| Message ID | 20181115012842.2353-2-mike.leach@linaro.org (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
| Series | Update AMBA driver for enhanced component ID spec | expand |
Hi Mike, On 11/15/2018 01:28 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. > > Bits 11:8 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> The patch looks good to me. A couple of minor comments below. > --- > drivers/amba/bus.c | 48 ++++++++++++++++++++++++++++++++++++---- > include/linux/amba/bus.h | 33 +++++++++++++++++++++++++++ > 2 files changed, 77 insertions(+), 4 deletions(-) > > diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c > index 41b706403ef7..6eab977f4314 100644 > --- a/drivers/amba/bus.c > +++ b/drivers/amba/bus.c > @@ -26,6 +26,28 @@ > > #define to_amba_driver(d) container_of(d, struct amba_driver, drv) > > +/* called on periphid match and class 0x9 coresight device. */ > +static int amba_uci_match(const struct amba_id *table, struct amba_device *dev) nit : Could we rename this function to make it explicit about the "coresight" class ? say, amba_cs_ucid_id_match() ? > +{ > + int ret = 0; > + struct amba_cs_uci_id *uci; > + > + uci = table->data; > + > + /* no table data - return match on periphid */ > + if (!uci) > + return 1; > + > + if (uci->devarch) { > + ret = (dev->uci.devtype == uci->devtype) && > + ((dev->uci.devarch & uci->mask) == uci->devarch); > + } else { > + /* devtype only if devarch set to 0 */ > + ret = dev->uci.devtype == uci->devtype; > + } > + return ret; > +} > + > static const struct amba_id * > amba_lookup(const struct amba_id *table, struct amba_device *dev) > { > @@ -33,11 +55,17 @@ amba_lookup(const struct amba_id *table, struct amba_device *dev) > > while (table->mask) { > ret = (dev->periphid & table->mask) == table->id; > - if (ret) > - break; > + /* matched on periphid - check UCI if CoreSight */ > + if (ret) { > + if (dev->cid == CORESIGHT_CID) { > + ret = amba_uci_match(table, dev); > + if (ret) > + break; > + } else > + break; > + } > table++; This code looks a bit too complex with the ifs and breaks. Could we change it a bit to : /* For CoreSight class devices, match the UCI id */ if ((dev->periphid & table->mask) == table->id) && ((dev->cid != CORESIGHT_CID) || amba_uci_match(table, dev))) return table; table++; > } > - > return ret ? table : NULL; > } > > @@ -399,10 +427,22 @@ 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..a83a0a3dece8 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 11:8 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 mask; It is worth changing the mask to reflect that it applies to the "devarch" field, than being a generic mask which is unexplained. > + 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; > }; > @@ -61,6 +93,7 @@ enum amba_vendor { > (((conf) & 0xff) << 24 | ((rev) & 0xf) << 20 | \ > AMBA_VENDOR_LINUX << 12 | ((part) & 0xfff)) > > + spurious change ? > extern struct bus_type amba_bustype; > > #define to_amba_device(d) container_of(d, struct amba_device, dev) Otherwise looks good to me. Suzuki
Hi Suzuki, Thanks for the feedback. Agree with all comments and will revise along the lines you suggest. Mike On Mon, 19 Nov 2018 at 14:54, Suzuki K Poulose <suzuki.poulose@arm.com> wrote: > > Hi Mike, > > On 11/15/2018 01:28 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. > > > > Bits 11:8 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> > > The patch looks good to me. A couple of minor comments below. > > > --- > > drivers/amba/bus.c | 48 ++++++++++++++++++++++++++++++++++++---- > > include/linux/amba/bus.h | 33 +++++++++++++++++++++++++++ > > 2 files changed, 77 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c > > index 41b706403ef7..6eab977f4314 100644 > > --- a/drivers/amba/bus.c > > +++ b/drivers/amba/bus.c > > @@ -26,6 +26,28 @@ > > > > #define to_amba_driver(d) container_of(d, struct amba_driver, drv) > > > > +/* called on periphid match and class 0x9 coresight device. */ > > +static int amba_uci_match(const struct amba_id *table, struct amba_device *dev) > nit : Could we rename this function to make it explicit about the > "coresight" class ? say, amba_cs_ucid_id_match() ? > > > +{ > > + int ret = 0; > > + struct amba_cs_uci_id *uci; > > + > > + uci = table->data; > > + > > + /* no table data - return match on periphid */ > > + if (!uci) > > + return 1; > > + > > + if (uci->devarch) { > > + ret = (dev->uci.devtype == uci->devtype) && > > + ((dev->uci.devarch & uci->mask) == uci->devarch); > > + } else { > > + /* devtype only if devarch set to 0 */ > > + ret = dev->uci.devtype == uci->devtype; > > + } > > + return ret; > > +} > > + > > static const struct amba_id * > > amba_lookup(const struct amba_id *table, struct