From: Hao Wu <wuhaotsh@google.com>
The PCI Mailbox Module is a high-bandwidth communcation module
between a Nuvoton BMC and CPU. It features 16KB RAM that are both
accessible by the BMC and core CPU. and supports interrupt for
both sides.
This patch implements the BMC side of the PCI mailbox module.
Communication with the core CPU is emulated via a chardev and
will be in a follow-up patch.
Change-Id: Iaca22f81c4526927d437aa367079ed038faf43f2
Signed-off-by: Hao Wu <wuhaotsh@google.com>
Signed-off-by: Nabih Estefan <nabihestefan@google.com>
Reviewed-by: Tyrone Ting <kfting@nuvoton.com>
---
hw/misc/meson.build | 1 +
hw/misc/npcm7xx_pci_mbox.c | 333 +++++++++++++++++++++++++++++
hw/misc/trace-events | 5 +
include/hw/misc/npcm7xx_pci_mbox.h | 81 +++++++
4 files changed, 420 insertions(+)
create mode 100644 hw/misc/npcm7xx_pci_mbox.c
create mode 100644 include/hw/misc/npcm7xx_pci_mbox.h
diff --git a/hw/misc/meson.build b/hw/misc/meson.build
index 36c20d5637..0ead2e9ede 100644
--- a/hw/misc/meson.build
+++ b/hw/misc/meson.build
@@ -73,6 +73,7 @@ system_ss.add(when: 'CONFIG_NPCM7XX', if_true: files(
'npcm7xx_clk.c',
'npcm7xx_gcr.c',
'npcm7xx_mft.c',
+ 'npcm7xx_pci_mbox.c',
'npcm7xx_pwm.c',
'npcm7xx_rng.c',
))
diff --git a/hw/misc/npcm7xx_pci_mbox.c b/hw/misc/npcm7xx_pci_mbox.c
new file mode 100644
index 0000000000..cf56311514
--- /dev/null
+++ b/hw/misc/npcm7xx_pci_mbox.c
@@ -0,0 +1,333 @@
+/*
+ * Nuvoton NPCM7xx PCI Mailbox Module
+ *
+ * Copyright 2024 Google LLC
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#include "qemu/osdep.h"
+#include "chardev/char-fe.h"
+#include "hw/irq.h"
+#include "hw/qdev-clock.h"
+#include "hw/qdev-properties-system.h"
+#include "hw/misc/npcm7xx_pci_mbox.h"
+#include "hw/registerfields.h"
+#include "migration/vmstate.h"
+#include "qapi/error.h"
+#include "qapi/visitor.h"
+#include "qemu/bitops.h"
+#include "qemu/error-report.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+#include "qemu/timer.h"
+#include "qemu/units.h"
+#include "trace.h"
+
+REG32(NPCM7XX_PCI_MBOX_BMBXSTAT, 0x00);
+REG32(NPCM7XX_PCI_MBOX_BMBXCTL, 0x04);
+REG32(NPCM7XX_PCI_MBOX_BMBXCMD, 0x08);
+
+enum NPCM7xxPCIMBoxOperation {
+ NPCM7XX_PCI_MBOX_OP_READ = 1,
+ NPCM7XX_PCI_MBOX_OP_WRITE,
+};
+
+#define NPCM7XX_PCI_MBOX_OFFSET_BYTES 8
+
+/* Response code */
+#define NPCM7XX_PCI_MBOX_OK 0
+#define NPCM7XX_PCI_MBOX_INVALID_OP 0xa0
+#define NPCM7XX_PCI_MBOX_INVALID_SIZE 0xa1
+#define NPCM7XX_PCI_MBOX_UNSPECIFIED_ERROR 0xff
+
+#define NPCM7XX_PCI_MBOX_NR_CI 8
+#define NPCM7XX_PCI_MBOX_CI_MASK MAKE_64BIT_MASK(0, NPCM7XX_PCI_MBOX_NR_CI)
+
+static void npcm7xx_pci_mbox_update_irq(NPCM7xxPCIMBoxState *s)
+{
+ /* We should send an interrupt when one of the CIE and CIF are both 1. */
+ if (s->regs[R_NPCM7XX_PCI_MBOX_BMBXSTAT] &
+ s->regs[R_NPCM7XX_PCI_MBOX_BMBXCTL] &
+ NPCM7XX_PCI_MBOX_CI_MASK) {
+ qemu_irq_raise(s->irq);
+ trace_npcm7xx_pci_mbox_irq(1);
+ } else {
+ qemu_irq_lower(s->irq);
+ trace_npcm7xx_pci_mbox_irq(0);
+ }
+}
+
+static void npcm7xx_pci_mbox_send_response(NPCM7xxPCIMBoxState *s, uint8_t code)
+{
+ qemu_chr_fe_write(&s->chr, &code, 1);
+ if (code == NPCM7XX_PCI_MBOX_OK && s->op == NPCM7XX_PCI_MBOX_OP_READ) {
+ qemu_chr_fe_write(&s->chr, (uint8_t *)(&s->data), s->size);
+ }
+}
+
+static void npcm7xx_pci_mbox_handle_read(NPCM7xxPCIMBoxState *s)
+{
+ uint8_t offset_bytes[4];
+ MemTxResult r = memory_region_dispatch_read(
+ &s->ram, s->offset, &s->data, MO_LE | size_memop(s->size),
+ MEMTXATTRS_UNSPECIFIED);
+
+ stl_le_p(offset_bytes, r);
+ npcm7xx_pci_mbox_send_response(s, offset_bytes[0]);
+}
+
+static void npcm7xx_pci_mbox_handle_write(NPCM7xxPCIMBoxState *s)
+{
+ uint8_t offset_bytes[4];
+ MemTxResult r = memory_region_dispatch_write(
+ &s->ram, s->offset, s->data, MO_LE | size_memop(s->size),
+ MEMTXATTRS_UNSPECIFIED);
+
+ stl_le_p(offset_bytes, r);
+ npcm7xx_pci_mbox_send_response(s, offset_bytes[0]);
+}
+
+// The device is using a Little Endian Protocol.
