[PATCH V4 02/16] MIPS: Loongson: Add basic Loongson-3 CPU support.

Huacai Chen
2012-08-03T07:07:07Z

Basic Loongson-3 CPU support include: CPU probing, TLB and cache
initializing, cache flushing method, etc.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Hongliang Tao <taohl@lemote.com>
Signed-off-by: Hua Yan <yanh@lemote.com>
---
arch/mips/kernel/Makefile | 1 +
arch/mips/kernel/cpu-probe.c | 12 ++++-
arch/mips/lib/Makefile | 1 +
arch/mips/mm/Makefile | 1 +
arch/mips/mm/c-r4k.c | 94 +++++++++++++++++++++++++++++++++++++++++-
arch/mips/mm/tlb-r4k.c | 2 +-
arch/mips/mm/tlbex.c | 1 +
7 files changed, 106 insertions(+), 6 deletions(-)

diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index fdaf65e..a0fc07f 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_MODULES) += mips_ksyms.o module.o
obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o

obj-$(CONFIG_CPU_LOONGSON2) += r4k_fpu.o r4k_switch.o
+obj-$(CONFIG_CPU_LOONGSON3) += r4k_fpu.o r4k_switch.o
obj-$(CONFIG_CPU_MIPS32) += r4k_fpu.o r4k_switch.o
obj-$(CONFIG_CPU_MIPS64) += r4k_fpu.o r4k_switch.o
obj-$(CONFIG_CPU_R3000) += r2300_fpu.o r2300_switch.o
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 8ea65c5..515c5e3 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -768,16 +768,22 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
c->tlbsize = 64;
break;
case PRID_IMP_LOONGSON2:
- c->cputype = CPU_LOONGSON2;
- __cpu_name[cpu] = "ICT Loongson-2";
-
switch (c->processor_id & PRID_REV_MASK) {
case PRID_REV_LOONGSON2E:
+ c->cputype = CPU_LOONGSON2;
+ __cpu_name[cpu] = "ICT Loongson-2";
set_elf_platform(cpu, "loongson2e");
break;
case PRID_REV_LOONGSON2F:
+ c->cputype = CPU_LOONGSON2;
+ __cpu_name[cpu] = "ICT Loongson-2";
set_elf_platform(cpu, "loongson2f");
break;
+ case PRID_REV_LOONGSON3A:
+ c->cputype = CPU_LOONGSON3;
+ __cpu_name[cpu] = "ICT Loongson-3";
+ set_elf_platform(cpu, "loongson3a");
+ break;
}

c->isa_level = MIPS_CPU_ISA_III;
diff --git a/arch/mips/lib/Makefile b/arch/mips/lib/Makefile
index 399a50a..2ef5535 100644
--- a/arch/mips/lib/Makefile
+++ b/arch/mips/lib/Makefile
@@ -9,6 +9,7 @@ obj-y += iomap.o
obj-$(CONFIG_PCI) += iomap-pci.o

obj-$(CONFIG_CPU_LOONGSON2) += dump_tlb.o
+obj-$(CONFIG_CPU_LOONGSON3) += dump_tlb.o
obj-$(CONFIG_CPU_MIPS32) += dump_tlb.o
obj-$(CONFIG_CPU_MIPS64) += dump_tlb.o
obj-$(CONFIG_CPU_NEVADA) += dump_tlb.o
diff --git a/arch/mips/mm/Makefile b/arch/mips/mm/Makefile
index fd6203f..a79b6d1 100644
--- a/arch/mips/mm/Makefile
+++ b/arch/mips/mm/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_HIGHMEM) += highmem.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o

obj-$(CONFIG_CPU_LOONGSON2) += c-r4k.o cex-gen.o tlb-r4k.o
+obj-$(CONFIG_CPU_LOONGSON3) += c-r4k.o cex-gen.o tlb-r4k.o
obj-$(CONFIG_CPU_MIPS32) += c-r4k.o cex-gen.o tlb-r4k.o
obj-$(CONFIG_CPU_MIPS64) += c-r4k.o cex-gen.o tlb-r4k.o
obj-$(CONFIG_CPU_NEVADA) += c-r4k.o cex-gen.o tlb-r4k.o
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index ce0dbee..3462094 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -60,6 +60,13 @@ static inline void r4k_on_each_cpu(void (*func) (void *info), void *info)
#define cpu_has_safe_index_cacheops 1
#endif

+/* Loongson-3 maintain cache coherency by hardware */
+#if defined(CONFIG_CPU_LOONGSON3)
+#define cpu_has_coherent_cache 1
+#else
+#define cpu_has_coherent_cache 0
+#endif
+
/*
* Must die.
*/
@@ -345,6 +352,10 @@ static inline void local_r4k___flush_cache_all(void * args)
r4k_blast_scache();
return;
#endif
+
+ if (cpu_has_coherent_cache)
+ return;
+
r4k_blast_dcache();
r4k_blast_icache();

@@ -382,11 +393,17 @@ static inline int has_valid_asid(const struct mm_struct *mm)

static void r4k__flush_cache_vmap(void)
{
+ if (cpu_has_coherent_cache)
+ return;
+
r4k_blast_dcache();
}

static void r4k__flush_cache_vunmap(void)
{
+ if (cpu_has_coherent_cache)
+ return;
+
r4k_blast_dcache();
}

