Quoting patrick.rudolph@9elements.com (2020-04-07 01:29:07)
From: Patrick Rudolph patrick.rudolph@9elements.com
Make all coreboot table entries available to userland. This is useful for tools that are currently using /dev/mem.
Besides the tag and size also expose the raw table data itself.
Update the ABI documentation to explain the new sysfs interface.
Tools can easily scan for the right coreboot table by reading /sys/bus/coreboot/devices/coreboot*/attributes/id The binary table data can then be read from /sys/bus/coreboot/devices/coreboot*/attributes/data
Signed-off-by: Patrick Rudolph patrick.rudolph@9elements.com
Reviewed-by: Stephen Boyd swboyd@chromium.org
Minor nits below:
-v2: - Add ABI documentation - Add 0x prefix on hex values - Remove wrong ioremap hint as found by CI -v3: - Use BIN_ATTR_RO -v4: - Updated ABI documentation
Documentation/ABI/stable/sysfs-bus-coreboot | 30 +++++++++++ drivers/firmware/google/coreboot_table.c | 58 +++++++++++++++++++++ 2 files changed, 88 insertions(+)
diff --git a/Documentation/ABI/stable/sysfs-bus-coreboot b/Documentation/ABI/stable/sysfs-bus-coreboot index 6055906f41f2..328153a1b3f4 100644 --- a/Documentation/ABI/stable/sysfs-bus-coreboot +++ b/Documentation/ABI/stable/sysfs-bus-coreboot diff --git a/drivers/firmware/google/coreboot_table.c b/drivers/firmware/google/coreboot_table.c index 0205987a4fd4..d0fc3eb93f4f 100644 --- a/drivers/firmware/google/coreboot_table.c +++ b/drivers/firmware/google/coreboot_table.c @@ -3,9 +3,11 @@
- coreboot_table.c
- Module providing coreboot table access.
- Exports coreboot tables as attributes in sysfs.
- Copyright 2017 Google Inc.
- Copyright 2017 Samuel Holland samuel@sholland.org
*/
- Copyright 2019 9elements Agency GmbH
#include <linux/acpi.h> @@ -84,6 +86,60 @@ void coreboot_driver_unregister(struct coreboot_driver *driver) } EXPORT_SYMBOL(coreboot_driver_unregister);
+static ssize_t id_show(struct device *dev,
struct device_attribute *attr, char *buffer)+{
struct coreboot_device *device = CB_DEV(dev);
Wouldn't hurt to throw const in front of these.
return sprintf(buffer, "0x%08x\n", device->entry.tag);+}
+static ssize_t size_show(struct device *dev,
struct device_attribute *attr, char *buffer)+{
struct coreboot_device *device = CB_DEV(dev);
And these. But the function is so short probably doesn't really matter.
return sprintf(buffer, "%u\n", device->entry.size);+}
+static DEVICE_ATTR_RO(id); +static DEVICE_ATTR_RO(size);
+static struct attribute *cb_dev_attrs[] = {
&dev_attr_id.attr,&dev_attr_size.attr,NULL+};
+static ssize_t data_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,char *buffer, loff_t offset, size_t count)+{
struct device *dev = kobj_to_dev(kobj);struct coreboot_device *device = CB_DEV(dev);return memory_read_from_buffer(buffer, count, &offset,&device->entry, device->entry.size);+}
+static BIN_ATTR_RO(data, 0);
Still no way to figure out the actual size? Can we add the bin_attribute at runtime?
+static struct bin_attribute *cb_dev_bin_attrs[] = {
&bin_attr_data,NULL+};