[Qemu-devel] [PATCH v1 06/16] target-microblaze: Convert use-fpu to a CPU property

["Edgar E. Iglesias" <edgar.iglesias@gmail.com>]

From: Alistair Francis <alistair.francis@xilinx.com>

Originally the use-fpu PVR bits were manually set for each machine. This
is a hassle and difficult to read, instead set them based on the CPU
properties.

Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
---
 hw/microblaze/petalogix_ml605_mmu.c |  7 +++++--
 target-microblaze/cpu-qom.h         |  1 +
 target-microblaze/cpu.c             | 13 ++++++++++---
 target-microblaze/translate.c       | 10 +++-------
 4 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/hw/microblaze/petalogix_ml605_mmu.c b/hw/microblaze/petalogix_ml605_mmu.c
index 48c264b..05c120a 100644
--- a/hw/microblaze/petalogix_ml605_mmu.c
+++ b/hw/microblaze/petalogix_ml605_mmu.c
@@ -71,9 +71,8 @@ static void machine_cpu_reset(MicroBlazeCPU *cpu)
     env->pvr.regs[10] = 0x0e000000; /* virtex 6 */
     /* setup pvr to match kernel setting */
     env->pvr.regs[5] |= PVR5_DCACHE_WRITEBACK_MASK;
-    env->pvr.regs[0] |= PVR0_USE_FPU_MASK | PVR0_ENDI;
+    env->pvr.regs[0] |= PVR0_ENDI;
     env->pvr.regs[0] = (env->pvr.regs[0] & ~PVR0_VERSION_MASK) | (0x14 << 8);
-    env->pvr.regs[2] ^= PVR2_USE_FPU2_MASK;
     env->pvr.regs[4] = 0xc56b8000;
     env->pvr.regs[5] = 0xc56be000;
 }
@@ -95,6 +94,10 @@ petalogix_ml605_init(MachineState *machine)
 
     /* init CPUs */
     cpu = MICROBLAZE_CPU(object_new(TYPE_MICROBLAZE_CPU));
+    /* Use FPU but don't use floating point conversion and square
+     * root instructions
+     */
+    object_property_set_int(OBJECT(cpu), 1, "use-fpu", &error_abort);
     object_property_set_bool(OBJECT(cpu), true, "realized", &error_abort);
 
     /* Attach emulated BRAM through the LMB.  */
diff --git a/target-microblaze/cpu-qom.h b/target-microblaze/cpu-qom.h
index dd04199..a6474f9 100644
--- a/target-microblaze/cpu-qom.h
+++ b/target-microblaze/cpu-qom.h
@@ -63,6 +63,7 @@ typedef struct MicroBlazeCPU {
     struct {
         bool stackprot;
         uint32_t base_vectors;
+        uint8_t usefpu;
     } cfg;
 
     CPUMBState env;
diff --git a/target-microblaze/cpu.c b/target-microblaze/cpu.c
index 0f805d3..b857056 100644
--- a/target-microblaze/cpu.c
+++ b/target-microblaze/cpu.c
@@ -110,12 +110,14 @@ static void mb_cpu_realizefn(DeviceState *dev, Error **errp)
                         | PVR2_USE_DIV_MASK \
                         | PVR2_USE_HW_MUL_MASK \
                         | PVR2_USE_MUL64_MASK \
-                        | PVR2_USE_FPU_MASK \
-                        | PVR2_USE_FPU2_MASK \
                         | PVR2_FPU_EXC_MASK \
                         | 0;
 
-    env->pvr.regs[0] |= cpu->cfg.stackprot ? PVR0_SPROT_MASK : 0;
+    env->pvr.regs[0] |= (cpu->cfg.stackprot ? PVR0_SPROT_MASK : 0) |
+                        (cpu->cfg.usefpu ? PVR0_USE_FPU_MASK : 0);
+
+    env->pvr.regs[2] |= (cpu->cfg.usefpu ? PVR2_USE_FPU_MASK : 0) |
+                        (cpu->cfg.usefpu > 1 ? PVR2_USE_FPU2_MASK : 0);
 
     env->pvr.regs[10] = 0x0c000000; /* Default to spartan 3a dsp family.  */
     env->pvr.regs[11] = PVR11_USE_MMU | (16 << 17);
@@ -161,6 +163,11 @@ static Property mb_properties[] = {
     DEFINE_PROP_UINT32("base-vectors", MicroBlazeCPU, cfg.base_vectors, 0),
     DEFINE_PROP_BOOL("use-stack-protection", MicroBlazeCPU, cfg.stackprot,
                      true),
+    /* If use-fpu > 0 - FPU is enabled
+     * If use-fpu = 2 - Floating point conversion and square root instructions
+     *                  are enabled
+     */
+    DEFINE_PROP_UINT8("use-fpu", MicroBlazeCPU, cfg.usefpu, 2),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/target-microblaze/translate.c b/target-microblaze/translate.c
index bd10b40..8187700 100644
--- a/target-microblaze/translate.c
+++ b/target-microblaze/translate.c
@@ -1411,15 +1411,11 @@ static void dec_rts(DisasContext *dc)
 
 static int dec_check_fpuv2(DisasContext *dc)
 {
-    int r;
-
-    r = dc->cpu->env.pvr.regs[2] & PVR2_USE_FPU2_MASK;
-
-    if (!r && (dc->tb_flags & MSR_EE_FLAG)) {
+    if ((dc->cpu->cfg.usefpu != 2) && (dc->tb_flags & MSR_EE_FLAG)) {
         tcg_gen_movi_tl(cpu_SR[SR_ESR], ESR_EC_FPU);
         t_gen_raise_exception(dc, EXCP_HW_EXCP);
     }
-    return r;
+    return (dc->cpu->cfg.usefpu == 2) ? 0 : PVR2_USE_FPU2_MASK;
 }
 
 static void dec_fpu(DisasContext *dc)
@@ -1428,7 +1424,7 @@ static void dec_fpu(DisasContext *dc)
 
     if ((dc->tb_flags & MSR_EE_FLAG)
           && (dc->cpu->env.pvr.regs[2] & PVR2_ILL_OPCODE_EXC_MASK)
-          && !((dc->cpu->env.pvr.regs[2] & PVR2_USE_FPU_MASK))) {
+          && (dc->cpu->cfg.usefpu != 1)) {
         tcg_gen_movi_tl(cpu_SR[SR_ESR], ESR_EC_ILLEGAL_OP);
         t_gen_raise_exception(dc, EXCP_HW_EXCP);
         return;
-- 
1.9.1