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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 19/44] target/mips/cpu: Make cp0_count_rate a property
Date: Sat, 17 Oct 2020 16:02:18 +0200
Message-ID: <20201017140243.1078718-20-f4bug@amsat.org> (raw)
In-Reply-To: <20201017140243.1078718-1-f4bug@amsat.org>

Since not all CPU implementations use a cores use a CP0 timer
at half the frequency of the CPU, make this variable a property.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20201012095804.3335117-11-f4bug@amsat.org>
---
 target/mips/cpu.h |  9 +++++++++
 target/mips/cpu.c | 19 +++++++++++--------
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/target/mips/cpu.h b/target/mips/cpu.h
index 085a88e9550..baeceb892ef 100644
--- a/target/mips/cpu.h
+++ b/target/mips/cpu.h
@@ -1151,6 +1151,7 @@ struct CPUMIPSState {
 /**
  * MIPSCPU:
  * @env: #CPUMIPSState
+ * @cp0_count_rate: rate at which the coprocessor 0 counter increments
  *
  * A MIPS CPU.
  */
@@ -1161,6 +1162,14 @@ struct MIPSCPU {
 
     CPUNegativeOffsetState neg;
     CPUMIPSState env;
+    /*
+     * The Count register acts as a timer, incrementing at a constant rate,
+     * whether or not an instruction is executed, retired, or any forward
+     * progress is made through the pipeline. The rate at which the counter
+     * increments is implementation dependent, and is a function of the
+     * pipeline clock of the processor, not the issue width of the processor.
+     */
+    unsigned cp0_count_rate;
 };
 
 
diff --git a/target/mips/cpu.c b/target/mips/cpu.c
index 46188139b7b..461edfe22b7 100644
--- a/target/mips/cpu.c
+++ b/target/mips/cpu.c
@@ -26,7 +26,7 @@
 #include "qemu/module.h"
 #include "sysemu/kvm.h"
 #include "exec/exec-all.h"
-
+#include "hw/qdev-properties.h"
 
 static void mips_cpu_set_pc(CPUState *cs, vaddr value)
 {
@@ -135,12 +135,7 @@ 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
+ * Since commit 6af0bf9c7c3 this model assumes a CPU clocked at 200MHz.
  */
 #define CPU_FREQ_HZ_DEFAULT     200000000
 #define CP0_COUNT_RATE_DEFAULT  2
@@ -149,7 +144,7 @@ static void mips_cp0_period_set(MIPSCPU *cpu)
 {
     CPUMIPSState *env = &cpu->env;
 
-    env->cp0_count_ns = muldiv64(NANOSECONDS_PER_SECOND, CP0_COUNT_RATE_DEFAULT,
+    env->cp0_count_ns = muldiv64(NANOSECONDS_PER_SECOND, cpu->cp0_count_rate,
                                  CPU_FREQ_HZ_DEFAULT);
 }
 
@@ -202,6 +197,13 @@ static ObjectClass *mips_cpu_class_by_name(const char *cpu_model)
     return oc;
 }
 
+static Property mips_cpu_properties[] = {
+    /* CP0 timer running at half the clock of the CPU */
+    DEFINE_PROP_UINT32("cp0-count-rate", MIPSCPU, cp0_count_rate,
+                       CP0_COUNT_RATE_DEFAULT),
+    DEFINE_PROP_END_OF_LIST()
+};
+
 static void mips_cpu_class_init(ObjectClass *c, void *data)
 {
     MIPSCPUClass *mcc = MIPS_CPU_CLASS(c);
@@ -211,6 +213,7 @@ static void mips_cpu_class_init(ObjectClass *c, void *data)
     device_class_set_parent_realize(dc, mips_cpu_realizefn,
                                     &mcc->parent_realize);
     device_class_set_parent_reset(dc, mips_cpu_reset, &mcc->parent_reset);
+    device_class_set_props(dc, mips_cpu_properties);
 
     cc->class_by_name = mips_cpu_class_by_name;
     cc->has_work = mips_cpu_has_work;
-- 
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 ` [PULL 17/44] target/mips: Move cp0_count_ns to CPUMIPSState Philippe Mathieu-Daudé
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 ` Philippe Mathieu-Daudé [this message]
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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