u-boot/common/memsize.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

102 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2004
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*/
#include <common.h>
DECLARE_GLOBAL_DATA_PTR;
#ifdef __PPC__
/*
* At least on G2 PowerPC cores, sequential accesses to non-existent
* memory must be synchronized.
*/
# include <asm/io.h> /* for sync() */
#else
# define sync() /* nothing */
#endif
/*
* Check memory range for valid RAM. A simple memory test determines
* the actually available RAM size between addresses `base' and
* `base + maxsize'.
*/
long get_ram_size(long *base, long maxsize)
{
volatile long *addr;
long save[31];
long save_base;
long cnt;
long val;
long size;
int i = 0;
for (cnt = (maxsize / sizeof(long)) >> 1; cnt > 0; cnt >>= 1) {
addr = base + cnt; /* pointer arith! */
sync();
save[i++] = *addr;
sync();
*addr = ~cnt;
}
addr = base;
sync();
save_base = *addr;
sync();
*addr = 0;
sync();
if ((val = *addr) != 0) {
/* Restore the original data before leaving the function. */
sync();
*base = save_base;
for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
addr = base + cnt;
sync();
*addr = save[--i];
}
return (0);
}
for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
addr = base + cnt; /* pointer arith! */
val = *addr;
*addr = save[--i];
if (val != ~cnt) {
size = cnt * sizeof(long);
/*
* Restore the original data
* before leaving the function.
*/
for (cnt <<= 1;
cnt < maxsize / sizeof(long);
cnt <<= 1) {
addr = base + cnt;
*addr = save[--i];
}
/* warning: don't restore save_base in this case,
* it is already done in the loop because
* base and base+size share the same physical memory
* and *base is saved after *(base+size) modification
* in first loop
*/
return (size);
}
}
*base = save_base;
return (maxsize);
}
phys_size_t __weak get_effective_memsize(void)
{
#ifndef CONFIG_VERY_BIG_RAM
return gd->ram_size;
#else
/* limit stack to what we can reasonable map */
return ((gd->ram_size > CONFIG_MAX_MEM_MAPPED) ?
CONFIG_MAX_MEM_MAPPED : gd->ram_size);
#endif
}