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Commit dce80a56 authored by Feng Tang's avatar Feng Tang Committed by Len Brown
Browse files

SFI: add sysfs interface for SFI tables. 



Analogous to ACPI's /sys/firmware/acpi/tables/...

create /sys/firmware/sfi/tables/

The tables are primariy for the kernel,
but sometimes it is useful for user-space to be
able to read them.

Signed-off-by: default avatarFeng Tang <feng.tang@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 5487ab4a

Documentation/ABI/testing/sysfs-firmware-sfi

0 → 100644
+15 −0
Original line number Diff line number Diff line 
What:		/sys/firmware/sfi/tables/

Date:		May 2010

Contact:	Len Brown <lenb@kernel.org>

Description:

		SFI defines a number of small static memory tables

		so the kernel can get platform information from firmware.



		The tables are defined in the latest SFI specification:

		http://simplefirmware.org/documentation



		While the tables are used by the kernel, user-space

		can observe them this way:



		# cd /sys/firmware/sfi/tables

		# cat $TABLENAME > $TABLENAME.bin

drivers/sfi/sfi_acpi.c

+41 −0
Original line number Diff line number Diff line
@@ -173,3 +173,44 @@ int sfi_acpi_table_parse(char *signature, char *oem_id, char *oem_table_id, 
	sfi_acpi_put_table(table);

	return ret;

}



static ssize_t sfi_acpi_table_show(struct file *filp, struct kobject *kobj,

			       struct bin_attribute *bin_attr, char *buf,

			       loff_t offset, size_t count)

{

	struct sfi_table_attr *tbl_attr =

	    container_of(bin_attr, struct sfi_table_attr, attr);

	struct acpi_table_header *th = NULL;

	struct sfi_table_key key;

	ssize_t cnt;



	key.sig = tbl_attr->name;

	key.oem_id = NULL;

	key.oem_table_id = NULL;



	th = sfi_acpi_get_table(&key);

	if (!th)

		return 0;



	cnt =  memory_read_from_buffer(buf, count, &offset,

					th, th->length);

	sfi_acpi_put_table(th);



	return cnt;

}





void __init sfi_acpi_sysfs_init(void)

{

	u32 tbl_cnt, i;

	struct sfi_table_attr *tbl_attr;



	tbl_cnt = XSDT_GET_NUM_ENTRIES(xsdt_va, u64);

	for (i = 0; i < tbl_cnt; i++) {

		tbl_attr =

			sfi_sysfs_install_table(xsdt_va->table_offset_entry[i]);

		tbl_attr->attr.read = sfi_acpi_table_show;

	}



	return;

}

drivers/sfi/sfi_core.c

+103 −0
Original line number Diff line number Diff line
@@ -67,6 +67,7 @@ 
#include <linux/acpi.h>

#include <linux/init.h>

#include <linux/sfi.h>

#include <linux/slab.h>



#include "sfi_core.h"
@@ -382,6 +383,102 @@ static __init int sfi_find_syst(void) 
	return -1;

}



static struct kobject *sfi_kobj;

static struct kobject *tables_kobj;



static ssize_t sfi_table_show(struct file *filp, struct kobject *kobj,

			       struct bin_attribute *bin_attr, char *buf,

			       loff_t offset, size_t count)

{

	struct sfi_table_attr *tbl_attr =

	    container_of(bin_attr, struct sfi_table_attr, attr);

	struct sfi_table_header *th = NULL;

	struct sfi_table_key key;

	ssize_t cnt;



	key.sig = tbl_attr->name;

	key.oem_id = NULL;

	key.oem_table_id = NULL;



	if (strncmp(SFI_SIG_SYST, tbl_attr->name, SFI_SIGNATURE_SIZE)) {

		th = sfi_get_table(&key);

		if (!th)

			return 0;



		cnt =  memory_read_from_buffer(buf, count, &offset,

						th, th->len);

		sfi_put_table(th);

	} else

		cnt =  memory_read_from_buffer(buf, count, &offset,

					syst_va, syst_va->header.len);



	return cnt;

}



struct sfi_table_attr __init *sfi_sysfs_install_table(u64 pa)

{

	struct sfi_table_attr *tbl_attr;

	struct sfi_table_header *th;

	int ret;



	tbl_attr = kzalloc(sizeof(struct sfi_table_attr), GFP_KERNEL);

	if (!tbl_attr)

		return NULL;



	th = sfi_map_table(pa);

	if (!th || !th->sig[0]) {

		kfree(tbl_attr);

		return NULL;

	}



	sysfs_attr_init(&tbl_attr->attr.attr);

	memcpy(tbl_attr->name, th->sig, SFI_SIGNATURE_SIZE);



	tbl_attr->attr.size = 0;

	tbl_attr->attr.read = sfi_table_show;

	tbl_attr->attr.attr.name = tbl_attr->name;

	tbl_attr->attr.attr.mode = 0400;



	ret = sysfs_create_bin_file(tables_kobj,

				  &tbl_attr->attr);

	if (ret)

		kfree(tbl_attr);



	sfi_unmap_table(th);

	return tbl_attr;

}



static int __init sfi_sysfs_init(void)

{

	int tbl_cnt, i;



	if (sfi_disabled)

		return 0;



	sfi_kobj = kobject_create_and_add("sfi", firmware_kobj);

	if (!sfi_kobj)

		return 0;



	tables_kobj = kobject_create_and_add("tables", sfi_kobj);

	if (!tables_kobj) {

		kobject_put(sfi_kobj);

		return 0;

	}



	sfi_sysfs_install_table(syst_pa);



	tbl_cnt = SFI_GET_NUM_ENTRIES(syst_va, u64);



	for (i = 0; i < tbl_cnt; i++)

		sfi_sysfs_install_table(syst_va->pentry[i]);



	sfi_acpi_sysfs_init();

	kobject_uevent(sfi_kobj, KOBJ_ADD);

	kobject_uevent(tables_kobj, KOBJ_ADD);

	pr_info("SFI sysfs interfaces init success\n");

	return 0;

}



void __init sfi_init(void)

{

	if (!acpi_disabled)
@@ -414,3 +511,9 @@ void __init sfi_init_late(void) 


	sfi_acpi_init();

}



/*

 * The reason we put it here becasue we need wait till the /sys/firmware

 * is setup, then our interface can be registered in /sys/firmware/sfi

 */

core_initcall(sfi_sysfs_init);

drivers/sfi/sfi_core.h

+8 −0
Original line number Diff line number Diff line
@@ -61,6 +61,12 @@ struct sfi_table_key{ 
	char	*oem_table_id;

};



/* sysfs interface */

struct sfi_table_attr {

	struct bin_attribute attr;

	char name[8];

};



#define SFI_ANY_KEY { .sig = NULL, .oem_id = NULL, .oem_table_id = NULL }



extern int __init sfi_acpi_init(void);
@@ -68,3 +74,5 @@ extern struct sfi_table_header *sfi_check_table(u64 paddr, 
					struct sfi_table_key *key);

struct sfi_table_header *sfi_get_table(struct sfi_table_key *key);

extern void sfi_put_table(struct sfi_table_header *table);

extern struct sfi_table_attr __init *sfi_sysfs_install_table(u64 pa);

extern void __init sfi_acpi_sysfs_init(void);