diff mbox

[U-Boot,v2] armv8: ls2085a: Add workaround of errata A009635

Message ID 1446621873-26180-1-git-send-email-prabhakar@freescale.com
State Superseded
Delegated to: York Sun
Headers show

Commit Message

Prabhakar Kushwaha Nov. 4, 2015, 7:24 a.m. UTC
If the core runs at higher than x3 speed of the platform, there is
possiblity about sev instruction to getting missed by other cores. 
This is because of SoC Run Control block may not able to sample
the EVENTI(Sev) signals.

Configure Run Control and EPU to periodically send out EVENTI signals to
wake up A57 cores.

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
---
Chages for v2: Updated description

 arch/arm/cpu/armv8/fsl-layerscape/cpu.c           |  6 ++++
 arch/arm/cpu/armv8/fsl-layerscape/soc.c           | 39 +++++++++++++++++++++++
 arch/arm/include/asm/arch-fsl-layerscape/config.h |  9 ++++++
 arch/arm/include/asm/arch-fsl-layerscape/soc.h    |  3 ++
 4 files changed, 57 insertions(+)

Comments

York Sun Nov. 4, 2015, 6:57 p.m. UTC | #1
On 11/03/2015 11:24 PM, Prabhakar Kushwaha wrote:
> If the core runs at higher than x3 speed of the platform, there is
> possiblity about sev instruction to getting missed by other cores. 
> This is because of SoC Run Control block may not able to sample
> the EVENTI(Sev) signals.
> 
> Configure Run Control and EPU to periodically send out EVENTI signals to
> wake up A57 cores.
> 
> Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
> ---
> Chages for v2: Updated description
> 
>  arch/arm/cpu/armv8/fsl-layerscape/cpu.c           |  6 ++++
>  arch/arm/cpu/armv8/fsl-layerscape/soc.c           | 39 +++++++++++++++++++++++
>  arch/arm/include/asm/arch-fsl-layerscape/config.h |  9 ++++++
>  arch/arm/include/asm/arch-fsl-layerscape/soc.h    |  3 ++
>  4 files changed, 57 insertions(+)
> 
> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> index 0cb0afa..dbb12c2 100644
> --- a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> +++ b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> @@ -484,7 +484,13 @@ int arch_early_init_r(void)
>  {
>  #ifdef CONFIG_MP
>  	int rv = 1;
> +#endif
> +
> +#ifdef CONFIG_SYS_FSL_ERRATUM_A009635
> +	erratum_a009635();
> +#endif
>  
> +#ifdef CONFIG_MP
>  	rv = fsl_layerscape_wake_seconday_cores();
>  	if (rv)
>  		printf("Did not wake secondary cores\n");
> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/soc.c b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> index 637853d..e8cdb10 100644
> --- a/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> +++ b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> @@ -9,10 +9,49 @@
>  #include <asm/arch/soc.h>
>  #include <asm/io.h>
>  #include <asm/global_data.h>
> +#include <asm/arch-fsl-layerscape/config.h>
>  
>  DECLARE_GLOBAL_DATA_PTR;
>  
>  #ifdef CONFIG_LS2085A
> +#ifdef CONFIG_SYS_FSL_ERRATUM_A009635
> +#define PLATFORM_CYCLE_ENV_VAR	"a009635_interval_val"
> +
> +static unsigned long get_internval_val_mhz(void)
> +{
> +	char *interval = getenv(PLATFORM_CYCLE_ENV_VAR);

Why do you need a variable to override the calculation?


> +	ulong interval_mhz = get_bus_freq(0) / (1000 * 1000);

Please add a comment here to explain what the interval does and why it is
calculated this way.

