linux-kernel - [PATCH v2 03/13] openrisc: Add support for liteuart emergency printing

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220517005510.3500105-4-shorne@gmail.com>
Date:   Tue, 17 May 2022 09:55:00 +0900
From:   Stafford Horne <shorne@...il.com>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     Openrisc <openrisc@...ts.librecores.org>,
        Stafford Horne <shorne@...il.com>,
        Jonas Bonn <jonas@...thpole.se>,
        Stefan Kristiansson <stefan.kristiansson@...nalahti.fi>,
        Randy Dunlap <rdunlap@...radead.org>
Subject: [PATCH v2 03/13] openrisc: Add support for liteuart emergency printing

This patch adds support for sending emergency print output, such as
unhandled exception details, to a liteuart serial device.  This is the
default device available on litex platforms.

If a developer want to use this they should update UART_BASE_ADD
to the address of liteuart.

Signed-off-by: Stafford Horne <shorne@...il.com>
---
Changes since v1:
 - Update for patch 2/12 ifdef changes

 arch/openrisc/kernel/head.S | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S
index 7bfa6e4b60c5..21db50563f97 100644
--- a/arch/openrisc/kernel/head.S
+++ b/arch/openrisc/kernel/head.S
@@ -1555,7 +1555,18 @@ ENTRY(_emergency_putc)
 	l.movhi r4,hi(UART_BASE_ADD)
 	l.ori	r4,r4,lo(UART_BASE_ADD)
 
-#if defined(CONFIG_SERIAL_8250)
+#if defined(CONFIG_SERIAL_LITEUART)
+	/* Check OFF_TXFULL status */
+1:      l.lwz	r5,4(r4)
+	l.andi	r5,r5,0xff
+	l.sfnei	r5,0
+	l.bf	1b
+	 l.nop
+
+	/* Write character */
+	l.andi	r7,r7,0xff
+	l.sw	0(r4),r7
+#elif defined(CONFIG_SERIAL_8250)
 	/* Check UART LSR THRE (hold) bit */
 	l.addi  r6,r0,0x20
 1:      l.lbz   r5,5(r4)
-- 
2.31.1