Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753714AbaJGKtr (ORCPT ); Tue, 7 Oct 2014 06:49:47 -0400 Received: from ozlabs.org ([103.22.144.67]:40961 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753652AbaJGKtm (ORCPT ); Tue, 7 Oct 2014 06:49:42 -0400 From: Michael Neuling To: greg@kroah.com, arnd@arndb.de, mpe@ellerman.id.au, benh@kernel.crashing.org Cc: mikey@neuling.org, anton@samba.org, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, jk@ozlabs.org, imunsie@au.ibm.com, cbe-oss-dev@lists.ozlabs.org, "Aneesh Kumar K.V" Subject: [PATCH v3 12/16] cxl: Add base builtin support Date: Tue, 7 Oct 2014 21:48:18 +1100 Message-Id: <1412678902-18672-13-git-send-email-mikey@neuling.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1412678902-18672-1-git-send-email-mikey@neuling.org> References: <1412678902-18672-1-git-send-email-mikey@neuling.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ian Munsie This adds the base cxl support that needs to be build into the kernel to use cxl as a module. This is needed so that the cxl call backs from the core powerpc mm code 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 for the cxl module being loaded. If the modules is not loaded we return, otherwise we call into the cxl SLB invalidation code. This also adds the cxl_ctx_in_use() function for use in the mm code to see if any cxl contexts are currently in use. This is used by the tlbie() to determine if it can do local TLB invalidations or not. This also adds get/put calls for the cxl driver module to refcount the active cxl contexts. Signed-off-by: Ian Munsie Signed-off-by: Michael Neuling --- drivers/misc/Kconfig | 1 + drivers/misc/Makefile | 1 + drivers/misc/cxl/Kconfig | 8 +++++ drivers/misc/cxl/Makefile | 1 + drivers/misc/cxl/base.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 97 insertions(+) create mode 100644 drivers/misc/cxl/Kconfig create mode 100644 drivers/misc/cxl/Makefile create mode 100644 drivers/misc/cxl/base.c diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index b841180..bbeb451 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -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 diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 5497d02..7d5c4cd 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -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/ diff --git a/drivers/misc/cxl/Kconfig b/drivers/misc/cxl/Kconfig new file mode 100644 index 0000000..5cdd319 --- /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 0000000..e30ad0a --- /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 0000000..0654ad8 --- /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 +#include +#include +#include +#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); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/