From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (bilbo.ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3zsxZg3VYtzF1lr for ; Fri, 2 Mar 2018 15:46:03 +1100 (AEDT) From: Michael Ellerman To: Alexander.Levin@microsoft.com Cc: stable@vger.kernel.org, linuxppc-dev@ozlabs.org, npiggin@gmail.com Subject: [PATCH v4.1 backport 12/15] powerpc/64s: Allow control of RFI flush via debugfs Date: Fri, 2 Mar 2018 15:45:46 +1100 Message-Id: <20180302044549.14930-13-mpe@ellerman.id.au> In-Reply-To: <20180302044549.14930-1-mpe@ellerman.id.au> References: <20180302044549.14930-1-mpe@ellerman.id.au> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , commit 236003e6b5443c45c18e613d2b0d776a9f87540e upstream. Expose the state of the RFI flush (enabled/disabled) via debugfs, and allow it to be enabled/disabled at runtime. eg: $ cat /sys/kernel/debug/powerpc/rfi_flush 1 $ echo 0 > /sys/kernel/debug/powerpc/rfi_flush $ cat /sys/kernel/debug/powerpc/rfi_flush 0 Signed-off-by: Michael Ellerman Reviewed-by: Nicholas Piggin Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/setup_64.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 55d8da909db5..ec01a98a5978 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -38,6 +38,7 @@ #include #include #include +#include #include #include @@ -896,5 +897,34 @@ void __init setup_rfi_flush(enum l1d_flush_type types, bool enable) if (!no_rfi_flush) rfi_flush_enable(enable); } + +#ifdef CONFIG_DEBUG_FS +static int rfi_flush_set(void *data, u64 val) +{ + if (val == 1) + rfi_flush_enable(true); + else if (val == 0) + rfi_flush_enable(false); + else + return -EINVAL; + + return 0; +} + +static int rfi_flush_get(void *data, u64 *val) +{ + *val = rfi_flush ? 1 : 0; + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(fops_rfi_flush, rfi_flush_get, rfi_flush_set, "%llu\n"); + +static __init int rfi_flush_debugfs_init(void) +{ + debugfs_create_file("rfi_flush", 0600, powerpc_debugfs_root, NULL, &fops_rfi_flush); + return 0; +} +device_initcall(rfi_flush_debugfs_init); +#endif #endif /* CONFIG_PPC_BOOK3S_64 */ #endif -- 2.14.1