| Message ID | 20190129104942.31705-3-Eugeniy.Paltsev@synopsys.com |
|---|---|
| State | New |
| Headers | show |
| Series | introduce unaligned access under a Kconfig option | expand |
On 1/29/19 2:49 AM, Eugeniy Paltsev wrote: > As of today we enable unaligned access unconditionally on ARCv2. > Lets move it under Kconfig option so we can disable it in case of > using HW configuration which lacks of it. > > Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> > --- > arch/arc/Kconfig | 8 ++++++++ > arch/arc/include/asm/irqflags-arcv2.h | 4 ++++ > arch/arc/kernel/intc-arcv2.c | 4 +++- > 3 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig > index 376366a7db81..37c8aeefa3a5 100644 > --- a/arch/arc/Kconfig > +++ b/arch/arc/Kconfig > @@ -387,6 +387,14 @@ config ARC_HAS_SWAPE > > if ISA_ARCV2 > > +config ARC_USE_UNALIGNED_MEM_ACCESS > + bool "Handle unaligned access in HW and use it" > + default y > + help > + The ARC HS architecture supports unaligned memory access > + which is disabled by default. Enable unaligned access in > + hardware and use it in software. > + > config ARC_HAS_LL64 > bool "Insn: 64bit LDD/STD" > help > diff --git a/arch/arc/include/asm/irqflags-arcv2.h b/arch/arc/include/asm/irqflags-arcv2.h > index 8a4f77ea3238..9b911e2c6b31 100644 > --- a/arch/arc/include/asm/irqflags-arcv2.h > +++ b/arch/arc/include/asm/irqflags-arcv2.h > @@ -44,8 +44,12 @@ > #define ARCV2_IRQ_DEF_PRIO 1 > > /* seed value for status register */ > +#ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS > #define ISA_INIT_STATUS_BITS (STATUS_IE_MASK | STATUS_AD_MASK | \ > (ARCV2_IRQ_DEF_PRIO << 1)) > +#else > +#define ISA_INIT_STATUS_BITS (STATUS_IE_MASK | (ARCV2_IRQ_DEF_PRIO << 1)) > +#endif /* CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS */ I'd prefer to change the define of STATUS_AD_MASK itself and keep all of this unchanged ! > > #ifndef __ASSEMBLY__ > > diff --git a/arch/arc/kernel/intc-arcv2.c b/arch/arc/kernel/intc-arcv2.c > index 067ea362fb3e..84b1c7157d1b 100644 > --- a/arch/arc/kernel/intc-arcv2.c > +++ b/arch/arc/kernel/intc-arcv2.c > @@ -93,7 +93,9 @@ void arc_init_IRQ(void) > > /* setup status32, don't enable intr yet as kernel doesn't want */ > tmp = read_aux_reg(ARC_REG_STATUS32); > - tmp |= STATUS_AD_MASK | (ARCV2_IRQ_DEF_PRIO << 1); > + if (IS_ENABLED(ARC_USE_UNALIGNED_MEM_ACCESS)) > + tmp |= STATUS_AD_MASK; > + tmp |= ARCV2_IRQ_DEF_PRIO << 1; This will change after rebase as we just need to delete the code here, done in head.S > tmp &= ~STATUS_IE_MASK; > asm volatile("kflag %0 \n"::"r"(tmp)); > }
On Tue, 2019-01-29 at 21:44 +0000, Vineet Gupta wrote: > On 1/29/19 2:49 AM, Eugeniy Paltsev wrote: > > As of today we enable unaligned access unconditionally on ARCv2. > > Lets move it under Kconfig option so we can disable it in case of > > using HW configuration which lacks of it. > > > > Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> > > --- > > arch/arc/Kconfig | 8 ++++++++ > > arch/arc/include/asm/irqflags-arcv2.h | 4 ++++ > > arch/arc/kernel/intc-arcv2.c | 4 +++- > > 3 files changed, 15 insertions(+), 1 deletion(-) > > > > diff --git a/arch/arc/include/asm/irqflags-arcv2.h b/arch/arc/include/asm/irqflags-arcv2.h > > index 8a4f77ea3238..9b911e2c6b31 100644 > > --- a/arch/arc/include/asm/irqflags-arcv2.h > > +++ b/arch/arc/include/asm/irqflags-arcv2.h > > @@ -44,8 +44,12 @@ > > #define ARCV2_IRQ_DEF_PRIO 1 > > > > /* seed value for status register */ > > +#ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS > > #define ISA_INIT_STATUS_BITS (STATUS_IE_MASK | STATUS_AD_MASK | \ > > (ARCV2_IRQ_DEF_PRIO << 1)) > > +#else > > +#define ISA_INIT_STATUS_BITS (STATUS_IE_MASK | (ARCV2_IRQ_DEF_PRIO << 1)) > > +#endif /* CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS */ > > I'd prefer to change the define of STATUS_AD_MASK itself and keep all of this > unchanged ! > Actually I'd prefer to leave STATUS_AD_MASK untouched. Otherwise we will implicitly assign wrong value to STATUS_AD_MASK which is quite misleading. BTW, STATUS_AD_MASK is used in ASM code in v2 patch and it shouldn't be dependent on CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS.
