Allow drivers to register DPLL pins without manually specifying a pin
index.
Currently, drivers must provide a unique pin index when calling
dpll_pin_get(). This works well for hardware-mapped pins but creates
friction for drivers handling virtual pins or those without a strict
hardware indexing scheme.
Introduce DPLL_PIN_IDX_UNSPEC (U32_MAX). When a driver passes this
value as the pin index:
1. The core allocates a unique index using an IDA
2. The allocated index is mapped to a range starting above `INT_MAX`
This separation ensures that dynamically allocated indices never collide
with standard driver-provided hardware indices, which are assumed to be
within the `0` to `INT_MAX` range. The index is automatically freed when
the pin is released in dpll_pin_put().
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
drivers/dpll/dpll_core.c | 48 ++++++++++++++++++++++++++++++++++++++--
include/linux/dpll.h | 2 ++
2 files changed, 48 insertions(+), 2 deletions(-)
diff --git a/drivers/dpll/dpll_core.c b/drivers/dpll/dpll_core.c
index 4efa7fbd8f21f..0c24f60b3025f 100644
--- a/drivers/dpll/dpll_core.c
+++ b/drivers/dpll/dpll_core.c
@@ -10,6 +10,7 @@
#include <linux/device.h>
#include <linux/err.h>
+#include <linux/idr.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/string.h>
@@ -24,6 +25,7 @@ DEFINE_XARRAY_FLAGS(dpll_device_xa, XA_FLAGS_ALLOC);
DEFINE_XARRAY_FLAGS(dpll_pin_xa, XA_FLAGS_ALLOC);
static RAW_NOTIFIER_HEAD(dpll_notifier_chain);
+static DEFINE_IDA(dpll_pin_idx_ida);
static u32 dpll_device_xa_id;
static u32 dpll_pin_xa_id;
@@ -468,6 +470,36 @@ void dpll_device_unregister(struct dpll_device *dpll,
}
EXPORT_SYMBOL_GPL(dpll_device_unregister);
+static int dpll_pin_idx_alloc(u32 *pin_idx)
+{
+ int ret;
+
+ if (!pin_idx)
+ return -EINVAL;
+
+ /* Alloc unique number from IDA. Number belongs to <0, INT_MAX> range */
+ ret = ida_alloc(&dpll_pin_idx_ida, GFP_KERNEL);
+ if (ret < 0)
+ return ret;
+
+ /* Map the value to dynamic pin index range <INT_MAX+1, U32_MAX> */
+ *pin_idx = (u32)ret + INT_MAX + 1;
+
+ return 0;
+}
+
+static void dpll_pin_idx_free(u32 pin_idx)
+{
+ if (pin_idx <= INT_MAX)
+ return; /* Not a dynamic pin index */
+
+ /* Map the index value from dynamic pin index range to IDA range and
+ * free it.
+ */
+ pin_idx -= INT_MAX + 1;
+ ida_free(&dpll_pin_idx_ida, pin_idx);
+}
+
static void dpll_pin_prop_free(struct dpll_pin_properties *prop)
{
kfree(prop->package_label);
@@ -525,9 +557,18 @@ dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
struct dpll_pin *pin;
int ret;
+ if (pin_idx == DPLL_PIN_IDX_UNSPEC) {
+ ret = dpll_pin_idx_alloc(&pin_idx);
+ if (ret)
+ return ERR_PTR(ret);
+ } else if (pin_idx > INT_MAX) {
+ return ERR_PTR(-EINVAL);
+ }
pin = kzalloc(sizeof(*pin), GFP_KERNEL);
- if (!pin)
- return ERR_PTR(-ENOMEM);
+ if (!pin) {
+ ret = -ENOMEM;
+ goto err_pin_alloc;
+ }
pin->pin_idx = pin_idx;
pin->clock_id = clock_id;
pin->module = module;
@@ -555,6 +596,8 @@ dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
dpll_pin_prop_free(&pin->prop);
err_pin_prop:
kfree(pin);
+err_pin_alloc:
+ dpll_pin_idx_free(pin_idx);
return ERR_PTR(ret);
}
@@ -658,6 +701,7 @@ void dpll_pin_put(struct dpll_pin *pin)
xa_destroy(&pin->ref_sync_pins);
dpll_pin_prop_free(&pin->prop);
fwnode_handle_put(pin->fwnode);
+ dpll_pin_idx_free(pin->pin_idx);
kfree_rcu(pin, rcu);
}
mutex_unlock(&dpll_lock);
diff --git a/include/linux/dpll.h b/include/linux/dpll.h
index 092abf400552b..65e86c687a6c4 100644
--- a/include/linux/dpll.h
+++ b/include/linux/dpll.h
@@ -250,6 +250,8 @@ int dpll_device_register(struct dpll_device *dpll, enum dpll_type type,
void dpll_device_unregister(struct dpll_device *dpll,
const struct dpll_device_ops *ops, void *priv);
+#define DPLL_PIN_IDX_UNSPEC U32_MAX
+
struct dpll_pin *
dpll_pin_get(u64 clock_id, u32 dev_driver_id, struct module *module,
const struct dpll_pin_properties *prop);
--
2.52.0Hi Ivan,
kernel test robot noticed the following build warnings:
[auto build test WARNING on net-next/main]
url: https://github.com/intel-lab-lkp/linux/commits/Ivan-Vecera/dt-bindings-dpll-add-common-dpll-pin-consumer-schema/20260109-022618
base: net-next/main
patch link: https://lore.kernel.org/r/20260108182318.20935-7-ivecera%40redhat.com
patch subject: [Intel-wired-lan] [PATCH net-next 06/12] dpll: Support dynamic pin index allocation
config: hexagon-allmodconfig (https://download.01.org/0day-ci/archive/20260113/202601130301.7QjXjwFp-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260113/202601130301.7QjXjwFp-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601130301.7QjXjwFp-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/dpll/dpll_core.c:499:21: warning: overflow in expression; result is -2147483648 with type 'int' [-Winteger-overflow]
499 | pin_idx -= INT_MAX + 1;
| ^
1 warning generated.
vim +/int +499 drivers/dpll/dpll_core.c
490
491 static void dpll_pin_idx_free(u32 pin_idx)
492 {
493 if (pin_idx <= INT_MAX)
494 return; /* Not a dynamic pin index */
495
496 /* Map the index value from dynamic pin index range to IDA range and
497 * free it.
