opensbi/lib/sbi/sbi_scratch.c

77 lines
1.7 KiB
C

/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2019 Western Digital Corporation or its affiliates.
*
* Authors:
* Anup Patel <anup.patel@wdc.com>
*/
#include <sbi/riscv_locks.h>
#include <sbi/sbi_hart.h>
#include <sbi/sbi_platform.h>
#include <sbi/sbi_scratch.h>
#include <sbi/sbi_string.h>
static spinlock_t extra_lock = SPIN_LOCK_INITIALIZER;
static unsigned long extra_offset = SBI_SCRATCH_EXTRA_SPACE_OFFSET;
unsigned long sbi_scratch_alloc_offset(unsigned long size, const char *owner)
{
u32 i;
void *ptr;
unsigned long ret = 0;
struct sbi_scratch *scratch, *rscratch;
const struct sbi_platform *plat;
/*
* We have a simple brain-dead allocator which never expects
* anything to be free-ed hence it keeps incrementing the
* next allocation offset until it runs-out of space.
*
* In future, we will have more sophisticated allocator which
* will allow us to re-claim free-ed space.
*/
if (!size)
return 0;
if (size & (__SIZEOF_POINTER__ - 1))
size = (size & ~(__SIZEOF_POINTER__ - 1)) + __SIZEOF_POINTER__;
spin_lock(&extra_lock);
if (SBI_SCRATCH_SIZE < (extra_offset + size))
goto done;
ret = extra_offset;
extra_offset += size;
done:
spin_unlock(&extra_lock);
if (ret) {
scratch = sbi_scratch_thishart_ptr();
plat = sbi_platform_ptr(scratch);
for (i = 0; i < sbi_platform_hart_count(plat); i++) {
rscratch = sbi_hart_id_to_scratch(scratch, i);
ptr = sbi_scratch_offset_ptr(rscratch, ret);
sbi_memset(ptr, 0, size);
}
}
return ret;
}
void sbi_scratch_free_offset(unsigned long offset)
{
if ((offset < SBI_SCRATCH_EXTRA_SPACE_OFFSET) ||
(SBI_SCRATCH_SIZE <= offset))
return;
/*
* We don't actually free-up because it's a simple
* brain-dead allocator.
*/
}