linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* Re: [PATCH v3] MIPS: add support for buggy MT7621S core detection
@ 2021-09-16  2:56 Greg Ungerer
  2021-09-16  6:33 ` Sergio Paracuellos
  2021-09-16  8:54 ` Strontium
  0 siblings, 2 replies; 11+ messages in thread
From: Greg Ungerer @ 2021-09-16  2:56 UTC (permalink / raw)
  To: ilya.lipnitskiy
  Cc: linux-kernel, linux-mips, liwei391, macro, nbd, tsbogend, yangtiezhu

Hi Ilya,

> Most MT7621 SoCs have 2 cores, which is detected and supported properly
> by CPS.
> 
> Unfortunately, MT7621 SoC has a less common S variant with only one core.
> On MT7621S, GCR_CONFIG still reports 2 cores, which leads to hangs when
> starting SMP. CPULAUNCH registers can be used in that case to detect the
> absence of the second core and override the GCR_CONFIG PCORES field.
> 
> Rework a long-standing OpenWrt patch to override the value of
> mips_cps_numcores on single-core MT7621 systems.
> 
> Tested on a dual-core MT7621 device (Ubiquiti ER-X) and a single-core
> MT7621 device (Netgear R6220).

This is breaking core detection on my MT7621 based platforms.
I only get 2 cores detected now running 5.13. Reverting this change gives
me 4 cores back.

 From a fully working (pre-change) system I get:

# cat /proc/cpuinfo
system type		: MediaTek MT7621 ver:1 eco:3
machine			: Digi EX15
processor		: 0
cpu model		: MIPS 1004Kc V2.15
BogoMIPS		: 586.13
wait instruction	: yes
microsecond timers	: yes
tlb_entries		: 32
extra interrupt vector	: yes
hardware watchpoint	: yes, count: 4, address/irw mask: [0x0ffc, 0x0ffc, 0x0ffb, 0x0ffb]
isa			: mips1 mips2 mips32r1 mips32r2
ASEs implemented	: mips16 dsp mt
shadow register sets	: 1
kscratch registers	: 0
package			: 0
core			: 0
VPE			: 0
VCED exceptions		: not available
VCEI exceptions		: not available

processor		: 1
cpu model		: MIPS 1004Kc V2.15
BogoMIPS		: 586.13
wait instruction	: yes
microsecond timers	: yes
tlb_entries		: 32
extra interrupt vector	: yes
hardware watchpoint	: yes, count: 4, address/irw mask: [0x0ffc, 0x0ffc, 0x0ffb, 0x0ffb]
isa			: mips1 mips2 mips32r1 mips32r2
ASEs implemented	: mips16 dsp mt
shadow register sets	: 1
kscratch registers	: 0
package			: 0
core			: 0
VPE			: 1
VCED exceptions		: not available
VCEI exceptions		: not available

processor		: 2
cpu model		: MIPS 1004Kc V2.15
BogoMIPS		: 586.13
wait instruction	: yes
microsecond timers	: yes
tlb_entries		: 32
extra interrupt vector	: yes
hardware watchpoint	: yes, count: 4, address/irw mask: [0x0ffc, 0x0ffc, 0x0ffb, 0x0ffb]
isa			: mips1 mips2 mips32r1 mips32r2
ASEs implemented	: mips16 dsp mt
shadow register sets	: 1
kscratch registers	: 0
package			: 0
core			: 1
VPE			: 0
VCED exceptions		: not available
VCEI exceptions		: not available

processor		: 3
cpu model		: MIPS 1004Kc V2.15
BogoMIPS		: 586.13
wait instruction	: yes
microsecond timers	: yes
tlb_entries		: 32
extra interrupt vector	: yes
hardware watchpoint	: yes, count: 4, address/irw mask: [0x0ffc, 0x0ffc, 0x0ffb, 0x0ffb]
isa			: mips1 mips2 mips32r1 mips32r2
ASEs implemented	: mips16 dsp mt
shadow register sets	: 1
kscratch registers	: 0
package			: 0
core			: 1
VPE			: 1
VCED exceptions		: not available
VCEI exceptions		: not available


