static int __init disabled_on_cmdline(void)
{
unsigned long root, chosen;
const char *p;
root = of_get_flat_dt_root();
chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
if (chosen == -FDT_ERR_NOTFOUND)
return false;
p = of_get_flat_dt_prop(chosen, "bootargs", NULL);
if (!p)
return false;
if (strstr(p, "dt_cpu_ftrs=off"))
return true;
return false;
}
/*
* If we're running under a hypervisor, we need to check the contents of
* /chosen/ibm,architecture-vec-5 to see if the hypervisor is willing to do
* radix. If not, we clear the radix feature bit so we fall back to hash.
*/
static void __init early_check_vec5(void)
{
unsigned long root, chosen;
int size;
const u8 *vec5;
u8 mmu_supported;
root = of_get_flat_dt_root();
chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
if (chosen == -FDT_ERR_NOTFOUND) {
cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
return;
}
vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size);
if (!vec5) {
cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
return;
}
if (size <= OV5_INDX(OV5_MMU_SUPPORT)) {
cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
return;
}
/* Check for supported configuration */
mmu_supported = vec5[OV5_INDX(OV5_MMU_SUPPORT)] &
OV5_FEAT(OV5_MMU_SUPPORT);
if (mmu_supported == OV5_FEAT(OV5_MMU_RADIX)) {
/* Hypervisor only supports radix - check enabled && GTSE */
if (!early_radix_enabled()) {
pr_warn("WARNING: Ignoring cmdline option disable_radix\n");
}
if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] &
OV5_FEAT(OV5_RADIX_GTSE))) {
pr_warn("WARNING: Hypervisor doesn't support RADIX with GTSE\n");
}
/* Do radix anyway - the hypervisor said we had to */
cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
} else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) {
/* Hypervisor only supports hash - disable radix */
cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
}
}
