target-xtensa: implement CACHEATTR SR

In XEA1, the Options for Memory Protection and Translation and the corresponding TLB management instructions are not available. Instead, functionality similar to the Region Protection Option is available through the cache attribute register. See ISA, A.2.14 for details. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
yakuizhao · Dec 8, 2012 · 4e41d2f · 4e41d2f
1 parent fcc803d
commit 4e41d2f
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Showing 5 changed files with 25 additions and 1 deletion.
diff --git a/target-xtensa/cpu.c b/target-xtensa/cpu.c
@@ -48,6 +48,7 @@ static void xtensa_cpu_reset(CPUState *s)
             XTENSA_OPTION_INTERRUPT) ? 0x1f : 0x10;
     env->sregs[VECBASE] = env->config->vecbase;
     env->sregs[IBREAKENABLE] = 0;
+    env->sregs[CACHEATTR] = 0x22222222;
     env->sregs[ATOMCTL] = xtensa_option_enabled(env->config,
             XTENSA_OPTION_ATOMCTL) ? 0x28 : 0x15;
 

diff --git a/target-xtensa/cpu.h b/target-xtensa/cpu.h
@@ -94,6 +94,7 @@ enum {
     XTENSA_OPTION_REGION_PROTECTION,
     XTENSA_OPTION_REGION_TRANSLATION,
     XTENSA_OPTION_MMU,
+    XTENSA_OPTION_CACHEATTR,
 
     /* Other */
     XTENSA_OPTION_WINDOWED_REGISTER,
@@ -129,6 +130,7 @@ enum {
     ITLBCFG = 91,
     DTLBCFG = 92,
     IBREAKENABLE = 96,
+    CACHEATTR = 98,
     ATOMCTL = 99,
     IBREAKA = 128,
     DBREAKA = 144,

diff --git a/target-xtensa/helper.c b/target-xtensa/helper.c
@@ -438,6 +438,24 @@ static unsigned region_attr_to_access(uint32_t attr)
     return access[attr & 0xf];
 }
 
+/*!
+ * Convert cacheattr to PAGE_{READ,WRITE,EXEC} mask.
+ * See ISA, A.2.14 The Cache Attribute Register
+ */
+static unsigned cacheattr_attr_to_access(uint32_t attr)
+{
+    static const unsigned access[16] = {
+         [0] = PAGE_READ | PAGE_WRITE             | PAGE_CACHE_WT,
+         [1] = PAGE_READ | PAGE_WRITE | PAGE_EXEC | PAGE_CACHE_WT,
+         [2] = PAGE_READ | PAGE_WRITE | PAGE_EXEC | PAGE_CACHE_BYPASS,
+         [3] =                          PAGE_EXEC | PAGE_CACHE_WB,
+         [4] = PAGE_READ | PAGE_WRITE | PAGE_EXEC | PAGE_CACHE_WB,
+        [14] = PAGE_READ | PAGE_WRITE             | PAGE_CACHE_ISOLATE,
+    };
+
+    return access[attr & 0xf];
+}
+
 static bool is_access_granted(unsigned access, int is_write)
 {
     switch (is_write) {
@@ -584,7 +602,8 @@ int xtensa_get_physical_addr(CPUXtensaState *env, bool update_tlb,
     } else {
         *paddr = vaddr;
         *page_size = TARGET_PAGE_SIZE;
-        *access = PAGE_READ | PAGE_WRITE | PAGE_EXEC | PAGE_CACHE_BYPASS;
+        *access = cacheattr_attr_to_access(
+                env->sregs[CACHEATTR] >> ((vaddr & 0xe0000000) >> 27));
         return 0;
     }
 }

diff --git a/target-xtensa/overlay_tool.h b/target-xtensa/overlay_tool.h
@@ -91,6 +91,7 @@
     XCHAL_OPTION(XCHAL_HAVE_XLT_CACHEATTR, \
             XTENSA_OPTION_REGION_TRANSLATION) | \
     XCHAL_OPTION(XCHAL_HAVE_PTP_MMU, XTENSA_OPTION_MMU) | \
+    XCHAL_OPTION(XCHAL_HAVE_CACHEATTR, XTENSA_OPTION_CACHEATTR) | \
     /* Other, TODO */ \
     XCHAL_OPTION(XCHAL_HAVE_WINDOWED, XTENSA_OPTION_WINDOWED_REGISTER) | \
     XCHAL_OPTION(XCHAL_HAVE_DEBUG, XTENSA_OPTION_DEBUG))

diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
@@ -99,6 +99,7 @@ static const char * const sregnames[256] = {
     [ITLBCFG] = "ITLBCFG",
     [DTLBCFG] = "DTLBCFG",
     [IBREAKENABLE] = "IBREAKENABLE",
+    [CACHEATTR] = "CACHEATTR",
     [ATOMCTL] = "ATOMCTL",
     [IBREAKA] = "IBREAKA0",
     [IBREAKA + 1] = "IBREAKA1",