From 0993ae06858f82ec9e6d0f59e286b0afc281e448 Mon Sep 17 00:00:00 2001
From: Michael Scire <SciresM@gmail.com>
Date: Thu, 30 Jul 2020 14:51:45 -0700
Subject: [PATCH] kern: SvcFlushDataCache, SvcFlushEntireDataCache

---
 .../mesosphere/arch/arm64/kern_cpu.hpp        |  4 +++
 .../source/arch/arm64/kern_cpu.cpp            |  4 +--
 .../kern_debug_log_impl.board.nintendo_nx.cpp |  2 +-
 .../source/svc/kern_svc_cache.cpp             | 34 ++++++++++++++++---
 4 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/libraries/libmesosphere/include/mesosphere/arch/arm64/kern_cpu.hpp b/libraries/libmesosphere/include/mesosphere/arch/arm64/kern_cpu.hpp
index 41a8d7d0b..e3e519020 100644
--- a/libraries/libmesosphere/include/mesosphere/arch/arm64/kern_cpu.hpp
+++ b/libraries/libmesosphere/include/mesosphere/arch/arm64/kern_cpu.hpp
@@ -64,6 +64,10 @@ namespace ams::kern::arch::arm64::cpu {
         EnsureInstructionConsistency();
     }
 
+    ALWAYS_INLINE void Yield() {
+        __asm__ __volatile__("yield" ::: "memory");
+    }
+
     ALWAYS_INLINE void SwitchProcess(u64 ttbr, u32 proc_id) {
         SetTtbr0El1(ttbr);
         ContextIdRegisterAccessor(0).SetProcId(proc_id).Store();
diff --git a/libraries/libmesosphere/source/arch/arm64/kern_cpu.cpp b/libraries/libmesosphere/source/arch/arm64/kern_cpu.cpp
index 2a443d539..170ae14e0 100644
--- a/libraries/libmesosphere/source/arch/arm64/kern_cpu.cpp
+++ b/libraries/libmesosphere/source/arch/arm64/kern_cpu.cpp
@@ -60,7 +60,7 @@ namespace ams::kern::arch::arm64::cpu {
 
                 void Wait() {
                     while (!this->done) {
-                        __asm__ __volatile__("yield");
+                        cpu::Yield();
                     }
                 }
 
@@ -173,7 +173,7 @@ namespace ams::kern::arch::arm64::cpu {
                             Kernel::GetInterruptManager().SendInterProcessorInterrupt(KInterruptName_CacheOperation, target_mask);
                             this->ProcessOperation();
                             while (this->target_cores != 0) {
-                                __asm__ __volatile__("yield");
+                                cpu::Yield();
                             }
                         } else {
                             /* Request all cores. */
diff --git a/libraries/libmesosphere/source/kern_debug_log_impl.board.nintendo_nx.cpp b/libraries/libmesosphere/source/kern_debug_log_impl.board.nintendo_nx.cpp
index c3be814f5..dc90e1c9e 100644
--- a/libraries/libmesosphere/source/kern_debug_log_impl.board.nintendo_nx.cpp
+++ b/libraries/libmesosphere/source/kern_debug_log_impl.board.nintendo_nx.cpp
@@ -86,7 +86,7 @@ namespace ams::kern {
     void KDebugLogImpl::PutChar(char c) {
         while (ReadUartRegister(UartRegister_LSR) & 0x100) {
             /* While the FIFO is full, yield. */
-            __asm__ __volatile__("yield" ::: "memory");
+            cpu::Yield();
         }
         WriteUartRegister(UartRegister_THR, c);
         cpu::DataSynchronizationBarrier();
diff --git a/libraries/libmesosphere/source/svc/kern_svc_cache.cpp b/libraries/libmesosphere/source/svc/kern_svc_cache.cpp
index 62487b361..8deb3f595 100644
--- a/libraries/libmesosphere/source/svc/kern_svc_cache.cpp
+++ b/libraries/libmesosphere/source/svc/kern_svc_cache.cpp
@@ -73,6 +73,32 @@ namespace ams::kern::svc {
             return ResultSuccess();
         }
 
+        void FlushEntireDataCache() {
+            /* Flushing cache takes up to 1ms, so determine our minimum end tick. */
+            const s64 timeout = KHardwareTimer::GetTick() + ams::svc::Tick(TimeSpan::FromMilliSeconds(1));
+
+            /* Flush the entire data cache. */
+            cpu::FlushEntireDataCache();
+
+            /* Wait for 1ms to have passed. */
+            while (KHardwareTimer::GetTick() < timeout) {
+                cpu::Yield();
+            }
+        }
+
+        Result FlushDataCache(uintptr_t address, size_t size) {
+            /* Succeed if there's nothing to do. */
+            R_SUCCEED_IF(size == 0);
+
+            /* Validate that the region is within range. */
+            R_UNLESS(GetCurrentProcess().GetPageTable().Contains(address, size), svc::ResultInvalidCurrentMemory());
+
+            /* Flush the cache. */
+            R_TRY(cpu::FlushDataCache(reinterpret_cast<void *>(address), size));
+
+            return ResultSuccess();
+        }
+
         Result InvalidateProcessDataCache(ams::svc::Handle process_handle, uint64_t address, uint64_t size) {
             /* Validate address/size. */
             R_UNLESS(size > 0,                                   svc::ResultInvalidSize());
@@ -148,11 +174,11 @@ namespace ams::kern::svc {
     /* =============================    64 ABI    ============================= */
 
     void FlushEntireDataCache64() {
-        MESOSPHERE_PANIC("Stubbed SvcFlushEntireDataCache64 was called.");
+        return FlushEntireDataCache();
     }
 
     Result FlushDataCache64(ams::svc::Address address, ams::svc::Size size) {
-        MESOSPHERE_PANIC("Stubbed SvcFlushDataCache64 was called.");
+        return FlushDataCache(address, size);
     }
 
     Result InvalidateProcessDataCache64(ams::svc::Handle process_handle, uint64_t address, uint64_t size) {
@@ -170,11 +196,11 @@ namespace ams::kern::svc {
     /* ============================= 64From32 ABI ============================= */
 
     void FlushEntireDataCache64From32() {
-        MESOSPHERE_PANIC("Stubbed SvcFlushEntireDataCache64From32 was called.");
+        return FlushEntireDataCache();
     }
 
     Result FlushDataCache64From32(ams::svc::Address address, ams::svc::Size size) {
-        MESOSPHERE_PANIC("Stubbed SvcFlushDataCache64From32 was called.");
+        return FlushDataCache(address, size);
     }
 
     Result InvalidateProcessDataCache64From32(ams::svc::Handle process_handle, uint64_t address, uint64_t size) {