Fri, Jun 09, 2023 at 02:18:46PM CEST, arkadiusz.kubalewski@xxxxxxxxx wrote:
>From: Vadim Fedorenko <vadim.fedorenko@xxxxxxxxx>
>
>DPLL framework is used to represent and configure DPLL devices
>in systems. Each device that has DPLL and can configure inputs
>and outputs can use this framework.
>
>Implement core framework functions for further interactions
>with device drivers implementing dpll subsystem, as well as for
>interactions of DPLL netlink framework part with the subsystem
>itself.
>
>Co-developed-by: Milena Olech <milena.olech@xxxxxxxxx>
>Signed-off-by: Milena Olech <milena.olech@xxxxxxxxx>
>Co-developed-by: Michal Michalik <michal.michalik@xxxxxxxxx>
>Signed-off-by: Michal Michalik <michal.michalik@xxxxxxxxx>
>Signed-off-by: Vadim Fedorenko <vadim.fedorenko@xxxxxxxxx>
>Co-developed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@xxxxxxxxx>
>Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@xxxxxxxxx>
>---
> drivers/dpll/dpll_core.c | 953 +++++++++++++++++++++++++++++++++++++++
> drivers/dpll/dpll_core.h | 104 +++++
Overall, looks very good! I pinpointed couple of nits below, nothing big.
General question: Why do you put documentation comment to every static
function? Does not make any sense to me. Even for non-exported functions
I think it is overkill. Most of them (if not all) give the reader no
additional information and only make the code a bit harder to read.
Care to drop them?
> 2 files changed, 1057 insertions(+)
> create mode 100644 drivers/dpll/dpll_core.c
> create mode 100644 drivers/dpll/dpll_core.h
>
>diff --git a/drivers/dpll/dpll_core.c b/drivers/dpll/dpll_core.c
>new file mode 100644
>index 000000000000..ee515b7c18be
>--- /dev/null
>+++ b/drivers/dpll/dpll_core.c
>@@ -0,0 +1,953 @@
>+// SPDX-License-Identifier: GPL-2.0
>+/*
>+ * dpll_core.c - Generic DPLL Management class support.
What's "management class support"? Does not sound recognizable.
>+ *
>+ * Copyright (c) 2023 Meta Platforms, Inc. and affiliates
>+ * Copyright (c) 2023 Intel Corporation.
>+ */
>+
>+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>+
>+#include <linux/device.h>
>+#include <linux/err.h>
>+#include <linux/slab.h>
>+#include <linux/string.h>
>+
>+#include "dpll_core.h"
>+
>+DEFINE_MUTEX(dpll_lock);
>+
>+DEFINE_XARRAY_FLAGS(dpll_device_xa, XA_FLAGS_ALLOC);
>+DEFINE_XARRAY_FLAGS(dpll_pin_xa, XA_FLAGS_ALLOC);
>+
>+#define ASSERT_DPLL_REGISTERED(d) \
>+ WARN_ON_ONCE(!xa_get_mark(&dpll_device_xa, (d)->id, DPLL_REGISTERED))
>+#define ASSERT_DPLL_NOT_REGISTERED(d) \
>+ WARN_ON_ONCE(xa_get_mark(&dpll_device_xa, (d)->id, DPLL_REGISTERED))
>+
>+/**
>+ * dpll_device_get_by_id - find dpll device by it's id
>+ * @id: id of searched dpll
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return:
>+ * * dpll_device struct if found
>+ * * NULL otherwise
>+ */
>+struct dpll_device *dpll_device_get_by_id(int id)
>+{
>+ if (xa_get_mark(&dpll_device_xa, id, DPLL_REGISTERED))
>+ return xa_load(&dpll_device_xa, id);
>+
>+ return NULL;
>+}
>+
>+/**
>+ * dpll_pin_registration_find - find a pin registration record
>+ * @ref: reference between dpll and pin
>+ * @ops: searched pin ops pointer
>+ * @priv: searched pin priv pointer
>+ *
>+ * Search dpll's registered pins for given ops and priv data.
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return:
>+ * * NULL - if pin was not found
>+ * * pointer to `struct dpll_pin_registration` if found
>+ */
>+static struct dpll_pin_registration *
>+dpll_pin_registration_find(struct dpll_pin_ref *ref,
>+ const struct dpll_pin_ops *ops, void *priv)
>+{
>+ struct dpll_pin_registration *reg;
>+
>+ list_for_each_entry(reg, &ref->registration_list, list) {
>+ if (reg->ops == ops && reg->priv == priv)
>+ return reg;
>+ }
>+ return NULL;
>+}
>+
>+/**
>+ * dpll_xa_ref_pin_add - add pin reference to a given xarray
>+ * @xa_pins: dpll_pin_ref xarray holding pins
>+ * @pin: pin being added
>+ * @ops: ops for a pin
>+ * @priv: pointer to private data of owner
>+ *
>+ * Allocate and create reference of a pin and enlist a registration
>+ * structure storing ops and priv pointers of a caller registant.
