linux-kernel - [PATCH] SPCR: check bit width for the 16550 UART

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-next>] [day] [month] [year] [list]

Message-Id: <20161205130534.11080-1-aleksey.makarov@linaro.org>
Date:   Mon,  5 Dec 2016 19:05:12 +0600
From:   Aleksey Makarov <aleksey.makarov@...aro.org>
To:     "Rafael J . Wysocki" <rjw@...ysocki.net>
Cc:     linux-acpi@...r.kernel.org, linux-serial@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Russell King <linux@....linux.org.uk>,
        Peter Hurley <peter@...leysoftware.com>,
        Aleksey Makarov <aleksey.makarov@...aro.org>,
        Jon Masters <jcm@...hat.com>, Mark Salter <msalter@...hat.com>,
        Duc Dang <dhdang@....com>,
        Graeme Gregory <graeme.gregory@...aro.org>,
        Len Brown <lenb@...nel.org>
Subject: [PATCH] SPCR: check bit width for the 16550 UART

Check the 'Register Bit Width' field of the ACPI Generic Address
Structure that specifies the address of the UART registers to
decide if the driver should use "mmio32" access instead of "mmio".

If the driver is other than 16550 the access with is defined
by the Interface Type field of the SPCR table.

For discussion:

https://lkml.kernel.org/r/7fa523de-3fbb-1566-f521-927143f73d1e@redhat.com

Signed-off-by: Aleksey Makarov <aleksey.makarov@...aro.org>
Signed-off-by: Graeme Gregory <graeme.gregory@...aro.org>
Reported-by: Heyi Guo <heyi.guo@...aro.org>
---
 drivers/acpi/spcr.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c
index e8d7bc7..6c6710b 100644
--- a/drivers/acpi/spcr.c
+++ b/drivers/acpi/spcr.c
@@ -70,6 +70,10 @@ int __init parse_spcr(bool earlycon)
 		break;
 	case ACPI_DBG2_16550_COMPATIBLE:
 	case ACPI_DBG2_16550_SUBSET:
+		if (table->serial_port.space_id ==
+			ACPI_ADR_SPACE_SYSTEM_MEMORY &&
+		    table->serial_port.bit_width == 32)
+			iotype = "mmio32";
 		uart = "uart";
 		break;
 	default:
-- 
2.10.2