diff mbox

[v2,2/2] firmware: dmi-sysfs: add SMBIOS entry point area attribute

Message ID 1422278918-31477-3-git-send-email-ivan.khoronzhuk@linaro.org
State New
Headers show

Commit Message

Ivan Khoronzhuk Jan. 26, 2015, 1:28 p.m. UTC
There are situations when code needs to access SMBIOS entry table
area, but cannot use /dev/mem for this. As the table format is
consistent only for a version, and can be changed, use binary
attribute to give access to raw SMBIOS entry table area.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
---
 drivers/firmware/dmi-sysfs.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

Comments

Ard Biesheuvel Jan. 26, 2015, 1:34 p.m. UTC | #1
On 26 January 2015 at 13:28, Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org> wrote:
> There are situations when code needs to access SMBIOS entry table
> area, but cannot use /dev/mem for this. As the table format is
> consistent only for a version, and can be changed, use binary
> attribute to give access to raw SMBIOS entry table area.
>
> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> ---
>  drivers/firmware/dmi-sysfs.c | 42 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
>
> diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c
> index e0f1cb3..61b6a38 100644
> --- a/drivers/firmware/dmi-sysfs.c
> +++ b/drivers/firmware/dmi-sysfs.c
> @@ -29,6 +29,8 @@
>  #define MAX_ENTRY_TYPE 255 /* Most of these aren't used, but we consider
>                               the top entry type is only 8 bits */
>
> +static const u8 *smbios_raw_header;
> +
>  struct dmi_sysfs_entry {
>         struct dmi_header dh;
>         struct kobject kobj;
> @@ -646,9 +648,37 @@ static void cleanup_entry_list(void)
>         }
>  }
>
> +static ssize_t smbios_entry_area_raw_read(struct file *filp,
> +                                         struct kobject *kobj,
> +                                         struct bin_attribute *bin_attr,
> +                                         char *buf, loff_t pos, size_t count)
> +{
> +       ssize_t size;
> +
> +       size = bin_attr->size;
> +
> +       if (size > pos)
> +               size -= pos;
> +       else
> +               return 0;
> +
> +       if (count < size)
> +               size = count;
> +
> +       memcpy(buf, &smbios_raw_header[pos], size);
> +
> +       return size;
> +}
> +
> +static struct bin_attribute smbios_raw_area_attr = {
> +       .read = smbios_entry_area_raw_read,
> +       .attr = {.name = "smbios_raw_header", .mode = 0400},
> +};
> +
>  static int __init dmi_sysfs_init(void)
>  {
>         int error = -ENOMEM;
> +       int size;
>         int val;
>
>         /* Set up our directory */
> @@ -669,6 +699,18 @@ static int __init dmi_sysfs_init(void)
>                 goto err;
>         }
>
> +       smbios_raw_header = dmi_get_smbios_entry_area(&size);
> +       if (!smbios_raw_header) {
> +               pr_debug("dmi-sysfs: SMBIOS raw data is not available.\n");
> +               error = -ENODATA;
> +               goto err;
> +       }
> +
> +       /* Create the raw binary file to access the entry area */
> +       smbios_raw_area_attr.size = size;
> +       if (sysfs_create_bin_file(dmi_kobj, &smbios_raw_area_attr))
> +               goto err;
> +
>         pr_debug("dmi-sysfs: loaded.\n");
>
>         return 0;
> --
> 1.9.1
>
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diff mbox

Patch

diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c
index e0f1cb3..61b6a38 100644
--- a/drivers/firmware/dmi-sysfs.c
+++ b/drivers/firmware/dmi-sysfs.c
@@ -29,6 +29,8 @@ 
 #define MAX_ENTRY_TYPE 255 /* Most of these aren't used, but we consider
 			      the top entry type is only 8 bits */
 
+static const u8 *smbios_raw_header;
+
 struct dmi_sysfs_entry {
 	struct dmi_header dh;
 	struct kobject kobj;
@@ -646,9 +648,37 @@  static void cleanup_entry_list(void)
 	}
 }
 
+static ssize_t smbios_entry_area_raw_read(struct file *filp,
+					  struct kobject *kobj,
+					  struct bin_attribute *bin_attr,
+					  char *buf, loff_t pos, size_t count)
+{
+	ssize_t size;
+
+	size = bin_attr->size;
+
+	if (size > pos)
+		size -= pos;
+	else
+		return 0;
+
+	if (count < size)
+		size = count;
+
+	memcpy(buf, &smbios_raw_header[pos], size);
+
+	return size;
+}
+
+static struct bin_attribute smbios_raw_area_attr = {
+	.read = smbios_entry_area_raw_read,
+	.attr = {.name = "smbios_raw_header", .mode = 0400},
+};
+
 static int __init dmi_sysfs_init(void)
 {
 	int error = -ENOMEM;
+	int size;
 	int val;
 
 	/* Set up our directory */
@@ -669,6 +699,18 @@  static int __init dmi_sysfs_init(void)
 		goto err;
 	}
 
+	smbios_raw_header = dmi_get_smbios_entry_area(&size);
+	if (!smbios_raw_header) {
+		pr_debug("dmi-sysfs: SMBIOS raw data is not available.\n");
+		error = -ENODATA;
+		goto err;
+	}
+
+	/* Create the raw binary file to access the entry area */
+	smbios_raw_area_attr.size = size;
+	if (sysfs_create_bin_file(dmi_kobj, &smbios_raw_area_attr))
+		goto err;
+
 	pr_debug("dmi-sysfs: loaded.\n");
 
 	return 0;