[RESEND,v3,1/2] drivers: amba: Updates to component identification for driver matching.

Message ID 20181218215944.2444-2-mike.leach@linaro.org
State Superseded
Headers show
Series
  • Update AMBA driver for enhanced component ID spec.
Related show

Commit Message

Mike Leach Dec. 18, 2018, 9:59 p.m.
The CoreSight specification (ARM IHI 0029E), updates the ID register
requirements for components on an AMBA bus, to cover both traditional
ARM Primecell type devices, and newer CoreSight and other components.

The Peripheral ID (PID) / Component ID (CID) pair is extended in certain
cases to uniquely identify components. CoreSight components related to
a single function can share Peripheral ID values, and must be further
identified using a Unique Component Identifier (UCI). e.g. the ETM, CTI,
PMU and Debug hardware of the A35 all share the same PID.

Bits 15:12 of the CID are defined to be the device class.
Class 0xF remains for PrimeCell and legacy components.
Class 0x9 defines the component as CoreSight (CORESIGHT_CID above)
Class 0x0, 0x1, 0xB, 0xE define components that do not have driver support
at present.
Class 0x2-0x8,0xA and 0xD-0xD are presently reserved.

The specification futher defines which classes of device use the standard
CID/PID pair, and when additional ID registers are required.

The patches provide an update of amba_device and matching code to handle
the additional registers required for the Class 0x9 (CoreSight) UCI.
The *data pointer in the amba_id is used by the driver to provide extended
ID register values for matching.

CoreSight components where PID/CID pair is currently sufficient for
unique identification need not provide this additional information.

Signed-off-by: Mike Leach <mike.leach@linaro.org>

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

---
 drivers/amba/bus.c       | 45 +++++++++++++++++++++++++++++++++-------
 include/linux/amba/bus.h | 32 ++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+), 8 deletions(-)

-- 
2.19.1

Comments

Suzuki K Poulose Jan. 11, 2019, 11:43 a.m. | #1
Hi Mike,

On 18/12/2018 21:59, Mike Leach wrote:
> The CoreSight specification (ARM IHI 0029E), updates the ID register

> requirements for components on an AMBA bus, to cover both traditional

> ARM Primecell type devices, and newer CoreSight and other components.

> 

> The Peripheral ID (PID) / Component ID (CID) pair is extended in certain

> cases to uniquely identify components. CoreSight components related to

> a single function can share Peripheral ID values, and must be further

> identified using a Unique Component Identifier (UCI). e.g. the ETM, CTI,

> PMU and Debug hardware of the A35 all share the same PID.

> 

> Bits 15:12 of the CID are defined to be the device class.

> Class 0xF remains for PrimeCell and legacy components.

> Class 0x9 defines the component as CoreSight (CORESIGHT_CID above)

> Class 0x0, 0x1, 0xB, 0xE define components that do not have driver support

> at present.

> Class 0x2-0x8,0xA and 0xD-0xD are presently reserved.

> 

> The specification futher defines which classes of device use the standard

> CID/PID pair, and when additional ID registers are required.

> 

> The patches provide an update of amba_device and matching code to handle

> the additional registers required for the Class 0x9 (CoreSight) UCI.

> The *data pointer in the amba_id is used by the driver to provide extended

> ID register values for matching.

> 

> CoreSight components where PID/CID pair is currently sufficient for

> unique identification need not provide this additional information.

> 

> Signed-off-by: Mike Leach <mike.leach@linaro.org>

> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>


Looks like you missed my Reviewed tags on the previous version. Anyways,

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Sai Prakash Ranjan Jan. 25, 2019, 7:20 a.m. | #2
Hi Mike,

Thanks for the patch.

BTW somehow I can't find the latest series in my inbox, so commenting
on this here.

Mathieu pointed me to this patch series.This solves CPU debug module
sharing same PID as ETM on MSM8996. I will be posting patch for CPU
debug UCI table soon.

But please find my one comment inline.

On 12/19/2018 3:29 AM, Mike Leach wrote:
> The CoreSight specification (ARM IHI 0029E), updates the ID register

> requirements for components on an AMBA bus, to cover both traditional

> ARM Primecell type devices, and newer CoreSight and other components.

> 

> The Peripheral ID (PID) / Component ID (CID) pair is extended in certain

> cases to uniquely identify components. CoreSight components related to

> a single function can share Peripheral ID values, and must be further

> identified using a Unique Component Identifier (UCI). e.g. the ETM, CTI,

> PMU and Debug hardware of the A35 all share the same PID.

> 


[..]

> +static const struct amba_id *

> +amba_lookup(const struct amba_id *table, struct amba_device *dev)

> +{

>   	while (table->mask) {

> -		ret = (dev->periphid & table->mask) == table->id;

> -		if (ret)

> -			break;

> +		if (((dev->periphid & table->mask) == table->id) &&

> +			((dev->cid != CORESIGHT_CID) ||

> +			 (amba_cs_uci_id_match(table, dev))))


Shouldn't the check be (dev->cid == CORESIGHT_CID) ?
Without this STM fails to probe on both SDM845 and MSM8996.

