powerpc/64s: Add support for RFI flush of L1-D cache

[platform/kernel/linux-exynos.git] / arch / powerpc / kernel / setup_64.c

diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index b89c6aa..79e81a7 100644 (file)
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -784,3 +784,82 @@ static int __init disable_hardlockup_detector(void)
        return 0;
 }
 early_initcall(disable_hardlockup_detector);
+
+#ifdef CONFIG_PPC_BOOK3S_64
+static enum l1d_flush_type enabled_flush_types;
+static void *l1d_flush_fallback_area;
+bool rfi_flush;
+
+static void do_nothing(void *unused)
+{
+       /*
+        * We don't need to do the flush explicitly, just enter+exit kernel is
+        * sufficient, the RFI exit handlers will do the right thing.
+        */
+}
+
+void rfi_flush_enable(bool enable)
+{
+       if (rfi_flush == enable)
+               return;
+
+       if (enable) {
+               do_rfi_flush_fixups(enabled_flush_types);
+               on_each_cpu(do_nothing, NULL, 1);
+       } else
+               do_rfi_flush_fixups(L1D_FLUSH_NONE);
+
+       rfi_flush = enable;
+}
+
+static void init_fallback_flush(void)
+{
+       u64 l1d_size, limit;
+       int cpu;
+
+       l1d_size = ppc64_caches.l1d.size;
+       limit = min(safe_stack_limit(), ppc64_rma_size);
+
+       /*
+        * Align to L1d size, and size it at 2x L1d size, to catch possible
+        * hardware prefetch runoff. We don't have a recipe for load patterns to
+        * reliably avoid the prefetcher.
+        */
+       l1d_flush_fallback_area = __va(memblock_alloc_base(l1d_size * 2, l1d_size, limit));
+       memset(l1d_flush_fallback_area, 0, l1d_size * 2);
+
+       for_each_possible_cpu(cpu) {
+               /*
+                * The fallback flush is currently coded for 8-way
+                * associativity. Different associativity is possible, but it
+                * will be treated as 8-way and may not evict the lines as
+                * effectively.
+                *
+                * 128 byte lines are mandatory.
+                */
+               u64 c = l1d_size / 8;
+
+               paca[cpu].rfi_flush_fallback_area = l1d_flush_fallback_area;
+               paca[cpu].l1d_flush_congruence = c;
+               paca[cpu].l1d_flush_sets = c / 128;
+       }
+}
+
+void __init setup_rfi_flush(enum l1d_flush_type types, bool enable)
+{
+       if (types & L1D_FLUSH_FALLBACK) {
+               pr_info("rfi-flush: Using fallback displacement flush\n");
+               init_fallback_flush();
+       }
+
+       if (types & L1D_FLUSH_ORI)
+               pr_info("rfi-flush: Using ori type flush\n");
+
+       if (types & L1D_FLUSH_MTTRIG)
+               pr_info("rfi-flush: Using mttrig type flush\n");
+
+       enabled_flush_types = types;
+
+       rfi_flush_enable(enable);
+}
+#endif /* CONFIG_PPC_BOOK3S_64 */