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authorIan Munsie <imunsie@au1.ibm.com>2014-10-08 19:55:01 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2014-10-08 20:15:56 +1100
commit10542ca0156f60571ef41799d44d40dd4cb0a473 (patch)
treeb917dbb91e1e2b1cffd5a351cd16ff431cc16f41 /drivers/misc/cxl
parent4c6d9acce1f4ca815881f0e3adca192795eca1c5 (diff)
cxl: Add base builtin support
This adds the base cxl support that cannot be built as a module. Specifically it adds the cxl callbacks that are called from the core powerpc mm code which must always exist irrespective of if the cxl module is loaded or not. This is similar to how cell works with CONFIG_SPU_BASE. This adds a cxl_slbia() call (similar to spu_flush_all_slbs()) which checks if the cxl module is loaded and in use, returning immediately if it is not. If it is in use it calls into the cxl SLB invalidation code. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/misc/cxl')
-rw-r--r--drivers/misc/cxl/Kconfig8
-rw-r--r--drivers/misc/cxl/Makefile1
-rw-r--r--drivers/misc/cxl/base.c86
3 files changed, 95 insertions, 0 deletions
diff --git a/drivers/misc/cxl/Kconfig b/drivers/misc/cxl/Kconfig
new file mode 100644
index 000000000000..5cdd3199f97d
--- /dev/null
+++ b/drivers/misc/cxl/Kconfig
@@ -0,0 +1,8 @@
+#
+# IBM Coherent Accelerator (CXL) compatible devices
+#
+
+config CXL_BASE
+ bool
+ default n
+ select PPC_COPRO_BASE
diff --git a/drivers/misc/cxl/Makefile b/drivers/misc/cxl/Makefile
new file mode 100644
index 000000000000..e30ad0ab0cf5
--- /dev/null
+++ b/drivers/misc/cxl/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_CXL_BASE) += base.o
diff --git a/drivers/misc/cxl/base.c b/drivers/misc/cxl/base.c
new file mode 100644
index 000000000000..0654ad83675e
--- /dev/null
+++ b/drivers/misc/cxl/base.c
@@ -0,0 +1,86 @@
+/*
+ * 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;
+
+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 */
+
+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);