With this,

Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>


Thanks,
Sai

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
Mike Leach Jan. 25, 2019, 10:37 a.m. | #3
Hello Sai
On Fri, 25 Jan 2019 at 07:20, Sai Prakash Ranjan
<saiprakash.ranjan@codeaurora.org> wrote:
>

> Hi Mike,

>

> Thanks for the patch.

>

> BTW somehow I can't find the latest series in my inbox, so commenting

> on this here.

>

> Mathieu pointed me to this patch series.This solves CPU debug module

> sharing same PID as ETM on MSM8996. I will be posting patch for CPU

> debug UCI table soon.

>

> But please find my one comment inline.

>

> On 12/19/2018 3:29 AM, Mike Leach wrote:

> > The CoreSight specification (ARM IHI 0029E), updates the ID register

> > requirements for components on an AMBA bus, to cover both traditional

> > ARM Primecell type devices, and newer CoreSight and other components.

> >

> > The Peripheral ID (PID) / Component ID (CID) pair is extended in certain

> > cases to uniquely identify components. CoreSight components related to

> > a single function can share Peripheral ID values, and must be further

> > identified using a Unique Component Identifier (UCI). e.g. the ETM, CTI,

> > PMU and Debug hardware of the A35 all share the same PID.

> >

>

> [..]

>

> > +static const struct amba_id *

> > +amba_lookup(const struct amba_id *table, struct amba_device *dev)

> > +{

> >       while (table->mask) {

> > -             ret = (dev->periphid & table->mask) == table->id;

> > -             if (ret)

> > -                     break;

> > +             if (((dev->periphid & table->mask) == table->id) &&

> > +                     ((dev->cid != CORESIGHT_CID) ||

> > +                      (amba_cs_uci_id_match(table, dev))))

>

> Shouldn't the check be (dev->cid == CORESIGHT_CID) ?

> Without this STM fails to probe on both SDM845 and MSM8996.

>

I believe the test is correct

To expand the logic here:

if  (dev->periphid & table->mask) == table->id) {
      //** match on peripheral ID at this point
     if (CID != CORESIGHT_ID)
               return table; //** not coresight - match on peripheral ID only
     //** or
     if (amba_cs_uci_id_match() )
                return table;  //** is coresight - match on UCI if
available - otherwise peripheral ID only;

However - looking at the coresight STM driver - this is using the
private .data field in the amba_id for a name - which I had not
spotted before.
I will have to revisit this patchset to fix either the amba id struct
or the method for getting the uci data into the amba_id.data which
allows for multiple uses.

Regards

Mike


> With this,

>

> Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>

>

> Thanks,

> Sai

>

> --

> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member

> of Code Aurora Forum, hosted by The Linux Foundation




-- 
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK
Suzuki K Poulose Jan. 25, 2019, 10:42 a.m. | #4
Mike,

On 25/01/2019 10:37, Mike Leach wrote:
> Hello Sai

> On Fri, 25 Jan 2019 at 07:20, Sai Prakash Ranjan

> <saiprakash.ranjan@codeaurora.org> wrote:

>>

>> Hi Mike,

>>

>> Thanks for the patch.

>>

>> BTW somehow I can't find the latest series in my inbox, so commenting

>> on this here.

>>

>> Mathieu pointed me to this patch series.This solves CPU debug module

>> sharing same PID as ETM on MSM8996. I will be posting patch for CPU

>> debug UCI table soon.

>>

>> But please find my one comment inline.

>>

>> On 12/19/2018 3:29 AM, Mike Leach wrote:

>>> The CoreSight specification (ARM IHI 0029E), updates the ID register

>>> requirements for components on an AMBA bus, to cover both traditional

>>> ARM Primecell type devices, and newer CoreSight and other components.

>>>

>>> The Peripheral ID (PID) / Component ID (CID) pair is extended in certain

>>> cases to uniquely identify components. CoreSight components related to

>>> a single function can share Peripheral ID values, and must be further

>>> identified using a Unique Component Identifier (UCI). e.g. the ETM, CTI,

>>> PMU and Debug hardware of the A35 all share the same PID.

>>>

>>

>> [..]

>>

>>> +static const struct amba_id *

>>> +amba_lookup(const struct amba_id *table, struct amba_device *dev)

>>> +{

>>>        while (table->mask) {

>>> -             ret = (dev->periphid & table->mask) == table->id;

>>> -             if (ret)

>>> -                     break;

>>> +             if (((dev->periphid & table->mask) == table->id) &&

>>> +                     ((dev->cid != CORESIGHT_CID) ||

>>> +                      (amba_cs_uci_id_match(table, dev))))

>>

>> Shouldn't the check be (dev->cid == CORESIGHT_CID) ?

>> Without this STM fails to probe on both SDM845 and MSM8996.

