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From: "Philippe Mathieu-Daudé" <f4bug@amsat.org>
To: qemu-devel@nongnu.org
Cc: "Aleksandar Rikalo" <aleksandar.rikalo@syrmia.com>,
	"Paul Burton" <paulburton@kernel.org>,
	"Philippe Mathieu-Daudé" <f4bug@amsat.org>,
	"Hervé Poussineau" <hpoussin@reactos.org>,
	"Huacai Chen" <chenhc@lemote.com>,
	"Aurelien Jarno" <aurelien@aurel32.net>
Subject: [PULL 17/44] target/mips: Move cp0_count_ns to CPUMIPSState
Date: Sat, 17 Oct 2020 16:02:16 +0200
Message-ID: <20201017140243.1078718-18-f4bug@amsat.org> (raw)
In-Reply-To: <20201017140243.1078718-1-f4bug@amsat.org>

Currently the CP0 timer period is fixed at 10 ns, corresponding
to a fixed CPU frequency of 200 MHz (using half the speed of the
CPU).

In few commits we will be able to use a different CPU frequency.
In preparation, move the cp0_count_ns variable to CPUMIPSState
so we can modify it.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Message-Id: <20201012095804.3335117-9-f4bug@amsat.org>
---
 target/mips/cpu.h       |  1 +
 target/mips/cp0_timer.c | 23 ++++++-----------------
 target/mips/cpu.c       | 21 +++++++++++++++++++++
 3 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/target/mips/cpu.h b/target/mips/cpu.h
index 7cf7f5239f7..085a88e9550 100644
--- a/target/mips/cpu.h
+++ b/target/mips/cpu.h
@@ -1145,6 +1145,7 @@ struct CPUMIPSState {
     struct MIPSITUState *itu;
     MemoryRegion *itc_tag; /* ITC Configuration Tags */
     target_ulong exception_base; /* ExceptionBase input to the core */
+    uint64_t cp0_count_ns; /* CP0_Count clock period (in nanoseconds) */
 };
 
 /**
diff --git a/target/mips/cp0_timer.c b/target/mips/cp0_timer.c
index 6fec5fe0ff7..5ec0d6249e9 100644
--- a/target/mips/cp0_timer.c
+++ b/target/mips/cp0_timer.c
@@ -27,18 +27,6 @@
 #include "sysemu/kvm.h"
 #include "internal.h"
 
-/*
- * Since commit 6af0bf9c7c3 this model assumes a CPU clocked at 200MHz
- * and a CP0 timer running at half the clock of the CPU (cp0_count_rate = 2).
- *
- * TIMER_FREQ_HZ = CPU_FREQ_HZ / CP0_COUNT_RATE = 200 MHz / 2 = 100 MHz
- *
- * TIMER_PERIOD_NS = 1 / TIMER_FREQ_HZ = 10 ns
- */
-#define CPU_FREQ_HZ_DEFAULT     200000000
-#define CP0_COUNT_RATE_DEFAULT  2
-#define TIMER_PERIOD            10  /* 1 / (CPU_FREQ_HZ / CP0_COUNT_RATE) */
-
 /* MIPS R4K timer */
 static void cpu_mips_timer_update(CPUMIPSState *env)
 {
@@ -47,8 +35,8 @@ static void cpu_mips_timer_update(CPUMIPSState *env)
 
     now_ns = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
     wait = env->CP0_Compare - env->CP0_Count -
-           (uint32_t)(now_ns / TIMER_PERIOD);
-    next_ns = now_ns + (uint64_t)wait * TIMER_PERIOD;
+           (uint32_t)(now_ns / env->cp0_count_ns);
+    next_ns = now_ns + (uint64_t)wait * env->cp0_count_ns;
     timer_mod(env->timer, next_ns);
 }
 
@@ -76,7 +64,7 @@ uint32_t cpu_mips_get_count(CPUMIPSState *env)
             cpu_mips_timer_expire(env);
         }
 
-        return env->CP0_Count + (uint32_t)(now_ns / TIMER_PERIOD);
+        return env->CP0_Count + (uint32_t)(now_ns / env->cp0_count_ns);
     }
 }
 
@@ -92,7 +80,8 @@ void cpu_mips_store_count(CPUMIPSState *env, uint32_t count)
     } else {
         /* Store new count register */
         env->CP0_Count = count -
-               (uint32_t)(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / TIMER_PERIOD);
+               (uint32_t)(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) /
+                          env->cp0_count_ns);
         /* Update timer timer */
         cpu_mips_timer_update(env);
     }
@@ -119,7 +108,7 @@ void cpu_mips_stop_count(CPUMIPSState *env)
 {
     /* Store the current value */
     env->CP0_Count += (uint32_t)(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) /
-                                 TIMER_PERIOD);
+                                 env->cp0_count_ns);
 }
 
 static void mips_timer_cb(void *opaque)
diff --git a/target/mips/cpu.c b/target/mips/cpu.c
index e86cd065483..84b727fefa8 100644
--- a/target/mips/cpu.c
+++ b/target/mips/cpu.c
@@ -134,6 +134,25 @@ static void mips_cpu_disas_set_info(CPUState *s, disassemble_info *info)
     }
 }
 
