Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758941Ab3DZLGQ (ORCPT ); Fri, 26 Apr 2013 07:06:16 -0400 Received: from mail-pb0-f49.google.com ([209.85.160.49]:51419 "EHLO mail-pb0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753265Ab3DZLGP (ORCPT ); Fri, 26 Apr 2013 07:06:15 -0400 From: Pranavkumar Sawargaonkar To: linux-arm-kernel@lists.infradead.org Cc: kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, rusty@rustcorp.com.au, linaro-kernel@lists.linaro.org, patches@linaro.org, anup.patel@linaro.org, Pranavkumar Sawargaonkar Subject: [PATCH 0/2] Early printk support for virtio console devices. Date: Fri, 26 Apr 2013 16:34:54 +0530 Message-Id: <1366974299-17877-1-git-send-email-pranavkumar@linaro.org> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1372 Lines: 28 This patch-set implements early printk support for virtio console devices without using any hypercalls. The current virtio early printk code in kernel expects that hypervisor will provide some mechanism generally a hypercall to support early printk. This patch-set does not break existing hypercall based early print support. This implementation adds: 1. Early writeonly register named early_wr in virtio console's config space. 2. Host feature flags namely VIRTIO_CONSOLE_F_EARLY_WRITE for telling guest about early-write capability in console device. Early write mechanism: 1. When a guest wants to out some character, it has to simply write the character to early_wr register in config space of virtio console device. Pranavkumar Sawargaonkar (2): virtio: console: Add early writeonly register to config space arm64: earlyprintk support for virtio-mmio console Documentation/virtual/virtio-spec.txt | 13 ++++++++++-- arch/arm64/kernel/early_printk.c | 35 +++++++++++++++++++++++++++++++++ include/uapi/linux/virtio_console.h | 3 +++ 3 files changed, 49 insertions(+), 2 deletions(-) -- 1.7.9.5 -- 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/