>>

> I believe the test is correct

> 

> To expand the logic here:

> 

> if  (dev->periphid & table->mask) == table->id) {

>        //** match on peripheral ID at this point

>       if (CID != CORESIGHT_ID)

>                 return table; //** not coresight - match on peripheral ID only

>       //** or

>       if (amba_cs_uci_id_match() )

>                  return table;  //** is coresight - match on UCI if

> available - otherwise peripheral ID only;

> 

> However - looking at the coresight STM driver - this is using the

> private .data field in the amba_id for a name - which I had not

> spotted before.


Good point. We also use this field for Coresight SOC-600 ETR for
advertising the caps not detected from hardware.

> I will have to revisit this patchset to fix either the amba id struct

> or the method for getting the uci data into the amba_id.data which

> allows for multiple uses.


Thanks Mike !

Cheers
Suzuki

Patch

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 41b706403ef7..524296a0eba0 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -26,19 +26,36 @@ 
 
 #define to_amba_driver(d)	container_of(d, struct amba_driver, drv)
 
-static const struct amba_id *
-amba_lookup(const struct amba_id *table, struct amba_device *dev)
+/* called on periphid match and class 0x9 coresight device. */
+static int
+amba_cs_uci_id_match(const struct amba_id *table, struct amba_device *dev)
 {
 	int ret = 0;
+	struct amba_cs_uci_id *uci;
+
+	uci = table->data;
 
+	/* no table data - return match on periphid */
+	if (!uci)
+		return 1;
+
+	/* test against read devtype and masked devarch value */
+	ret = (dev->uci.devtype == uci->devtype) &&
+		((dev->uci.devarch & uci->devarch_mask) == uci->devarch);
+	return ret;
+}
+
+static const struct amba_id *
+amba_lookup(const struct amba_id *table, struct amba_device *dev)
+{
 	while (table->mask) {
-		ret = (dev->periphid & table->mask) == table->id;
-		if (ret)
-			break;
+		if (((dev->periphid & table->mask) == table->id) &&
+			((dev->cid != CORESIGHT_CID) ||
+			 (amba_cs_uci_id_match(table, dev))))
+			return table;
 		table++;
 	}
-
-	return ret ? table : NULL;
+	return NULL;
 }
 
 static int amba_match(struct device *dev, struct device_driver *drv)
@@ -399,10 +416,22 @@  static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
 			cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
 				(i * 8);
 
+		if (cid == CORESIGHT_CID) {
+			/* set the base to the start of the last 4k block */
+			void __iomem *csbase = tmp + size - 4096;
+
+			dev->uci.devarch =
+				readl(csbase + UCI_REG_DEVARCH_OFFSET);
+			dev->uci.devtype =
+				readl(csbase + UCI_REG_DEVTYPE_OFFSET) & 0xff;
+		}
+
 		amba_put_disable_pclk(dev);
 
-		if (cid == AMBA_CID || cid == CORESIGHT_CID)
+		if (cid == AMBA_CID || cid == CORESIGHT_CID) {
 			dev->periphid = pid;
+			dev->cid = cid;
+		}
 
 		if (!dev->periphid)
 			ret = -ENODEV;
diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h
index d143c13bed26..8c0f392e4da2 100644
--- a/include/linux/amba/bus.h
+++ b/include/linux/amba/bus.h
@@ -25,6 +25,36 @@ 
 #define AMBA_CID	0xb105f00d
 #define CORESIGHT_CID	0xb105900d
 
+/*
+ * CoreSight Architecture specification updates the ID specification
+ * for components on the AMBA bus. (ARM IHI 0029E)
+ *
+ * Bits 15:12 of the CID are the device class.
+ *
+ * Class 0xF remains for PrimeCell and legacy components. (AMBA_CID above)
+ * Class 0x9 defines the component as CoreSight (CORESIGHT_CID above)
+ * Class 0x0, 0x1, 0xB, 0xE define components that do not have driver support
+ * at present.
+ * Class 0x2-0x8,0xA and 0xD-0xD are presently reserved.
+ *
+ * Remaining CID bits stay as 0xb105-00d
+ */
+
+/*
+ * Class 0x9 components use additional values to form a Unique Component
+ * Identifier (UCI), where peripheral ID values are identical for different
+ * components. Passed to the amba bus code from the component driver via
+ * the amba_id->data pointer.
+ */
+struct amba_cs_uci_id {
+	unsigned int devarch;
+	unsigned int devarch_mask;
+	unsigned int devtype;
+};
+
+#define UCI_REG_DEVTYPE_OFFSET	0xFCC
+#define UCI_REG_DEVARCH_OFFSET	0xFBC
+
 struct clk;
 
 struct amba_device {
@@ -32,6 +62,8 @@  struct amba_device {
 	struct resource		res;
 	struct clk		*pclk;
 	unsigned int		periphid;
+	unsigned int		cid;
+	struct amba_cs_uci_id	uci;
 	unsigned int		irq[AMBA_NR_IRQS];
 	char			*driver_override;
 };