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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-11 20:34:00 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-11 20:34:00 -0400 |
commit | fd9879b9bb3258ebc27a4cc6d2d29f528f71901f (patch) | |
tree | 48b68994f5e8083aafe116533e8143cb2bf30c85 /drivers/misc/cxl/base.c | |
parent | 81ae31d78239318610d7c2acb3e2610d622a5aa4 (diff) | |
parent | d53ba6b3bba33432cc37b7101a86f8f3392c46e7 (diff) | |
download | linux-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.c | 86 |
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); |