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Date:      Tue, 17 Jun 2014 20:58:27 +0200
From:      Michael Tuexen <tuexen@freebsd.org>
To:        Mark R V Murray <markm@FreeBSD.org>
Cc:        Hans Petter Selasky <hps@selasky.org>, svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org
Subject:   Re: svn commit: r266083 - in head/sys/arm: arm include
Message-ID:  <CDC9896A-FE7A-47EA-B8D0-EE34EFA0D6F4@freebsd.org>
In-Reply-To: <7124948D-6F58-4E01-AA61-E381AC223F39@FreeBSD.org>
References:  <201405141911.s4EJBFZZ097826@svn.freebsd.org> <537D0952.2040001@selasky.org> <7610C8E6-3F01-4317-BC1A-67645A162CD7@FreeBSD.org> <53871493.2010502@selasky.org> <EE7E19AA-BE18-4740-A636-4DA3023A5392@FreeBSD.org> <9412A358-EBCB-4A5A-B728-2A15C50FC217@fh-muenster.de> <D118F546-0F32-429F-86F2-69BEE0EC2D2F@FreeBSD.org> <CC36082E-1DFD-4576-9653-970F93A3699C@fh-muenster.de> <FD5DF228-1B2B-48F9-8445-54BF5959FEDA@FreeBSD.org> <9B438991-C970-46A7-8116-A490E02D7139@fh-muenster.de> <3841D090-5973-40B0-B61C-F15E8C1978C9@FreeBSD.org> <3664DBD3-7CEA-43E8-9757-E835BB21FE9E@freebsd.org> <5F36DFA5-C5B1-4E5D-88EE-9D60240B40FD@FreeBSD.org> <494BE7DA-26BC-43A7-8BC0-ECAE8A75E1EF@freebsd.org> <6268E444-F6C7-4B8B-86B7-244A2BB3C4DE@FreeBSD.org> <44F7EEB4-46D1-49C7-A4CA-4EA5D41BDF31@freebsd.org> <C2B493ED-DF51-4EC4-9655-EB14499E44C2@FreeBSD.org> <1F3FE585-4C04-499E-86CE-BA4DC3F05D97@freebsd.org> <7124948D-6F58-4E01-AA61-E381AC223F39@FreeBSD.org>

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

> Hi Michael,
>=20
> If that works, then Brilliant! :-) :-)
>=20
> Could you please fix this so the _PMC_USER_READ_WRITE_ is all in one =
place (it=92s 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
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- 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



>=20
> With that, its good to commit, I=92d say. I=92ll 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
>=20
> M
>=20
> On 17 Jun 2014, at 10:52, Michael Tuexen <tuexen@freebsd.org> wrote:
>=20
>> On 16 Jun 2014, at 22:13, Mark R V Murray <markm@FreeBSD.org> wrote:
>> Hi Mark,
>>=20
>> I just adopted the comments to the code change. So here is the =
improved patch:
>>=20
>> Index: cpufunc.c
>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>> --- 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=20
>> +	 */
>> +	__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
>>=20
>> Let me know if I can help.
>>=20
>> Best regards
>> Michael
>>>=20
>>> On 16 Jun 2014, at 20:38, Michael Tuexen <tuexen@freebsd.org> wrote:
>>>> Hmm, the documentation reads
>>>=20
>>> Which docs are you using?
>>>=20
>>> I=92m using DDI0360F. (And that could easily be a wrong choice).
>>>=20
>>> M
>>> --=20
>>> Mark R V Murray
>>>=20
>>>=20
>>=20
>=20
> --=20
> Mark R V Murray
>=20
>=20




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