+/*
+ * Since commit 6af0bf9c7c3 this model assumes a CPU clocked at 200MHz
+ * and a CP0 timer running at half the clock of the CPU (cp0_count_rate = 2).
+ *
+ * TIMER_FREQ_HZ = CPU_FREQ_HZ / CP0_COUNT_RATE = 200 MHz / 2 = 100 MHz
+ *
+ * TIMER_PERIOD_NS = 1 / TIMER_FREQ_HZ = 10 ns
+ */
+#define CPU_FREQ_HZ_DEFAULT     200000000
+#define CP0_COUNT_RATE_DEFAULT  2
+#define TIMER_PERIOD_DEFAULT    10  /* 1 / (CPU_FREQ_HZ / CP0_COUNT_RATE) */
+
+static void mips_cp0_period_set(MIPSCPU *cpu)
+{
+    CPUMIPSState *env = &cpu->env;
+
+    env->cp0_count_ns = TIMER_PERIOD_DEFAULT;
+}
+
 static void mips_cpu_realizefn(DeviceState *dev, Error **errp)
 {
     CPUState *cs = CPU(dev);
@@ -141,6 +160,8 @@ static void mips_cpu_realizefn(DeviceState *dev, Error **errp)
     MIPSCPUClass *mcc = MIPS_CPU_GET_CLASS(dev);
     Error *local_err = NULL;
 
+    mips_cp0_period_set(cpu);
+
     cpu_exec_realizefn(cs, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
-- 
2.26.2



  parent reply index

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-17 14:01 [PULL 00/44] mips-next patches for 2020-10-17 Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 01/44] util/cutils: Introduce freq_to_str() to display Hertz units Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 02/44] hw/qdev-clock: Display error hint when clock is missing from device Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 03/44] hw/core/clock: Add the clock_new helper function Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 04/44] target/mips: Fix some comment spelling errors Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 05/44] target/mips: Demacro helpers for <ABS|CHS>.<D|S|PS> Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 06/44] target/mips: Demacro helpers for M<ADD|SUB>F.<D|S> Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 07/44] target/mips: Demacro helpers for <MAX|MAXA|MIN|MINA>.<D|S> Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 08/44] target/mips: Add loongson-ext lswc2 group of instructions (Part 1) Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 09/44] target/mips: Add loongson-ext lswc2 group of instructions (Part 2) Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 10/44] target/mips: Add loongson-ext lsdc2 group of instructions Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 11/44] target/mips/op_helper: Convert multiple if() to switch case Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 12/44] target/mips/op_helper: Document Invalidate/Writeback opcodes as no-op Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 13/44] target/mips/op_helper: Log unimplemented cache opcode Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 14/44] target/mips: Move cpu_mips_get_random() with CP0 helpers Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 15/44] target/mips/cp0_timer: Explicit unit in variable name Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 16/44] target/mips/cp0_timer: Document TIMER_PERIOD origin Philippe Mathieu-Daudé
2020-10-17 14:02 ` Philippe Mathieu-Daudé [this message]
2020-10-17 14:02 ` [PULL 18/44] target/mips/cpu: Calculate the CP0 timer period using the CPU frequency Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 19/44] target/mips/cpu: Make cp0_count_rate a property Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 20/44] target/mips/cpu: Allow the CPU to use dynamic frequencies Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 21/44] target/mips/cpu: Introduce mips_cpu_create_with_clock() helper Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 22/44] hw/mips/r4k: Explicit CPU frequency is 200 MHz Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 23/44] hw/mips/fuloong2e: Set CPU frequency to 533 MHz Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 24/44] hw/mips/mipssim: Correct CPU frequency Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 25/44] hw/mips/jazz: Correct CPU frequencies Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 26/44] hw/mips/cps: Expose input clock and connect it to CPU cores Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 27/44] hw/mips/boston: Set CPU frequency to 1 GHz Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 28/44] hw/mips/malta: Set CPU frequency to 320 MHz Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 29/44] hw/mips/cps: Do not allow use without input clock Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 30/44] target/mips/cpu: Display warning when CPU is used " Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 31/44] hw/mips/malta: Fix FPGA I/O region size Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 32/44] hw/mips/malta: Move gt64120 related code together Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 33/44] hw/mips/malta: Use clearer qdev style Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 34/44] hw/mips: Simplify loading 64-bit ELF kernels Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 35/44] hw/mips: Simplify code using ROUND_UP(INITRD_PAGE_SIZE) Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 36/44] hw/mips: Rename TYPE_MIPS_BOSTON to TYPE_BOSTON Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 37/44] hw/mips: Remove exit(1) in case of missing ROM Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 38/44] tests/acceptance: Add MIPS record/replay tests Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 39/44] docs/system: Update MIPS CPU documentation Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 40/44] MAINTAINERS: Remove myself Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 41/44] MAINTAINERS: Put myself forward for MIPS target Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 42/44] MAINTAINERS: Downgrade MIPS Boston to 'Odd Fixes', fix Paul Burton mail Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 43/44] MAINTAINERS: Remove duplicated Malta test entries Philippe Mathieu-Daudé
2020-10-17 14:02 ` [PULL 44/44] target/mips: Increase number of TLB entries on the 34Kf core (16 -> 64) Philippe Mathieu-Daudé
2020-10-19 10:45 ` [PULL 00/44] mips-next patches for 2020-10-17 Peter Maydell

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