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return:
>+ * * 0 on success
>+ * * -ENOMEM on failed allocation
>+ */
>+static int
>+dpll_xa_ref_pin_add(struct xarray *xa_pins, struct dpll_pin *pin,
>+ const struct dpll_pin_ops *ops, void *priv)
>+{
>+ struct dpll_pin_registration *reg;
>+ struct dpll_pin_ref *ref;
>+ bool ref_exists = false;
>+ unsigned long i;
>+ int ret;
>+
>+ xa_for_each(xa_pins, i, ref) {
>+ if (ref->pin != pin)
>+ continue;
>+ reg = dpll_pin_registration_find(ref, ops, priv);
>+ if (reg) {
>+ refcount_inc(&ref->refcount);
>+ return 0;
>+ }
>+ ref_exists = true;
>+ break;
>+ }
>+
>+ if (!ref_exists) {
>+ ref = kzalloc(sizeof(*ref), GFP_KERNEL);
>+ if (!ref)
>+ return -ENOMEM;
>+ ref->pin = pin;
>+ INIT_LIST_HEAD(&ref->registration_list);
>+ ret = xa_insert(xa_pins, pin->pin_idx, ref, GFP_KERNEL);
>+ if (ret) {
>+ kfree(ref);
>+ return ret;
>+ }
>+ refcount_set(&ref->refcount, 1);
>+ }
>+
>+ reg = kzalloc(sizeof(*reg), GFP_KERNEL);
>+ if (!reg) {
>+ if (!ref_exists)
>+ kfree(ref);
>+ return -ENOMEM;
>+ }
>+ reg->ops = ops;
>+ reg->priv = priv;
>+ if (ref_exists)
If you set refcount to 0 couple of lines above, you can drop the check
here.
>+ refcount_inc(&ref->refcount);
>+ list_add_tail(®->list, &ref->registration_list);
>+
>+ return 0;
>+}
>+
>+/**
>+ * dpll_xa_ref_pin_del - remove reference of a pin from xarray
>+ * @xa_pins: dpll_pin_ref xarray holding pins
>+ * @pin: pointer to a pin being removed
>+ * @ops: pointer to ops of pin being removed
>+ * @priv: pointer to private data of registerer who invoked pin removal
>+ *
>+ * Decrement refcount of existing pin reference on given xarray.
>+ * If all registrations are lifted delete the reference and free its memory.
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return:
>+ * * 0 on success
>+ * * -EINVAL if reference to a pin was not found
>+ */
>+static int dpll_xa_ref_pin_del(struct xarray *xa_pins, struct dpll_pin *pin,
>+ const struct dpll_pin_ops *ops, void *priv)
>+{
>+ struct dpll_pin_registration *reg;
>+ struct dpll_pin_ref *ref;
>+ unsigned long i;
>+
>+ xa_for_each(xa_pins, i, ref) {
>+ if (ref->pin != pin)
>+ continue;
>+ reg = dpll_pin_registration_find(ref, ops, priv);
>+ if (WARN_ON(!reg))
>+ return -EINVAL;
>+ if (refcount_dec_and_test(&ref->refcount)) {
>+ list_del(®->list);
>+ kfree(reg);
>+ xa_erase(xa_pins, i);
>+ WARN_ON(!list_empty(&ref->registration_list));
>+ kfree(ref);
>+ }
>+ return 0;
>+ }
>+
>+ return -EINVAL;
>+}
>+
>+/**
>+ * dpll_xa_ref_dpll_add - add dpll reference to a given xarray
>+ * @xa_dplls: dpll_pin_ref xarray holding dplls
>+ * @dpll: dpll being added
>+ * @ops: pin-reference ops for a dpll
>+ * @priv: pointer to private data of owner
>+ *
>+ * Allocate and create reference of a dpll-pin ops or increase refcount
>+ * on existing dpll reference on given xarray.
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return:
>+ * * 0 on success
>+ * * -ENOMEM on failed allocation
>+ */
>+static int
>+dpll_xa_ref_dpll_add(struct xarray *xa_dplls, struct dpll_device *dpll,
>+ const struct dpll_pin_ops *ops, void *priv)
>+{
>+ struct dpll_pin_registration *reg;
>+ struct dpll_pin_ref *ref;
>+ bool ref_exists = false;
>+ unsigned long i;
>+ int ret;
>+
>+ xa_for_each(xa_dplls, i, ref) {
>+ if (ref->dpll != dpll)
>+ continue;
>+ reg = dpll_pin_registration_find(ref, ops, priv);
>+ if (reg) {
>+ refcount_inc(&ref->refcount);
>+ return 0;
>+ }
>+ ref_exists = true;
>+ break;
>+ }
>+
>+ if (!ref_exists) {
>+ ref = kzalloc(sizeof(*ref), GFP_KERNEL);
>+ if (!ref)
>+ return -ENOMEM;
>+ ref->dpll = dpll;
>+ INIT_LIST_HEAD(&ref->registration_list);
>+ ret = xa_insert(xa_dplls, dpll->device_idx, ref, GFP_KERNEL);
>+ if (ret) {
>+ kfree(ref);
>+ return ret;
>+ }
>+ refcount_set(&ref->refcount, 1);
>+ }
>+
>+ reg = kzalloc(sizeof(*reg), GFP_KERNEL);
>+ if (!reg) {
>+ if (!ref_exists)
>+ kfree(ref);
>+ return -ENOMEM;
>+ }
>+ reg->ops = ops;
>+ reg->priv = priv;
>+ if (ref_exists)
If you set refcount to 0 couple of lines above, you can drop the check
here.
