blob: 3568149b956200c4cae0c7f7650dd5372b0c122d [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* dpll_core.c - DPLL subsystem kernel-space interface implementation.
*
* 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"
#include "dpll_netlink.h"
/* Mutex lock to protect DPLL subsystem devices and pins */
DEFINE_MUTEX(dpll_lock);
DEFINE_XARRAY_FLAGS(dpll_device_xa, XA_FLAGS_ALLOC);
DEFINE_XARRAY_FLAGS(dpll_pin_xa, XA_FLAGS_ALLOC);
static u32 dpll_xa_id;
#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))
#define ASSERT_PIN_REGISTERED(p) \
WARN_ON_ONCE(!xa_get_mark(&dpll_pin_xa, (p)->id, DPLL_REGISTERED))
struct dpll_device_registration {
struct list_head list;
const struct dpll_device_ops *ops;
void *priv;
};
struct dpll_pin_registration {
struct list_head list;
const struct dpll_pin_ops *ops;
void *priv;
};
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;
}
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;
}
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) {
xa_erase(xa_pins, pin->pin_idx);
kfree(ref);
}
return -ENOMEM;
}
reg->ops = ops;
reg->priv = priv;
if (ref_exists)
refcount_inc(&ref->refcount);
list_add_tail(&reg->list, &ref->registration_list);
return 0;
}
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(&reg->list);
kfree(reg);
xa_erase(xa_pins, i);
WARN_ON(!list_empty(&ref->registration_list));
kfree(ref);
}
return 0;
}
return -EINVAL;
}
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->id, 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) {
xa_erase(xa_dplls, dpll->id);
kfree(ref);
}
return -ENOMEM;
}
reg->ops = ops;
reg->priv = priv;
if (ref_exists)
refcount_inc(&ref->refcount);
list_add_tail(&reg->list, &ref->registration_list);
return 0;
}
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(&reg->list);
kfree(reg);
xa_erase(xa_dplls, i);
WARN_ON(!list_empty(&ref->registration_list));
kfree(ref);
}
return;
}
}
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;
}
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_cyclic(&dpll_device_xa, &dpll->id, dpll, xa_limit_32b,
&dpll_xa_id, GFP_KERNEL);
if (ret < 0) {
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(X) - error
*/
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)
{
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
* * negative - error value
*/
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(!ops->mode_get))
return -EINVAL;
if (WARN_ON(!ops->lock_status_get))
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 -ENOMEM;
}
reg->ops = ops;
reg->priv = priv;
dpll->type = type;
first_registration = list_empty(&dpll->registration_list);
list_add_tail(&reg->list, &dpll->registration_list);
if (!first_registration) {
mutex_unlock(&dpll_lock);
return 0;
}
xa_set_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
dpll_device_create_ntf(dpll);
mutex_unlock(&dpll_lock);
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(&reg->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);
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: Acquires a lock (dpll_lock)
* Return:
* * valid allocated dpll_pin struct pointer if succeeded
* * ERR_PTR(X) - 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;
mutex_lock(&dpll_lock);
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);
mutex_unlock(&dpll_lock);
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: Acquires a lock (dpll_lock)
*/
void dpll_pin_put(struct dpll_pin *pin)
{
mutex_lock(&dpll_lock);
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);
}
mutex_unlock(&dpll_lock);
}
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;
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;
xa_set_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
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
* * negative - error value
*/
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) ||
WARN_ON(!ops->state_on_dpll_get) ||
WARN_ON(!ops->direction_get))
return -EINVAL;
if (ASSERT_DPLL_REGISTERED(dpll))
return -EINVAL;
mutex_lock(&dpll_lock);
if (WARN_ON(!(dpll->module == pin->module &&
dpll->clock_id == pin->clock_id)))
ret = -EINVAL;
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);
if (xa_empty(&pin->dpll_refs))
xa_clear_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
}
/**
* 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;
if (WARN_ON(!xa_empty(&pin->parent_refs)))
return;
mutex_lock(&dpll_lock);
dpll_pin_delete_ntf(pin);
__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
* * negative - error value
*/
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;
if (WARN_ON(!ops) ||
WARN_ON(!ops->state_on_pin_get) ||
WARN_ON(!ops->direction_get))
return -EINVAL;
if (ASSERT_PIN_REGISTERED(parent))
return -EINVAL;
mutex_lock(&dpll_lock);
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) {
ret = __dpll_pin_register(ref->dpll, pin, ops, priv);
if (ret) {
stop = i;
goto dpll_unregister;
}
dpll_pin_create_ntf(pin);
}
mutex_unlock(&dpll_lock);
return ret;
dpll_unregister:
xa_for_each(&parent->dpll_refs, i, ref)
if (i < stop) {
__dpll_pin_unregister(ref->dpll, pin, ops, priv);
dpll_pin_delete_ntf(pin);
}
refcount_dec(&pin->refcount);
dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv);
unlock:
mutex_unlock(&dpll_lock);
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);
mutex_unlock(&dpll_lock);
}
EXPORT_SYMBOL_GPL(dpll_pin_on_pin_unregister);
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;
}
void *dpll_priv(struct dpll_device *dpll)
{
struct dpll_device_registration *reg;
reg = dpll_device_registration_first(dpll);
return reg->priv;
}
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;
}
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;
}
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;
}
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;
}
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;
}
static int __init dpll_init(void)
{
int ret;
ret = genl_register_family(&dpll_nl_family);
if (ret)
goto error;
return 0;
error:
mutex_destroy(&dpll_lock);
return ret;
}
static void __exit dpll_exit(void)
{
genl_unregister_family(&dpll_nl_family);
mutex_destroy(&dpll_lock);
}
subsys_initcall(dpll_init);
module_exit(dpll_exit);