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authorLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>2013-11-14 16:12:31 +0000
committerRalf Baechle <ralf@linux-mips.org>2014-01-22 20:19:00 +0100
commit75b5b5e0a262790fa11043fe45700499c7e3d818 (patch)
tree3c5af9caa9c5478668159ff34db0ab34b51d7511 /arch/mips/kernel
parent601cfa7b6fb657cff9e8f77bbcce79f75dd7ab74 (diff)
MIPS: Add support for FTLBs
The Fixed Page Size TLB (FTLB) is a set-associative dual entry TLB. Its purpose is to reduce the number of TLB misses by increasing the effective TLB size and keep the implementation complexity to minimum levels. A supported core can have both VTLB and FTLB. Reviewed-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Signed-off-by: John Crispin <blogic@openwrt.org> Patchwork: http://patchwork.linux-mips.org/patch/6139/
Diffstat (limited to 'arch/mips/kernel')
-rw-r--r--arch/mips/kernel/cpu-probe.c79
-rw-r--r--arch/mips/kernel/genex.S1
-rw-r--r--arch/mips/kernel/traps.c30
3 files changed, 103 insertions, 7 deletions
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index f86414ebe05e..65b61bb8882d 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -163,6 +163,25 @@ static void set_isa(struct cpuinfo_mips *c, unsigned int isa)
static char unknown_isa[] = KERN_ERR \
"Unsupported ISA type, c0.config0: %d.";
+static void set_ftlb_enable(struct cpuinfo_mips *c, int enable)
+{
+ unsigned int config6;
+ /*
+ * Config6 is implementation dependent and it's currently only
+ * used by proAptiv
+ */
+ if (c->cputype == CPU_PROAPTIV) {
+ config6 = read_c0_config6();
+ if (enable)
+ /* Enable FTLB */
+ write_c0_config6(config6 | MIPS_CONF6_FTLBEN);
+ else
+ /* Disable FTLB */
+ write_c0_config6(config6 & ~MIPS_CONF6_FTLBEN);
+ back_to_back_c0_hazard();
+ }
+}
+
static inline unsigned int decode_config0(struct cpuinfo_mips *c)
{
unsigned int config0;
@@ -170,8 +189,13 @@ static inline unsigned int decode_config0(struct cpuinfo_mips *c)
config0 = read_c0_config();
- if (((config0 & MIPS_CONF_MT) >> 7) == 1)
+ /*
+ * Look for Standard TLB or Dual VTLB and FTLB
+ */
+ if ((((config0 & MIPS_CONF_MT) >> 7) == 1) ||
+ (((config0 & MIPS_CONF_MT) >> 7) == 4))
c->options |= MIPS_CPU_TLB;
+
isa = (config0 & MIPS_CONF_AT) >> 13;
switch (isa) {
case 0:
@@ -226,8 +250,11 @@ static inline unsigned int decode_config1(struct cpuinfo_mips *c)
c->options |= MIPS_CPU_FPU;
c->options |= MIPS_CPU_32FPR;
}
- if (cpu_has_tlb)
+ if (cpu_has_tlb) {
c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
+ c->tlbsizevtlb = c->tlbsize;
+ c->tlbsizeftlbsets = 0;
+ }
return config1 & MIPS_CONF_M;
}
@@ -281,16 +308,50 @@ static inline unsigned int decode_config3(struct cpuinfo_mips *c)
static inline unsigned int decode_config4(struct cpuinfo_mips *c)
{
unsigned int config4;
+ unsigned int newcf4;
+ unsigned int mmuextdef;
+ unsigned int ftlb_page = MIPS_CONF4_FTLBPAGESIZE;
config4 = read_c0_config4();
- if ((config4 & MIPS_CONF4_MMUEXTDEF) == MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT
- && cpu_has_tlb)
- c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
-
if (cpu_has_tlb) {
if (((config4 & MIPS_CONF4_IE) >> 29) == 2)
c->options |= MIPS_CPU_TLBINV;
+ mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF;
+ switch (mmuextdef) {
+ case MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT:
+ c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40;
+ c->tlbsizevtlb = c->tlbsize;
+ break;
+ case MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT:
+ c->tlbsizevtlb +=
+ ((config4 & MIPS_CONF4_VTLBSIZEEXT) >>
+ MIPS_CONF4_VTLBSIZEEXT_SHIFT) * 0x40;
+ c->tlbsize = c->tlbsizevtlb;
