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authorLinus Torvalds <torvalds@linux-foundation.org>2014-10-11 20:34:00 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-11 20:34:00 -0400
commitfd9879b9bb3258ebc27a4cc6d2d29f528f71901f (patch)
tree48b68994f5e8083aafe116533e8143cb2bf30c85 /drivers/misc/cxl/base.c
parent81ae31d78239318610d7c2acb3e2610d622a5aa4 (diff)
parentd53ba6b3bba33432cc37b7101a86f8f3392c46e7 (diff)
downloadlinux-fd9879b9bb3258ebc27a4cc6d2d29f528f71901f.tar.bz2
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux
Pull powerpc updates from Michael Ellerman: "Here's a first pull request for powerpc updates for 3.18. The bulk of the additions are for the "cxl" driver, for IBM's Coherent Accelerator Processor Interface (CAPI). Most of it's in drivers/misc, which Greg & Arnd maintain, Greg said he was happy for us to take it through our tree. There's the usual minor cleanups and fixes, including a bit of noise in drivers from some of those. A bunch of updates to our EEH code, which has been getting more testing. Several nice speedups from Anton, including 20% in clear_page(). And a bunch of updates for freescale from Scott" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (130 commits) cxl: Fix afu_read() not doing finish_wait() on signal or non-blocking cxl: Add documentation for userspace APIs cxl: Add driver to Kbuild and Makefiles cxl: Add userspace header file cxl: Driver code for powernv PCIe based cards for userspace access cxl: Add base builtin support powerpc/mm: Add hooks for cxl powerpc/opal: Add PHB to cxl mode call powerpc/mm: Add new hash_page_mm() powerpc/powerpc: Add new PCIe functions for allocating cxl interrupts cxl: Add new header for call backs and structs powerpc/powernv: Split out set MSI IRQ chip code powerpc/mm: Export mmu_kernel_ssize and mmu_linear_psize powerpc/msi: Improve IRQ bitmap allocator powerpc/cell: Make spu_flush_all_slbs() generic powerpc/cell: Move data segment faulting code out of cell platform powerpc/cell: Move spu_handle_mm_fault() out of cell platform powerpc/pseries: Use new defines when calling H_SET_MODE powerpc: Update contact info in Documentation files powerpc/perf/hv-24x7: Simplify catalog_read() ...
Diffstat (limited to 'drivers/misc/cxl/base.c')
-rw-r--r--drivers/misc/cxl/base.c86
1 files changed, 86 insertions, 0 deletions
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);