From: Leonid Yegoshin <Leonid.Yegoshin@xxxxxxxxxx>
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@xxxxxxxxxx>
Reviewed-by: Paul Burton <paul.burton@xxxxxxxxxx>
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@xxxxxxxxxx>
Signed-off-by: Markos Chandras <markos.chandras@xxxxxxxxxx>
---
arch/mips/include/asm/cpu-info.h | 3 ++
arch/mips/include/asm/mipsregs.h | 2 +
arch/mips/include/asm/page.h | 25 +++++++++++++
arch/mips/kernel/cpu-probe.c | 79 ++++++++++++++++++++++++++++++++++++----
arch/mips/kernel/genex.S | 1 +
arch/mips/kernel/traps.c | 30 +++++++++++++++
arch/mips/mm/tlb-r4k.c | 29 +++++++++++----
7 files changed, 155 insertions(+), 14 deletions(-)
diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h
index 21c8e29..8f7adf0 100644
--- a/arch/mips/include/asm/cpu-info.h
+++ b/arch/mips/include/asm/cpu-info.h
@@ -52,6 +52,9 @@ struct cpuinfo_mips {
unsigned int cputype;
int isa_level;
int tlbsize;
+ int tlbsizevtlb;
+ int tlbsizeftlbsets;
+ int tlbsizeftlbways;
struct cache_desc icache; /* Primary I-cache */
struct cache_desc dcache; /* Primary D or combined I/D cache */
struct cache_desc scache; /* Secondary cache */
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index d9910a1..cb57e07 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -645,6 +645,8 @@
#define MIPS_CONF5_K (_ULCAST_(1) << 30)
#define MIPS_CONF6_SYND (_ULCAST_(1) << 13)
+/* proAptiv FTLB on/off bit */
+#define MIPS_CONF6_FTLBEN (_ULCAST_(1) << 15)
#define MIPS_CONF7_WII (_ULCAST_(1) << 31)
diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h
index f6be474..5e08bcc 100644
--- a/arch/mips/include/asm/page.h
+++ b/arch/mips/include/asm/page.h
@@ -11,6 +11,8 @@
#include <spaces.h>
#include <linux/const.h>
+#include <linux/kernel.h>
+#include <asm/mipsregs.h>
/*
* PAGE_SHIFT determines the page size
@@ -33,6 +35,29 @@
#define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
#define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
+/*
+ * This is used for calculating the real page sizes
+ * for FTLB or VTLB + FTLB confugrations.
+ */
+static inline unsigned int page_size_ftlb(unsigned int mmuextdef)
+{
+ switch (mmuextdef) {
+ case MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT:
+ if (PAGE_SIZE == (1 << 30))
+ return 5;
+ if (PAGE_SIZE == (1llu << 32))
+ return 6;
+ if (PAGE_SIZE > (256 << 10))
+ return 7; /* reserved */
+ /* fall through */
+ case MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT:
+ return (PAGE_SHIFT - 10) / 2;
+ default:
+ panic("Invalid FTLB configuration with Conf4_mmuextdef=%d value\n",
+ mmuextdef >> 14);
+ }
+}
+
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
#define HPAGE_SHIFT (PAGE_SHIFT + PAGE_SHIFT - 3)
#define HPAGE_SIZE (_AC(1,UL) << HPAGE_SHIFT)
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 3f2468f..5487822 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 47d7583..d84f6a5 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 cc20415..7541855 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);
@@ -1447,6 +1448,34 @@ 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.
@@ -1996,6 +2025,7 @@ 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)
diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
index 427dcac..ae4ca24 100644
--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -72,7 +72,7 @@ void local_flush_tlb_all(void)
{
unsigned long flags;
unsigned long old_ctx;
- int entry;
+ int entry, ftlbhighset;
ENTER_CRITICAL(flags);
/* Save old context and create impossible VPN2 value */
@@ -83,10 +83,21 @@ void local_flush_tlb_all(void)
entry = read_c0_wired();
/* Blast 'em all away. */
- if (cpu_has_tlbinv && current_cpu_data.tlbsize) {
- write_c0_index(0);
- mtc0_tlbw_hazard();
- tlbinvf(); /* invalidate VTLB */
+ if (cpu_has_tlbinv) {
+ if (current_cpu_data.tlbsizevtlb) {
+ write_c0_index(0);
+ mtc0_tlbw_hazard();
+ tlbinvf(); /* invalidate VTLB */
+ }
+ ftlbhighset = current_cpu_data.tlbsizevtlb +
+ current_cpu_data.tlbsizeftlbsets;
+ for (entry = current_cpu_data.tlbsizevtlb;
+ entry < ftlbhighset;
+ entry++) {
+ write_c0_index(entry);
+ mtc0_tlbw_hazard();
+ tlbinvf(); /* invalidate one FTLB set */
+ }
} else {
while (entry < current_cpu_data.tlbsize) {
/* Make sure all entries differ. */
@@ -134,7 +145,9 @@ void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
start = round_down(start, PAGE_SIZE << 1);
end = round_up(end, PAGE_SIZE << 1);
size = (end - start) >> (PAGE_SHIFT + 1);
- if (size <= current_cpu_data.tlbsize/2) {
+ if (size <= (current_cpu_data.tlbsizeftlbsets ?
+ current_cpu_data.tlbsize / 8 :
+ current_cpu_data.tlbsize / 2)) {
int oldpid = read_c0_entryhi();
int newpid = cpu_asid(cpu, mm);
@@ -173,7 +186,9 @@ void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
ENTER_CRITICAL(flags);
size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
size = (size + 1) >> 1;
- if (size <= current_cpu_data.tlbsize / 2) {
+ if (size <= (current_cpu_data.tlbsizeftlbsets ?
+ current_cpu_data.tlbsize / 8 :
+ current_cpu_data.tlbsize / 2)) {
int pid = read_c0_entryhi();
start &= (PAGE_MASK << 1);
--
1.8.4.3