+ ftlb_page = MIPS_CONF4_VFTLBPAGESIZE;
+ /* fall through */
+ case MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT:
+ newcf4 = (config4 & ~ftlb_page) |
+ (page_size_ftlb(mmuextdef) <<
+ MIPS_CONF4_FTLBPAGESIZE_SHIFT);
+ write_c0_config4(newcf4);
+ back_to_back_c0_hazard();
+ config4 = read_c0_config4();
+ if (config4 != newcf4) {
+ pr_err("PAGE_SIZE 0x%lx is not supported by FTLB (config4=0x%x)\n",
+ PAGE_SIZE, config4);
+ /* Switch FTLB off */
+ set_ftlb_enable(c, 0);
+ break;
+ }
+ c->tlbsizeftlbsets = 1 <<
+ ((config4 & MIPS_CONF4_FTLBSETS) >>
+ MIPS_CONF4_FTLBSETS_SHIFT);
+ c->tlbsizeftlbways = ((config4 & MIPS_CONF4_FTLBWAYS) >>
+ MIPS_CONF4_FTLBWAYS_SHIFT) + 2;
+ c->tlbsize += c->tlbsizeftlbways * c->tlbsizeftlbsets;
+ break;
+ }
}
c->kscratch_mask = (config4 >> 16) & 0xff;
@@ -319,6 +380,9 @@ static void decode_configs(struct cpuinfo_mips *c)
c->scache.flags = MIPS_CACHE_NOT_PRESENT;
+ /* Enable FTLB if present */
+ set_ftlb_enable(c, 1);
+
ok = decode_config0(c); /* Read Config registers. */
BUG_ON(!ok); /* Arch spec violation! */
if (ok)
@@ -682,7 +746,6 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
{
- decode_configs(c);
switch (c->processor_id & PRID_IMP_MASK) {
case PRID_IMP_4KC:
c->cputype = CPU_4KC;
@@ -756,6 +819,8 @@ static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
break;
}
+ decode_configs(c);
+
spram_config();
}
diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S
index 47d7583cd67f..d84f6a509502 100644
--- a/arch/mips/kernel/genex.S
+++ b/arch/mips/kernel/genex.S
@@ -476,6 +476,7 @@ NESTED(nmi_handler, PT_SIZE, sp)
BUILD_HANDLER ov ov sti silent /* #12 */
BUILD_HANDLER tr tr sti silent /* #13 */
BUILD_HANDLER fpe fpe fpe silent /* #15 */
+ BUILD_HANDLER ftlb ftlb none silent /* #16 */
BUILD_HANDLER mdmx mdmx sti silent /* #22 */
#ifdef CONFIG_HARDWARE_WATCHPOINTS
/*
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index e98f3ab2a018..39370e1d4362 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -78,6 +78,7 @@ extern asmlinkage void handle_cpu(void);
extern asmlinkage void handle_ov(void);
extern asmlinkage void handle_tr(void);
extern asmlinkage void handle_fpe(void);
+extern asmlinkage void handle_ftlb(void);
extern asmlinkage void handle_mdmx(void);
extern asmlinkage void handle_watch(void);
extern asmlinkage void handle_mt(void);
@@ -1460,6 +1461,34 @@ asmlinkage void cache_parity_error(void)
panic("Can't handle the cache error!");
}
+asmlinkage void do_ftlb(void)
+{
+ const int field = 2 * sizeof(unsigned long);
+ unsigned int reg_val;
+
+ /* For the moment, report the problem and hang. */
+ if (cpu_has_mips_r2 &&
+ ((current_cpu_data.processor_id && 0xff0000) == PRID_COMP_MIPS)) {
+ pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
+ read_c0_ecc());
+ pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
+ reg_val = read_c0_cacheerr();
+ pr_err("c0_cacheerr == %08x\n", reg_val);
+
+ if ((reg_val & 0xc0000000) == 0xc0000000) {
+ pr_err("Decoded c0_cacheerr: FTLB parity error\n");
+ } else {
+ pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
+ reg_val & (1<<30) ? "secondary" : "primary",
+ reg_val & (1<<31) ? "data" : "insn");
+ }
+ } else {
+ pr_err("FTLB error exception\n");
+ }
+ /* Just print the cacheerr bits for now */
+ cache_parity_error();
+}
+
/*
* SDBBP EJTAG debug exception handler.
* We skip the instruction and return to the next instruction.
@@ -2009,6 +2038,7 @@ void __init trap_init(void)
if (cpu_has_fpu && !cpu_has_nofpuex)
set_except_vector(15, handle_fpe);
+ set_except_vector(16, handle_ftlb);
set_except_vector(22, handle_mdmx);
if (cpu_has_mcheck)

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