York
Prabhakar Kushwaha Nov. 5, 2015, 3:58 a.m. UTC | #2
> -----Original Message-----
> From: York Sun [mailto:yorksun@freescale.com]
> Sent: Thursday, November 05, 2015 12:27 AM
> To: Kushwaha Prabhakar-B32579 <prabhakar@freescale.com>; u-
> boot@lists.denx.de
> Subject: Re: [PATCH][v2] armv8: ls2085a: Add workaround of errata A009635
> 
> 
> 
> On 11/03/2015 11:24 PM, Prabhakar Kushwaha wrote:
> > If the core runs at higher than x3 speed of the platform, there is
> > possiblity about sev instruction to getting missed by other cores.
> > This is because of SoC Run Control block may not able to sample the
> > EVENTI(Sev) signals.
> >
> > Configure Run Control and EPU to periodically send out EVENTI signals
> > to wake up A57 cores.
> >
> > Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
> > ---
> > Chages for v2: Updated description
> >
> >  arch/arm/cpu/armv8/fsl-layerscape/cpu.c           |  6 ++++
> >  arch/arm/cpu/armv8/fsl-layerscape/soc.c           | 39
> +++++++++++++++++++++++
> >  arch/arm/include/asm/arch-fsl-layerscape/config.h |  9 ++++++
> >  arch/arm/include/asm/arch-fsl-layerscape/soc.h    |  3 ++
> >  4 files changed, 57 insertions(+)
> >
> > diff --git a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> > b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> > index 0cb0afa..dbb12c2 100644
> > --- a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> > +++ b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> > @@ -484,7 +484,13 @@ int arch_early_init_r(void)  {  #ifdef CONFIG_MP
> >  	int rv = 1;
> > +#endif
> > +
> > +#ifdef CONFIG_SYS_FSL_ERRATUM_A009635
> > +	erratum_a009635();
> > +#endif
> >
> > +#ifdef CONFIG_MP
> >  	rv = fsl_layerscape_wake_seconday_cores();
> >  	if (rv)
> >  		printf("Did not wake secondary cores\n");
> > diff --git a/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> > index 637853d..e8cdb10 100644
> > --- a/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> > +++ b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> > @@ -9,10 +9,49 @@
> >  #include <asm/arch/soc.h>
> >  #include <asm/io.h>
> >  #include <asm/global_data.h>
> > +#include <asm/arch-fsl-layerscape/config.h>
> >
> >  DECLARE_GLOBAL_DATA_PTR;
> >
> >  #ifdef CONFIG_LS2085A
> > +#ifdef CONFIG_SYS_FSL_ERRATUM_A009635
> > +#define PLATFORM_CYCLE_ENV_VAR	"a009635_interval_val"
> > +
> > +static unsigned long get_internval_val_mhz(void)
> > +{
> > +	char *interval = getenv(PLATFORM_CYCLE_ENV_VAR);
> 
> Why do you need a variable to override the calculation?
> 

Following needs to be supported as part of errata workaround
1. Ability to modify platform clock value to increase time interval
2. Disable workaround in platform clock 0

As per Errata workaround, 
 "For <interval> value above,  it is the number of platform cycles between wake up events generated by EPU.  For example: 
A typical value is 1 microsecond.  If the platform frequency is 500MHz, each cycle is 2ns. interval = 1us/2ns=500=0x1F4."

> 
> > +	ulong interval_mhz = get_bus_freq(0) / (1000 * 1000);
> 
> Please add a comment here to explain what the interval does and why it is
> calculated this way.
> 