amba_device *dev) > > { > > @@ -33,11 +55,17 @@ amba_lookup(const struct amba_id *table, struct amba_device *dev) > > > > while (table->mask) { > > ret = (dev->periphid & table->mask) == table->id; > > - if (ret) > > - break; > > + /* matched on periphid - check UCI if CoreSight */ > > + if (ret) { > > + if (dev->cid == CORESIGHT_CID) { > > + ret = amba_uci_match(table, dev); > > + if (ret) > > + break; > > + } else > > + break; > > + } > > table++; > > This code looks a bit too complex with the ifs and breaks. Could we > change it a bit to : > > /* For CoreSight class devices, match the UCI id */ > if ((dev->periphid & table->mask) == table->id) && > ((dev->cid != CORESIGHT_CID) || amba_uci_match(table, dev))) > return table; > table++; > > > > } > > - > > return ret ? table : NULL; > > > > } > > > > @@ -399,10 +427,22 @@ 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..a83a0a3dece8 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 11:8 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 mask; > > It is worth changing the mask to reflect that it applies to the > "devarch" field, than being a generic mask which is unexplained. > > > + 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; > > }; > > @@ -61,6 +93,7 @@ enum amba_vendor { > > (((conf) & 0xff) << 24 | ((rev) & 0xf) << 20 | \ > > AMBA_VENDOR_LINUX << 12 | ((part) & 0xfff)) > > > > + > > spurious change ? > > > extern struct bus_type amba_bustype; > > > > #define to_amba_device(d) container_of(d, struct amba_device, dev) > > Otherwise looks good to me. > > Suzuki
Hi Mike, On Thu, Nov 15, 2018 at 01:28:40AM +0000, 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 11:8 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> > --- > drivers/amba/bus.c | 48 ++++++++++++++++++++++++++++++++++++---- > include/linux/amba/bus.h | 33 +++++++++++++++++++++++++++ > 2 files changed, 77 insertions(+), 4 deletions(-) > > diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c > index 41b706403ef7..6eab977f4314 100644 > --- a/drivers/amba/bus.c > +++ b/drivers/amba/bus.c > @@ -26,6 +26,28 @@ > > #define to_amba_driver(d) container_of(d, struct amba_driver, drv) > > +/* called on periphid match and class 0x9 coresight device. */ > +static int amba_uci_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; > + > + if (uci->devarch) { > + ret = (dev->uci.devtype == uci->devtype) && > + ((dev->uci.devarch & uci->mask) == uci->devarch); > + } else { > + /* devtype only if devarch set to 0 */ > + ret = dev->uci.devtype == uci->devtype; > + } > + return ret; > +} > + > static const struct amba_id * > amba_lookup(const struct amba_id *table, struct amba_device *dev) > { > @@ -33,11 +55,17 @@ amba_lookup(const struct amba_id *table, struct amba_device *dev) > > while (table->mask) { > ret = (dev->periphid & table->mask) == table->id; > - if (ret) > - break; > + /* matched on periphid - check UCI if CoreSight */ > + if (ret) { > + if (dev->cid == CORESIGHT_CID) { > + ret = amba_uci_match(table, dev); > + if (ret) > + break; > + } else > + break; > + } > table++; > } > - Carefull with the line removal. > return ret ? table : NULL; > } > > @@ -399,10 +427,22 @@ 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; Any reason for not masking @devarch the same way you're doing for @devtype? If we were to mask here we wouldn't have to carry the mask in struct amba_cs_uci_id and deal with it in amba_uci_match(). Russell King maintains AMBA. Please address your next revision to him and CC the rest of us, as specified by get_maintainer.pl. Thanks, Mathieu > + } > + > 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..a83a0a3dece8 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 11:8 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 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; > }; > @@ -61,6 +93,7 @@ enum amba_vendor { > (((conf) & 0xff) << 24 | ((rev) & 0xf) << 20 | \ > AMBA_VENDOR_LINUX << 12 | ((part) & 0xfff)) > > + > extern struct bus_type amba_bustype; > > #define to_amba_device(d) container_of(d, struct amba_device, dev) > -- > 2.19.1 >
