mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-29 23:53:55 +08:00
e2eb63927b
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
150 lines
3.1 KiB
C
150 lines
3.1 KiB
C
/*
|
|
* c 2001 PPC 64 Team, IBM Corp
|
|
*
|
|
* 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.
|
|
*
|
|
* /dev/nvram driver for PPC64
|
|
*
|
|
* This perhaps should live in drivers/char
|
|
*/
|
|
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/spinlock.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/nvram.h>
|
|
#include <asm/rtas.h>
|
|
#include <asm/prom.h>
|
|
#include <asm/machdep.h>
|
|
|
|
static unsigned int nvram_size;
|
|
static int nvram_fetch, nvram_store;
|
|
static char nvram_buf[NVRW_CNT]; /* assume this is in the first 4GB */
|
|
static DEFINE_SPINLOCK(nvram_lock);
|
|
|
|
|
|
static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index)
|
|
{
|
|
unsigned int i;
|
|
unsigned long len;
|
|
int done;
|
|
unsigned long flags;
|
|
char *p = buf;
|
|
|
|
|
|
if (nvram_size == 0 || nvram_fetch == RTAS_UNKNOWN_SERVICE)
|
|
return -ENODEV;
|
|
|
|
if (*index >= nvram_size)
|
|
return 0;
|
|
|
|
i = *index;
|
|
if (i + count > nvram_size)
|
|
count = nvram_size - i;
|
|
|
|
spin_lock_irqsave(&nvram_lock, flags);
|
|
|
|
for (; count != 0; count -= len) {
|
|
len = count;
|
|
if (len > NVRW_CNT)
|
|
len = NVRW_CNT;
|
|
|
|
if ((rtas_call(nvram_fetch, 3, 2, &done, i, __pa(nvram_buf),
|
|
len) != 0) || len != done) {
|
|
spin_unlock_irqrestore(&nvram_lock, flags);
|
|
return -EIO;
|
|
}
|
|
|
|
memcpy(p, nvram_buf, len);
|
|
|
|
p += len;
|
|
i += len;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&nvram_lock, flags);
|
|
|
|
*index = i;
|
|
return p - buf;
|
|
}
|
|
|
|
static ssize_t pSeries_nvram_write(char *buf, size_t count, loff_t *index)
|
|
{
|
|
unsigned int i;
|
|
unsigned long len;
|
|
int done;
|
|
unsigned long flags;
|
|
const char *p = buf;
|
|
|
|
if (nvram_size == 0 || nvram_store == RTAS_UNKNOWN_SERVICE)
|
|
return -ENODEV;
|
|
|
|
if (*index >= nvram_size)
|
|
return 0;
|
|
|
|
i = *index;
|
|
if (i + count > nvram_size)
|
|
count = nvram_size - i;
|
|
|
|
spin_lock_irqsave(&nvram_lock, flags);
|
|
|
|
for (; count != 0; count -= len) {
|
|
len = count;
|
|
if (len > NVRW_CNT)
|
|
len = NVRW_CNT;
|
|
|
|
memcpy(nvram_buf, p, len);
|
|
|
|
if ((rtas_call(nvram_store, 3, 2, &done, i, __pa(nvram_buf),
|
|
len) != 0) || len != done) {
|
|
spin_unlock_irqrestore(&nvram_lock, flags);
|
|
return -EIO;
|
|
}
|
|
|
|
p += len;
|
|
i += len;
|
|
}
|
|
spin_unlock_irqrestore(&nvram_lock, flags);
|
|
|
|
*index = i;
|
|
return p - buf;
|
|
}
|
|
|
|
static ssize_t pSeries_nvram_get_size(void)
|
|
{
|
|
return nvram_size ? nvram_size : -ENODEV;
|
|
}
|
|
|
|
int __init pSeries_nvram_init(void)
|
|
{
|
|
struct device_node *nvram;
|
|
const unsigned int *nbytes_p;
|
|
unsigned int proplen;
|
|
|
|
nvram = of_find_node_by_type(NULL, "nvram");
|
|
if (nvram == NULL)
|
|
return -ENODEV;
|
|
|
|
nbytes_p = of_get_property(nvram, "#bytes", &proplen);
|
|
if (nbytes_p == NULL || proplen != sizeof(unsigned int))
|
|
return -EIO;
|
|
|
|
nvram_size = *nbytes_p;
|
|
|
|
nvram_fetch = rtas_token("nvram-fetch");
|
|
nvram_store = rtas_token("nvram-store");
|
|
printk(KERN_INFO "PPC64 nvram contains %d bytes\n", nvram_size);
|
|
of_node_put(nvram);
|
|
|
|
ppc_md.nvram_read = pSeries_nvram_read;
|
|
ppc_md.nvram_write = pSeries_nvram_write;
|
|
ppc_md.nvram_size = pSeries_nvram_get_size;
|
|
|
|
return 0;
|
|
}
|