device_initcall(stf_barrier_debugfs_init);
#endif /* CONFIG_DEBUG_FS */
-static void no_count_cache_flush(void)
+static void update_branch_cache_flush(void)
{
- count_cache_flush_type = BRANCH_CACHE_FLUSH_NONE;
- pr_info("count-cache-flush: flush disabled.\n");
-}
-
-static void toggle_branch_cache_flush(bool enable)
-{
- if (!security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE) &&
- !security_ftr_enabled(SEC_FTR_FLUSH_LINK_STACK))
- enable = false;
-
- if (!enable) {
- patch_instruction_site(&patch__call_flush_branch_caches,
- ppc_inst(PPC_INST_NOP));
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+ // This controls the branch from guest_exit_cont to kvm_flush_link_stack
+ if (link_stack_flush_type == BRANCH_CACHE_FLUSH_NONE) {
patch_instruction_site(&patch__call_kvm_flush_link_stack,
ppc_inst(PPC_INST_NOP));
-#endif
- pr_info("link-stack-flush: flush disabled.\n");
- link_stack_flush_type = BRANCH_CACHE_FLUSH_NONE;
- no_count_cache_flush();
- return;
+ } else {
+ patch_branch_site(&patch__call_kvm_flush_link_stack,
+ (u64)&kvm_flush_link_stack, BRANCH_SET_LINK);
}
-
- // This enables the branch from _switch to flush_branch_caches
- patch_branch_site(&patch__call_flush_branch_caches,
- (u64)&flush_branch_caches, BRANCH_SET_LINK);
-
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
- // This enables the branch from guest_exit_cont to kvm_flush_link_stack
- patch_branch_site(&patch__call_kvm_flush_link_stack,
- (u64)&kvm_flush_link_stack, BRANCH_SET_LINK);
#endif
- pr_info("link-stack-flush: software flush enabled.\n");
- link_stack_flush_type = BRANCH_CACHE_FLUSH_SW;
+ // This controls the branch from _switch to flush_branch_caches
+ if (count_cache_flush_type == BRANCH_CACHE_FLUSH_NONE &&
+ link_stack_flush_type == BRANCH_CACHE_FLUSH_NONE) {
+ patch_instruction_site(&patch__call_flush_branch_caches,
+ ppc_inst(PPC_INST_NOP));
+ } else {
+ patch_branch_site(&patch__call_flush_branch_caches,
+ (u64)&flush_branch_caches, BRANCH_SET_LINK);
+
+ // If we just need to flush the link stack, early return
+ if (count_cache_flush_type == BRANCH_CACHE_FLUSH_NONE) {
+ patch_instruction_site(&patch__flush_link_stack_return,
+ ppc_inst(PPC_INST_BLR));
+
+ // If we have flush instruction, early return
+ } else if (count_cache_flush_type == BRANCH_CACHE_FLUSH_HW) {
+ patch_instruction_site(&patch__flush_count_cache_return,
+ ppc_inst(PPC_INST_BLR));
+ }
+ }
+}
+
+static void toggle_branch_cache_flush(bool enable)
+{
+ if (!enable || !security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE)) {
+ if (count_cache_flush_type != BRANCH_CACHE_FLUSH_NONE)
+ count_cache_flush_type = BRANCH_CACHE_FLUSH_NONE;
- // If we just need to flush the link stack, patch an early return
- if (!security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE)) {
- patch_instruction_site(&patch__flush_link_stack_return,
- ppc_inst(PPC_INST_BLR));
- no_count_cache_flush();
- return;
+ pr_info("count-cache-flush: flush disabled.\n");
+ } else {
+ if (security_ftr_enabled(SEC_FTR_BCCTR_FLUSH_ASSIST)) {
+ count_cache_flush_type = BRANCH_CACHE_FLUSH_HW;
+ pr_info("count-cache-flush: hardware flush enabled.\n");
+ } else {
+ count_cache_flush_type = BRANCH_CACHE_FLUSH_SW;
+ pr_info("count-cache-flush: software flush enabled.\n");
+ }
}
- if (!security_ftr_enabled(SEC_FTR_BCCTR_FLUSH_ASSIST)) {
- count_cache_flush_type = BRANCH_CACHE_FLUSH_SW;
- pr_info("count-cache-flush: software flush enabled.\n");
- return;
+ if (!enable || !security_ftr_enabled(SEC_FTR_FLUSH_LINK_STACK)) {
+ if (link_stack_flush_type != BRANCH_CACHE_FLUSH_NONE)
+ link_stack_flush_type = BRANCH_CACHE_FLUSH_NONE;
+
+ pr_info("link-stack-flush: flush disabled.\n");
+ } else {
+ link_stack_flush_type = BRANCH_CACHE_FLUSH_SW;
+ pr_info("link-stack-flush: software flush enabled.\n");
}
- patch_instruction_site(&patch__flush_count_cache_return, ppc_inst(PPC_INST_BLR));
- count_cache_flush_type = BRANCH_CACHE_FLUSH_HW;
- pr_info("count-cache-flush: hardware flush enabled.\n");
+ update_branch_cache_flush();
}
void setup_count_cache_flush(void)