New Loongson 3 CPU (since Loongson-3A R2, as opposed to Loongson-3A R1,
Loongson-3B R1 and Loongson-3B R2) has many enhancements, such as FTLB,
L1-VCache, EI/DI/Wait/Prefetch instruction, DSP/DSPv2 ASE, User Local
register, Read-Inhibit/Execute-Inhibit, SFB (Store Fill Buffer), Fast
TLB refill support, etc.
This patch introduce a config option, CONFIG_LOONGSON3_ENHANCEMENT, to
enable those enhancements which are not probed at run time. If you want
a generic kernel to run on all Loongson 3 machines, please say 'N'
here. If you want a high-performance kernel to run on new Loongson 3
machines only, please say 'Y' here.
Some additional explanations:
1) SFB locates between core and L1 cache, it causes memory access out
of order, so writel/outl (and other similar functions) need a I/O
reorder barrier.
2) Loongson 3 has a bug that di instruction can not save the irqflag,
so arch_local_irq_save() is modified. Since CPU_MIPSR2 is selected
by CONFIG_LOONGSON3_ENHANCEMENT, generic kernel doesn't use ei/di
at all.
3) CPU_HAS_PREFETCH is selected by CONFIG_LOONGSON3_ENHANCEMENT, so
MIPS_CPU_PREFETCH (used by uasm) probing is also put in this patch.
Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
---
arch/mips/Kconfig | 18 ++++++++++++++++++
arch/mips/include/asm/hazards.h | 7 ++++---
arch/mips/include/asm/io.h | 10 +++++-----
arch/mips/include/asm/irqflags.h | 5 +++++
.../include/asm/mach-loongson64/kernel-entry-init.h | 12 ++++++++++++
arch/mips/mm/c-r4k.c | 2 ++
arch/mips/mm/page.c | 9 +++++++++
7 files changed, 55 insertions(+), 8 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 38c0b11..24bb973 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1350,6 +1350,24 @@ config CPU_LOONGSON3
The Loongson 3 processor implements the MIPS64R2 instruction
set with many extensions.
+config LOONGSON3_ENHANCEMENT
+ bool "New Loongson 3 CPU Enhancements"
+ default n
+ select CPU_MIPSR2
+ select CPU_HAS_PREFETCH
+ depends on CPU_LOONGSON3
+ help
+ New Loongson 3 CPU (since Loongson-3A R2, as opposed to Loongson-3A
+ R1, Loongson-3B R1 and Loongson-3B R2) has many enhancements, such as
+ FTLB, L1-VCache, EI/DI/Wait/Prefetch instruction, DSP/DSPv2 ASE, User
+ Local register, Read-Inhibit/Execute-Inhibit, SFB (Store Fill Buffer),
+ Fast TLB refill support, etc.
+
+ This option enable those enhancements which are not probed at run
+ time. If you want a generic kernel to run on all Loongson 3 machines,
+ please say 'N' here. If you want a high-performance kernel to run on
+ new Loongson 3 machines only, please say 'Y' here.
+
config CPU_LOONGSON2E
bool "Loongson 2E"
depends on SYS_HAS_CPU_LOONGSON2E
diff --git a/arch/mips/include/asm/hazards.h b/arch/mips/include/asm/hazards.h
index 7b99efd..dbb1eb6 100644
--- a/arch/mips/include/asm/hazards.h
+++ b/arch/mips/include/asm/hazards.h
@@ -22,7 +22,8 @@
/*
* TLB hazards
*/
-#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6) && !defined(CONFIG_CPU_CAVIUM_OCTEON)
+#if (defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)) && \
+ !defined(CONFIG_CPU_CAVIUM_OCTEON) && !defined(CONFIG_LOONGSON3_ENHANCEMENT)
/*
* MIPSR2 defines ehb for hazard avoidance
@@ -155,8 +156,8 @@ do { \
} while (0)
#elif defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_CPU_CAVIUM_OCTEON) || \
- defined(CONFIG_CPU_LOONGSON2) || defined(CONFIG_CPU_R10000) || \
- defined(CONFIG_CPU_R5500) || defined(CONFIG_CPU_XLR)
+ defined(CONFIG_CPU_LOONGSON2) || defined(CONFIG_LOONGSON3_ENHANCEMENT) || \
+ defined(CONFIG_CPU_R10000) || defined(CONFIG_CPU_R5500) || defined(CONFIG_CPU_XLR)
/*
* R10000 rocks - all hazards handled in hardware, so this becomes a nobrainer.
diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 2b4dc7a..ecabc00 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -304,10 +304,10 @@ static inline void iounmap(const volatile void __iomem *addr)
#undef __IS_KSEG1
}
-#ifdef CONFIG_CPU_CAVIUM_OCTEON
-#define war_octeon_io_reorder_wmb() wmb()
+#if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_LOONGSON3_ENHANCEMENT)
+#define war_io_reorder_wmb() wmb()
#else
-#define war_octeon_io_reorder_wmb() do { } while (0)
+#define war_io_reorder_wmb() do { } while (0)
#endif
#define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, irq) \
@@ -318,7 +318,7 @@ static inline void pfx##write##bwlq(type val, \
volatile type *__mem; \
type __val; \
\
- war_octeon_io_reorder_wmb(); \
+ war_io_reorder_wmb(); \
\
__mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem)); \
\
@@ -387,7 +387,7 @@ static inline void pfx##out##bwlq##p(type val, unsigned long port) \
volatile type *__addr; \
type __val; \
\
- war_octeon_io_reorder_wmb(); \
+ war_io_reorder_wmb(); \
\
__addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
\
diff --git a/arch/mips/include/asm/irqflags.h b/arch/mips/include/asm/irqflags.h
index 65c351e..9d3610b 100644
--- a/arch/mips/include/asm/irqflags.h
+++ b/arch/mips/include/asm/irqflags.h
@@ -41,7 +41,12 @@ static inline unsigned long arch_local_irq_save(void)
" .set push \n"
" .set reorder \n"
" .set noat \n"
+#if defined(CONFIG_CPU_LOONGSON3)
+ " mfc0 %[flags], $12 \n"
+ " di \n"
+#else
" di %[flags] \n"
+#endif
" andi %[flags], 1 \n"
" " __stringify(__irq_disable_hazard) " \n"
" .set pop \n"
diff --git a/arch/mips/include/asm/mach-loongson64/kernel-entry-init.h b/arch/mips/include/asm/mach-loongson64/kernel-entry-init.h
index da83482..8393bc54 100644
--- a/arch/mips/include/asm/mach-loongson64/kernel-entry-init.h
+++ b/arch/mips/include/asm/mach-loongson64/kernel-entry-init.h
@@ -26,6 +26,12 @@
mfc0 t0, $5, 1
or t0, (0x1 << 29)
mtc0 t0, $5, 1
+#ifdef CONFIG_LOONGSON3_ENHANCEMENT
+ /* Enable STFill Buffer */
+ mfc0 t0, $16, 6
+ or t0, 0x100
+ mtc0 t0, $16, 6
+#endif
_ehb
.set pop
#endif
@@ -46,6 +52,12 @@
mfc0 t0, $5, 1
or t0, (0x1 << 29)
mtc0 t0, $5, 1
+#ifdef CONFIG_LOONGSON3_ENHANCEMENT
+ /* Enable STFill Buffer */
+ mfc0 t0, $16, 6
+ or t0, 0x100
+ mtc0 t0, $16, 6
+#endif
_ehb
.set pop
#endif
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 8df4a94..51cc4f0 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -1149,6 +1149,8 @@ static void probe_pcache(void)
c->dcache.ways *
c->dcache.linesz;
c->dcache.waybit = 0;
+ if ((prid & PRID_REV_MASK) >= PRID_REV_LOONGSON3A_R2)
+ c->options |= MIPS_CPU_PREFETCH;
break;
case CPU_CAVIUM_OCTEON3:
diff --git a/arch/mips/mm/page.c b/arch/mips/mm/page.c
index 885d73f..c41953c 100644
--- a/arch/mips/mm/page.c
+++ b/arch/mips/mm/page.c
@@ -188,6 +188,15 @@ static void set_prefetch_parameters(void)
}
break;
+ case CPU_LOONGSON3:
+ /* Loongson-3 only support the Pref_Load/Pref_Store. */
+ pref_bias_clear_store = 128;
+ pref_bias_copy_load = 128;
+ pref_bias_copy_store = 128;
+ pref_src_mode = Pref_Load;
+ pref_dst_mode = Pref_Store;
+ break;
+
default:
pref_bias_clear_store = 128;
pref_bias_copy_load = 256;
--
2.7.0
