target/mips: Implement CP0.Config7.WII bit support

Some pre-release 6 cores use CP0.Config7.WII bit to indicate that a
disabled interrupt should wake up a sleeping CPU.
Enable this bit by default for M14K(c) and P5600. There are potentially
other cores that support this feature, but I do not have a complete
list.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@fungible.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230216051717.3911212-4-marcin.nowakowski@fungible.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

diff --git a/target/mips/cpu-defs.c.inc b/target/mips/cpu-defs.c.inc
index 480e60aeec8f7db355f4277c7d2da6f70baf6c71..fdde04dfb96128ce7f34e9d79f55a8f26c5818d4 100644 (file)
--- a/target/mips/cpu-defs.c.inc
+++ b/target/mips/cpu-defs.c.inc
@@ -333,6 +333,7 @@ const mips_def_t mips_defs[] =
         .CP0_Config1 = MIPS_CONFIG1,
         .CP0_Config2 = MIPS_CONFIG2,
         .CP0_Config3 = MIPS_CONFIG3 | (0x2 << CP0C3_ISA) | (1 << CP0C3_VInt),
+        .CP0_Config7 = 1 << CP0C7_WII,
         .CP0_LLAddr_rw_bitmask = 0,
         .CP0_LLAddr_shift = 4,
         .SYNCI_Step = 32,
@@ -354,6 +355,7 @@ const mips_def_t mips_defs[] =
                        (0 << CP0C1_DS) | (3 << CP0C1_DL) | (1 << CP0C1_DA),
         .CP0_Config2 = MIPS_CONFIG2,
         .CP0_Config3 = MIPS_CONFIG3 | (0x2 << CP0C3_ISA) | (0 << CP0C3_VInt),
+        .CP0_Config7 = 1 << CP0C7_WII,
         .CP0_LLAddr_rw_bitmask = 0,
         .CP0_LLAddr_shift = 4,
         .SYNCI_Step = 32,
@@ -392,6 +394,7 @@ const mips_def_t mips_defs[] =
         .CP0_Config5_rw_bitmask = (1 << CP0C5_K) | (1 << CP0C5_CV) |
                                   (1 << CP0C5_MSAEn) | (1 << CP0C5_UFE) |
                                   (1 << CP0C5_FRE) | (1 << CP0C5_UFR),
+        .CP0_Config7 = 1 << CP0C7_WII,
         .CP0_LLAddr_rw_bitmask = 0,
         .CP0_LLAddr_shift = 0,
         .SYNCI_Step = 32,

diff --git a/target/mips/cpu.c b/target/mips/cpu.c
index 05caf5499982617a93667e1e9c1cc0bd1f861ca8..543da911e381c011343dc6dcb866fa3a09dec519 100644 (file)
--- a/target/mips/cpu.c
+++ b/target/mips/cpu.c
@@ -143,11 +143,13 @@ static bool mips_cpu_has_work(CPUState *cs)
     /*
      * Prior to MIPS Release 6 it is implementation dependent if non-enabled
      * interrupts wake-up the CPU, however most of the implementations only
-     * check for interrupts that can be taken.
+     * check for interrupts that can be taken. For pre-release 6 CPUs,
+     * check for CP0 Config7 'Wait IE ignore' bit.
      */
     if ((cs->interrupt_request & CPU_INTERRUPT_HARD) &&
         cpu_mips_hw_interrupts_pending(env)) {
         if (cpu_mips_hw_interrupts_enabled(env) ||
+            (env->CP0_Config7 & (1 << CP0C7_WII)) ||
             (env->insn_flags & ISA_MIPS_R6)) {
             has_work = true;
         }

diff --git a/target/mips/cpu.h b/target/mips/cpu.h
index caf2b069119b7322504b052a60a28c9ec31744f3..142c55af478b074587d6d147efda830848be8532 100644 (file)
--- a/target/mips/cpu.h
+++ b/target/mips/cpu.h
@@ -980,6 +980,7 @@ typedef struct CPUArchState {
 #define CP0C6_DATAPREF        0
     int32_t CP0_Config7;
     int64_t CP0_Config7_rw_bitmask;
+#define CP0C7_WII          31
 #define CP0C7_NAPCGEN       2
 #define CP0C7_UNIMUEN       1
 #define CP0C7_VFPUCGEN      0