Merge pull request #6515 from keithc-ca/ppc_cache_line_size

Fix computation of cache-line size on Power
eclipse · May 16, 2022 · c67d754 · c67d754
2 parents c862fbb + 8b3bf5b
commit c67d754
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Showing 4 changed files with 46 additions and 57 deletions.
diff --git a/include_core/omrutil.h b/include_core/omrutil.h
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 1991, 2021 IBM Corp. and others
+ * Copyright (c) 1991, 2022 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -330,9 +330,9 @@ getPageTypeStringWithLeadingSpace(uintptr_t pageFlags);
 /**
 * @brief
 * @param void
-* @return uintptr_t
+* @return uint32_t
 */
-uintptr_t getCacheLineSize(void);
+uint32_t getCacheLineSize(void);
 
 
 /**

diff --git a/port/unix/omrcpu.c b/port/unix/omrcpu.c
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 1991, 2020 IBM Corp. and others
+ * Copyright (c) 1991, 2022 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -34,6 +34,7 @@
 #include <string.h>
 #endif
 #include "omrport.h"
+#include "omrutil.h"
 #if defined(RS6000) || defined (LINUXPPC) || defined (PPC)
 #include "omrportpriv.h"
 #include "omrportpg.h"
@@ -61,27 +62,10 @@
 int32_t
 omrcpu_startup(struct OMRPortLibrary *portLibrary)
 {
+#if defined(LINUXPPC) || defined(PPC) || defined(RS6000)
 	/* initialize the ppc level 1 cache line size */
-#if defined(RS6000) || defined (LINUXPPC) || defined (PPC)
-	int32_t ppcCacheLineSize;
-
-	int  i;
-	char buf[1024];
-	memset(buf, 255, 1024);
-
-	__asm__(
-		"dcbz 0, %0"
-		: /* no outputs */
-		:"r"((void *) &buf[512]));
-
-	for (i = 0, ppcCacheLineSize = 0; i < 1024; i++) {
-		if (buf[i] == 0) {
-			ppcCacheLineSize++;
-		}
-	}
-
-	PPG_mem_ppcCacheLineSize = ppcCacheLineSize;
-#endif
+	PPG_mem_ppcCacheLineSize = getCacheLineSize();
+#endif /* defined(LINUXPPC) || defined(PPC) || defined(RS6000) */
 
 	return 0;
 }
@@ -113,13 +97,12 @@ omrcpu_shutdown(struct OMRPortLibrary *portLibrary)
 void
 omrcpu_flush_icache(struct OMRPortLibrary *portLibrary, void *memoryPointer, uintptr_t byteAmount)
 {
-#if defined(RS6000) || defined (LINUXPPC) || defined (PPC)
-
-	int32_t cacheLineSize = PPG_mem_ppcCacheLineSize;
-	unsigned char  *addr;
-	unsigned char  *limit;
-	limit = (unsigned char *)(((unsigned long)memoryPointer + (unsigned int)byteAmount + (cacheLineSize - 1))
-							  / cacheLineSize * cacheLineSize);
+#if defined(LINUXPPC) || defined(PPC) || defined(RS6000)
+	uint32_t cacheLineSize = PPG_mem_ppcCacheLineSize;
+	unsigned char *addr = NULL;
+	unsigned char *limit = (unsigned char *)
+			(((uintptr_t)memoryPointer + byteAmount + (cacheLineSize - 1))
+					/ cacheLineSize * cacheLineSize);
 
 	/* for each cache line, do a data cache block flush */
 	for (addr = (unsigned char *)memoryPointer ; addr < limit; addr += cacheLineSize) {
@@ -142,15 +125,14 @@ omrcpu_flush_icache(struct OMRPortLibrary *portLibrary, void *memoryPointer, uin
 	__asm__("sync");
 	__asm__("isync");
 
-#elif defined(ARM) || defined(AARCH64) /* defined(RS6000) || defined(LINUXPPC) || defined(PPC) */
+#elif defined(AARCH64) || defined(ARM) /* defined(LINUXPPC) || defined(PPC) || defined(RS6000) */
 #if defined(__GNUC__)
 	// GCC built-in function
-	__builtin___clear_cache(memoryPointer, (void *)((char *)memoryPointer+byteAmount));
-#else
+	__builtin___clear_cache(memoryPointer, (void *)((unsigned char *)memoryPointer + byteAmount));
+#else /* defined(__GNUC__) */
 #error Not supported
 #endif /* defined(__GNUC__) */
-#endif /* defined(ARM) || defined(AARCH64) */
-
+#endif /* defined(LINUXPPC) || defined(PPC) || defined(RS6000) */
 }
 