>+ refcount_inc(&ref->refcount);
>+ list_add_tail(®->list, &ref->registration_list);
>+
>+ return 0;
>+}
>+
>+/**
>+ * dpll_xa_ref_dpll_del - remove reference of a dpll from xarray
>+ * @xa_dplls: dpll_pin_ref xarray holding dplls
>+ * @dpll: pointer to a dpll to remove
>+ * @ops: pointer to ops of dpll being removed
>+ * @priv: pointer to private data of registerer who invoked dpll removal
>+ *
>+ * Decrement refcount of existing dpll reference on given xarray.
>+ * If all references are dropped, delete the reference and free its memory.
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ */
>+static void
>+dpll_xa_ref_dpll_del(struct xarray *xa_dplls, struct dpll_device *dpll,
>+ const struct dpll_pin_ops *ops, void *priv)
>+{
>+ struct dpll_pin_registration *reg;
>+ struct dpll_pin_ref *ref;
>+ unsigned long i;
>+
>+ xa_for_each(xa_dplls, i, ref) {
>+ if (ref->dpll != dpll)
>+ continue;
>+ reg = dpll_pin_registration_find(ref, ops, priv);
>+ if (WARN_ON(!reg))
>+ return;
>+ if (refcount_dec_and_test(&ref->refcount)) {
>+ list_del(®->list);
>+ kfree(reg);
>+ xa_erase(xa_dplls, i);
>+ WARN_ON(!list_empty(&ref->registration_list));
>+ kfree(ref);
>+ }
>+ return;
>+ }
>+}
>+
>+/**
>+ * dpll_xa_ref_dpll_find - find dpll reference on xarray
>+ * @xa_refs: dpll_pin_ref xarray holding dpll references
>+ * @dpll: pointer to a dpll being searched
>+ *
>+ * Search for dpll-pin ops reference struct of a given dpll on given xarray.
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return:
>+ * * pin reference struct pointer on success
>+ * * NULL - reference to a pin was not found
>+ */
>+struct dpll_pin_ref *
>+dpll_xa_ref_dpll_find(struct xarray *xa_refs, const struct dpll_device *dpll)
>+{
>+ struct dpll_pin_ref *ref;
>+ unsigned long i;
>+
>+ xa_for_each(xa_refs, i, ref) {
>+ if (ref->dpll == dpll)
>+ return ref;
>+ }
>+
>+ return NULL;
>+}
>+
>+/**
>+ * dpll_xa_ref_dpll_first - find first record of given xarray
>+ * @xa_refs: xarray
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return: first element on given xaaray
>+ */
>+struct dpll_pin_ref *dpll_xa_ref_dpll_first(struct xarray *xa_refs)
>+{
>+ struct dpll_pin_ref *ref;
>+ unsigned long i = 0;
>+
>+ ref = xa_find(xa_refs, &i, ULONG_MAX, XA_PRESENT);
>+ WARN_ON(!ref);
>+ return ref;
>+}
>+
>+/**
>+ * dpll_device_alloc - allocate the memory for dpll device
>+ * @clock_id: clock_id of creator
>+ * @device_idx: id given by dev driver
>+ * @module: reference to registering module
>+ *
>+ * Allocates memory and initialize dpll device, hold its reference on global
>+ * xarray.
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return:
>+ * * valid dpll_device struct pointer if succeeded
>+ * * ERR_PTR(-ENOMEM) - failed memory allocation
>+ * * ERR_PTR(X) - failed allocation on dpll's xa
>+ */
>+static struct dpll_device *
>+dpll_device_alloc(const u64 clock_id, u32 device_idx, struct module *module)
>+{
>+ struct dpll_device *dpll;
>+ int ret;
>+
>+ dpll = kzalloc(sizeof(*dpll), GFP_KERNEL);
>+ if (!dpll)
>+ return ERR_PTR(-ENOMEM);
>+ refcount_set(&dpll->refcount, 1);
>+ INIT_LIST_HEAD(&dpll->registration_list);
>+ dpll->device_idx = device_idx;
>+ dpll->clock_id = clock_id;
>+ dpll->module = module;
>+ ret = xa_alloc(&dpll_device_xa, &dpll->id, dpll, xa_limit_16b,
>+ GFP_KERNEL);
>+ if (ret) {
>+ kfree(dpll);
>+ return ERR_PTR(ret);
>+ }
>+ xa_init_flags(&dpll->pin_refs, XA_FLAGS_ALLOC);
>+
>+ return dpll;
>+}
>+
>+/**
>+ * dpll_device_get - find existing or create new dpll device
>+ * @clock_id: clock_id of creator
>+ * @device_idx: idx given by device driver
>+ * @module: reference to registering module
>+ *
>+ * Get existing object of a dpll device, unique for given arguments.