Sure, 

--PK
York Sun Nov. 5, 2015, 4:07 a.m. UTC | #3
On 11/04/2015 07:58 PM, Kushwaha Prabhakar-B32579 wrote:
> 
>> -----Original Message-----
>> From: York Sun [mailto:yorksun@freescale.com]
>> Sent: Thursday, November 05, 2015 12:27 AM
>> To: Kushwaha Prabhakar-B32579 <prabhakar@freescale.com>; u-
>> boot@lists.denx.de
>> Subject: Re: [PATCH][v2] armv8: ls2085a: Add workaround of errata A009635
>>
>>
>>
>> On 11/03/2015 11:24 PM, Prabhakar Kushwaha wrote:
>>> If the core runs at higher than x3 speed of the platform, there is
>>> possiblity about sev instruction to getting missed by other cores.
>>> This is because of SoC Run Control block may not able to sample the
>>> EVENTI(Sev) signals.
>>>
>>> Configure Run Control and EPU to periodically send out EVENTI signals
>>> to wake up A57 cores.
>>>
>>> Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
>>> ---
>>> Chages for v2: Updated description
>>>
>>>  arch/arm/cpu/armv8/fsl-layerscape/cpu.c           |  6 ++++
>>>  arch/arm/cpu/armv8/fsl-layerscape/soc.c           | 39
>> +++++++++++++++++++++++
>>>  arch/arm/include/asm/arch-fsl-layerscape/config.h |  9 ++++++
>>>  arch/arm/include/asm/arch-fsl-layerscape/soc.h    |  3 ++
>>>  4 files changed, 57 insertions(+)
>>>
>>> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
>>> b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
>>> index 0cb0afa..dbb12c2 100644
>>> --- a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
>>> +++ b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
>>> @@ -484,7 +484,13 @@ int arch_early_init_r(void)  {  #ifdef CONFIG_MP
>>>  	int rv = 1;
>>> +#endif
>>> +
>>> +#ifdef CONFIG_SYS_FSL_ERRATUM_A009635
>>> +	erratum_a009635();
>>> +#endif
>>>
>>> +#ifdef CONFIG_MP
>>>  	rv = fsl_layerscape_wake_seconday_cores();
>>>  	if (rv)
>>>  		printf("Did not wake secondary cores\n");
>>> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/soc.c
>> b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
>>> index 637853d..e8cdb10 100644
>>> --- a/arch/arm/cpu/armv8/fsl-layerscape/soc.c
>>> +++ b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
>>> @@ -9,10 +9,49 @@
>>>  #include <asm/arch/soc.h>
>>>  #include <asm/io.h>
>>>  #include <asm/global_data.h>
>>> +#include <asm/arch-fsl-layerscape/config.h>
>>>
>>>  DECLARE_GLOBAL_DATA_PTR;
>>>
>>>  #ifdef CONFIG_LS2085A
>>> +#ifdef CONFIG_SYS_FSL_ERRATUM_A009635
>>> +#define PLATFORM_CYCLE_ENV_VAR	"a009635_interval_val"
>>> +
>>> +static unsigned long get_internval_val_mhz(void)
>>> +{
>>> +	char *interval = getenv(PLATFORM_CYCLE_ENV_VAR);
>>
>> Why do you need a variable to override the calculation?
>>
> 
> Following needs to be supported as part of errata workaround
> 1. Ability to modify platform clock value to increase time interval
> 2. Disable workaround in platform clock 0
> 
> As per Errata workaround, 
>  "For <interval> value above,  it is the number of platform cycles between wake up events generated by EPU.  For example: 
> A typical value is 1 microsecond.  If the platform frequency is 500MHz, each cycle is 2ns. interval = 1us/2ns=500=0x1F4."

This is taken care of by the formula. Is there any need to adjust the time
interval? If you do, you are risking of running too fast or too slow. If setting
the variable as 0, does it have the same effect as not running this workaround?
If this is a debug technique, please remove if not required by the workaround.
If you really want to support override, please add a comment inline and in
commit message.

> 
>>
>>> +	ulong interval_mhz = get_bus_freq(0) / (1000 * 1000);
>>
>> Please add a comment here to explain what the interval does and why it is
>> calculated this way.
>>
> 
> Sure, 

