[PATCH v2] target/ppc: Add E500 L2CSR0 write helper

[Bin Meng]

From: Bin Meng <bin.meng@windriver.com>

Per EREF 2.0 [1] chapter 3.11.2:

The following bits in L2CSR0 (exists in the e500mc/e5500/e6500 core):

- L2FI  (L2 cache flash invalidate)
- L2FL  (L2 cache flush)
- L2LFC (L2 cache lock flash clear)

when set, a cache operation is initiated by hardware, and these bits
will be cleared when the operation is complete.

Since we don't model cache in QEMU, let's add a write helper to emulate
the cache operations completing instantly.

[1] https://www.nxp.com/files-static/32bit/doc/ref_manual/EREFRM.pdf

Signed-off-by: Bin Meng <bin.meng@windriver.com>

---

Changes in v2:
- Add Freescale manual link and clarifications in the commit message

 target/ppc/cpu.h                |  6 ++++++
 target/ppc/translate_init.c.inc | 16 ++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index 2609e40..e77911a 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -1919,6 +1919,7 @@ typedef PowerPCCPU ArchCPU;
 #define SPR_750FX_HID2        (0x3F8)
 #define SPR_Exxx_L1FINV0      (0x3F8)
 #define SPR_L2CR              (0x3F9)
+#define SPR_Exxx_L2CSR0       (0x3F9)
 #define SPR_L3CR              (0x3FA)
 #define SPR_750_TDCH          (0x3FA)
 #define SPR_IABR2             (0x3FA)
@@ -1974,6 +1975,11 @@ typedef PowerPCCPU ArchCPU;
 #define   L1CSR1_ICFI   0x00000002  /* Instruction Cache Flash Invalidate */
 #define   L1CSR1_ICE    0x00000001  /* Instruction Cache Enable */
 
+/* E500 L2CSR0 */
+#define E500_L2CSR0_L2FI    (1 << 21)   /* L2 cache flash invalidate */
+#define E500_L2CSR0_L2FL    (1 << 11)   /* L2 cache flush */
+#define E500_L2CSR0_L2LFC   (1 << 10)   /* L2 cache lock flash clear */
+
 /* HID0 bits */
 #define HID0_DEEPNAP        (1 << 24)           /* pre-2.06 */
 #define HID0_DOZE           (1 << 23)           /* pre-2.06 */
diff --git a/target/ppc/translate_init.c.inc b/target/ppc/translate_init.c.inc
index 9867d0a..3ec45cb 100644
--- a/target/ppc/translate_init.c.inc
+++ b/target/ppc/translate_init.c.inc
@@ -1735,6 +1735,16 @@ static void spr_write_e500_l1csr1(DisasContext *ctx, int 
sprn, int gprn)
     tcg_temp_free(t0);
 }
 
+static void spr_write_e500_l2csr0(DisasContext *ctx, int sprn, int gprn)
+{
+    TCGv t0 = tcg_temp_new();
+
+    tcg_gen_andi_tl(t0, cpu_gpr[gprn],
+                    ~(E500_L2CSR0_L2FI | E500_L2CSR0_L2FL | 
E500_L2CSR0_L2LFC));
+    gen_store_spr(sprn, t0);
+    tcg_temp_free(t0);
+}
+
 static void spr_write_booke206_mmucsr0(DisasContext *ctx, int sprn, int gprn)
 {
     gen_helper_booke206_tlbflush(cpu_env, cpu_gpr[gprn]);
@@ -5029,6 +5039,12 @@ static void init_proc_e500(CPUPPCState *env, int version)
                  SPR_NOACCESS, SPR_NOACCESS,
                  &spr_read_generic, &spr_write_e500_l1csr1,
                  0x00000000);
+    if (version != fsl_e500v1 && version != fsl_e500v2) {
+        spr_register(env, SPR_Exxx_L2CSR0, "L2CSR0",
+                     SPR_NOACCESS, SPR_NOACCESS,
+                     &spr_read_generic, &spr_write_e500_l2csr0,
+                     0x00000000);
+    }
     spr_register(env, SPR_BOOKE_MCSRR0, "MCSRR0",
                  SPR_NOACCESS, SPR_NOACCESS,
                  &spr_read_generic, &spr_write_generic,
-- 
2.7.4