On 1/30/19 8:44 AM, Eugeniy Paltsev wrote: >> I'd prefer to change the define of STATUS_AD_MASK itself and keep all of this >> unchanged ! >> > Actually I'd prefer to leave STATUS_AD_MASK untouched. Otherwise we will implicitly assign > wrong value to STATUS_AD_MASK which is quite misleading. > > BTW, STATUS_AD_MASK is used in ASM code in v2 patch and it shouldn't be dependent on > CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS. Agree ! -Vineet
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index 376366a7db81..37c8aeefa3a5 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -387,6 +387,14 @@ config ARC_HAS_SWAPE if ISA_ARCV2 +config ARC_USE_UNALIGNED_MEM_ACCESS + bool "Handle unaligned access in HW and use it" + default y + help + The ARC HS architecture supports unaligned memory access + which is disabled by default. Enable unaligned access in + hardware and use it in software. + config ARC_HAS_LL64 bool "Insn: 64bit LDD/STD" help diff --git a/arch/arc/include/asm/irqflags-arcv2.h b/arch/arc/include/asm/irqflags-arcv2.h index 8a4f77ea3238..9b911e2c6b31 100644 --- a/arch/arc/include/asm/irqflags-arcv2.h +++ b/arch/arc/include/asm/irqflags-arcv2.h @@ -44,8 +44,12 @@ #define ARCV2_IRQ_DEF_PRIO 1 /* seed value for status register */ +#ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS #define ISA_INIT_STATUS_BITS (STATUS_IE_MASK | STATUS_AD_MASK | \ (ARCV2_IRQ_DEF_PRIO << 1)) +#else +#define ISA_INIT_STATUS_BITS (STATUS_IE_MASK | (ARCV2_IRQ_DEF_PRIO << 1)) +#endif /* CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS */ #ifndef __ASSEMBLY__ diff --git a/arch/arc/kernel/intc-arcv2.c b/arch/arc/kernel/intc-arcv2.c index 067ea362fb3e..84b1c7157d1b 100644 --- a/arch/arc/kernel/intc-arcv2.c +++ b/arch/arc/kernel/intc-arcv2.c @@ -93,7 +93,9 @@ void arc_init_IRQ(void) /* setup status32, don't enable intr yet as kernel doesn't want */ tmp = read_aux_reg(ARC_REG_STATUS32); - tmp |= STATUS_AD_MASK | (ARCV2_IRQ_DEF_PRIO << 1); + if (IS_ENABLED(ARC_USE_UNALIGNED_MEM_ACCESS)) + tmp |= STATUS_AD_MASK; + tmp |= ARCV2_IRQ_DEF_PRIO << 1; tmp &= ~STATUS_IE_MASK; asm volatile("kflag %0 \n"::"r"(tmp)); }
As of today we enable unaligned access unconditionally on ARCv2. Lets move it under Kconfig option so we can disable it in case of using HW configuration which lacks of it. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> --- arch/arc/Kconfig | 8 ++++++++ arch/arc/include/asm/irqflags-arcv2.h | 4 ++++ arch/arc/kernel/intc-arcv2.c | 4 +++- 3 files changed, 15 insertions(+), 1 deletion(-)