From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752316AbbIONsA (ORCPT ); Tue, 15 Sep 2015 09:48:00 -0400 Received: from mail-yk0-f174.google.com ([209.85.160.174]:34459 "EHLO mail-yk0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751806AbbIONr6 convert rfc822-to-8bit (ORCPT ); Tue, 15 Sep 2015 09:47:58 -0400 MIME-Version: 1.0 X-Originating-IP: [95.23.51.209] In-Reply-To: <1442234049-18637-3-git-send-email-emilio.lopez@collabora.co.uk> References: <1442234049-18637-1-git-send-email-emilio.lopez@collabora.co.uk> <1442234049-18637-3-git-send-email-emilio.lopez@collabora.co.uk> Date: Tue, 15 Sep 2015 15:47:57 +0200 Message-ID: Subject: Re: [PATCH v2 2/3] platform/chrome: Support reading/writing the vboot context From: Javier Martinez Canillas To: =?UTF-8?Q?Emilio_L=C3=B3pez?= Cc: Greg Kroah-Hartman , Olof Johansson , Kukjin Kim , =?UTF-8?Q?Krzysztof_Koz=C5=82owski?= , Guenter Roeck , Linux Kernel , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-samsung-soc@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Emilio, Patch looks mostly good to me, I just have a few comments. On Mon, Sep 14, 2015 at 2:34 PM, Emilio López wrote: > Some EC implementations include a small nvram space used to store > verified boot context data. This patch offers a way to expose this > data to userspace. > > Signed-off-by: Emilio López > --- > Changes from v1: > - Use is_bin_visible instead of is_visible > > Documentation/devicetree/bindings/mfd/cros-ec.txt | 4 + > drivers/platform/chrome/Makefile | 5 +- > drivers/platform/chrome/cros_ec_dev.c | 1 + > drivers/platform/chrome/cros_ec_vbc.c | 137 ++++++++++++++++++++++ > include/linux/mfd/cros_ec.h | 1 + > 5 files changed, 147 insertions(+), 1 deletion(-) > create mode 100644 drivers/platform/chrome/cros_ec_vbc.c > > diff --git a/Documentation/devicetree/bindings/mfd/cros-ec.txt b/Documentation/devicetree/bindings/mfd/cros-ec.txt > index 1777916..136e0c2 100644 > --- a/Documentation/devicetree/bindings/mfd/cros-ec.txt > +++ b/Documentation/devicetree/bindings/mfd/cros-ec.txt > @@ -34,6 +34,10 @@ Required properties (LPC): > - compatible: "google,cros-ec-lpc" > - reg: List of (IO address, size) pairs defining the interface uses > > +Optional properties (all): > +- google,has-vbc-nvram: Some implementations of the EC include a small > + nvram space used to store verified boot context data. This boolean flag > + is used to specify whether this nvram is present or not. > > Example for I2C: > I would split the DT binding part from the actual implementation, see Documentation/devicetree/bindings/submitting-patches.txt. > diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile > index 4a11b01..787be61 100644 > --- a/drivers/platform/chrome/Makefile > +++ b/drivers/platform/chrome/Makefile > @@ -1,7 +1,10 @@ > > obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o > obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o > -cros_ec_devs-objs := cros_ec_dev.o cros_ec_sysfs.o cros_ec_lightbar.o > +cros_ec_devs-objs := cros_ec_dev.o > +cros_ec_devs-objs += cros_ec_lightbar.o > +cros_ec_devs-objs += cros_ec_sysfs.o > +cros_ec_devs-objs += cros_ec_vbc.o Why are you changing the Makefile? AFAIK += is usually used when the compilation is conditional based on a Kconfig symbol but since these are build unconditionally, I'll just keep it as foo := bar baz Which makes me think, do we need a Kconfig option for this feature since not all machines have it? > obj-$(CONFIG_CROS_EC_CHARDEV) += cros_ec_devs.o > obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpc.o > obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o > diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c > index e8fcdc2..d19263f 100644 > --- a/drivers/platform/chrome/cros_ec_dev.c > +++ b/drivers/platform/chrome/cros_ec_dev.c > @@ -32,6 +32,7 @@ static int ec_major; > static const struct attribute_group *cros_ec_groups[] = { > &cros_ec_attr_group, > &cros_ec_lightbar_attr_group, > + &cros_ec_vbc_attr_group, > NULL, > }; > > diff --git a/drivers/platform/chrome/cros_ec_vbc.c