>+ * Create new if doesn't exist yet.
>+ *
>+ * Context: Acquires a lock (dpll_lock)
>+ * Return:
>+ * * valid dpll_device struct pointer if succeeded
>+ * * ERR_PTR(-ENOMEM) - failed memory allocation
>+ * * ERR_PTR(X) - failed allocation on dpll's xa
>+ */
>+struct dpll_device *
>+dpll_device_get(u64 clock_id, u32 device_idx, struct module *module)
>+{
>+ struct dpll_device *dpll, *ret = NULL;
>+ unsigned long index;
>+
>+ mutex_lock(&dpll_lock);
>+ xa_for_each(&dpll_device_xa, index, dpll) {
>+ if (dpll->clock_id == clock_id &&
>+ dpll->device_idx == device_idx &&
>+ dpll->module == module) {
>+ ret = dpll;
>+ refcount_inc(&ret->refcount);
>+ break;
>+ }
>+ }
>+ if (!ret)
>+ ret = dpll_device_alloc(clock_id, device_idx, module);
>+ mutex_unlock(&dpll_lock);
>+
>+ return ret;
>+}
>+EXPORT_SYMBOL_GPL(dpll_device_get);
>+
>+/**
>+ * dpll_device_put - decrease the refcount and free memory if possible
>+ * @dpll: dpll_device struct pointer
>+ *
>+ * Context: Acquires a lock (dpll_lock)
>+ * Drop reference for a dpll device, if all references are gone, delete
>+ * dpll device object.
>+ */
>+void dpll_device_put(struct dpll_device *dpll)
>+{
>+ if (!dpll)
Drop this check and rely on a basic driver sanity. I'm pretty sure I
asked you to drop checks like this during the last version review.
>+ return;
>+ mutex_lock(&dpll_lock);
>+ if (refcount_dec_and_test(&dpll->refcount)) {
>+ ASSERT_DPLL_NOT_REGISTERED(dpll);
>+ WARN_ON_ONCE(!xa_empty(&dpll->pin_refs));
>+ xa_destroy(&dpll->pin_refs);
>+ xa_erase(&dpll_device_xa, dpll->id);
>+ WARN_ON(!list_empty(&dpll->registration_list));
>+ kfree(dpll);
>+ }
>+ mutex_unlock(&dpll_lock);
>+}
>+EXPORT_SYMBOL_GPL(dpll_device_put);
>+
>+static struct dpll_device_registration *
>+dpll_device_registration_find(struct dpll_device *dpll,
>+ const struct dpll_device_ops *ops, void *priv)
>+{
>+ struct dpll_device_registration *reg;
>+
>+ list_for_each_entry(reg, &dpll->registration_list, list) {
>+ if (reg->ops == ops && reg->priv == priv)
>+ return reg;
>+ }
>+ return NULL;
>+}
>+
>+/**
>+ * dpll_device_register - register the dpll device in the subsystem
>+ * @dpll: pointer to a dpll
>+ * @type: type of a dpll
>+ * @ops: ops for a dpll device
>+ * @priv: pointer to private information of owner
>+ *
>+ * Make dpll device available for user space.
>+ *
>+ * Context: Acquires a lock (dpll_lock)
>+ * Return:
>+ * * 0 on success
>+ * * -EINVAL on failure due to wrong arguments provided
>+ * * -EEXIST if device was already registered
>+ */
>+int dpll_device_register(struct dpll_device *dpll, enum dpll_type type,
>+ const struct dpll_device_ops *ops, void *priv)
>+{
>+ struct dpll_device_registration *reg;
>+ bool first_registration = false;
>+
>+ if (WARN_ON(!ops))
>+ return -EINVAL;
>+ if (WARN_ON(type < DPLL_TYPE_PPS || type > DPLL_TYPE_MAX))
>+ return -EINVAL;
>+
>+ mutex_lock(&dpll_lock);
>+ reg = dpll_device_registration_find(dpll, ops, priv);
>+ if (reg) {
>+ mutex_unlock(&dpll_lock);
>+ return -EEXIST;
>+ }
>+
>+ reg = kzalloc(sizeof(*reg), GFP_KERNEL);
>+ if (!reg) {
>+ mutex_unlock(&dpll_lock);
>+ return -EEXIST;
-ENOMEM;
>+ }
>+ reg->ops = ops;
>+ reg->priv = priv;
>+ dpll->type = type;
>+ first_registration = list_empty(&dpll->registration_list);
>+ list_add_tail(®->list, &dpll->registration_list);
>+ if (!first_registration) {
>+ mutex_unlock(&dpll_lock);
>+ return 0;
>+ }
>+
>+ xa_set_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
>+ mutex_unlock(&dpll_lock);
>+ dpll_device_create_ntf(dpll);
>+
>+ return 0;
>+}
>+EXPORT_SYMBOL_GPL(dpll_device_register);
>+
>+/**
>+ * dpll_device_unregister - unregister dpll device
>+ * @dpll: registered dpll pointer
>+ * @ops: ops for a dpll device
>+ * @priv: pointer to private information of owner
>+ *
>+ * Unregister device, make it unavailable for userspace.
