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

[Michael Tuexen]

On 17 Jun 2014, at 20:33, Mark R V Murray <markm at FreeBSD.org> wrote:

> 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.
So you want something like:

Index: cpufunc.c
===================================================================
--- cpufunc.c	(revision 267575)
+++ cpufunc.c	(working copy)
@@ -1410,12 +1410,27 @@
  * you want!
  */
 #ifdef _PMC_USER_READ_WRITE_
+#if defined(CPU_ARM1136) || defined(CPU_ARM1176)
+	/* 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));
+#else
 	/* 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:
+#endif
+#if defined(CPU_ARM1136) || defined(CPU_ARM1176)
+	/* Set PMCR[2,0] to enable counters and reset CCNT */
+	__asm volatile ("mcr	p15, 0, %0, c15, c12, 0\n\t"
+			:
+			: "r"(0x00000005));
+#else
+	/* 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 +1441,7 @@
 			: "r"(0xFFFFFFFF),
 			  "r"(0x00000005),
 			  "r"(0x80000000));
+#endif
 }
 #endif



> 
> With that, its good to commit, I’d say. I’ll likely follow up and exclude the architectures that are unproven.
You can commit this and your patch to include/cpu.h. I think it would be good to
have both fixes in one commit...

Best regards
Michael
> 
> 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
> 
>