Le 02/02/2016 17:46, Peter Maydell a écrit :
On 26 January 2016 at 21:45, Jean-Christophe Dubois <j...@tribudubois.net> 
wrote:
This controller is also present in i.MX5X devices but they are not
yet emulated by Qemu.
QEMU is all-caps.

Signed-off-by: Jean-Christophe Dubois <j...@tribudubois.net>
---
  hw/misc/Makefile.objs      |   1 +
  hw/misc/imx6_src.c         | 353 +++++++++++++++++++++++++++++++++++++++++++++
  include/hw/misc/imx6_src.h |  72 +++++++++
  3 files changed, 426 insertions(+)
  create mode 100644 hw/misc/imx6_src.c
  create mode 100644 include/hw/misc/imx6_src.h

diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index a2a8e91..6bac654 100644
--- a/hw/misc/Makefile.objs
+++ b/hw/misc/Makefile.objs
@@ -29,6 +29,7 @@ obj-$(CONFIG_IMX) += imx_ccm.o
  obj-$(CONFIG_IMX) += imx31_ccm.o
  obj-$(CONFIG_IMX) += imx25_ccm.o
  obj-$(CONFIG_IMX) += imx6_ccm.o
+obj-$(CONFIG_IMX) += imx6_src.o
  obj-$(CONFIG_MILKYMIST) += milkymist-hpdmc.o
  obj-$(CONFIG_MILKYMIST) += milkymist-pfpu.o
  obj-$(CONFIG_MAINSTONE) += mst_fpga.o
diff --git a/hw/misc/imx6_src.c b/hw/misc/imx6_src.c
new file mode 100644
index 0000000..d1be7c1
--- /dev/null
+++ b/hw/misc/imx6_src.c
@@ -0,0 +1,353 @@
+/*
+ * IMX6 System Reset Controller
+ *
+ * Copyright (c) 2015 Jean-Christophe Dubois <j...@tribudubois.net>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "hw/misc/imx6_src.h"
+#include "sysemu/sysemu.h"
+#include "qemu/bitops.h"
+
+#ifndef DEBUG_IMX6_SRC
+#define DEBUG_IMX6_SRC 0
+#endif
+
+#define DPRINTF(fmt, args...) \
+    do { \
+        if (DEBUG_IMX6_SRC) { \
+            fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX6_SRC, \
+                                             __func__, ##args); \
+        } \
+    } while (0)
+
+static char const *imx6_src_reg_name(uint32_t reg)
+{
+    static char unknown[20];
+
+    switch (reg) {
+    case SRC_SCR:
+        return "SRC_SCR";
+    case SRC_SBMR1:
+        return "SRC_SBMR1";
+    case SRC_SRSR:
+        return "SRC_SRSR";
+    case SRC_SISR:
+        return "SRC_SISR";
+    case SRC_SIMR:
+        return "SRC_SIMR";
+    case SRC_SBMR2:
+        return "SRC_SBMR2";
+    case SRC_GPR1:
+        return "SRC_GPR1";
+    case SRC_GPR2:
+        return "SRC_GPR2";
+    case SRC_GPR3:
+        return "SRC_GPR3";
+    case SRC_GPR4:
+        return "SRC_GPR4";
+    case SRC_GPR5:
+        return "SRC_GPR5";
+    case SRC_GPR6:
+        return "SRC_GPR6";
+    case SRC_GPR7:
+        return "SRC_GPR7";
+    case SRC_GPR8:
+        return "SRC_GPR8";
+    case SRC_GPR9:
+        return "SRC_GPR9";
+    case SRC_GPR10:
+        return "SRC_GPR10";
+    default:
+        sprintf(unknown, "%d ?", reg);
+        return unknown;
+    }
+}
+
+static const VMStateDescription vmstate_imx6_src = {
+    .name = TYPE_IMX6_SRC,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(regs, IMX6SRCState, SRC_MAX),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static void imx6_src_reset(DeviceState *dev)
+{
+    IMX6SRCState *s = IMX6_SRC(dev);
+
+    DPRINTF("\n");
+
+    /*
+     * We only clear the first registers as all GPR registers are preserved
+     * over resets
+     */
+    memset(s->regs, 0, SRC_GPR1 * sizeof(uint32_t));
Reset for a QEMU device means "full power cycle reset", so we should
return the state to the same as if QEMU had just been started.

Is there any way to support the warm reset then?