>+ * Note: It does not free the memory
>+ * Context: Acquires a lock (dpll_lock)
>+ */
>+void dpll_device_unregister(struct dpll_device *dpll,
>+ const struct dpll_device_ops *ops, void *priv)
>+{
>+ struct dpll_device_registration *reg;
>+
>+ mutex_lock(&dpll_lock);
>+ ASSERT_DPLL_REGISTERED(dpll);
>+ dpll_device_delete_ntf(dpll);
>+ reg = dpll_device_registration_find(dpll, ops, priv);
>+ if (WARN_ON(!reg)) {
>+ mutex_unlock(&dpll_lock);
>+ return;
>+ }
>+ list_del(®->list);
>+ kfree(reg);
>+
>+ if (!list_empty(&dpll->registration_list)) {
>+ mutex_unlock(&dpll_lock);
>+ return;
>+ }
>+ xa_clear_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
>+ mutex_unlock(&dpll_lock);
>+}
>+EXPORT_SYMBOL_GPL(dpll_device_unregister);
>+
>+/**
>+ * dpll_pin_alloc - allocate the memory for dpll pin
>+ * @clock_id: clock_id of creator
>+ * @pin_idx: idx given by dev driver
>+ * @module: reference to registering module
>+ * @prop: dpll pin properties
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return:
>+ * * valid allocated dpll_pin struct pointer if succeeded
>+ * * ERR_PTR(-ENOMEM) - failed memory allocation
>+ * * ERR_PTR(-EINVAL) - wrong pin type property value
>+ */
>+static struct dpll_pin *
>+dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
>+ const struct dpll_pin_properties *prop)
>+{
>+ struct dpll_pin *pin;
>+ int ret;
>+
>+ pin = kzalloc(sizeof(*pin), GFP_KERNEL);
>+ if (!pin)
>+ return ERR_PTR(-ENOMEM);
>+ pin->pin_idx = pin_idx;
>+ pin->clock_id = clock_id;
>+ pin->module = module;
>+ if (WARN_ON(prop->type < DPLL_PIN_TYPE_MUX ||
>+ prop->type > DPLL_PIN_TYPE_MAX)) {
>+ ret = -EINVAL;
>+ goto err;
>+ }
>+ pin->prop = prop;
>+ refcount_set(&pin->refcount, 1);
>+ xa_init_flags(&pin->dpll_refs, XA_FLAGS_ALLOC);
>+ xa_init_flags(&pin->parent_refs, XA_FLAGS_ALLOC);
>+ ret = xa_alloc(&dpll_pin_xa, &pin->id, pin, xa_limit_16b, GFP_KERNEL);
>+ if (ret)
>+ goto err;
>+ return pin;
>+err:
>+ xa_destroy(&pin->dpll_refs);
>+ xa_destroy(&pin->parent_refs);
>+ kfree(pin);
>+ return ERR_PTR(ret);
>+}
>+
>+/**
>+ * dpll_pin_get - find existing or create new dpll pin
>+ * @clock_id: clock_id of creator
>+ * @pin_idx: idx given by dev driver
>+ * @module: reference to registering module
>+ * @prop: dpll pin properties
>+ *
>+ * Get existing object of a pin (unique for given arguments) or create new
>+ * if doesn't exist yet.
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return:
>+ * * valid allocated dpll_pin struct pointer if succeeded
>+ * * ERR_PTR of an error
>+ */
>+struct dpll_pin *
>+dpll_pin_get(u64 clock_id, u32 pin_idx, struct module *module,
>+ const struct dpll_pin_properties *prop)
>+{
>+ struct dpll_pin *pos, *ret = NULL;
>+ unsigned long i;
>+
>+ xa_for_each(&dpll_pin_xa, i, pos) {
>+ if (pos->clock_id == clock_id &&
>+ pos->pin_idx == pin_idx &&
>+ pos->module == module) {
>+ ret = pos;
>+ refcount_inc(&ret->refcount);
>+ break;
>+ }
>+ }
>+ if (!ret)
>+ ret = dpll_pin_alloc(clock_id, pin_idx, module, prop);
>+
>+ return ret;
>+}
>+EXPORT_SYMBOL_GPL(dpll_pin_get);
>+
>+/**
>+ * dpll_pin_put - decrease the refcount and free memory if possible
>+ * @pin: pointer to a pin to be put
>+ *
>+ * Drop reference for a pin, if all references are gone, delete pin object.
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ */
>+void dpll_pin_put(struct dpll_pin *pin)
>+{
>+ if (!pin)
Drop this check.