b/drivers/platform/chrome/cros_ec_vbc.c > new file mode 100644 > index 0000000..a0e8d38 > --- /dev/null > +++ b/drivers/platform/chrome/cros_ec_vbc.c > @@ -0,0 +1,137 @@ > +/* > + * cros_ec_vbc - Expose the vboot context nvram to userspace > + * > + * Copyright (C) 2015 Collabora Ltd. > + * > + * based on vendor driver, > + * > + * Copyright (C) 2012 The Chromium OS Authors > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include > +#include > +#include > +#include > +#include > + > +static ssize_t vboot_context_read(struct file *filp, struct kobject *kobj, > + struct bin_attribute *att, char *buf, > + loff_t pos, size_t count) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev, > + class_dev); > + struct cros_ec_device *ecdev = ec->ec_dev; > + struct ec_params_vbnvcontext *params; > + struct cros_ec_command *msg; > + int err; > + const size_t para_sz = sizeof(struct ec_params_vbnvcontext); > + const size_t resp_sz = sizeof(struct ec_response_vbnvcontext); > + const size_t payload = max(para_sz, resp_sz); > + > + msg = kmalloc(sizeof(*msg) + payload, GFP_KERNEL); > + if (!msg) > + return -ENOMEM; > + > + params = (struct ec_params_vbnvcontext *)msg->data; > + params->op = EC_VBNV_CONTEXT_OP_READ; > + > + msg->version = EC_VER_VBNV_CONTEXT; > + msg->command = EC_CMD_VBNV_CONTEXT; > + msg->outsize = sizeof(params->op); Shouldn't this be para_sz ? Since you are sending to the EC the whole struct ec_params_vbnvcontext and not only the op field. Or if the EC only expects to get the u32 op field, then I think your max payload calculation is not correct. > + msg->insize = resp_sz; > + > + err = cros_ec_cmd_xfer(ecdev, msg); > + if (err < 0) { > + dev_err(dev, "Error sending read request: %d\n", err); > + kfree(msg); > + return err; > + } > + > + BUILD_BUG_ON(resp_sz > PAGE_SIZE); Why you need this? struct ec_response_vbnvcontext is really small AFAICT. > + memcpy(buf, msg->data, resp_sz); > + > + kfree(msg); > + return resp_sz; > +} > + > +static ssize_t vboot_context_write(struct file *filp, struct kobject *kobj, > + struct bin_attribute *attr, char *buf, > + loff_t pos, size_t count) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev, > + class_dev); > + struct cros_ec_device *ecdev = ec->ec_dev; > + struct ec_params_vbnvcontext *params; > + struct cros_ec_command *msg; > + int err; > + const size_t para_sz = sizeof(*params); > + const size_t data_sz = sizeof(params->block); > + > + /* Only write full values */ > + if (count != data_sz) > + return -EINVAL; > + > + msg = kmalloc(sizeof(*msg) + para_sz, GFP_KERNEL); > + if (!msg) > + return -ENOMEM; > + > + params = (struct ec_params_vbnvcontext *)msg->data; > + params->op = EC_VBNV_CONTEXT_OP_WRITE; > + memcpy(params->block, buf, data_sz); > + > + msg->version = EC_VER_VBNV_CONTEXT; > + msg->command = EC_CMD_VBNV_CONTEXT; > + msg->outsize = para_sz; > + msg->insize = 0; > + > + err = cros_ec_cmd_xfer(ecdev, msg); > + if (err < 0) { > + dev_err(dev, "Error sending write request: %d\n", err); > + kfree(msg); > + return err; > + } > + > + kfree(msg); > + return data_sz; > +} > + > +static umode_t cros_ec_vbc_is_visible(struct kobject *kobj, > + struct bin_attribute *a, int n) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev, > + class_dev); > + struct device_node *np = ec->ec_dev->dev->of_node; > + > + if (IS_ENABLED(CONFIG_OF) && np) { > + if (of_property_read_bool(np, "google,has-vbc-nvram")) > + return a->attr.mode; > + } > + > + return 0; > +} > + > +static BIN_ATTR_RW(vboot_context, 16); > + > +static struct bin_attribute *cros_ec_vbc_bin_attrs[] = { > + &bin_attr_vboot_context, > + NULL > +}; > + > +struct attribute_group cros_ec_vbc_attr_group = { > + .name = "vbc", > + .bin_attrs = cros_ec_vbc_bin_attrs, > + .is_bin_visible = cros_ec_vbc_is_visible, > +}; > diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h > index da72671..494682c 100644 > --- a/include/linux/mfd/cros_ec.h > +++ b/include/linux/mfd/cros_ec.h > @@ -255,5 +255,6 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev); > /* sysfs