 int32_t
@@ -177,7 +159,3 @@ omrcpu_get_cache_line_size(struct OMRPortLibrary *portLibrary, int32_t *lineSize
 	}
 	return rc;
 }
-
-
-
-
diff --git a/port/unix_include/omrportpg.h b/port/unix_include/omrportpg.h
@@ -95,7 +95,7 @@ typedef struct OMRPortPlatformGlobals {
 	BOOLEAN globalConverterEnabled;
 	char *si_executableName;
 #if defined(RS6000) || defined (LINUXPPC) || defined (PPC)
-	int32_t mem_ppcCacheLineSize;
+	uint32_t mem_ppcCacheLineSize;
 #endif
 #if defined(OMR_CONFIGURABLE_SUSPEND_SIGNAL)
 	int32_t introspect_threadSuspendSignal;

diff --git a/util/omrutil/j9memclr.cpp b/util/omrutil/j9memclr.cpp
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 1991, 2021 IBM Corp. and others
+ * Copyright (c) 1991, 2022 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -44,8 +44,8 @@ extern "C" void J9ZERZ10(void *ptr, uintptr_t length);
 #endif
 
 #if defined(AIXPPC) || defined(LINUXPPC)
-static uintptr_t cacheLineSize = 0;
-#endif
+static uint32_t cacheLineSize = 0;
+#endif /* defined(AIXPPC) || defined(LINUXPPC) */
 
 #if defined(J9ZOS390)
 struct IHAPSA {
@@ -65,8 +65,7 @@ OMRZeroMemory(void *ptr, uintptr_t length)
 
 #if defined(AIXPPC) || defined(LINUXPPC)
 	char *addr = static_cast<char*>(ptr);
-	char *limit;
-	uintptr_t localCacheLineSize;
+	char *limit = NULL;
 
 #if defined(LINUXPPC)
 	if (length < 2048) {
@@ -80,16 +79,16 @@ OMRZeroMemory(void *ptr, uintptr_t length)
 		cacheLineSize = getCacheLineSize();
 	}
 
+	uint32_t localCacheLineSize = cacheLineSize;
+
 	/* Zeroing by dcbz is effective if requested length is at least twice larger then Data Cache Block size */
-	if (length < (2 * cacheLineSize)) {
+	if (length < (2 * localCacheLineSize)) {
 		memset(ptr, 0, (size_t)length);
 		return;
 	}
 
 	/* VMDESIGN 1314 - Allow the compile to unroll the loop below by avoiding using the global in the loop */
 
-	localCacheLineSize = cacheLineSize;
-
 	/* Zero any initial portion to first cache line boundary
 	 * Assumed here that size of first portion (from start to aligned address) is smaller then total requested size
 	 * This is correct because sizes smaller then 2 * Data Cache Block size are served already
@@ -107,7 +106,11 @@ OMRZeroMemory(void *ptr, uintptr_t length)
 	/* dcbz forms a group on POWER4, so there is no reason to unroll */
 	limit = (char *)(((uintptr_t)ptr + length) & ~(localCacheLineSize - 1));
 	for (; addr < limit; addr += localCacheLineSize) {
-		__asm__ __volatile__("dcbz 0,%0" : /* no outputs */ : "r"(addr));
+		__asm__ __volatile__(
+				"dcbz 0, %0"
+				: /* no outputs */
+				: "r"(addr)
+				: /* clobbers */ "memory");
 	}
 
 	/* zero final portion smaller than a cache line */
@@ -143,21 +146,29 @@ OMRZeroMemory(void *ptr, uintptr_t length)
 }
 
 
-uintptr_t
+uint32_t
 getCacheLineSize(void)
 {
 #if defined(AIXPPC) || defined (LINUXPPC)
 	char buf[1024];
-	uintptr_t i, ppcCacheLineSize;
+	uint32_t i = 0;
+	uint32_t ppcCacheLineSize = 0;
 
 	/* xlc -O3 inlines/unrolls this memset */
-	memset(buf, 255, 1024);
-	__asm__ __volatile__("dcbz 0,%0" : /* no outputs */ : "r"(&buf[512]));
-	for (i = 0, ppcCacheLineSize = 0; i < 1024; i++) {
-		if (buf[i] == 0) {
-			ppcCacheLineSize++;
+	memset(buf, 255, sizeof(buf));
+
+	__asm__ __volatile__(
+			"dcbz 0, %0"
+			: /* no outputs */
+			: "r"((void *)&buf[512])
+			: /* clobbers */ "memory");
+
+	for (i = 0, ppcCacheLineSize = 0; i < sizeof(buf); ++i) {
+		if (0 == buf[i]) {
+			ppcCacheLineSize += 1;
 		}
 	}
+
 	return ppcCacheLineSize;
 #else
 	return 0;