From 80d1f2003fcdc82a551f8606139c443c191720c1 Mon Sep 17 00:00:00 2001
From: Jason Lee <jasonlee@lanl.gov>
Date: Mon, 1 Jul 2024 15:29:52 -0600
Subject: [PATCH] rwlock to mutex

---
 include/dpusm/provider.h |  7 ++-----
 src/dpusm.c              |  6 +++---
 src/provider.c           | 32 +++++++++++---------------------
 3 files changed, 16 insertions(+), 29 deletions(-)

diff --git a/include/dpusm/provider.h b/include/dpusm/provider.h
index 1e1c1fd..cd90443 100644
--- a/include/dpusm/provider.h
+++ b/include/dpusm/provider.h
@@ -4,7 +4,7 @@
 #include <linux/atomic.h>
 #include <linux/list.h>
 #include <linux/module.h>
-#include <linux/spinlock.h>
+#include <linux/mutex.h>
 
 #include <dpusm/provider_api.h>
 
@@ -20,7 +20,7 @@ typedef struct dpusm_provider_handle {
 typedef struct {
     struct list_head providers;  /* list of providers */
     size_t count;                /* count of registered providers */
-    rwlock_t lock;
+    struct mutex lock;
     atomic_t active;             /* how many providers are active (may be larger than count) */
                                  /* this is not tied to the provider/count */
 } dpusm_t;
@@ -34,9 +34,6 @@ int dpusm_provider_unregister(dpusm_t *dpusm, struct module *module);
 dpusm_ph_t **dpusm_provider_get(dpusm_t *dpusm, const char *name);
 int dpusm_provider_put(dpusm_t *dpusm, void *handle);
 
-void dpusm_provider_write_lock(dpusm_t *dpusm);
-void dpusm_provider_write_unlock(dpusm_t *dpusm);
-
 /*
  * call when backing DPU goes down unexpectedly
  *
diff --git a/src/dpusm.c b/src/dpusm.c
index 9d661e3..712f6f7 100644
--- a/src/dpusm.c
+++ b/src/dpusm.c
@@ -66,7 +66,7 @@ static int __init
 dpusm_init(void) {
     INIT_LIST_HEAD(&dpusm.providers);
     dpusm.count = 0;
-    rwlock_init(&dpusm.lock);
+    mutex_init(&dpusm.lock);
 
     atomic_set(&dpusm.active, 0);
     dpusm_mem_init();
@@ -77,7 +77,7 @@ dpusm_init(void) {
 
 static void __exit
 dpusm_exit(void) {
-    dpusm_provider_write_lock(&dpusm);
+    mutex_lock(&dpusm.lock);
 
     const int active = atomic_read(&dpusm.active);
     if (unlikely(active)) {
@@ -100,7 +100,7 @@ dpusm_exit(void) {
         dpusm_provider_unregister_handle(&dpusm, &provider->self);
     }
 
-    dpusm_provider_write_unlock(&dpusm);
+    mutex_unlock(&dpusm.lock);
 
 #if DPUSM_TRACK_ALLOCS
     size_t alloc_count = 0;
diff --git a/src/provider.c b/src/provider.c
index 8607879..9b5f2fa 100644
--- a/src/provider.c
+++ b/src/provider.c
@@ -265,19 +265,19 @@ dpusm_provider_register(dpusm_t *dpusm, struct module *module, const dpusm_pf_t
         return -EINVAL;
     }
 
-    dpusm_provider_write_lock(dpusm);
+    mutex_lock(&dpusm->lock);;
 
     dpusm_ph_t **found = find_provider(dpusm, module_name(module));
     if (found) {
         printk("%s: DPUSM Provider with the name \"%s\" (%p) already exists. %zu providers registered.\n",
                __func__, module_name(module), *found, dpusm->count);
-        dpusm_provider_write_unlock(dpusm);
+        mutex_unlock(&dpusm->lock);;
         return -EEXIST;
     }
 
     dpusm_ph_t *provider = dpusmph_init(module, funcs);
     if (!provider) {
-        dpusm_provider_write_unlock(dpusm);
+        mutex_unlock(&dpusm->lock);;
         return -ECANCELED;
     }
 
@@ -286,7 +286,7 @@ dpusm_provider_register(dpusm_t *dpusm, struct module *module, const dpusm_pf_t
     printk("%s: DPUSM Provider \"%s\" (%p) added. Now %zu providers registered.\n",
            __func__, module_name(module), provider, dpusm->count);
 
-    dpusm_provider_write_unlock(dpusm);
+    mutex_unlock(&dpusm->lock);;
 
     return 0;
 }
@@ -320,12 +320,12 @@ dpusm_provider_unregister_handle(dpusm_t *dpusm, dpusm_ph_t **provider) {
 
 int
 dpusm_provider_unregister(dpusm_t *dpusm, struct module *module) {
-    dpusm_provider_write_lock(dpusm);
+    mutex_lock(&dpusm->lock);;
 
     dpusm_ph_t **provider = find_provider(dpusm, module_name(module));
     if (!provider) {
         printk("%s: Could not find provider with name \"%s\"\n", __func__, module_name(module));
-        dpusm_provider_write_unlock(dpusm);
+        mutex_unlock(&dpusm->lock);;
         return DPUSM_ERROR;
     }
 
@@ -333,7 +333,7 @@ dpusm_provider_unregister(dpusm_t *dpusm, struct module *module) {
     const int rc = dpusm_provider_unregister_handle(dpusm, provider);
     printk("%s: Unregistered \"%s\" (%p): %d\n", __func__, module_name(module), addr, rc);
 
-    dpusm_provider_write_unlock(dpusm);
+    mutex_unlock(&dpusm->lock);;
     return rc;
 }
 
@@ -345,7 +345,7 @@ dpusm_provider_unregister(dpusm_t *dpusm, struct module *module) {
 /* get a provider by name */
 dpusm_ph_t **
 dpusm_provider_get(dpusm_t *dpusm, const char *name) {
-    read_lock(&dpusm->lock);
+    mutex_lock(&dpusm->lock);
     dpusm_ph_t **provider = find_provider(dpusm, name);
     if (provider) {
         struct module *module = (*provider)->module;
@@ -369,7 +369,7 @@ dpusm_provider_get(dpusm_t *dpusm, const char *name) {
         printk("%s: Error: Did not find provider \"%s\"\n",
                __func__, name);
     }
-    read_unlock(&dpusm->lock);
+    mutex_unlock(&dpusm->lock);
     return provider;
 }
 
@@ -404,18 +404,8 @@ dpusm_provider_put(dpusm_t *dpusm, void *handle) {
     return DPUSM_OK;
 }
 
-void
-dpusm_provider_write_lock(dpusm_t *dpusm) {
-    write_lock(&dpusm->lock);
-}
-
-void
-dpusm_provider_write_unlock(dpusm_t *dpusm) {
-    write_unlock(&dpusm->lock);
-}
-
 void dpusm_provider_invalidate(dpusm_t *dpusm, const char *name) {
-    dpusm_provider_write_lock(dpusm);
+    mutex_lock(&dpusm->lock);;
     dpusm_ph_t **provider = find_provider(dpusm, name);
     if (provider && *provider) {
         (*provider)->funcs = NULL;
@@ -428,5 +418,5 @@ void dpusm_provider_invalidate(dpusm_t *dpusm, const char *name) {
         printk("%s: Error: Did not find provider \"%s\"\n",
                __func__, name);
     }
-    dpusm_provider_write_unlock(dpusm);
+    mutex_unlock(&dpusm->lock);;
 }