>+ return;
>+ if (refcount_dec_and_test(&pin->refcount)) {
>+ xa_destroy(&pin->dpll_refs);
>+ xa_destroy(&pin->parent_refs);
>+ xa_erase(&dpll_pin_xa, pin->id);
>+ kfree(pin);
>+ }
>+}
>+EXPORT_SYMBOL_GPL(dpll_pin_put);
>+
>+static int
>+__dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
>+ const struct dpll_pin_ops *ops, void *priv)
>+{
>+ int ret;
>+
>+ if (WARN_ON(!ops))
>+ return -EINVAL;
>+
>+ ret = dpll_xa_ref_pin_add(&dpll->pin_refs, pin, ops, priv);
>+ if (ret)
>+ return ret;
>+ ret = dpll_xa_ref_dpll_add(&pin->dpll_refs, dpll, ops, priv);
>+ if (ret)
>+ goto ref_pin_del;
>+ else
>+ dpll_pin_create_ntf(pin);
>+
>+ return ret;
>+
>+ref_pin_del:
>+ dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv);
>+ return ret;
>+}
>+
>+/**
>+ * dpll_pin_register - register the dpll pin in the subsystem
>+ * @dpll: pointer to a dpll
>+ * @pin: pointer to a dpll pin
>+ * @ops: ops for a dpll pin ops
>+ * @priv: pointer to private information of owner
>+ *
>+ * Context: Acquires a lock (dpll_lock)
>+ * Return:
>+ * * 0 on success
>+ * * -EINVAL - missing pin ops
>+ * * -ENOMEM - failed to allocate memory
>+ */
>+int
>+dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
>+ const struct dpll_pin_ops *ops, void *priv)
>+{
>+ int ret;
>+
>+ mutex_lock(&dpll_lock);
>+ if (WARN_ON(!(dpll->module == pin->module &&
>+ dpll->clock_id == pin->clock_id)))
>+ ret = -EFAULT;
In other cases like this you return -EINVAL. I think it is better. One
way or another, be consistent please.
>+ else
>+ ret = __dpll_pin_register(dpll, pin, ops, priv);
>+ mutex_unlock(&dpll_lock);
>+
>+ return ret;
>+}
>+EXPORT_SYMBOL_GPL(dpll_pin_register);
>+
>+static void
>+__dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
>+ const struct dpll_pin_ops *ops, void *priv)
>+{
>+ dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv);
>+ dpll_xa_ref_dpll_del(&pin->dpll_refs, dpll, ops, priv);
>+}
>+
>+/**
>+ * dpll_pin_unregister - unregister dpll pin from dpll device
>+ * @dpll: registered dpll pointer
>+ * @pin: pointer to a pin
>+ * @ops: ops for a dpll pin
>+ * @priv: pointer to private information of owner
>+ *
>+ * Note: It does not free the memory
>+ * Context: Acquires a lock (dpll_lock)
>+ */
>+void dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
>+ const struct dpll_pin_ops *ops, void *priv)
>+{
>+ if (WARN_ON(xa_empty(&dpll->pin_refs)))
>+ return;
>+
>+ mutex_lock(&dpll_lock);
>+ __dpll_pin_unregister(dpll, pin, ops, priv);
>+ mutex_unlock(&dpll_lock);
>+}
>+EXPORT_SYMBOL_GPL(dpll_pin_unregister);
>+
>+/**
>+ * dpll_pin_on_pin_register - register a pin with a parent pin
>+ * @parent: pointer to a parent pin
>+ * @pin: pointer to a pin
>+ * @ops: ops for a dpll pin
>+ * @priv: pointer to private information of owner
>+ *
>+ * Register a pin with a parent pin, create references between them and
>+ * between newly registered pin and dplls connected with a parent pin.
>+ *
>+ * Context: Acquires a lock (dpll_lock)
>+ * Return:
>+ * * 0 on success
>+ * * -EINVAL missing pin or parent
>+ * * -ENOMEM failed allocation
>+ * * -EPERM if parent is not allowed
>+ */
>+int dpll_pin_on_pin_register(struct dpll_pin *parent, struct dpll_pin *pin,
>+ const struct dpll_pin_ops *ops, void *priv)
>+{
>+ struct dpll_pin_ref *ref;
>+ unsigned long i, stop;
>+ int ret;
>+
>+ if (WARN_ON(parent->prop->type != DPLL_PIN_TYPE_MUX))
>+ return -EINVAL;
>+ ret = dpll_xa_ref_pin_add(&pin->parent_refs, parent, ops, priv);
>+ if (ret)
>+ goto unlock;
>+ refcount_inc(&pin->refcount);
>+ xa_for_each(&parent->dpll_refs, i, ref) {
>+ mutex_lock(&dpll_lock);
>+ ret = __dpll_pin_register(ref->dpll, pin, ops, priv);
>+ mutex_unlock(&dpll_lock);
>+ if (ret) {
>+ stop = i;
>+ goto dpll_unregister;
>+ }
>+ dpll_pin_create_ntf(pin);
>+ }
>+
>+ return ret;
>+
>+dpll_unregister:
>+ xa_for_each(&parent->dpll_refs, i, ref) {
>+ if (i < stop) {
>+ mutex_lock(&dpll_lock);
>+ __dpll_pin_unregister(ref->dpll, pin, ops, priv);
>+ mutex_unlock(&dpll_lock);
>+ }
>+ }
>+ refcount_dec(&pin->refcount);
>+ dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv);
>+unlock:
>+ return ret;
>+}
>+EXPORT_SYMBOL_GPL(dpll_pin_on_pin_register);
>+
>+/**
>+ * dpll_pin_on_pin_unregister - unregister dpll pin from a parent pin
>+ * @parent: pointer to a parent pin
>+ * @pin: pointer to a pin
>+ * @ops: ops for a dpll pin
>+ * @priv: pointer to private information of owner
>+ *
>+ * Context: Acquires a lock (dpll_lock)
>+ * Note: It does not free the memory
>+ */
>+void dpll_pin_on_pin_unregister(struct dpll_pin *parent, struct dpll_pin *pin,
>+ const struct dpll_pin_ops *ops, void *priv)
>+{
>+ struct dpll_pin_ref *ref;
>+ unsigned long i;
>+
>+ mutex_lock(&dpll_lock);
>+ dpll_pin_delete_ntf(pin);
>+ dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv);
>+ refcount_dec(&pin->refcount);
>+ xa_for_each(&pin->dpll_refs, i, ref) {
>+ __dpll_pin_unregister(ref->dpll, pin, ops, priv);
>+ }
Drop "{}"s for one line statement. Didn't checkpack warn you?