Hi Matthieu, On Tue, 20 Nov 2018 at 20:57, Mathieu Poirier <mathieu.poirier@linaro.org> wrote: > > Hi Mike, > > On Thu, Nov 15, 2018 at 01:28:40AM +0000, 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 11:8 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> > > --- > > drivers/amba/bus.c | 48 ++++++++++++++++++++++++++++++++++++---- > > include/linux/amba/bus.h | 33 +++++++++++++++++++++++++++ > > 2 files changed, 77 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c > > index 41b706403ef7..6eab977f4314 100644 > > --- a/drivers/amba/bus.c > > +++ b/drivers/amba/bus.c > > @@ -26,6 +26,28 @@ > > > > #define to_amba_driver(d) container_of(d, struct amba_driver, drv) > > > > +/* called on periphid match and class 0x9 coresight device. */ > > +static int amba_uci_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; > > + > > + if (uci->devarch) { > > + ret = (dev->uci.devtype == uci->devtype) && > > + ((dev->uci.devarch & uci->mask) == uci->devarch); > > + } else { > > + /* devtype only if devarch set to 0 */ > > + ret = dev->uci.devtype == uci->devtype; > > + } > > + return ret; > > +} > > + > > static const struct amba_id * > > amba_lookup(const struct amba_id *table, struct amba_device *dev) > > { > > @@ -33,11 +55,17 @@ amba_lookup(const struct amba_id *table, struct amba_device *dev) > > > > while (table->mask) { > > ret = (dev->periphid & table->mask) == table->id; > > - if (ret) > > - break; > > + /* matched on periphid - check UCI if CoreSight */ > > + if (ret) { > > + if (dev->cid == CORESIGHT_CID) { > > + ret = amba_uci_match(table, dev); > > + if (ret) > > + break; > > + } else > > + break; > > + } > > table++; > > } > > - > > Carefull with the line removal. > This function is significantly re-written in the next version per Suzuki's suggestions. > > return ret ? table : NULL; > > } > > > > @@ -399,10 +427,22 @@ 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; > > Any reason for not masking @devarch the same way you're doing for @devtype? If > we were to mask here we wouldn't have to carry the mask in struct amba_cs_uci_id > and deal with it in amba_uci_match(). > @devarch is defined as a 32 bit value. This is masked to widen / narrow matching. By default the mask will be the ARCHID field - bits 15:0, selected in the driver in the same way as the drivers currently have a mask for peripheral ID. This ignores the architect and version fields as most CS component drivers should handle differences. However - this is also an optional register - if all 32 bits are 0, then we ignore and use just the @devtype. This logic is contained in amba_uci_match() @devtype is architecturally specified as having only 8 significant bits, thus is masked at this point. > Russell King maintains AMBA. Please address your next revision to him and CC > the rest of us, as specified by get_maintainer.pl. > get_maintainer.pl returned no specific 'maintainer' for this patch - though looking again I do see Russell noted as 'odd fixer'. Will ensure this is directed to him next revision. Thanks for the feedback, Mike > Thanks, > Mathieu > > > + } > > + > > 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..a83a0a3dece8 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 11:8 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 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; > > }; > > @@ -61,6 +93,7 @@ enum amba_vendor { > > (((conf) & 0xff) << 24 | ((rev) & 0xf) << 20 | \ > > AMBA_VENDOR_LINUX << 12 | ((part) & 0xfff)) > > > > + > > extern struct bus_type amba_bustype; > > > > #define to_amba_device(d) container_of(d, struct amba_device, dev) > > -- > > 2.19.1 > > -- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK
> @devarch is defined as a 32 bit value. This is masked to widen / narrow > matching. By default the mask will be the ARCHID field - bits 15:0, selected in the > driver in the same way as the drivers currently have a mask for peripheral ID. > This ignores the architect and version fields as most CS component drivers > should handle differences. The architect field defines what the ARCHID field means (the ARCHID values are specific to each architect), it's not the same as the implementer field. You need to check both if you want to know what component driver to use. The correct mask for that is 0xfff0ffff. Selecting on ARCHID alone, would only be valid if you are requiring the architect always to be ARM (0x23b) and have already checked that. Al IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Al, On Wed, 21 Nov 2018 at 14:25, Al Grant <Al.Grant@arm.com> wrote: > > > @devarch is defined as a 32 bit value. This is masked to widen / narrow > > matching. By default the mask will be the ARCHID field - bits 15:0, selected in the > > driver in the same way as the drivers currently have a mask for peripheral ID. > > This ignores the architect and version fields as most CS component drivers > > should handle differences. > > The architect field defines what the ARCHID field means (the ARCHID > values are specific to each architect), it's not the same as the implementer > field. You need to check both if you want to know what component driver > to use. The correct mask for that is 0xfff0ffff. > > Selecting on ARCHID alone, would only be valid if you are requiring the > architect always to be ARM (0x23b) and have already checked that. > This is a fair point - thought