+
+    /* Set reset values */
+    s->regs[SRC_SCR] = 0x521;
+    s->regs[SRC_SRSR] = 0x1;
+    s->regs[SRC_SIMR] = 0x1F;
+}
+
+static CPUState *imx6_src_get_cpu_by_id(uint32_t id)
+{
+    CPUState *cpu;
+
+    DPRINTF("cpu %d\n", id);
+
+    CPU_FOREACH(cpu) {
+        ARMCPU *armcpu = ARM_CPU(cpu);
+
+        if (armcpu->mp_affinity == id) {
+            return cpu;
+        }
+    }
+
+    qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Resquesting unknown CPU %d\n",
+                  TYPE_IMX6_SRC, __func__, id);
+
+    return NULL;
+}
+
+static void imx6_src_cpu_on(uint32_t cpuid, uint32_t entry, uint32_t 
context_id)
+{
+    CPUState *target_cpu_state;
+    ARMCPU *target_cpu;
+    CPUClass *target_cpu_class;
+
+    DPRINTF("cpu %d @ 0x%08x with R0 = 0x%08x\n", cpuid, entry, context_id);
+
+    /* change to the cpu we are powering up */
+    target_cpu_state = imx6_src_get_cpu_by_id(cpuid);
+    if (!target_cpu_state) {
+        return;
+    }
+    target_cpu = ARM_CPU(target_cpu_state);
+    if (!target_cpu->powered_off) {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: CPU %d is already running\n",
+                      TYPE_IMX6_SRC, __func__, cpuid);
+        return;
+    }
+    target_cpu_class = CPU_GET_CLASS(target_cpu);
+
+    /* Initialize the cpu we are turning on */
+    cpu_reset(target_cpu_state);
+    target_cpu->powered_off = false;
+    target_cpu_state->halted = 0;
+
+    target_cpu->env.regs[0] = context_id;
+    target_cpu->env.thumb = entry & 1;
+
+    target_cpu_class->set_pc(target_cpu_state, entry);
This all looks pretty dangerous to me. Handling power-on of
another CPU needs careful thought, especially since we're moving
towards multi-threaded TCG, in which case the other CPU might
in thory be really running.

In i.MX6 (and SOC using the SRC in general) all cores (except core 0 obviously) are initialized in "powered-off" mode. Therefore they should not be running before this function is called.

Basically this code is just an adaptation of a similar code in target-arm/psci.c.

Now it might not be the right way to to things (event if it does work) and I would be thankful if you could point me in the right direction.


+}
+
+static void imx6_src_cpu_off(uint32_t cpuid)
+{
+    CPUState *target_cpu_state;
+    ARMCPU *target_cpu;
+
+    DPRINTF("cpu %d\n", cpuid);
+
+    /* change to the cpu we are powering up */
+    target_cpu_state = imx6_src_get_cpu_by_id(cpuid);
+    if (!target_cpu_state) {
+        return;
+    }
+    target_cpu = ARM_CPU(target_cpu_state);
+    if (target_cpu->powered_off) {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: CPU %d is already off\n",
+                      TYPE_IMX6_SRC, __func__, cpuid);
+        return;
+    }
+
+    target_cpu->powered_off = true;
+    target_cpu_state->halted = 1;
+    target_cpu_state->exception_index = EXCP_HLT;
+    cpu_loop_exit(target_cpu_state);
+}
+
+static void imx6_src_cpu_reset(uint32_t cpuid)
+{
+    CPUState *target_cpu_state;
+    ARMCPU *target_cpu;
+
+    DPRINTF("cpu %d\n", cpuid);
+
+    /* change to the cpu we are powering up */
+    target_cpu_state = imx6_src_get_cpu_by_id(cpuid);
+    if (!target_cpu_state) {
+        return;
+    }
+    target_cpu = ARM_CPU(target_cpu_state);
+    if (target_cpu->powered_off) {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: CPU %d is off\n",
+                      TYPE_IMX6_SRC, __func__, cpuid);
+        return;
+    }
+
+    /* Reset the cpu we are turning on */
+    cpu_reset(target_cpu_state);
+}
+
+static uint64_t imx6_src_read(void *opaque, hwaddr offset, unsigned size)
+{
+    uint32 value = 0;
+    IMX6SRCState *s = (IMX6SRCState *)opaque;
+    uint32_t index = offset >> 2;
+
+    if (index < SRC_MAX) {
+        value = s->regs[index];
+    } else {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
+                      HWADDR_PRIx "\n", TYPE_IMX6_SRC, __func__, offset);
+
+    }
+
+    DPRINTF("reg[%s] => 0x%" PRIx32 "\n", imx6_src_reg_name(index), value);
+
+    return (uint64_t)value;
+}
+
+static void imx6_src_write(void *opaque, hwaddr offset, uint64_t value,
+                           unsigned size)
+{
+    IMX6SRCState *s = (IMX6SRCState *)opaque;
+    uint32_t index = offset >> 2;
+    uint64_t change_mask;
+
+    if (index >=  SRC_MAX) {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
+                      HWADDR_PRIx "\n", TYPE_IMX6_SRC, __func__, offset);
+        return;
+    }
+
+    DPRINTF("reg[%s] <= 0x%" PRIx32 "\n", imx6_src_reg_name(index),
+            (uint32_t)value);
+
+    change_mask = s->regs[index] ^ (uint32_t)value;
+
+    switch (index) {
+    case SRC_SCR:
+        if (EXTRACT(change_mask, CORE3_ENABLE)) {
+            if (EXTRACT(value, CORE3_ENABLE)) {
+                /* CORE 3 is brought up */
+                imx6_src_cpu_on(3, s->regs[SRC_GPR7], s->regs[SRC_GPR8]);
+            } else {
+                /* CORE 3 is shut down */
+                imx6_src_cpu_off(3);
+            }
+            /* We clear the reset bits as the processor chaged state */
"changed"

+#define EXTRACT(value, name) (((value) >> name##_SHIFT) & name##_MASK)
Again, please don't create local bit-manipulation functions or macros;
use the ones in bitops.h.

thanks
-- PMM



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