>+ mutex_unlock(&dpll_lock);
>+}
>+EXPORT_SYMBOL_GPL(dpll_pin_on_pin_unregister);
>+
>+
>+/**
>+ * dpll_device_registration_first - get first registration of dpll device
>+ * @dpll: pointer to a dpll
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return: pointer to the first registration of a dpll
>+ */
>+static struct dpll_device_registration *
>+dpll_device_registration_first(struct dpll_device *dpll)
>+{
>+ struct dpll_device_registration *reg;
>+
>+ reg = list_first_entry_or_null((struct list_head *) &dpll->registration_list,
>+ struct dpll_device_registration, list);
>+ WARN_ON(!reg);
>+ return reg;
>+}
>+
>+/**
>+ * dpll_priv - get the dpll device private owner data
>+ * @dpll: registered dpll pointer
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return: pointer to the first registration priv data
>+ */
>+void *dpll_priv(struct dpll_device *dpll)
>+{
>+ struct dpll_device_registration *reg;
>+
>+ reg = dpll_device_registration_first(dpll);
>+ return reg->priv;
>+}
>+
>+/**
>+ * dpll_device_ops - get the dpll device ops pointer
>+ * @dpll: registered dpll pointer
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return: pointer to the first registration ops of the dpll
>+ */
>+const struct dpll_device_ops *dpll_device_ops(struct dpll_device *dpll)
>+{
>+ struct dpll_device_registration *reg;
>+
>+ reg = dpll_device_registration_first(dpll);
>+ return reg->ops;
>+}
>+
>+/**
>+ * dpll_pin_registration_first - get first registration of dpll pin ref
>+ * @ref: pointer to a pin ref struct
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return: pointer to the first registration of a dpll_pin_ref
>+ */
>+static struct dpll_pin_registration *
>+dpll_pin_registration_first(struct dpll_pin_ref *ref)
>+{
>+ struct dpll_pin_registration *reg;
>+
>+ reg = list_first_entry_or_null(&ref->registration_list,
>+ struct dpll_pin_registration, list);
>+ WARN_ON(!reg);
>+ return reg;
>+}
>+
>+/**
>+ * dpll_pin_on_dpll_priv - get the dpll device private owner data
>+ * @dpll: registered dpll pointer
>+ * @pin: pointer to a pin
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return: pointer to the data
>+ */
>+void *dpll_pin_on_dpll_priv(struct dpll_device *dpll,
>+ struct dpll_pin *pin)
>+{
>+ struct dpll_pin_registration *reg;
>+ struct dpll_pin_ref *ref;
>+
>+ ref = xa_load(&dpll->pin_refs, pin->pin_idx);
>+ if (!ref)
>+ return NULL;
>+ reg = dpll_pin_registration_first(ref);
>+ return reg->priv;
>+}
>+
>+/**
>+ * dpll_pin_on_pin_priv - get the dpll pin private owner data
>+ * @parent: pointer to a parent pin
>+ * @pin: pointer to a pin
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return: pointer to the data
>+ */
>+void *dpll_pin_on_pin_priv(struct dpll_pin *parent,
>+ struct dpll_pin *pin)
>+{
>+ struct dpll_pin_registration *reg;
>+ struct dpll_pin_ref *ref;
>+
>+ ref = xa_load(&pin->parent_refs, parent->pin_idx);
>+ if (!ref)
>+ return NULL;
>+ reg = dpll_pin_registration_first(ref);
>+ return reg->priv;
>+}
>+
>+/**
>+ * dpll_pin_ops - get the pin ops pointer
>+ * @ref: dpll pin ref
>+ *
>+ * Context: shall be called under a lock (dpll_lock)
>+ * Return: pointer to the first ops registered with the pin
>+ */
>+const struct dpll_pin_ops *dpll_pin_ops(struct dpll_pin_ref *ref)
>+{
>+ struct dpll_pin_registration *reg;
>+
>+ reg = dpll_pin_registration_first(ref);
>+ return reg->ops;
>+}
>+
>+/**
>+ * dpll_init - initialize dpll subsystem
>+ *
>+ * Return:
>+ * 0 - success
>+ * negative - netlink init error
>+ */
>+static int __init dpll_init(void)
>+{
>+ int ret;
>+
>+ ret = dpll_netlink_init();
>+ if (ret)
>+ goto error;
>+
>+ return 0;