498 */
> 499 pin_idx -= INT_MAX + 1;
500 ida_free(&dpll_pin_idx_ida, pin_idx);
501 }
502
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Hi Ivan,
kernel test robot noticed the following build warnings:
[auto build test WARNING on net-next/main]
url: https://github.com/intel-lab-lkp/linux/commits/Ivan-Vecera/dt-bindings-dpll-add-common-dpll-pin-consumer-schema/20260109-022618
base: net-next/main
patch link: https://lore.kernel.org/r/20260108182318.20935-7-ivecera%40redhat.com
patch subject: [Intel-wired-lan] [PATCH net-next 06/12] dpll: Support dynamic pin index allocation
config: m68k-allmodconfig (https://download.01.org/0day-ci/archive/20260112/202601122216.BCarSN6K-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 15.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260112/202601122216.BCarSN6K-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601122216.BCarSN6K-lkp@intel.com/
All warnings (new ones prefixed by >>):
drivers/dpll/dpll_core.c: In function 'dpll_pin_idx_free':
>> drivers/dpll/dpll_core.c:499:28: warning: integer overflow in expression of type 'int' results in '-2147483648' [-Woverflow]
499 | pin_idx -= INT_MAX + 1;
| ^
vim +499 drivers/dpll/dpll_core.c
490
491 static void dpll_pin_idx_free(u32 pin_idx)
492 {
493 if (pin_idx <= INT_MAX)
494 return; /* Not a dynamic pin index */
495
496 /* Map the index value from dynamic pin index range to IDA range and
497 * free it.
498 */
> 499 pin_idx -= INT_MAX + 1;
500 ida_free(&dpll_pin_idx_ida, pin_idx);
501 }
502
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
On 1/12/26 4:13 PM, kernel test robot wrote:
> Hi Ivan,
>
> kernel test robot noticed the following build warnings:
>
> [auto build test WARNING on net-next/main]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Ivan-Vecera/dt-bindings-dpll-add-common-dpll-pin-consumer-schema/20260109-022618
> base: net-next/main
> patch link: https://lore.kernel.org/r/20260108182318.20935-7-ivecera%40redhat.com
> patch subject: [Intel-wired-lan] [PATCH net-next 06/12] dpll: Support dynamic pin index allocation
> config: m68k-allmodconfig (https://download.01.org/0day-ci/archive/20260112/202601122216.BCarSN6K-lkp@intel.com/config)
> compiler: m68k-linux-gcc (GCC) 15.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260112/202601122216.BCarSN6K-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202601122216.BCarSN6K-lkp@intel.com/
>
> All warnings (new ones prefixed by >>):
>
> drivers/dpll/dpll_core.c: In function 'dpll_pin_idx_free':
>>> drivers/dpll/dpll_core.c:499:28: warning: integer overflow in expression of type 'int' results in '-2147483648' [-Woverflow]
> 499 | pin_idx -= INT_MAX + 1;
> | ^
>
>
> vim +499 drivers/dpll/dpll_core.c
>
> 490
> 491 static void dpll_pin_idx_free(u32 pin_idx)
> 492 {
> 493 if (pin_idx <= INT_MAX)
> 494 return; /* Not a dynamic pin index */
> 495
> 496 /* Map the index value from dynamic pin index range to IDA range and
> 497 * free it.
> 498 */
> > 499 pin_idx -= INT_MAX + 1;
'pin_idx -= (u32)INT_MAX + 1' should be here..
Will fix.
I.
> 500 ida_free(&dpll_pin_idx_ida, pin_idx);
> 501 }
> 502
>
Hi Ivan,
kernel test robot noticed the following build warnings:
[auto build test WARNING on net-next/main]
url: https://github.com/intel-lab-lkp/linux/commits/Ivan-Vecera/dt-bindings-dpll-add-common-dpll-pin-consumer-schema/20260109-022618
base: net-next/main
patch link: https://lore.kernel.org/r/20260108182318.20935-7-ivecera%40redhat.com
patch subject: [Intel-wired-lan] [PATCH net-next 06/12] dpll: Support dynamic pin index allocation
config: x86_64-rhel-9.4 (https://download.01.org/0day-ci/archive/20260110/202601100030.nDiAPf7k-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260110/202601100030.nDiAPf7k-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601100030.nDiAPf7k-lkp@intel.com/
All warnings (new ones prefixed by >>):
drivers/dpll/dpll_core.c: In function 'dpll_pin_idx_free':
>> drivers/dpll/dpll_core.c:499:28: warning: integer overflow in expression of type 'int' results in '-2147483648' [-Woverflow]
499 | pin_idx -= INT_MAX + 1;
| ^
vim +499 drivers/dpll/dpll_core.c
490
491 static void dpll_pin_idx_free(u32 pin_idx)
492 {
493 if (pin_idx <= INT_MAX)
494 return; /* Not a dynamic pin index */
495
496 /* Map the index value from dynamic pin index range to IDA range and
497 * free it.
498 */
> 499 pin_idx -= INT_MAX + 1;
500 ida_free(&dpll_pin_idx_ida, pin_idx);
501 }
502
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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