York
Prabhakar Kushwaha Nov. 5, 2015, 4:18 a.m. UTC | #4
> -----Original Message-----
> From: York Sun [mailto:yorksun@freescale.com]
> Sent: Thursday, November 05, 2015 9:38 AM
> To: Kushwaha Prabhakar-B32579 <prabhakar@freescale.com>; u-
> boot@lists.denx.de
> Subject: Re: [PATCH][v2] armv8: ls2085a: Add workaround of errata A009635
> 
> 
> 
> On 11/04/2015 07:58 PM, Kushwaha Prabhakar-B32579 wrote:
> >
> >> -----Original Message-----
> >> From: York Sun [mailto:yorksun@freescale.com]
> >> Sent: Thursday, November 05, 2015 12:27 AM
> >> To: Kushwaha Prabhakar-B32579 <prabhakar@freescale.com>; u-
> >> boot@lists.denx.de
> >> Subject: Re: [PATCH][v2] armv8: ls2085a: Add workaround of errata
> >> A009635
> >>
> >>
> >>
> >> On 11/03/2015 11:24 PM, Prabhakar Kushwaha wrote:
> >>> If the core runs at higher than x3 speed of the platform, there is
> >>> possiblity about sev instruction to getting missed by other cores.
> >>> This is because of SoC Run Control block may not able to sample the
> >>> EVENTI(Sev) signals.
> >>>
> >>> Configure Run Control and EPU to periodically send out EVENTI
> >>> signals to wake up A57 cores.
> >>>
> >>> Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
> >>> ---
> >>> Chages for v2: Updated description
> >>>
> >>>  arch/arm/cpu/armv8/fsl-layerscape/cpu.c           |  6 ++++
> >>>  arch/arm/cpu/armv8/fsl-layerscape/soc.c           | 39
> >> +++++++++++++++++++++++
> >>>  arch/arm/include/asm/arch-fsl-layerscape/config.h |  9 ++++++
> >>>  arch/arm/include/asm/arch-fsl-layerscape/soc.h    |  3 ++
> >>>  4 files changed, 57 insertions(+)
> >>>
> >>> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> >>> b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> >>> index 0cb0afa..dbb12c2 100644
> >>> --- a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> >>> +++ b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> >>> @@ -484,7 +484,13 @@ int arch_early_init_r(void)  {  #ifdef CONFIG_MP
> >>>  	int rv = 1;
> >>> +#endif
> >>> +
> >>> +#ifdef CONFIG_SYS_FSL_ERRATUM_A009635
> >>> +	erratum_a009635();
> >>> +#endif
> >>>
> >>> +#ifdef CONFIG_MP
> >>>  	rv = fsl_layerscape_wake_seconday_cores();
> >>>  	if (rv)
> >>>  		printf("Did not wake secondary cores\n"); diff --git
> >>> a/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> >> b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> >>> index 637853d..e8cdb10 100644
> >>> --- a/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> >>> +++ b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> >>> @@ -9,10 +9,49 @@
> >>>  #include <asm/arch/soc.h>
> >>>  #include <asm/io.h>
> >>>  #include <asm/global_data.h>
> >>> +#include <asm/arch-fsl-layerscape/config.h>
> >>>
> >>>  DECLARE_GLOBAL_DATA_PTR;
> >>>
> >>>  #ifdef CONFIG_LS2085A
> >>> +#ifdef CONFIG_SYS_FSL_ERRATUM_A009635
> >>> +#define PLATFORM_CYCLE_ENV_VAR	"a009635_interval_val"
> >>> +
> >>> +static unsigned long get_internval_val_mhz(void) {
> >>> +	char *interval = getenv(PLATFORM_CYCLE_ENV_VAR);
> >>
> >> Why do you need a variable to override the calculation?
> >>
> >
> > Following needs to be supported as part of errata workaround 1.
> > Ability to modify platform clock value to increase time interval 2.
> > Disable workaround in platform clock 0
> >
> > As per Errata workaround,
> >  "For <interval> value above,  it is the number of platform cycles between
> wake up events generated by EPU.  For example:
> > A typical value is 1 microsecond.  If the platform frequency is 500MHz, each
> cycle is 2ns. interval = 1us/2ns=500=0x1F4."
> 
> This is taken care of by the formula. Is there any need to adjust the time
> interval? If you do, you are risking of running too fast or too slow. 

Yes, customer may like to increase or decrease the time interval to fine tune the system behavior. 

> If setting
> the variable as 0, does it have the same effect as not running this
> workaround?

Yes, setting 0 == Not running WA. I verified it. 

> If this is a debug technique, please remove if not required by the
> workaround.

This problem occur when core clock is > 2.5.x of platform clock.
If anyone using core clock < 2.5x of platform clock, this workaround is not required. 

> If you really want to support override, please add a comment inline and in
> commit message.

OK


> 
> >
> >>
> >>> +	ulong interval_mhz = get_bus_freq(0) / (1000 * 1000);
> >>
> >> Please add a comment here to explain what the interval does and why
> >> it is calculated this way.
> >>
> >
> > Sure,
> 
> York
diff mbox

Patch

diff --git a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
index 0cb0afa..dbb12c2 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
+++ b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
@@ -484,7 +484,13 @@  int arch_early_init_r(void)
 {
 #ifdef CONFIG_MP
 	int rv = 1;
+#endif
+
+#ifdef CONFIG_SYS_FSL_ERRATUM_A009635
+	erratum_a009635();
+#endif
 
