thermosphere: use barriers and caches *properly*. Cache code refactoring

- set/way cache ops create losses of coherency, do not broadcast and are only meant to be used on boot, period.

Cache ops by VA are **the only way** to do data cache maintenance.

Fix a bug where the L2 cache was evicted by each core. It shouldn't have.

- Cleaning dcache to PoU and invalidating icache to PoU, by VA is sufficient for self-modifying code

- Since we operate within a single cluster and don't do DMA, we almost always operate within the inner shareability domain

(commit untested on real hw)

thermosphere/src/caches.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2019 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "utils.h"
+#include "sysreg.h"
+
+static inline u32 cacheGetSmallestInstructionCacheLineSize(void)
+{
+    u32 ctr = (u32)GET_SYSREG(ctr_el0);
+    u32 shift = ctr & 0xF;
+    // "log2 of the number of words"...
+    return 4 << shift;
+}
+
+static inline u32 cacheGetSmallestDataCacheLineSize(void)
+{
+    u32 ctr = (u32)GET_SYSREG(ctr_el0);
+    u32 shift = (ctr >> 16) & 0xF;
+    // "log2 of the number of words"...
+    return 4 << shift;
+}
+
+static inline void cacheInvalidateInstructionCache(void)
+{
+    __asm__ __volatile__ ("ic ialluis" ::: "memory");
+    __isb();
+}
+
+static inline void cacheInvalidateInstructionCacheLocal(void)
+{
+    __asm__ __volatile__ ("ic iallu" ::: "memory");
+    __isb();
+}
+
+void cacheCleanInvalidateDataCacheRange(const void *addr, size_t size);
+void cacheCleanDataCacheRangePoU(const void *addr, size_t size);
+
+void cacheInvalidateInstructionCacheRangePoU(const void *addr, size_t size);
+
+void cacheHandleSelfModifyingCodePoU(const void *addr, size_t size);
+
+void cacheClearSharedDataCachesOnBoot(void);
+void cacheClearLocalDataCacheOnBoot(void);