From patchwork Mon Nov 7 11:13:37 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiao Guangrong X-Patchwork-Id: 9414865 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 06E7A60512 for ; Mon, 7 Nov 2016 11:35:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EB5FC28CCF for ; Mon, 7 Nov 2016 11:35:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DFD0728CD1; Mon, 7 Nov 2016 11:35:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 4A1F128CCF for ; Mon, 7 Nov 2016 11:35:17 +0000 (UTC) Received: from localhost ([::1]:53144 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c3iCo-00038R-3T for patchwork-qemu-devel@patchwork.kernel.org; Mon, 07 Nov 2016 06:35:14 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44486) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c3i6v-00079W-CP for qemu-devel@nongnu.org; Mon, 07 Nov 2016 06:29:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c3i6u-0001LF-Cy for qemu-devel@nongnu.org; Mon, 07 Nov 2016 06:29:09 -0500 Received: from mga11.intel.com ([192.55.52.93]:55637) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1c3i6u-0001Jt-5c for qemu-devel@nongnu.org; Mon, 07 Nov 2016 06:29:08 -0500 Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP; 07 Nov 2016 03:29:07 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos; i="5.31,606,1473145200"; d="scan'208"; a="1065006798" Received: from xiaoreal1.sh.intel.com (HELO xiaoreal1.sh.intel.com.sh.intel.com) ([10.239.48.133]) by fmsmga001.fm.intel.com with ESMTP; 07 Nov 2016 03:29:05 -0800 From: Xiao Guangrong To: pbonzini@redhat.com, imammedo@redhat.com Date: Mon, 7 Nov 2016 19:13:37 +0800 Message-Id: <1478517229-140028-3-git-send-email-guangrong.xiao@linux.intel.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1478517229-140028-1-git-send-email-guangrong.xiao@linux.intel.com> References: <1478517229-140028-1-git-send-email-guangrong.xiao@linux.intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.93 Subject: [Qemu-devel] [PATCH 02/14] nvdimm acpi: drop the lock of fit buffer X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Xiao Guangrong , ehabkost@redhat.com, kvm@vger.kernel.org, mst@redhat.com, gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, dan.j.williams@intel.com, rth@twiddle.net Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP as there is a global lock to protect vm-exit handlers and QMP/monitor, this lock can be dropped Suggested-by: Igor Mammedov Signed-off-by: Xiao Guangrong Reviewed-by: Stefan Hajnoczi Reviewed-by: Igor Mammedov --- hw/acpi/nvdimm.c | 11 +---------- include/hw/mem/nvdimm.h | 17 +++++------------ 2 files changed, 6 insertions(+), 22 deletions(-) diff --git a/hw/acpi/nvdimm.c b/hw/acpi/nvdimm.c index 623bb36..0fe3547 100644 --- a/hw/acpi/nvdimm.c +++ b/hw/acpi/nvdimm.c @@ -371,17 +371,14 @@ static GArray *nvdimm_build_device_structure(void) static void nvdimm_init_fit_buffer(NvdimmFitBuffer *fit_buf) { - qemu_mutex_init(&fit_buf->lock); fit_buf->fit = g_array_new(false, true /* clear */, 1); } static void nvdimm_build_fit_buffer(NvdimmFitBuffer *fit_buf) { - qemu_mutex_lock(&fit_buf->lock); g_array_free(fit_buf->fit, true); fit_buf->fit = nvdimm_build_device_structure(); fit_buf->dirty = true; - qemu_mutex_unlock(&fit_buf->lock); } void nvdimm_acpi_hotplug(AcpiNVDIMMState *state) @@ -395,11 +392,10 @@ static void nvdimm_build_nfit(AcpiNVDIMMState *state, GArray *table_offsets, NvdimmFitBuffer *fit_buf = &state->fit_buf; unsigned int header; - qemu_mutex_lock(&fit_buf->lock); /* NVDIMM device is not plugged? */ if (!fit_buf->fit->len) { - goto exit; + return; } acpi_add_table(table_offsets, table_data); @@ -413,9 +409,6 @@ static void nvdimm_build_nfit(AcpiNVDIMMState *state, GArray *table_offsets, build_header(linker, table_data, (void *)(table_data->data + header), "NFIT", sizeof(NvdimmNfitHeader) + fit_buf->fit->len, 1, NULL, NULL); - -exit: - qemu_mutex_unlock(&fit_buf->lock); } struct NvdimmDsmIn { @@ -544,7 +537,6 @@ static void nvdimm_dsm_func_read_fit(AcpiNVDIMMState *state, NvdimmDsmIn *in, read_fit = (NvdimmFuncReadFITIn *)in->arg3; le32_to_cpus(&read_fit->offset); - qemu_mutex_lock(&fit_buf->lock); fit = fit_buf->fit; nvdimm_debug("Read FIT: offset %#x FIT size %#x Dirty %s.\n", @@ -578,7 +570,6 @@ exit: cpu_physical_memory_write(dsm_mem_addr, read_fit_out, size); g_free(read_fit_out); - qemu_mutex_unlock(&fit_buf->lock); } static void nvdimm_dsm_reserved_root(AcpiNVDIMMState *state, NvdimmDsmIn *in, diff --git a/include/hw/mem/nvdimm.h b/include/hw/mem/nvdimm.h index 33cd421..d3ffb25 100644 --- a/include/hw/mem/nvdimm.h +++ b/include/hw/mem/nvdimm.h @@ -99,20 +99,13 @@ typedef struct NVDIMMClass NVDIMMClass; #define NVDIMM_ACPI_IO_LEN 4 /* - * The buffer, @fit, saves the FIT info for all the presented NVDIMM - * devices which is updated after the NVDIMM device is plugged or - * unplugged. - * - * Rules to use the buffer: - * 1) the user should hold the @lock to access the buffer. - * 2) mark @dirty whenever the buffer is updated. - * - * These rules preserve NVDIMM ACPI _FIT method to read incomplete - * or obsolete fit info if fit update happens during multiple RFIT - * calls. + * NvdimmFitBuffer: + * @fit: FIT structures for present NVDIMMs. It is updated when + * the NVDIMM device is plugged or unplugged. + * @dirty: It allows OSPM to detect change and restart read in + * progress if there is any. */ struct NvdimmFitBuffer { - QemuMutex lock; GArray *fit; bool dirty; };