After this patch is applied:

# cat /proc/cpuinfo
system type		: MediaTek MT7621 ver:1 eco:3
machine			: Digi EX15
processor		: 0
cpu model		: MIPS 1004Kc V2.15
BogoMIPS		: 586.13
wait instruction	: yes
microsecond timers	: yes
tlb_entries		: 32
extra interrupt vector	: yes
hardware watchpoint	: yes, count: 4, address/irw mask: [0x0ffc, 0x0ffc, 0x0ffb, 0x0ffb]
isa			: mips1 mips2 mips32r1 mips32r2
ASEs implemented	: mips16 dsp mt
shadow register sets	: 1
kscratch registers	: 0
package			: 0
core			: 0
VPE			: 0
VCED exceptions		: not available
VCEI exceptions		: not available

processor		: 1
cpu model		: MIPS 1004Kc V2.15
BogoMIPS		: 586.13
wait instruction	: yes
microsecond timers	: yes
tlb_entries		: 32
extra interrupt vector	: yes
hardware watchpoint	: yes, count: 4, address/irw mask: [0x0ffc, 0x0ffc, 0x0ffb, 0x0ffb]
isa			: mips1 mips2 mips32r1 mips32r2
ASEs implemented	: mips16 dsp mt
shadow register sets	: 1
kscratch registers	: 0
package			: 0
core			: 0
VPE			: 1
VCED exceptions		: not available
VCEI exceptions		: not available

Any ideas?

Regards
Greg


> Original 4.14 OpenWrt patch:
> Link: https://git.openwrt.org/?p=openwrt/openwrt.git;a=commitdiff;h=4cdbc90a376dd0555201c1434a2081e055e9ceb7
> Current 5.10 OpenWrt patch:
> Link: https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=target/linux/ramips/patches-5.10/320-mt7621-core-detect-hack.patch;h=c63f0f4c1ec742e24d8480e80553863744b58f6a;hb=10267e17299806f9885d086147878f6c492cb904
> 
> Suggested-by: Felix Fietkau <nbd@nbd.name>
> Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
> ---
>  arch/mips/include/asm/mips-cps.h | 23 ++++++++++++++++++++++-
>  1 file changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/mips/include/asm/mips-cps.h b/arch/mips/include/asm/mips-cps.h
> index fd43d876892e..35fb8ee6dd33 100644
> --- a/arch/mips/include/asm/mips-cps.h
> +++ b/arch/mips/include/asm/mips-cps.h
> @@ -10,6 +10,8 @@
>  #include <linux/io.h>
>  #include <linux/types.h>
>  
> +#include <asm/mips-boards/launch.h>
> +
>  extern unsigned long __cps_access_bad_size(void)
>  	__compiletime_error("Bad size for CPS accessor");
>  
> @@ -165,11 +167,30 @@ static inline uint64_t mips_cps_cluster_config(unsigned int cluster)
>   */
>  static inline unsigned int mips_cps_numcores(unsigned int cluster)
>  {
> +	unsigned int ncores;
> +
>  	if (!mips_cm_present())
>  		return 0;
>  
>  	/* Add one before masking to handle 0xff indicating no cores */
> -	return (mips_cps_cluster_config(cluster) + 1) & CM_GCR_CONFIG_PCORES;
> +	ncores = (mips_cps_cluster_config(cluster) + 1) & CM_GCR_CONFIG_PCORES;
> +
> +	if (IS_ENABLED(CONFIG_SOC_MT7621)) {
> +		struct cpulaunch *launch;
> +
> +		/*
> +		 * Ralink MT7621S SoC is single core, but the GCR_CONFIG method
> +		 * always reports 2 cores. Check the second core's LAUNCH_FREADY
> +		 * flag to detect if the second core is missing. This method
> +		 * only works before the core has been started.
> +		 */
> +		launch = (struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
> +		launch += 2; /* MT7621 has 2 VPEs per core */
> +		if (!(launch->flags & LAUNCH_FREADY))
> +			ncores = 1;
> +	}
> +
> +	return ncores;
>  }
>  
>  /**
> -- 
> 2.31.1


