64 PRA. */
 #define MIPS_CONF_MT           (_ULCAST_(7) <<  7)
+#define MIPS_CONF_MT_TLB       (_ULCAST_(1) <<  7)
+#define MIPS_CONF_MT_FTLB      (_ULCAST_(4) <<  7)
 #define MIPS_CONF_AR           (_ULCAST_(7) << 10)
 #define MIPS_CONF_AT           (_ULCAST_(3) << 13)
 #define MIPS_CONF_M            (_ULCAST_(1) << 31)

diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 571a8e6ea5bd0048a840bc539135f27c32fec621..397551cf2e7bc3235d4dcf4d55b22485a846d79e 100644 (file)
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -410,16 +410,18 @@ static int set_ftlb_enable(struct cpuinfo_mips *c, int enable)
 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
 {
        unsigned int config0;
-       int isa;
+       int isa, mt;
 
        config0 = read_c0_config();
 
        /*
         * Look for Standard TLB or Dual VTLB and FTLB
         */
-       if ((((config0 & MIPS_CONF_MT) >> 7) == 1) ||
-           (((config0 & MIPS_CONF_MT) >> 7) == 4))
+       mt = config0 & MIPS_CONF_MT;
+       if (mt == MIPS_CONF_MT_TLB)
                c->options |= MIPS_CPU_TLB;
+       else if (mt == MIPS_CONF_MT_FTLB)
+               c->options |= MIPS_CPU_TLB | MIPS_CPU_FTLB;
 
        isa = (config0 & MIPS_CONF_AT) >> 13;
        switch (isa) {