@@ -35,3 +35,4 @@ obj-$(CONFIG_PPC_SUBPAGE_PROT) += subpage-prot.o
obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o
obj-$(CONFIG_HIGHMEM) += highmem.o
obj-$(CONFIG_SPU_BASE) += copro_fault.o
+obj-$(CONFIG_CXL_BASE) += copro_fault.o
@@ -527,4 +527,5 @@ source "drivers/misc/vmw_vmci/Kconfig"
source "drivers/misc/mic/Kconfig"
source "drivers/misc/genwqe/Kconfig"
source "drivers/misc/echo/Kconfig"
+source "drivers/misc/cxl/Kconfig"
endmenu
@@ -55,3 +55,4 @@ obj-y += mic/
obj-$(CONFIG_GENWQE) += genwqe/
obj-$(CONFIG_ECHO) += echo/
obj-$(CONFIG_VEXPRESS_SYSCFG) += vexpress-syscfg.o
+obj-$(CONFIG_CXL_BASE) += cxl/
new file mode 100644
@@ -0,0 +1,7 @@
+#
+# IBM Coherent Accelerator (CXL) compatible devices
+#
+
+config CXL_BASE
+ bool
+ default n
new file mode 100644
@@ -0,0 +1 @@
+obj-$(CONFIG_CXL_BASE) += base.o
new file mode 100644
@@ -0,0 +1,102 @@
+/*
+ * 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 <linux/module.h>
+#include <linux/rcupdate.h>
+#include <asm/errno.h>
+#include <misc/cxl.h>
+#include "cxl.h"
+
+/* protected by rcu */
+static struct cxl_calls *cxl_calls;
+
+static atomic_t use_count = ATOMIC_INIT(0);
+
+#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 */
+
+void cxl_slbia(struct mm_struct *mm)
+{
+ struct cxl_calls *calls;
+
+ calls = cxl_calls_get();
+ if (!calls)
+ return;
+
+ calls->cxl_slbia(mm);
+ cxl_calls_put(calls);
+}
+EXPORT_SYMBOL(cxl_slbia);
+
+void cxl_ctx_get(void)
+{
+ atomic_inc(&use_count);
+}
+EXPORT_SYMBOL(cxl_ctx_get);
+
+void cxl_ctx_put(void)
+{
+ atomic_dec(&use_count);
+}
+EXPORT_SYMBOL(cxl_ctx_put);
+
+bool cxl_ctx_in_use(void)
+{
+ return (atomic_read(&use_count) != 0);
+}
+EXPORT_SYMBOL(cxl_ctx_in_use);
+
+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);