// SPDX-License-Identifier: GPL-2.0/* * Generic support for Memory System Cache Maintenance operations. * * Coherency maintenance drivers register with this simple framework that will * iterate over each registered instance to first kick off invalidation and * then to wait until it is complete. * * If no implementations are registered yet cpu_cache_has_invalidate_memregion() * will return false. If this runs concurrently with unregistration then a * race exists but this is no worse than the case where the operations instance * responsible for a given memory region has not yet registered. */#include <linux/cache_coherency.h>#include <linux/cleanup.h>#include <linux/container_of.h>#include <linux/export.h>#include <linux/kref.h>#include <linux/list.h>#include <linux/memregion.h>#include <linux/module.h>#include <linux/rwsem.h>#include <linux/slab.h> static LIST_HEAD(cache_ops_instance_list);static DECLARE_RWSEM(cache_ops_instance_list_lock); static void __cache_coherency_ops_instance_free(struct kref *kref){	struct cache_coherency_ops_inst *cci =		container_of(kref, struct cache_coherency_ops_inst, kref);	kfree(cci);} void cache_coherency_ops_instance_put(struct cache_coherency_ops_inst *cci){	kref_put(&cci->kref, __cache_coherency_ops_instance_free);}EXPORT_SYMBOL_GPL(cache_coherency_ops_instance_put); static int cache_inval_one(struct cache_coherency_ops_inst *cci, void *data){	if (!cci->ops)		return -EINVAL; 	return cci->ops->wbinv(cci, data);} static int cache_inval_done_one(struct cache_coherency_ops_inst *cci){	if (!cci->ops)		return -EINVAL; 	if (!cci->ops->done)		return 0; 	return cci->ops->done(cci);} static int cache_invalidate_memregion(phys_addr_t addr, size_t size){	int ret;	struct cache_coherency_ops_inst *cci;	struct cc_inval_params params = {		.addr = addr,		.size = size,	}; 	guard(rwsem_read)(&cache_ops_instance_list_lock);	list_for_each_entry(cci, &cache_ops_instance_list, node) {		ret = cache_inval_one(cci, &params);		if (ret)			return ret;	}	list_for_each_entry(cci, &cache_ops_instance_list, node) {		ret = cache_inval_done_one(cci);		if (ret)			return ret;	} 	return 0;} struct cache_coherency_ops_inst *_cache_coherency_ops_instance_alloc(const struct cache_coherency_ops *ops,				    size_t size){	struct cache_coherency_ops_inst *cci; 	if (!ops || !ops->wbinv)		return NULL; 	cci = kzalloc(size, GFP_KERNEL);	if (!cci)		return NULL; 	cci->ops = ops;	INIT_LIST_HEAD(&cci->node);	kref_init(&cci->kref); 	return cci;}EXPORT_SYMBOL_NS_GPL(_cache_coherency_ops_instance_alloc, "CACHE_COHERENCY"); int cache_coherency_ops_instance_register(struct cache_coherency_ops_inst *cci){	guard(rwsem_write)(&cache_ops_instance_list_lock);	list_add(&cci->node, &cache_ops_instance_list); 	return 0;}EXPORT_SYMBOL_NS_GPL(cache_coherency_ops_instance_register, "CACHE_COHERENCY"); void cache_coherency_ops_instance_unregister(struct cache_coherency_ops_inst *cci){	guard(rwsem_write)(&cache_ops_instance_list_lock);	list_del(&cci->node);}EXPORT_SYMBOL_NS_GPL(cache_coherency_ops_instance_unregister, "CACHE_COHERENCY"); int cpu_cache_invalidate_memregion(phys_addr_t start, size_t len){	return cache_invalidate_memregion(start, len);}EXPORT_SYMBOL_NS_GPL(cpu_cache_invalidate_memregion, "DEVMEM"); /* * Used for optimization / debug purposes only as removal can race * * Machines that do not support invalidation, e.g. VMs, will not have any * operations instance to register and so this will always return false. */bool cpu_cache_has_invalidate_memregion(void){	guard(rwsem_read)(&cache_ops_instance_list_lock);	return !list_empty(&cache_ops_instance_list);}EXPORT_SYMBOL_NS_GPL(cpu_cache_has_invalidate_memregion, "DEVMEM");