New Loongson-3 (Loongson-3A R2, Loongson-3A R3, and newer) has SFB (Store Fill Buffer) which can improve the performance of memory access. Now, SFB enablement is controlled by CONFIG_LOONGSON3_ENHANCEMENT, and the generic kernel has no benefit from SFB (even it is running on a new Loongson-3 machine). With this patch, we can enable SFB at runtime by detecting the CPU type (the expense is war_io_reorder_wmb() will always be a 'sync', which will hurt the performance of old Loongson-3). Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx> --- arch/mips/include/asm/io.h | 2 +- .../mips/include/asm/mach-loongson64/kernel-entry-init.h | 16 ++++++++++++---- 2 files changed, 13 insertions(+), 5 deletions(-) diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h index 44f766b..eb357c9 100644 --- a/arch/mips/include/asm/io.h +++ b/arch/mips/include/asm/io.h @@ -289,7 +289,7 @@ static inline void iounmap(const volatile void __iomem *addr) #undef __IS_KSEG1 } -#if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_LOONGSON3_ENHANCEMENT) +#if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_CPU_LOONGSON3) #define war_io_reorder_wmb() wmb() #else #define war_io_reorder_wmb() barrier() 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 3127391..cbac603 100644 --- a/arch/mips/include/asm/mach-loongson64/kernel-entry-init.h +++ b/arch/mips/include/asm/mach-loongson64/kernel-entry-init.h @@ -11,6 +11,8 @@ #ifndef __ASM_MACH_LOONGSON64_KERNEL_ENTRY_H #define __ASM_MACH_LOONGSON64_KERNEL_ENTRY_H +#include <asm/cpu.h> + /* * Override macros used in arch/mips/kernel/head.S. */ @@ -26,12 +28,15 @@ mfc0 t0, CP0_PAGEGRAIN or t0, (0x1 << 29) mtc0 t0, CP0_PAGEGRAIN -#ifdef CONFIG_LOONGSON3_ENHANCEMENT /* Enable STFill Buffer */ + mfc0 t0, CP0_PRID + andi t0, (PRID_IMP_MASK | PRID_REV_MASK) + slti t0, (PRID_IMP_LOONGSON_64 | PRID_REV_LOONGSON3A_R2) + bnez t0, 1f mfc0 t0, CP0_CONFIG6 or t0, 0x100 mtc0 t0, CP0_CONFIG6 -#endif +1: _ehb .set pop #endif @@ -52,12 +57,15 @@ mfc0 t0, CP0_PAGEGRAIN or t0, (0x1 << 29) mtc0 t0, CP0_PAGEGRAIN -#ifdef CONFIG_LOONGSON3_ENHANCEMENT /* Enable STFill Buffer */ + mfc0 t0, CP0_PRID + andi t0, (PRID_IMP_MASK | PRID_REV_MASK) + slti t0, (PRID_IMP_LOONGSON_64 | PRID_REV_LOONGSON3A_R2) + bnez t0, 1f mfc0 t0, CP0_CONFIG6 or t0, 0x100 mtc0 t0, CP0_CONFIG6 -#endif +1: _ehb .set pop #endif -- 2.7.0