>+
>+error:
>+ mutex_destroy(&dpll_lock);
>+ return ret;
>+}
>+subsys_initcall(dpll_init);
>diff --git a/drivers/dpll/dpll_core.h b/drivers/dpll/dpll_core.h
>new file mode 100644
>index 000000000000..ef95e272937c
>--- /dev/null
>+++ b/drivers/dpll/dpll_core.h
>@@ -0,0 +1,104 @@
>+/* SPDX-License-Identifier: GPL-2.0 */
>+/*
>+ * Copyright (c) 2023 Meta Platforms, Inc. and affiliates
>+ * Copyright (c) 2023 Intel and affiliates
>+ */
>+
>+#ifndef __DPLL_CORE_H__
>+#define __DPLL_CORE_H__
>+
>+#include <linux/dpll.h>
>+#include <linux/list.h>
>+#include <linux/refcount.h>
>+#include "dpll_netlink.h"
>+
>+#define DPLL_REGISTERED XA_MARK_1
>+
>+struct dpll_device_registration {
>+ struct list_head list;
>+ const struct dpll_device_ops *ops;
>+ void *priv;
You don't need this struct in the header. Move to .c
>+};
>+
>+/**
>+ * struct dpll_device - stores DPLL device internal data
>+ * @id: unique id number for each device given by kernel
Who's kernel? Say "dpll subsystem" instead.
>+ * @device_idx: id given by dev driver
>+ * @clock_id: unique identifier (clock_id) of a dpll
>+ * @module: module of creator
>+ * @type: type of a dpll
>+ * @pin_refs: stores pins registered within a dpll
>+ * @mode_supported_mask: mask of supported modes
>+ * @refcount: refcount
>+ * @registration_list: list of registered ops and priv data of dpll owners
>+ **/
>+struct dpll_device {
>+ u32 id;
>+ u32 device_idx;
>+ u64 clock_id;
>+ struct module *module;
>+ enum dpll_type type;
>+ struct xarray pin_refs;
>+ unsigned long mode_supported_mask;
>+ refcount_t refcount;
>+ struct list_head registration_list;
>+};
>+
>+/**
>+ * struct dpll_pin - structure for a dpll pin
>+ * @id: unique id number for pin given by kernel
Who's kernel? Say "dpll subsystem" instead.
>+ * @pin_idx: index of a pin given by dev driver
>+ * @clock_id: clock_id of creator
>+ * @module: module of creator
>+ * @dpll_refs: hold referencees to dplls pin was registered with
>+ * @parent_refs: hold references to parent pins pin was registered with
>+ * @prop: pointer to pin properties given by registerer
>+ * @rclk_dev_name: holds name of device when pin can recover clock from it
>+ * @refcount: refcount
>+ **/
>+struct dpll_pin {
>+ u32 id;
>+ u32 pin_idx;
>+ u64 clock_id;
>+ struct module *module;
>+ struct xarray dpll_refs;
>+ struct xarray parent_refs;
>+ const struct dpll_pin_properties *prop;
>+ char *rclk_dev_name;
>+ refcount_t refcount;
>+};
>+
>+struct dpll_pin_registration {
>+ struct list_head list;
>+ const struct dpll_pin_ops *ops;
>+ void *priv;
>+};
You don't need this struct in the header. Move to .c
>+
>+/**
>+ * struct dpll_pin_ref - structure for referencing either dpll or pins
>+ * @dpll: pointer to a dpll
>+ * @pin: pointer to a pin
>+ * @registration_list: list of ops and priv data registered with the ref
>+ * @refcount: refcount
>+ **/
>+struct dpll_pin_ref {
>+ union {
>+ struct dpll_device *dpll;
>+ struct dpll_pin *pin;
>+ };
>+ struct list_head registration_list;
>+ refcount_t refcount;
>+};
>+
>+void *dpll_priv(struct dpll_device *dpll);
>+void *dpll_pin_on_dpll_priv(struct dpll_device *dpll, struct dpll_pin *pin);
>+void *dpll_pin_on_pin_priv(struct dpll_pin *parent, struct dpll_pin *pin);
>+
>+const struct dpll_device_ops *dpll_device_ops(struct dpll_device *dpll);
>+struct dpll_device *dpll_device_get_by_id(int id);
>+const struct dpll_pin_ops *dpll_pin_ops(struct dpll_pin_ref *ref);
>+struct dpll_pin_ref *dpll_xa_ref_dpll_first(struct xarray *xa_refs);
>+extern struct xarray dpll_device_xa;
>+extern struct xarray dpll_pin_xa;
>+extern struct mutex dpll_lock;
>+#endif
>--
>2.37.3
>
