[Qemu-devel] [PATCH v2 1/2] arm_generic_timer: Add the ARM Generic Timer

[Alistair Francis <alistair.francis@xilinx.com>]

Add the ARM generic timer. This allows the guest to poll the timer for
values and also supports secure writes only.

Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
---
V2:
 - Fix couter/counter typo

 hw/timer/Makefile.objs               |   1 +
 hw/timer/arm_generic_timer.c         | 216 +++++++++++++++++++++++++++++++++++
 include/hw/timer/arm_generic_timer.h |  60 ++++++++++
 3 files changed, 277 insertions(+)
 create mode 100644 hw/timer/arm_generic_timer.c
 create mode 100644 include/hw/timer/arm_generic_timer.h

diff --git a/hw/timer/Makefile.objs b/hw/timer/Makefile.objs
index 7ba8c23..f88c468 100644
--- a/hw/timer/Makefile.objs
+++ b/hw/timer/Makefile.objs
@@ -17,6 +17,7 @@ common-obj-$(CONFIG_IMX) += imx_epit.o
 common-obj-$(CONFIG_IMX) += imx_gpt.o
 common-obj-$(CONFIG_LM32) += lm32_timer.o
 common-obj-$(CONFIG_MILKYMIST) += milkymist-sysctl.o
+common-obj-$(CONFIG_XLNX_ZYNQMP) += arm_generic_timer.o
 
