From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- drivers/misc/cxl/base.c | 129 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+) create mode 100644 drivers/misc/cxl/base.c (limited to 'drivers/misc/cxl/base.c') diff --git a/drivers/misc/cxl/base.c b/drivers/misc/cxl/base.c new file mode 100644 index 000000000..7557835cd --- /dev/null +++ b/drivers/misc/cxl/base.c @@ -0,0 +1,129 @@ +/* + * Copyright 2014 IBM Corp. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include "cxl.h" + +/* protected by rcu */ +static struct cxl_calls *cxl_calls; + +atomic_t cxl_use_count = ATOMIC_INIT(0); +EXPORT_SYMBOL(cxl_use_count); + +#ifdef CONFIG_CXL_MODULE + +static inline struct cxl_calls *cxl_calls_get(void) +{ + struct cxl_calls *calls = NULL; + + rcu_read_lock(); + calls = rcu_dereference(cxl_calls); + if (calls && !try_module_get(calls->owner)) + calls = NULL; + rcu_read_unlock(); + + return calls; +} + +static inline void cxl_calls_put(struct cxl_calls *calls) +{ + BUG_ON(calls != cxl_calls); + + /* we don't need to rcu this, as we hold a reference to the module */ + module_put(cxl_calls->owner); +} + +#else /* !defined CONFIG_CXL_MODULE */ + +static inline struct cxl_calls *cxl_calls_get(void) +{ + return cxl_calls; +} + +static inline void cxl_calls_put(struct cxl_calls *calls) { } + +#endif /* CONFIG_CXL_MODULE */ + +/* AFU refcount management */ +struct cxl_afu *cxl_afu_get(struct cxl_afu *afu) +{ + return (get_device(&afu->dev) == NULL) ? NULL : afu; +} +EXPORT_SYMBOL_GPL(cxl_afu_get); + +void cxl_afu_put(struct cxl_afu *afu) +{ + put_device(&afu->dev); +} +EXPORT_SYMBOL_GPL(cxl_afu_put); + +void cxl_slbia(struct mm_struct *mm) +{ + struct cxl_calls *calls; + + calls = cxl_calls_get(); + if (!calls) + return; + + if (cxl_ctx_in_use()) + calls->cxl_slbia(mm); + + cxl_calls_put(calls); +} + +int register_cxl_calls(struct cxl_calls *calls) +{ + if (cxl_calls) + return -EBUSY; + + rcu_assign_pointer(cxl_calls, calls); + return 0; +} +EXPORT_SYMBOL_GPL(register_cxl_calls); + +void unregister_cxl_calls(struct cxl_calls *calls) +{ + BUG_ON(cxl_calls->owner != calls->owner); + RCU_INIT_POINTER(cxl_calls, NULL); + synchronize_rcu(); +} +EXPORT_SYMBOL_GPL(unregister_cxl_calls); + +int cxl_update_properties(struct device_node *dn, + struct property *new_prop) +{ + return of_update_property(dn, new_prop); +} +EXPORT_SYMBOL_GPL(cxl_update_properties); + +static int __init cxl_base_init(void) +{ + struct device_node *np; + struct platform_device *dev; + int count = 0; + + /* + * Scan for compatible devices in guest only + */ + if (cpu_has_feature(CPU_FTR_HVMODE)) + return 0; + + for_each_compatible_node(np, NULL, "ibm,coherent-platform-facility") { + dev = of_platform_device_create(np, NULL, NULL); + if (dev) + count++; + } + pr_devel("Found %d cxl device(s)\n", count); + return 0; +} +device_initcall(cxl_base_init); -- cgit v1.2.3