Utilize hardware CRC32-support when possible

api/util/crc32.hpp

@@ -81,15 +81,41 @@ static uint32_t crc_32_tab[] =
 
   for (; len; --len, ++buf)
       partial = UPDC32(*buf, partial);
-  
+
   return partial;
 
 #undef UPDC32
 }
 
+#ifdef __SSE4_2__
+#include <immintrin.h>
+
+inline uint32_t crc32_hw(const uint8_t* buffer, size_t len)
+{
+  uint32_t hash = 0xFFFFFFFF;
+  for (size_t i = 0; i < len; i++) {
+    hash = _mm_crc32_u8(hash, buffer[i]);
+  }
+  return hash ^ 0xFFFFFFFF;
+}
+#endif
+
+/** Ethernet/ZIP **/
 inline uint32_t crc32(const void* buf, size_t len)
 {
   return ~crc32(0xFFFFFFFF, (const char*) buf, len);
 }
 
+/** Intel (iSCSI) or vanilla-polynomial, DONT mix with other code **/
+/** This variant uses the fastest CRC method possible, but we don't
+    know which polynomial it will use, so use with care! **/
+inline uint32_t crc32_fast(const void* buf, size_t len)
+{
+#ifdef __SSE4_2__
+  return crc32_hw((const uint8_t*) buf, len);
+#else
+  return ~crc32(0xFFFFFFFF, (const char*) buf, len);
+#endif
+}
+
 #endif

src/kernel/sanity_checks.cpp

@@ -40,9 +40,7 @@ static void self_test_gconstr() {
 
 static uint32_t generate_ro_crc() noexcept
 {
-  uint32_t crc = CRC32_BEGIN();
-  crc = crc32(crc, &_TEXT_START_, &_RODATA_END_ - &_TEXT_START_);
-  return CRC32_VALUE(crc);
+  return crc32_fast(&_TEXT_START_, &_RODATA_END_ - &_TEXT_START_);
 }
 
 extern "C"

src/kernel/softreset.cpp

@@ -35,7 +35,7 @@ void OS::resume_softreset(intptr_t addr)
   /// validate soft-reset data
   const uint32_t csum_copy = data->checksum;
   data->checksum = 0;
-  uint32_t crc = crc32(data, sizeof(softreset_t));
+  uint32_t crc = crc32_fast(data, sizeof(softreset_t));
   if (crc != csum_copy) {
     kprintf("[!] Failed to verify CRC of softreset data: %08x vs %08x\n",
             crc, csum_copy);
@@ -66,7 +66,7 @@ void* __os_store_soft_reset(void* extra, size_t extra_len)
   data->extra       = extra;
   data->extra_len   = extra_len;
 
-  uint32_t csum = crc32(data, sizeof(softreset_t));
+  uint32_t csum = crc32_fast(data, sizeof(softreset_t));
   data->checksum = csum;
   return data;
 }