 obj-$(CONFIG_EXYNOS4) += exynos4210_mct.o
 obj-$(CONFIG_EXYNOS4) += exynos4210_pwm.o
diff --git a/hw/timer/arm_generic_timer.c b/hw/timer/arm_generic_timer.c
new file mode 100644
index 0000000..7642206
--- /dev/null
+++ b/hw/timer/arm_generic_timer.c
@@ -0,0 +1,216 @@
+/*
+ * QEMU model of the ARM Generic Timer
+ *
+ * Copyright (c) 2016 Xilinx Inc.
+ * Written by Alistair Francis <alistair.francis@xilinx.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/timer/arm_generic_timer.h"
+#include "qemu/timer.h"
+#include "qemu/log.h"
+
+#ifndef ARM_GEN_TIMER_ERR_DEBUG
+#define ARM_GEN_TIMER_ERR_DEBUG 0
+#endif
+
+static void counter_control_postw(RegisterInfo *reg, uint64_t val64)
+{
+    ARMGenTimer *s = ARM_GEN_TIMER(reg->opaque);
+    bool new_status = extract32(s->regs[R_COUNTER_CONTROL_REGISTER],
+                                R_COUNTER_CONTROL_REGISTER_EN_SHIFT,
+                                R_COUNTER_CONTROL_REGISTER_EN_LENGTH);
+    uint64_t current_ticks;
+
+    current_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL),
+                             NANOSECONDS_PER_SECOND, 1000000);
+
+    if ((s->enabled && !new_status) ||
+        (!s->enabled && new_status)) {
+        /* The timer is being disabled or enabled */
+        s->tick_offset = current_ticks - s->tick_offset;
+    }
+
+    s->enabled = new_status;
+}
+
+static uint64_t counter_low_value_postr(RegisterInfo *reg, uint64_t val64)
+{
+    ARMGenTimer *s = ARM_GEN_TIMER(reg->opaque);
+    uint64_t current_ticks, total_ticks;
+    uint32_t low_ticks;
+
+    if (s->enabled) {
+        current_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL),
+                                 NANOSECONDS_PER_SECOND, 1000000);
+        total_ticks = current_ticks - s->tick_offset;
+        low_ticks = (uint32_t) total_ticks;
+    } else {
+        /* Timer is disabled, return the time when it was disabled */
+        low_ticks = (uint32_t) s->tick_offset;
+    }
+
+    return low_ticks;
+}
+
+static uint64_t counter_high_value_postr(RegisterInfo *reg, uint64_t val64)
+{
+    ARMGenTimer *s = ARM_GEN_TIMER(reg->opaque);
+    uint64_t current_ticks, total_ticks;
+    uint32_t high_ticks;
+
+    if (s->enabled) {
+        current_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL),
+                                 NANOSECONDS_PER_SECOND, 1000000);
+        total_ticks = current_ticks - s->tick_offset;
+        high_ticks = (uint32_t) (total_ticks >> 32);
+    } else {
+        /* Timer is disabled, return the time when it was disabled */
+        high_ticks = (uint32_t) (s->tick_offset >> 32);
+    }
+
+    return high_ticks;
+}
+
+
+static RegisterAccessInfo arm_gen_timer_regs_info[] = {
+    {   .name = "COUNTER_CONTROL_REGISTER",
+        .addr = A_COUNTER_CONTROL_REGISTER,
+        .rsvd = 0xfffffffc,
+        .post_write = counter_control_postw,
+    },{ .name = "COUNTER_STATUS_REGISTER",
+        .addr = A_COUNTER_STATUS_REGISTER,
+        .rsvd = 0xfffffffd, .ro = 0x2,
+    },{ .name = "CURRENT_COUNTER_VALUE_LOWER_REGISTER",
+        .addr = A_CURRENT_COUNTER_VALUE_LOWER_REGISTER,
+        .post_read = counter_low_value_postr,
+    },{ .name = "CURRENT_COUNTER_VALUE_UPPER_REGISTER",
+        .addr = A_CURRENT_COUNTER_VALUE_UPPER_REGISTER,
+        .post_read = counter_high_value_postr,
+    },{ .name = "BASE_FREQUENCY_ID_REGISTER",
+        .addr = A_BASE_FREQUENCY_ID_REGISTER,
+    }
+};
+
+static void arm_gen_timer_reset(DeviceState *dev)
+{
+    ARMGenTimer *s = ARM_GEN_TIMER(dev);
+    unsigned int i;
+
+    for (i = 0; i < ARRAY_SIZE(s->regs_info); ++i) {
+        register_reset(&s->regs_info[i]);
+    }
+
+    s->tick_offset = 0;
+    s->enabled = false;
+}
+
+static MemTxResult arm_gen_timer_read(void *opaque,  hwaddr addr,
+                                      uint64_t *data, unsigned size,
+                                      MemTxAttrs attrs)
+{
+    /* Reads are always supported, just blindly pass them through */
+    *data = register_read_memory(opaque, addr, size);
+
+    return MEMTX_OK;
+}
+
+static MemTxResult arm_gen_timer_write(void *opaque, hwaddr addr,
+                                       uint64_t data, unsigned size,
+                                       MemTxAttrs attrs)
+{
+    /* Block insecure writes */
+    if (!attrs.secure) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "Non secure writes to the system timestamp generator " \
+                      "are invalid\n");
+        return MEMTX_ERROR;
+    }
+
+    register_write_memory(opaque, addr, data, size);
+
+    return MEMTX_OK;
+}
+
+static const MemoryRegionOps arm_gen_timer_ops = {
+    .read_with_attrs = arm_gen_timer_read,
+    .write_with_attrs = arm_gen_timer_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4,
+    },
+};
+
+static const VMStateDescription vmstate_arm_gen_timer = {
+    .name = TYPE_ARM_GEN_TIMER,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(regs, ARMGenTimer, R_ARM_GEN_TIMER_MAX),
+        VMSTATE_END_OF_LIST(),
+    }
+};
+
+static void arm_gen_timer_init(Object *obj)
+{
+    ARMGenTimer *s = ARM_GEN_TIMER(obj);
+    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+    RegisterInfoArray *reg_array;
+
+    memory_region_init_io(&s->iomem, obj, &arm_gen_timer_ops, s,
+                          TYPE_ARM_GEN_TIMER, R_ARM_GEN_TIMER_MAX * 4);
+    reg_array =
+        register_init_block32(DEVICE(obj), arm_gen_timer_regs_info,
+                              ARRAY_SIZE(arm_gen_timer_regs_info),
+                              s->regs_info, s->regs,
+                              &arm_gen_timer_ops,
+                              ARM_GEN_TIMER_ERR_DEBUG,
+                              R_ARM_GEN_TIMER_MAX * 4);
+    memory_region_add_subregion(&s->iomem,
+                                A_COUNTER_CONTROL_REGISTER,
+                                &reg_array->mem);
+    sysbus_init_mmio(sbd, &s->iomem);
+}
+
+static void arm_gen_timer_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->reset = arm_gen_timer_reset;
+    dc->vmsd = &vmstate_arm_gen_timer;
+}
+
+static const TypeInfo arm_gen_timer_info = {
+    .name          = TYPE_ARM_GEN_TIMER,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(ARMGenTimer),
+    .class_init    = arm_gen_timer_class_init,
+    .instance_init = arm_gen_timer_init,
+};
+
+static void arm_gen_timer_register_types(void)
+{
+    type_register_static(&arm_gen_timer_info);
+}
+
+type_init(arm_gen_timer_register_types)
diff --git a/include/hw/timer/arm_generic_timer.h b/include/hw/timer/arm_generic_timer.h
new file mode 100644
index 0000000..4cc0ac9
--- /dev/null
+++ b/include/hw/timer/arm_generic_timer.h
@@ -0,0 +1,60 @@
+/*
+ * QEMU model of the ARM Generic Timer
+ *
+ * Copyright (c) 2016 Xilinx Inc.
+ * Written by Alistair Francis <alistair.francis@xilinx.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef ARM_GEN_TIMER_H
+#define ARM_GEN_TIMER_H
+
+#include "hw/sysbus.h"
+#include "hw/register.h"
+
+#define TYPE_ARM_GEN_TIMER "arm.generic-timer"
+#define ARM_GEN_TIMER(obj) \
+            OBJECT_CHECK(ARMGenTimer, (obj), TYPE_ARM_GEN_TIMER)
+
+REG32(COUNTER_CONTROL_REGISTER, 0x00)
+    FIELD(COUNTER_CONTROL_REGISTER, EN, 1, 1)
+    FIELD(COUNTER_CONTROL_REGISTER, HDBG, 0, 1)
+REG32(COUNTER_STATUS_REGISTER, 0x04)
+    FIELD(COUNTER_STATUS_REGISTER, DBGH, 1, 1)
+REG32(CURRENT_COUNTER_VALUE_LOWER_REGISTER, 0x08)
+REG32(CURRENT_COUNTER_VALUE_UPPER_REGISTER, 0x0C)
+REG32(BASE_FREQUENCY_ID_REGISTER, 0x20)
+
+#define R_ARM_GEN_TIMER_MAX (R_BASE_FREQUENCY_ID_REGISTER + 1)
+
+typedef struct ARMGenTimer {
+    /* <private> */
+    SysBusDevice parent_obj;
+    MemoryRegion iomem;
+
+    /* <public> */
+    bool enabled;
+    uint64_t tick_offset;
+
+    uint32_t regs[R_ARM_GEN_TIMER_MAX];
+    RegisterInfo regs_info[R_ARM_GEN_TIMER_MAX];
+} ARMGenTimer;
+
+#endif
-- 
2.7.4