[Qemu-devel] [V2 PATCH 6/9] target-ppc: Load Quadword

[Tom Musta <tommusta@gmail.com>]

This patch adds the Book I (user space) Load Quadword (lq) instruction.
This instruction was introduced into Book I in Power ISA V2.07.  Previous
versions of the architecture supported this as a privileged instruction.
Previous versions of the architecture also did not support Little Endian
mode.

Note that this patch also adds the PPC_64BX flag to the Power8 model,
which enables the lq instruction.

Signed-off-by: Tom Musta <tommusta@gmail.com>
---
V2: Refactored the user-mode and LE checks per Alex Graf's review.

 target-ppc/translate.c      |   40 ++++++++++++++++++++++++----------------
 target-ppc/translate_init.c |    2 +-
 2 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index 6ec4127..e36686e 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -2872,36 +2872,44 @@ static void gen_ld(DisasContext *ctx)
 /* lq */
 static void gen_lq(DisasContext *ctx)
 {
-#if defined(CONFIG_USER_ONLY)
-    gen_inval_exception(ctx, POWERPC_EXCP_PRIV_OPC);
-#else
-    int ra, rd;
-    TCGv EA;
+    /* lq is a legal user mode instruction starting in ISA 2.07 */
+    bool legal_in_user_mode = (ctx->insns_flags2 & PPC2_LSQ_ISA207) != 0;
+    bool le_is_supported = (ctx->insns_flags2 & PPC2_LSQ_ISA207) != 0;
 
-    /* Restore CPU state */
-    if (unlikely(ctx->mem_idx == 0)) {
+    if (!legal_in_user_mode && is_user_mode(ctx)) {
         gen_inval_exception(ctx, POWERPC_EXCP_PRIV_OPC);
         return;
     }
+
+    if (!le_is_supported && ctx->le_mode) {
+        gen_exception_err(ctx, POWERPC_EXCP_ALIGN, POWERPC_EXCP_ALIGN_LE);
+        return;
+    }
+
+    int ra, rd;
+    TCGv EA;
+
     ra = rA(ctx->opcode);
     rd = rD(ctx->opcode);
     if (unlikely((rd & 1) || rd == ra)) {
         gen_inval_exception(ctx, POWERPC_EXCP_INVAL_INVAL);
         return;
     }
-    if (unlikely(ctx->le_mode)) {
-        /* Little-endian mode is not handled */
-        gen_exception_err(ctx, POWERPC_EXCP_ALIGN, POWERPC_EXCP_ALIGN_LE);
-        return;
-    }
+
     gen_set_access_type(ctx, ACCESS_INT);
     EA = tcg_temp_new();
     gen_addr_imm_index(ctx, EA, 0x0F);
-    gen_qemu_ld64(ctx, cpu_gpr[rd], EA);
-    gen_addr_add(ctx, EA, EA, 8);
-    gen_qemu_ld64(ctx, cpu_gpr[rd+1], EA);
+
+    if (unlikely(ctx->le_mode)) {
+        gen_qemu_ld64(ctx, cpu_gpr[rd+1], EA);
+        gen_addr_add(ctx, EA, EA, 8);
+        gen_qemu_ld64(ctx, cpu_gpr[rd], EA);
+    } else {
+        gen_qemu_ld64(ctx, cpu_gpr[rd], EA);
+        gen_addr_add(ctx, EA, EA, 8);
+        gen_qemu_ld64(ctx, cpu_gpr[rd+1], EA);
+    }
     tcg_temp_free(EA);
-#endif
 }
 #endif
 
diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
index 886238a..d7bcbba 100644
--- a/target-ppc/translate_init.c
+++ b/target-ppc/translate_init.c
@@ -7333,7 +7333,7 @@ POWERPC_FAMILY(POWER8)(ObjectClass *oc, void *data)
                        PPC_CACHE | PPC_CACHE_ICBI | PPC_CACHE_DCBZ |
                        PPC_MEM_SYNC | PPC_MEM_EIEIO |
                        PPC_MEM_TLBIE | PPC_MEM_TLBSYNC |
-                       PPC_64B | PPC_ALTIVEC |
+                       PPC_64B | PPC_64BX | PPC_ALTIVEC |
                        PPC_SEGMENT_64B | PPC_SLBI |
                        PPC_POPCNTB | PPC_POPCNTWD;
     pcc->insns_flags2 = PPC2_VSX | PPC2_VSX207 | PPC2_DFP | PPC2_DBRX |
-- 
1.7.1