| Message ID | 1315497854-13311-4-git-send-email-dave.martin@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Thursday 08 September 2011, Dave Martin wrote: > __asm__ __volatile__ ( > "mcr p15, 0, %1, c1, c0, 2\n\t" > +#ifdef __LINUX_ARM_ARCH__ >= 7 > + "isb\n\t" > +#else > "mrc p15, 0, %0, c1, c0, 2\n\t" > "mov %0, %0\n\t" > "sub pc, pc, #4\n\t" > +#endif > : "=r" (temp) : "r" (value)); > } I thought we had concluded that we don't actually need the #else path because there is no pre-v7 support for pj4 any more. Arnd
On Thu, 8 Sep 2011, Dave Martin wrote: > The iwmmxt code contains some code to implement a pseudo-ISB, but > this is not buildable for Thumb-2. > > This patch replaces the pseudo-ISB with a real one on v7 and above. > > Signed-off-by: Dave Martin <dave.martin@linaro.org> In arch/arm/mm/Kconfig: config CPU_PJ4 bool select CPU_V7 select ARM_THUMBEE So this code may only be ARMv7 aware now. Nicolas
On Thu, Sep 8, 2011 at 10:06 AM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: > On Thu, 8 Sep 2011, Dave Martin wrote: > >> The iwmmxt code contains some code to implement a pseudo-ISB, but >> this is not buildable for Thumb-2. >> >> This patch replaces the pseudo-ISB with a real one on v7 and above. >> >> Signed-off-by: Dave Martin <dave.martin@linaro.org> > > In arch/arm/mm/Kconfig: > > config CPU_PJ4 > bool > select CPU_V7 > select ARM_THUMBEE > > So this code may only be ARMv7 aware now. > True.
On Thu, Sep 08, 2011 at 06:44:21PM +0200, Arnd Bergmann wrote: > On Thursday 08 September 2011, Dave Martin wrote: > > __asm__ __volatile__ ( > > "mcr p15, 0, %1, c1, c0, 2\n\t" > > +#ifdef __LINUX_ARM_ARCH__ >= 7 > > + "isb\n\t" > > +#else > > "mrc p15, 0, %0, c1, c0, 2\n\t" > > "mov %0, %0\n\t" > > "sub pc, pc, #4\n\t" > > +#endif > > : "=r" (temp) : "r" (value)); > > } > > I thought we had concluded that we don't actually need the #else > path because there is no pre-v7 support for pj4 any more. > Ah, OK -- I somewhat missed the point, the was focusing on the other patches (I notice I didn't fix #ifdef to #if either...) Anyway, this patch can be drastically simplified -- i.e., the #if conditional should just go away, along with the xscale-style code (which really doesn't make sense for a v7-only file). So we'd end up with something like: __asm__ __volatile__ ( "mcr p15, 0, %0, c1, c0, 2\n\t" "isb" : "r" (value)); Better? Cheers ---Dave
diff --git a/arch/arm/kernel/pj4-cp0.c b/arch/arm/kernel/pj4-cp0.c index a4b1b07..5117d9d 100644 --- a/arch/arm/kernel/pj4-cp0.c +++ b/arch/arm/kernel/pj4-cp0.c @@ -66,9 +66,13 @@ static void __init pj4_cp_access_write(u32 value) __asm__ __volatile__ ( "mcr p15, 0, %1, c1, c0, 2\n\t" +#ifdef __LINUX_ARM_ARCH__ >= 7 + "isb\n\t" +#else "mrc p15, 0, %0, c1, c0, 2\n\t" "mov %0, %0\n\t" "sub pc, pc, #4\n\t" +#endif : "=r" (temp) : "r" (value)); }
The iwmmxt code contains some code to implement a pseudo-ISB, but this is not buildable for Thumb-2. This patch replaces the pseudo-ISB with a real one on v7 and above. Signed-off-by: Dave Martin <dave.martin@linaro.org> --- arch/arm/kernel/pj4-cp0.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-)