linux-kernel - [PATCH 3/3] platform/chrome: cros_ec_lpc: Add MKBP events support over ACPI

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] [day] [month] [year] [list]

Message-Id: <1481909698-26189-4-git-send-email-thierry.escande@collabora.com>
Date:   Fri, 16 Dec 2016 18:34:58 +0100
From:   Thierry Escande <thierry.escande@...labora.com>
To:     Benson Leung <bleung@...omium.org>
Cc:     linux-kernel@...r.kernel.org
Subject: [PATCH 3/3] platform/chrome: cros_ec_lpc: Add MKBP events support over ACPI

From: Gwendal Grignou <gwendal@...omium.org>

This patch installs a notify handler to process MKBP events for EC
firmware directing them over ACPI.

Signed-off-by: Gwendal Grignou <gwendal@...omium.org>
Signed-off-by: Thierry Escande <thierry.escande@...labora.com>
---
 drivers/platform/chrome/cros_ec_lpc.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
index 89afad7..eeb187e 100644
--- a/drivers/platform/chrome/cros_ec_lpc.c
+++ b/drivers/platform/chrome/cros_ec_lpc.c
@@ -227,9 +227,20 @@ static int cros_ec_lpc_readmem(struct cros_ec_device *ec, unsigned int offset,
 	return cnt;
 }
 
+static void cros_ec_lpc_acpi_notify(acpi_handle device, u32 value, void *data)
+{
+	struct cros_ec_device *ec_dev = data;
+
+	if (ec_dev->mkbp_event_supported && cros_ec_get_next_event(ec_dev) > 0)
+		blocking_notifier_call_chain(&ec_dev->event_notifier, 0,
+					     ec_dev);
+}
+
 static int cros_ec_lpc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	struct acpi_device *adev;
+	acpi_status status;
 	struct cros_ec_device *ec_dev;
 	u8 buf[2];
 	int ret;
@@ -277,12 +288,33 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	/*
+	 * Connect a notify handler to process MKBP messages if we have a
+	 * companion ACPI device.
+	 */
+	adev = ACPI_COMPANION(dev);
+	if (adev) {
+		status = acpi_install_notify_handler(adev->handle,
+						     ACPI_ALL_NOTIFY,
+						     cros_ec_lpc_acpi_notify,
+						     ec_dev);
+		if (ACPI_FAILURE(status))
+			dev_warn(dev, "Failed to register notifier %08x\n",
+				 status);
+	}
+
 	return 0;
 }
 
 static int cros_ec_lpc_remove(struct platform_device *pdev)
 {
 	struct cros_ec_device *ec_dev;
+	struct acpi_device *adev;
+
+	adev = ACPI_COMPANION(&pdev->dev);
+	if (adev)
+		acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY,
+					   cros_ec_lpc_acpi_notify);
 
 	ec_dev = platform_get_drvdata(pdev);
 	cros_ec_remove(ec_dev);
-- 
2.7.4