Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus

[firefly-linux-kernel-4.4.55.git] / arch / mips / kernel / cpu-probe.c

diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index de8dc4ca1a6915d4e385f36d3351e50eca62659c..5342674842f5826572b71ce10a76c7a2f635139f 100644 (file)
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -250,6 +250,32 @@ static void set_isa(struct cpuinfo_mips *c, unsigned int isa)
 static char unknown_isa[] = KERN_ERR \
        "Unsupported ISA type, c0.config0: %d.";
 
+static unsigned int calculate_ftlb_probability(struct cpuinfo_mips *c)
+{
+
+       unsigned int probability = c->tlbsize / c->tlbsizevtlb;
+
+       /*
+        * 0 = All TLBWR instructions go to FTLB
+        * 1 = 15:1: For every 16 TBLWR instructions, 15 go to the
+        * FTLB and 1 goes to the VTLB.
+        * 2 = 7:1: As above with 7:1 ratio.
+        * 3 = 3:1: As above with 3:1 ratio.
+        *
+        * Use the linear midpoint as the probability threshold.
+        */
+       if (probability >= 12)
+               return 1;
+       else if (probability >= 6)
+               return 2;
+       else
+               /*
+                * So FTLB is less than 4 times bigger than VTLB.
+                * A 3:1 ratio can still be useful though.
+                */
+               return 3;
+}
+
 static void set_ftlb_enable(struct cpuinfo_mips *c, int enable)
 {
        unsigned int config6;
@@ -260,9 +286,14 @@ static void set_ftlb_enable(struct cpuinfo_mips *c, int enable)
        case CPU_P5600:
                /* proAptiv & related cores use Config6 to enable the FTLB */
                config6 = read_c0_config6();
+               /* Clear the old probability value */
+               config6 &= ~(3 << MIPS_CONF6_FTLBP_SHIFT);
                if (enable)
                        /* Enable FTLB */
-                       write_c0_config6(config6 | MIPS_CONF6_FTLBEN);
+                       write_c0_config6(config6 |
+                                        (calculate_ftlb_probability(c)
+                                         << MIPS_CONF6_FTLBP_SHIFT)
+                                        | MIPS_CONF6_FTLBEN);
                else
                        /* Disable FTLB */
                        write_c0_config6(config6 &  ~MIPS_CONF6_FTLBEN);