/* show available compressors */
ssize_t zcomp_available_show(const char *comp, char *buf)
{
bool known_algorithm = false;
ssize_t sz = 0;
int i = 0;
for (; backends[i]; i++) {
if (!strcmp(comp, backends[i])) {
known_algorithm = true;
sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
"[%s] ", backends[i]);
} else {
sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
"%s ", backends[i]);
}
}
/*
* Out-of-tree module known to crypto api or a missing
* entry in `backends'.
*/
if (!known_algorithm && crypto_has_comp(comp, 0, 0) == 1)
sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
"[%s] ", comp);
sz += scnprintf(buf + sz, PAGE_SIZE - sz, "\n");
return sz;
}
static int __init zswap_comp_init(void)
{
if (!crypto_has_comp(zswap_compressor, 0, 0)) {
pr_info("%s compressor not available\n", zswap_compressor);
/* fall back to default compressor */
zswap_compressor = ZSWAP_COMPRESSOR_DEFAULT;
if (!crypto_has_comp(zswap_compressor, 0, 0))
/* can't even load the default compressor */
return -ENODEV;
}
pr_info("using %s compressor\n", zswap_compressor);
/* alloc percpu transforms */
zswap_comp_pcpu_tfms = alloc_percpu(struct crypto_comp *);
if (!zswap_comp_pcpu_tfms)
return -ENOMEM;
return 0;
}
static int __init zram_comp_init(void)
{
int ret;
ret = crypto_has_comp(zram_compressor, 0, 0);
if (!ret) {
pr_info("%s is not available\n", zram_compressor);
zram_compressor = ZRAM_COMPRESSOR_DEFAULT;
ret = crypto_has_comp(zram_compressor, 0, 0);
if (!ret)
return -ENODEV;
}
pr_info("using %s compressor\n", zram_compressor);
/* alloc percpu transforms */
zram_comp_pcpu_tfms = alloc_percpu(struct crypto_comp *);
if (!zram_comp_pcpu_tfms)
return -ENOMEM;
return 0;
}
static void allocate_buf_for_compression(void)
{
struct crypto_comp *ctx;
int size;
char *buf;
/* Skip if not built-in or compression backend not selected yet. */
if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend)
return;
/* Skip if no pstore backend yet or compression init already done. */
if (!psinfo || tfm)
return;
if (!crypto_has_comp(zbackend->name, 0, 0)) {
pr_err("Unknown compression: %s\n", zbackend->name);
return;
}
size = zbackend->zbufsize(psinfo->bufsize);
if (size <= 0) {
pr_err("Invalid compression size for %s: %d\n",
zbackend->name, size);
return;
}
buf = kmalloc(size, GFP_KERNEL);
if (!buf) {
pr_err("Failed %d byte compression buffer allocation for: %s\n",
size, zbackend->name);
return;
}
ctx = crypto_alloc_comp(zbackend->name, 0, 0);
if (IS_ERR_OR_NULL(ctx)) {
kfree(buf);
pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name,
PTR_ERR(ctx));
return;
}
/* A non-NULL big_oops_buf indicates compression is available. */
tfm = ctx;
big_oops_buf_sz = size;
big_oops_buf = buf;
pr_info("Using crash dump compression: %s\n", zbackend->name);
}
bool zcomp_available_algorithm(const char *comp)
{
int i = 0;
while (backends[i]) {
if (sysfs_streq(comp, backends[i]))
return true;
i++;
}
/*
* Crypto does not ignore a trailing new line symbol,
* so make sure you don't supply a string containing
* one.
* This also means that we permit zcomp initialisation
* with any compressing algorithm known to crypto api.
*/
return crypto_has_comp(comp, 0, 0) == 1;
}