Messages in this thread |  | | Date | Wed, 20 Nov 2019 12:45:38 +0100 | | From | Paul Cercueil <> | | Subject | Re: [PATCH 2/2 v3] MIPS: Ingenic: Disable abandoned HPTLB function. |
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Hi Zhou,
Le mar., nov. 19, 2019 at 22:28, Zhou Yanjie <zhouyanjie@zoho.com> a écrit : > JZ4760/JZ4770/JZ4775/X1000/X1500 has an abandoned huge page tlb, > this mode is not compatible with the MIPS standard, it will cause > tlbmiss and into an infinite loop (line 21 in the tlb-funcs.S) > when starting the init process. write 0xa9000000 to cp0 register 5 > sel 4 to disable this function to prevent getting stuck. Confirmed > by Ingenic, this operation will not adversely affect processors > without HPTLB function. > > Signed-off-by: Zhou Yanjie <zhouyanjie@zoho.com>
Acked-by: Paul Cercueil <paul@crapouillou.net>
> --- > arch/mips/include/asm/mipsregs.h | 6 ++++++ > arch/mips/kernel/cpu-probe.c | 21 +++++++++++++++++++-- > 2 files changed, 25 insertions(+), 2 deletions(-)
Still no changelog here :)
> diff --git a/arch/mips/include/asm/mipsregs.h > b/arch/mips/include/asm/mipsregs.h > index bdbdc19..0d5a309 100644 > --- a/arch/mips/include/asm/mipsregs.h > +++ b/arch/mips/include/asm/mipsregs.h > @@ -689,6 +689,9 @@ > #define MIPS_CONF7_IAR (_ULCAST_(1) << 10) > #define MIPS_CONF7_AR (_ULCAST_(1) << 16) > > +/* Ingenic HPTLB off bits */ > +#define XBURST_PAGECTRL_HPTLB_DIS 0xa9000000 > + > /* Ingenic Config7 bits */ > #define MIPS_CONF7_BTB_LOOP_EN (_ULCAST_(1) << 4) > > @@ -1971,6 +1974,9 @@ do { \ > #define read_c0_brcm_sleepcount() __read_32bit_c0_register($22, 7) > #define write_c0_brcm_sleepcount(val) __write_32bit_c0_register($22, > 7, val) > > +/* Ingenic page ctrl register */ > +#define write_c0_page_ctrl(val) __write_32bit_c0_register($5, 4, val) > + > /* > * Macros to access the guest system control coprocessor > */ > diff --git a/arch/mips/kernel/cpu-probe.c > b/arch/mips/kernel/cpu-probe.c > index 7a0e33c..3b5f4fb 100644 > --- a/arch/mips/kernel/cpu-probe.c > +++ b/arch/mips/kernel/cpu-probe.c > @@ -1965,13 +1965,30 @@ static inline void cpu_probe_ingenic(struct > cpuinfo_mips *c, unsigned int cpu) > break; > } > > + switch (c->processor_id & PRID_COMP_MASK) { > + /* > + * The config0 register in the XBurst CPUs with a processor ID of > + * PRID_COMP_INGENIC_D1 has an abandoned huge page tlb mode, this > + * mode is not compatible with the MIPS standard, it will cause > + * tlbmiss and into an infinite loop (line 21 in the tlb-funcs.S) > + * when starting the init process. After chip reset, the default > + * is HPTLB mode, Write 0xa9000000 to cp0 register 5 sel 4 to > + * switch back to VTLB mode to prevent getting stuck. > + */ > + case PRID_COMP_INGENIC_D1: > + write_c0_page_ctrl(XBURST_PAGECTRL_HPTLB_DIS); > + break; > /* > - * The config0 register in the Xburst CPUs with a processor ID of > + * The config0 register in the XBurst CPUs with a processor ID of > * PRID_COMP_INGENIC_D0 report themselves as MIPS32r2 compatible, > * but they don't actually support this ISA. > */ > - if ((c->processor_id & PRID_COMP_MASK) == PRID_COMP_INGENIC_D0) > + case PRID_COMP_INGENIC_D0: > c->isa_level &= ~MIPS_CPU_ISA_M32R2; > + break; > + default: > + break; > + } > } > > static inline void cpu_probe_netlogic(struct cpuinfo_mips *c, int > cpu) > -- > 2.7.4 > >
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