^ permalink raw reply	[flat|nested] 11+ messages in thread
* Re: [PATCH v2] MIPS: add support for buggy MT7621S core detection
@ 2021-04-07 13:52 Maciej W. Rozycki
  2021-04-07 20:07 ` [PATCH v3] " Ilya Lipnitskiy
  0 siblings, 1 reply; 11+ messages in thread
From: Maciej W. Rozycki @ 2021-04-07 13:52 UTC (permalink / raw)
  To: Ilya Lipnitskiy
  Cc: linux-kernel, linux-mips, liwei391, nbd, Thomas Bogendoerfer, yangtiezhu

On Mon, 5 Apr 2021, Ilya Lipnitskiy wrote:

> diff --git a/arch/mips/include/asm/mips-cps.h b/arch/mips/include/asm/mips-cps.h
> index fd43d876892e..9f495ffef2b7 100644
> --- a/arch/mips/include/asm/mips-cps.h
> +++ b/arch/mips/include/asm/mips-cps.h
> @@ -165,11 +167,29 @@ static inline uint64_t mips_cps_cluster_config(unsigned int cluster)
>   */
>  static inline unsigned int mips_cps_numcores(unsigned int cluster)
>  {
> +	struct cpulaunch *launch;
> +	unsigned int ncores;
> +
>  	if (!mips_cm_present())
>  		return 0;
>  
>  	/* Add one before masking to handle 0xff indicating no cores */
> -	return (mips_cps_cluster_config(cluster) + 1) & CM_GCR_CONFIG_PCORES;
> +	ncores = (mips_cps_cluster_config(cluster) + 1) & CM_GCR_CONFIG_PCORES;
> +
> +	if (IS_ENABLED(CONFIG_SOC_MT7621)) {
> +		/*
> +		 * Ralink MT7621S SoC is single core, but the GCR_CONFIG method
> +		 * always reports 2 cores. Check the second core's LAUNCH_FREADY
> +		 * flag to detect if the second core is missing. This method
> +		 * only works before the core has been started.
> +		 */
> +		launch = (struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
> +		launch += 2; /* MT7621 has 2 VPEs per core */
> +		if (!(launch->flags & LAUNCH_FREADY))
> +			ncores = 1;
> +	}
> +
> +	return ncores;
>  }
>  
>  /**

 Much better to me, but please move the declaration of `launch' into the 
conditional block, which is the only place that uses it.

  Maciej

^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2021-10-01  5:04 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-16  2:56 [PATCH v3] MIPS: add support for buggy MT7621S core detection Greg Ungerer
2021-09-16  6:33 ` Sergio Paracuellos
2021-09-16  6:54   ` Greg Ungerer
2021-09-16  8:54 ` Strontium
2021-09-30 12:41   ` Greg Ungerer
2021-09-30 13:35     ` Sergio Paracuellos
2021-09-30 16:41       ` Ilya Lipnitskiy
2021-09-30 22:36         ` Greg Ungerer
     [not found]         ` <d1eb4cb4-6e9e-3f3c-8ca7-a84d03bb9f53@gmail.com>
2021-10-01  5:04           ` Sergio Paracuellos
  -- strict thread matches above, loose matches on Subject: below --
2021-04-07 13:52 [PATCH v2] " Maciej W. Rozycki
2021-04-07 20:07 ` [PATCH v3] " Ilya Lipnitskiy
2021-04-12 15:03   ` Thomas Bogendoerfer

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).