at present the peripheral ID matching takes in the JDEC ID code of the component designer - in the ETM case ARM (though without a JDEC continuation code check). Given this field too is specified as "designer not implementer", it seems logically unlikely that designer != architect. If we did feel the need to alter the match value / mask values - this happens in the CS driver code, not in this patch - so will need to be addressed there. Thanks Mike > Al > IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> > The architect field defines what the ARCHID field means (the ARCHID > > values are specific to each architect), it's not the same as the > > implementer field. You need to check both if you want to know what > > component driver to use. The correct mask for that is 0xfff0ffff. > > This is a fair point - thought at present the peripheral ID matching takes in the > JDEC ID code of the component designer - in the ETM case ARM (though without > a JDEC continuation code check). > Given this field too is specified as "designer not implementer", it seems logically > unlikely that designer != architect. It might be exactly like that. On the system I'm using right now: DEVARCH=0x47714a13 meaning architect=ARM architecture=ETM PIDR= <somebody else> This is not a Cortex core designed by ARM, it's someone else's ARM compatible core and they designed their own ARM-compatible ETM. It conforms to the ETM architecture defined by ARM, so they set DEVARCH to indicate that (architect=ARM), but in the implementer/ designer code in PIDR they put their own JEDEC code. If you've got DEVARCH, that should be all you need to select the right driver and then the driver should be able to get everything it needs from the feature ID regs. It should only need to look at implementer code / product code as a last resort for errata workarounds or similar (e.g. if the feature ID regs are known to be incorrect). If you haven't got DEVARCH, you have to look at implementer code / product code. So for example if we see a componet with no DEVARCH but with designer=ARM product=0x961, that's "ARM product 0x961" i.e. a TMC, and we can write the driver according to the programming interface described in the manual for that product. Al > > If we did feel the need to alter the match value / mask values - this happens in > the CS driver code, not in this patch - so will need to be addressed there. > > Thanks > > Mike > > > Al > > IMPORTANT NOTICE: The contents of this email and any attachments are > confidential and may also be privileged. If you are not the intended recipient, > please notify the sender immediately and do not disclose the contents to any > other person, use it for any purpose, or store or copy the information in any > medium. Thank you. > > > > -- > Mike Leach > Principal Engineer, ARM Ltd. > Manchester Design Centre. UK IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index 41b706403ef7..6eab977f4314 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -26,6 +26,28 @@ #define to_amba_driver(d) container_of(d, struct amba_driver, drv) +/* called on periphid match and class 0x9 coresight device. */ +static int amba_uci_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; + + if (uci->devarch) { + ret = (dev->uci.devtype == uci->devtype) && + ((dev->uci.devarch & uci->mask) == uci->devarch); + } else { + /* devtype only if devarch set to 0 */ + ret = dev->uci.devtype == uci->devtype; + } + return ret; +} + static const struct amba_id * amba_lookup(const struct amba_id *table, struct amba_device *dev) { @@ -33,11 +55,17 @@ amba_lookup(const struct amba_id *table, struct amba_device *dev) while (table->mask) { ret = (dev->periphid & table->mask) == table->id; - if (ret) - break; + /* matched on periphid - check UCI if CoreSight */ + if (ret) { + if (dev->cid == CORESIGHT_CID) { + ret = amba_uci_match(table, dev); + if (ret) + break; + } else + break; + } table++; } - return ret ? table : NULL; } @@ -399,10 +427,22 @@ 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..a83a0a3dece8 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 11:8 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 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; }; @@ -61,6 +93,7 @@ enum amba_vendor { (((conf) & 0xff) << 24 | ((rev) & 0xf) << 20 | \ AMBA_VENDOR_LINUX << 12 | ((part) & 0xfff)) + extern struct bus_type amba_bustype; #define to_amba_device(d) container_of(d, struct amba_device, dev)
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 11:8 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> --- drivers/amba/bus.c | 48 ++++++++++++++++++++++++++++++++++++---- include/linux/amba/bus.h | 33 +++++++++++++++++++++++++++ 2 files changed, 77 insertions(+), 4 deletions(-)