stuff */ > extern struct attribute_group cros_ec_attr_group; > extern struct attribute_group cros_ec_lightbar_attr_group; > +extern struct attribute_group cros_ec_vbc_attr_group; > > #endif /* __LINUX_MFD_CROS_EC_H */ > -- > 2.1.4 Best regards, Javier From mboxrd@z Thu Jan 1 00:00:00 1970 From: javier@dowhile0.org (Javier Martinez Canillas) Date: Tue, 15 Sep 2015 15:47:57 +0200 Subject: [PATCH v2 2/3] platform/chrome: Support reading/writing the vboot context In-Reply-To: <1442234049-18637-3-git-send-email-emilio.lopez@collabora.co.uk> References: <1442234049-18637-1-git-send-email-emilio.lopez@collabora.co.uk> <1442234049-18637-3-git-send-email-emilio.lopez@collabora.co.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello Emilio, Patch looks mostly good to me, I just have a few comments. On Mon, Sep 14, 2015 at 2:34 PM, Emilio L?pez wrote: > Some EC implementations include a small nvram space used to store > verified boot context data. This patch offers a way to expose this > data to userspace. > > Signed-off-by: Emilio L?pez > --- > Changes from v1: > - Use is_bin_visible instead of is_visible > > Documentation/devicetree/bindings/mfd/cros-ec.txt | 4 + > drivers/platform/chrome/Makefile | 5 +- > drivers/platform/chrome/cros_ec_dev.c | 1 + > drivers/platform/chrome/cros_ec_vbc.c | 137 ++++++++++++++++++++++ > include/linux/mfd/cros_ec.h | 1 + > 5 files changed, 147 insertions(+), 1 deletion(-) > create mode 100644 drivers/platform/chrome/cros_ec_vbc.c > > diff --git a/Documentation/devicetree/bindings/mfd/cros-ec.txt b/Documentation/devicetree/bindings/mfd/cros-ec.txt > index 1777916..136e0c2 100644 > --- a/Documentation/devicetree/bindings/mfd/cros-ec.txt > +++ b/Documentation/devicetree/bindings/mfd/cros-ec.txt > @@ -34,6 +34,10 @@ Required properties (LPC): > - compatible: "google,cros-ec-lpc" > - reg: List of (IO address, size) pairs defining the interface uses > > +Optional properties (all): > +- google,has-vbc-nvram: Some implementations of the EC include a small > + nvram space used to store verified boot context data. This boolean flag > + is used to specify whether this nvram is present or not. > > Example for I2C: > I would split the DT binding part from the actual implementation, see Documentation/devicetree/bindings/submitting-patches.txt. > diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile > index 4a11b01..787be61 100644 > --- a/drivers/platform/chrome/Makefile > +++ b/drivers/platform/chrome/Makefile > @@ -1,7 +1,10 @@ > > obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o > obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o > -cros_ec_devs-objs := cros_ec_dev.o cros_ec_sysfs.o cros_ec_lightbar.o > +cros_ec_devs-objs := cros_ec_dev.o > +cros_ec_devs-objs += cros_ec_lightbar.o > +cros_ec_devs-objs += cros_ec_sysfs.o > +cros_ec_devs-objs += cros_ec_vbc.o Why are you changing the Makefile? AFAIK += is usually used when the compilation is conditional based on a Kconfig symbol but since these are build unconditionally, I'll just keep it as foo := bar baz Which makes me think, do we need a Kconfig option for this feature since not all machines have it? > obj-$(CONFIG_CROS_EC_CHARDEV) += cros_ec_devs.o > obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpc.o > obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o > diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c > index e8fcdc2..d19263f 100644 > --- a/drivers/platform/chrome/cros_ec_dev.c > +++ b/drivers/platform/chrome/cros_ec_dev.c > @@ -32,6 +32,7 @@ static int ec_major; > static const struct attribute_group *cros_ec_groups[] = { > &cros_ec_attr_group, > &cros_ec_lightbar_attr_group, > + &cros_ec_vbc_attr_group, > NULL, > }; > > diff --git a/drivers/platform/chrome/cros_ec_vbc.c b/drivers/platform/chrome/cros_ec_vbc.c > new file mode 100644 > index 0000000..a0e8d38 > --- /dev/null > +++ b/drivers/platform/chrome/cros_ec_vbc.c > @@ -0,0 +1,137 @@ > +/* > + * cros_ec_vbc - Expose the vboot context nvram to userspace > + * > + * Copyright (C) 2015 Collabora Ltd. > + * > + * based on vendor driver, > + * > + * Copyright (C) 2012 The Chromium OS Authors > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include > +#include > +#include > +#include > +#include > + > +static ssize_t vboot_context_read(struct file *filp, struct kobject *kobj, > + struct bin_attribute *att, char *buf, > + loff_t pos, size_t count) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev, > + class_dev); > + struct cros_ec_device *ecdev = ec->ec_dev; > + struct ec_params_vbnvcontext *params; > + struct cros_ec_command *msg; > + int err; > + const size_t para_sz = sizeof(struct ec_params_vbnvcontext); > + const size_t resp_sz = sizeof(struct ec_response_vbnvcontext); > + const size_t payload = max(para_sz, resp_sz); > + > + msg = kmalloc(sizeof(*msg) + payload, GFP_KERNEL); > + if (!msg) > + return -ENOMEM; > + > + params = (struct ec_params_vbnvcontext *)msg->data; > + params->op = EC_VBNV_CONTEXT_OP_READ; > + > + msg->version = EC_VER_VBNV_CONTEXT; > + msg->command = EC_CMD_VBNV_CONTEXT; > + msg->outsize = sizeof(params->op); Shouldn't this be para_sz ? Since you are sending to the EC the whole struct ec_params_vbnvcontext and not only the op field. Or if the EC only expects to get the u32 op field, then I think your max payload calculation is not correct. > + msg->insize = resp_sz; > + > + err = cros_ec_cmd_xfer(ecdev, msg); > + if (err < 0) { > + dev_err(dev, "Error sending read request: %d\n", err); > + kfree(msg); > + return err; > + } > + > + BUILD_BUG_ON(resp_sz > PAGE_SIZE); Why you need this? struct ec_response_vbnvcontext is really small AFAICT. > + memcpy(buf, msg->data, resp_sz); > + > + kfree(msg); > + return resp_sz; > +} > + > +static ssize_t vboot_context_write(struct file *filp, struct kobject *kobj, > + struct bin_attribute *attr, char *buf, > + loff_t pos, size_t count) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev, > + class_dev); > + struct cros_ec_device *ecdev = ec->ec_dev; > + struct ec_params_vbnvcontext *params; > + struct cros_ec_command *msg; > + int err; > + const size_t para_sz = sizeof(*params); > + const size_t data_sz = sizeof(params->block); > + > + /* Only write full values */ > + if (count != data_sz) > + return -EINVAL; > + > + msg = kmalloc(sizeof(*msg) + para_sz, GFP_KERNEL); > + if (!msg) > + return -ENOMEM; > + > + params = (struct ec_params_vbnvcontext *)msg->data; > + params->op = EC_VBNV_CONTEXT_OP_WRITE; > + memcpy(params->block, buf, data_sz); > + > + msg->version = EC_VER_VBNV_CONTEXT; > + msg->command = EC_CMD_VBNV_CONTEXT; > + msg->outsize = para_sz; > + msg->insize = 0; > + > + err = cros_ec_cmd_xfer(ecdev, msg); > + if (err < 0) { > + dev_err(dev, "Error sending write request: %d\n", err); > + kfree(msg); > + return err; > + } > + > + kfree(msg); > + return data_sz; > +} > + > +static umode_t cros_ec_vbc_is_visible(struct kobject *kobj, > + struct bin_attribute *a, int n) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev, > + class_dev); > + struct device_node *np = ec->ec_dev->dev->of_node; > + > + if (IS_ENABLED(CONFIG_OF) && np) { > + if (of_property_read_bool(np, "google,has-vbc-nvram")) > + return a->attr.mode; > + } > + > + return 0; > +} > + > +static BIN_ATTR_RW(vboot_context, 16); > + > +static struct bin_attribute *cros_ec_vbc_bin_attrs[] = { > + &bin_attr_vboot_context, > + NULL > +}; > + > +struct attribute_group cros_ec_vbc_attr_group = { > + .name = "vbc", > + .bin_attrs = cros_ec_vbc_bin_attrs, > + .is_bin_visible = cros_ec_vbc_is_visible, > +}; > diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h > index da72671..494682c 100644 > --- a/include/linux/mfd/cros_ec.h > +++ b/include/linux/mfd/cros_ec.h > @@ -255,5 +255,6 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev); > /* sysfs stuff */ > extern struct attribute_group cros_ec_attr_group; > extern struct attribute_group cros_ec_lightbar_attr_group; > +extern struct attribute_group cros_ec_vbc_attr_group; > > #endif /* __LINUX_MFD_CROS_EC_H */ > -- > 2.1.4 Best regards, Javier