@@ -406,8 +423,12 @@ static inline void local_r4k_flush_cache_range(void * args)
static void r4k_flush_cache_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
- int exec = vma->vm_flags & VM_EXEC;
+ int exec __maybe_unused;
+
+ if (cpu_has_coherent_cache)
+ return;

+ exec = vma->vm_flags & VM_EXEC;
if (cpu_has_dc_aliases || (exec && !cpu_has_ic_fills_f_dc))
r4k_on_each_cpu(local_r4k_flush_cache_range, vma);
}
@@ -527,7 +548,10 @@ static inline void local_r4k_flush_cache_page(void *args)
static void r4k_flush_cache_page(struct vm_area_struct *vma,
unsigned long addr, unsigned long pfn)
{
- struct flush_cache_page_args args;
+ struct flush_cache_page_args args __maybe_unused;
+
+ if (cpu_has_coherent_cache)
+ return;

args.vma = vma;
args.addr = addr;
@@ -543,6 +567,9 @@ static inline void local_r4k_flush_data_cache_page(void * addr)

static void r4k_flush_data_cache_page(unsigned long addr)
{
+ if (cpu_has_coherent_cache)
+ return;
+
if (in_atomic())
local_r4k_flush_data_cache_page((void *)addr);
else
@@ -701,6 +728,9 @@ static void local_r4k_flush_cache_sigtramp(void * arg)

static void r4k_flush_cache_sigtramp(unsigned long addr)
{
+ if (cpu_has_coherent_cache)
+ return;
+
r4k_on_each_cpu(local_r4k_flush_cache_sigtramp, (void *) addr);
}

@@ -952,6 +982,31 @@ static void __cpuinit probe_pcache(void)
c->dcache.waybit = 0;
break;

+ case CPU_LOONGSON3:
+ config1 = read_c0_config1();
+ if ((lsize = ((config1 >> 19) & 7)))
+ c->icache.linesz = 2 << lsize;
+ else
+ c->icache.linesz = lsize;
+ c->icache.sets = 64 << ((config1 >> 22) & 7);
+ c->icache.ways = 1 + ((config1 >> 16) & 7);
+ icache_size = c->icache.sets *
+ c->icache.ways *
+ c->icache.linesz;
+ c->icache.waybit = 0;
+
+ if ((lsize = ((config1 >> 10) & 7)))
+ c->dcache.linesz = 2 << lsize;
+ else
+ c->dcache.linesz = lsize;
+ c->dcache.sets = 64 << ((config1 >> 13) & 7);
+ c->dcache.ways = 1 + ((config1 >> 7) & 7);
+ dcache_size = c->dcache.sets *
+ c->dcache.ways *
+ c->dcache.linesz;
+ c->dcache.waybit = 0;
+ break;
+
default:
if (!(config & MIPS_CONF_M))
panic("Don't know how to probe P-caches on this cpu.");
@@ -1170,6 +1225,34 @@ static void __init loongson2_sc_init(void)
}
#endif

+#if defined(CONFIG_CPU_LOONGSON3)
+static void __init loongson3_sc_init(void)
+{
+ struct cpuinfo_mips *c = &current_cpu_data;
+ unsigned int config2, lsize;
+
+ config2 = read_c0_config2();
+ if ((lsize = ((config2 >> 4) & 15)))
+ c->scache.linesz = 2 << lsize;
+ else
+ c->scache.linesz = lsize;
+ c->scache.sets = 64 << ((config2 >> 8) & 15);
+ c->scache.ways = 1 + (config2 & 15);
+
+ scache_size = c->scache.sets *
+ c->scache.ways *
+ c->scache.linesz;
+ /* Loongson-3 has 4 cores, 1MB scache for each. scaches are shared */
+ scache_size *= 4;
+ c->scache.waybit = 0;
+ pr_info("Unified secondary cache %ldkB %s, linesize %d bytes.\n",
+ scache_size >> 10, way_string[c->scache.ways], c->scache.linesz);
+ if (scache_size)
+ c->options |= MIPS_CPU_INCLUSIVE_CACHES;
+ return;
+}
+#endif
+
extern int r5k_sc_init(void);
extern int rm7k_sc_init(void);
extern int mips_sc_init(void);
@@ -1224,6 +1307,13 @@ static void __cpuinit setup_scache(void)
loongson2_sc_init();
return;
#endif
+
+#if defined(CONFIG_CPU_LOONGSON3)
+ case CPU_LOONGSON3:
+ loongson3_sc_init();
+ return;
+#endif
+
case CPU_XLP:
/* don't need to worry about L2, fully coherent */
return;
diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
index d2572cb..11b9c88 100644
--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -50,7 +50,7 @@ extern void build_tlb_refill_handler(void);

#endif /* CONFIG_MIPS_MT_SMTC */

-#if defined(CONFIG_CPU_LOONGSON2)
+#if defined(CONFIG_CPU_LOONGSON2) || defined(CONFIG_CPU_LOONGSON3)
/*
* LOONGSON2 has a 4 entry itlb which is a subset of dtlb,
* unfortrunately, itlb is not totally transparent to software.
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 03eb0ef..4420250 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -507,6 +507,7 @@ static void __cpuinit build_tlb_write_entry(u32 **p, struct uasm_label **l,
case CPU_BMIPS4380:
case CPU_BMIPS5000:
case CPU_LOONGSON2:
+ case CPU_LOONGSON3:
case CPU_R5500:
if (m4kc_tlbp_war())
uasm_i_nop(p);
--
1.7.7.3