From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C5F3C43603 for ; Thu, 5 Dec 2019 16:42:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EC15C22525 for ; Thu, 5 Dec 2019 16:42:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575564169; bh=0ld8kOcqM2caAQmvxEjgIeog81bSQ16/K/Tq37PU/jo=; h=From:To:Cc:Subject:Date:List-ID:From; b=CWBq/HsNYBAC+A13UqOiwj+/n4FYTMt8Uu8WivmsQRqAQf5VVu3jhUkjrUkzYnpoo mtXWjUDL2ueTbfTwqzKQL3mnecPZPadFHFRnMb4DpoqSrKEdFvVCs4NX0Z2QfE63nF nwSw1YZ4kpZ+9Q4jN70WR+U2t5yBVC/1fcRkBwCM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729047AbfLEQms (ORCPT ); Thu, 5 Dec 2019 11:42:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:57044 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729022AbfLEQms (ORCPT ); Thu, 5 Dec 2019 11:42:48 -0500 Received: from e123331-lin.cambridge.arm.com (fw-tnat-cam5.arm.com [217.140.106.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 645AE22525; Thu, 5 Dec 2019 16:42:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575564167; bh=0ld8kOcqM2caAQmvxEjgIeog81bSQ16/K/Tq37PU/jo=; h=From:To:Cc:Subject:Date:From; b=rNj+vsYSMG+1P/A8FsTUf/RQjsvMsJqGVkDiKNcqQBJNxf2yvDtwL89iPuOupX2UI 9Heqip0gaLdQjtzL56JKex3NC4pOkSZx9bdlZMMFsx03ngz7mebGqHnMSwI6vBzBsy 7OE+qZ+ZlL+1WbYKelcrLZn7dIcXs6lyL5yFjc10= From: Ard Biesheuvel To: linux-efi@vger.kernel.org Cc: Andy Shevchenko , Ard Biesheuvel Subject: [PATCH v4] efi/earlycon: Remap entire framebuffer after page initialization Date: Thu, 5 Dec 2019 16:42:48 +0000 Message-Id: <20191205164248.14511-1-ardb@kernel.org> X-Mailer: git-send-email 2.17.1 Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org From: Andy Shevchenko When commit 69c1f396f25b "efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation" moved the x86 specific EFI earlyprintk implementation to a shared location, it also tweaked the behaviour. In particular, it dropped a trick with full framebuffer remapping after page initialization, leading to two regressions: 1) very slow scrolling after page initialization, 2) kernel hang when the 'keep_bootcon' command line argument is passed. Putting the tweak back fixes #2 and mitigates #1, i.e., it limits the slow behavior to the early boot stages, presumably due to eliminating heavy map()/unmap() operations per each pixel line on the screen. Fixes: 69c1f396f25b ("efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation") Signed-off-by: Andy Shevchenko [ardb: ensure efifb is unmapped again unless keep_bootcon is in effect] Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/earlycon.c | 40 +++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/drivers/firmware/efi/earlycon.c b/drivers/firmware/efi/earlycon.c index c9a0efca17b0..0bc4fe741415 100644 --- a/drivers/firmware/efi/earlycon.c +++ b/drivers/firmware/efi/earlycon.c @@ -13,18 +13,57 @@ #include +static const struct console *earlycon_console __initdata; static const struct font_desc *font; static u32 efi_x, efi_y; static u64 fb_base; static pgprot_t fb_prot; +static void *efi_fb; + +/* + * efi earlycon needs to use early_memremap() to map the framebuffer. + * But early_memremap() is not usable for 'earlycon=efifb keep_bootcon', + * memremap() should be used instead. memremap() will be available after + * paging_init() which is earlier than initcall callbacks. Thus adding this + * early initcall function early_efi_map_fb() to map the whole efi framebuffer. + */ +static int __init efi_earlycon_remap_fb(void) +{ + /* bail if there is no bootconsole or it has been disabled already */ + if (!earlycon_console || !(earlycon_console->flags & CON_ENABLED)) + return 0; + + if (pgprot_val(fb_prot) == pgprot_val(PAGE_KERNEL)) + efi_fb = memremap(fb_base, screen_info.lfb_size, MEMREMAP_WB); + else + efi_fb = memremap(fb_base, screen_info.lfb_size, MEMREMAP_WC); + + return efi_fb ? 0 : -ENOMEM; +} +early_initcall(efi_earlycon_remap_fb); + +static int __init efi_earlycon_unmap_fb(void) +{ + /* unmap the bootconsole fb unless keep_bootcon has left it enabled */ + if (efi_fb && !(earlycon_console->flags & CON_ENABLED)) + memunmap(efi_fb); + return 0; +} +late_initcall(efi_earlycon_unmap_fb); static __ref void *efi_earlycon_map(unsigned long start, unsigned long len) { + if (efi_fb) + return efi_fb + start; + return early_memremap_prot(fb_base + start, len, pgprot_val(fb_prot)); } static __ref void efi_earlycon_unmap(void *addr, unsigned long len) { + if (efi_fb) + return; + early_memunmap(addr, len); } @@ -201,6 +240,7 @@ static int __init efi_earlycon_setup(struct earlycon_device *device, efi_earlycon_scroll_up(); device->con->write = efi_earlycon_write; + earlycon_console = device->con; return 0; } EARLYCON_DECLARE(efifb, efi_earlycon_setup); -- 2.17.1