svn commit: r266083 - in head/sys/arm: arm include

[Mark R V Murray]

Hi Michael,

If that works, then Brilliant! :-) :-)

Could you please fix this so the _PMC_USER_READ_WRITE_ is all in one place (it’s too dangerous to split up), and put an architecture-specific #ifdef around just the MCR instruction we care about.

With that, its good to commit, I’d say. I’ll likely follow up and exclude the architectures that are unproven.

M

On 17 Jun 2014, at 10:52, Michael Tuexen <tuexen at freebsd.org> wrote:

> On 16 Jun 2014, at 22:13, Mark R V Murray <markm at FreeBSD.org> wrote:
> Hi Mark,
> 
> I just adopted the comments to the code change. So here is the improved patch:
> 
> Index: cpufunc.c
> ===================================================================
> --- cpufunc.c	(revision 267575)
> +++ cpufunc.c	(working copy)
> @@ -1404,18 +1404,36 @@
> static __inline void
> cpu_scc_setup_ccnt(void)
> {
> -/* This is how you give userland access to the CCNT and PMCn
> - * registers.
> - * BEWARE! This gives write access also, which may not be what
> - * you want!
> - */
> +#if defined(CPU_ARM1136) || defined(CPU_ARM1176)
> #ifdef _PMC_USER_READ_WRITE_
> -	/* Set PMUSERENR[0] to allow userland access */
> +	/* This is how you give userland access to the CCNT and PMCn
> +	 * registers.
> +	 * BEWARE! This gives write access also, which may not be what
> +	 * you want!
> +	 * Use the Secure User and Non-secure Access Validation Control Register
> +	 * to allow userland access 
> +	 */
> +	__asm volatile ("mcr	p15, 0, %0, c15, c9, 0\n\t"
> +			:
> +			: "r"(0x00000001));
> +#endif
> +	/* Set PMCR[2,0] to enable counters and reset CCNT */
> +	__asm volatile ("mcr	p15, 0, %0, c15, c12, 0\n\t"
> +			:
> +			: "r"(0x00000005));
> +#else
> +#ifdef _PMC_USER_READ_WRITE_
> +	/* This is how you give userland access to the CCNT and PMCn
> +	 * registers.
> +	 * BEWARE! This gives write access also, which may not be what
> +	 * you want!
> +	 * Set PMUSERENR[0] to allow userland access
> +	 */
> 	__asm volatile ("mcr	p15, 0, %0, c9, c14, 0\n\t"
> 			:
> 			: "r"(0x00000001));
> #endif
> -        /* Set up the PMCCNTR register as a cyclecounter:
> +	/* Set up the PMCCNTR register as a cyclecounter:
> 	 * Set PMINTENCLR to 0xFFFFFFFF to block interrupts
> 	 * Set PMCR[2,0] to enable counters and reset CCNT
> 	 * Set PMCNTENSET to 0x80000000 to enable CCNT */
> @@ -1426,6 +1444,7 @@
> 			: "r"(0xFFFFFFFF),
> 			  "r"(0x00000005),
> 			  "r"(0x80000000));
> +#endif
> }
> #endif
> 
> Let me know if I can help.
> 
> Best regards
> Michael
>> 
>> On 16 Jun 2014, at 20:38, Michael Tuexen <tuexen at freebsd.org> wrote:
>>> Hmm, the documentation reads
>> 
>> Which docs are you using?
>> 
>> I’m using DDI0360F. (And that could easily be a wrong choice).
>> 
>> M
>> -- 
>> Mark R V Murray
>> 
>> 
> 

-- 
Mark R V Murray