+#ifdef CONFIG_MP
 	rv = fsl_layerscape_wake_seconday_cores();
 	if (rv)
 		printf("Did not wake secondary cores\n");
diff --git a/arch/arm/cpu/armv8/fsl-layerscape/soc.c b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
index 637853d..e8cdb10 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/soc.c
+++ b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
@@ -9,10 +9,49 @@ 
 #include <asm/arch/soc.h>
 #include <asm/io.h>
 #include <asm/global_data.h>
+#include <asm/arch-fsl-layerscape/config.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
 #ifdef CONFIG_LS2085A
+#ifdef CONFIG_SYS_FSL_ERRATUM_A009635
+#define PLATFORM_CYCLE_ENV_VAR	"a009635_interval_val"
+
+static unsigned long get_internval_val_mhz(void)
+{
+	char *interval = getenv(PLATFORM_CYCLE_ENV_VAR);
+	ulong interval_mhz = get_bus_freq(0) / (1000 * 1000);
+
+	if (interval)
+		interval_mhz = simple_strtoul(interval, NULL, 10);
+
+	return interval_mhz;
+}
+
+void erratum_a009635(void)
+{
+	u32 val;
+	unsigned long interval_mhz = get_internval_val_mhz();
+
+	if (!interval_mhz)
+		return;
+
+	val = in_le32(DCSR_CGACRE5);
+	writel(val | 0x00000200, DCSR_CGACRE5);
+
+	val = in_le32(EPU_EPCMPR5);
+	writel(interval_mhz, EPU_EPCMPR5);
+	val = in_le32(EPU_EPCCR5);
+	writel(val | 0x82820000, EPU_EPCCR5);
+	val = in_le32(EPU_EPSMCR5);
+	writel(val | 0x002f0000, EPU_EPSMCR5);
+	val = in_le32(EPU_EPECR5);
+	writel(val | 0x20000000, EPU_EPECR5);
+	val = in_le32(EPU_EPGCR);
+	writel(val | 0x80000000, EPU_EPGCR);
+}
+#endif
+
 static void erratum_a008751(void)
 {
 #ifdef CONFIG_SYS_FSL_ERRATUM_A008751
diff --git a/arch/arm/include/asm/arch-fsl-layerscape/config.h b/arch/arm/include/asm/arch-fsl-layerscape/config.h
index 87bb937..c7169ab 100644
--- a/arch/arm/include/asm/arch-fsl-layerscape/config.h
+++ b/arch/arm/include/asm/arch-fsl-layerscape/config.h
@@ -84,11 +84,20 @@ 
 #define TZPCDECPROT_2_SET_BASE			(TZPC_BASE + 0x81C)
 #define TZPCDECPROT_2_CLR_BASE			(TZPC_BASE + 0x820)
 
+#define DCSR_CGACRE5		0x700070914ULL
+#define EPU_EPCMPR5		0x700060914ULL
+#define EPU_EPCCR5		0x700060814ULL
+#define EPU_EPSMCR5		0x700060228ULL
+#define EPU_EPECR5		0x700060314ULL
+#define EPU_EPCTR5		0x700060a14ULL
+#define EPU_EPGCR		0x700060000ULL
+
 #define CONFIG_SYS_FSL_ERRATUM_A008336
 #define CONFIG_SYS_FSL_ERRATUM_A008511
 #define CONFIG_SYS_FSL_ERRATUM_A008514
 #define CONFIG_SYS_FSL_ERRATUM_A008585
 #define CONFIG_SYS_FSL_ERRATUM_A008751
+#define CONFIG_SYS_FSL_ERRATUM_A009635
 #elif defined(CONFIG_LS1043A)
 #define CONFIG_MAX_CPUS				4
 #define CONFIG_SYS_CACHELINE_SIZE		64
diff --git a/arch/arm/include/asm/arch-fsl-layerscape/soc.h b/arch/arm/include/asm/arch-fsl-layerscape/soc.h
index 5ed456e..80354f0 100644
--- a/arch/arm/include/asm/arch-fsl-layerscape/soc.h
+++ b/arch/arm/include/asm/arch-fsl-layerscape/soc.h
@@ -50,4 +50,7 @@  void fsl_lsch2_early_init_f(void);
 #endif
 
 void cpu_name(char *name);
+#ifdef CONFIG_SYS_FSL_ERRATUM_A009635
+void erratum_a009635(void);
+#endif
 #endif /* _ASM_ARMV8_FSL_LAYERSCAPE_SOC_H_ */