+// If running into errors, please check what protocol is being expected.
+static void npcm7xx_pci_mbox_receive_char(NPCM7xxPCIMBoxState *s, uint8_t byte)
+{
+ switch (s->state) {
+ case NPCM7XX_PCI_MBOX_STATE_IDLE:
+ switch (byte) {
+ case NPCM7XX_PCI_MBOX_OP_READ:
+ case NPCM7XX_PCI_MBOX_OP_WRITE:
+ s->op = byte;
+ s->state = NPCM7XX_PCI_MBOX_STATE_OFFSET;
+ s->offset = 0;
+ s->receive_count = 0;
+ break;
+
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "received invalid op type: 0x%" PRIx8, byte);
+ npcm7xx_pci_mbox_send_response(s, NPCM7XX_PCI_MBOX_INVALID_OP);
+ break;
+ }
+ break;
+
+ case NPCM7XX_PCI_MBOX_STATE_OFFSET:
+ s->offset += (uint64_t)byte << (s->receive_count * BITS_PER_BYTE);
+ if (++s->receive_count >= NPCM7XX_PCI_MBOX_OFFSET_BYTES) {
+ s->state = NPCM7XX_PCI_MBOX_STATE_SIZE;
+ }
+ break;
+
+ case NPCM7XX_PCI_MBOX_STATE_SIZE:
+ s->size = byte;
+ if (s->size < 1 || s->size > sizeof(uint64_t)) {
+ qemu_log_mask(LOG_GUEST_ERROR, "received invalid size: %u", byte);
+ npcm7xx_pci_mbox_send_response(s, NPCM7XX_PCI_MBOX_INVALID_SIZE);
+ s->state = NPCM7XX_PCI_MBOX_STATE_IDLE;
+ break;
+ }
+ if (s->op == NPCM7XX_PCI_MBOX_OP_READ) {
+ npcm7xx_pci_mbox_handle_read(s);
+ s->state = NPCM7XX_PCI_MBOX_STATE_IDLE;
+ } else {
+ s->receive_count = 0;
+ s->data = 0;
+ s->state = NPCM7XX_PCI_MBOX_STATE_DATA;
+ }
+ break;
+
+ case NPCM7XX_PCI_MBOX_STATE_DATA:
+ g_assert(s->op == NPCM7XX_PCI_MBOX_OP_WRITE);
+ s->data += (uint64_t)byte << (s->receive_count * BITS_PER_BYTE);
+ if (++s->receive_count >= s->size) {
+ npcm7xx_pci_mbox_handle_write(s);
+ s->state = NPCM7XX_PCI_MBOX_STATE_IDLE;
+ }
+ break;
+
+ default:
+ g_assert_not_reached();
+ }
+}
+
+static uint64_t npcm7xx_pci_mbox_read(void *opaque, hwaddr offset,
+ unsigned size)
+{
+ NPCM7xxPCIMBoxState *s = NPCM7XX_PCI_MBOX(opaque);
+ uint16_t value = 0;
+
+ if (offset / sizeof(uint32_t) >= NPCM7XX_PCI_MBOX_NR_REGS) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: offset 0x%04" HWADDR_PRIx " out of range\n",
+ __func__, offset);
+ return 0;
+ }
+
+ value = s->regs[offset / sizeof(uint32_t)];
+ trace_npcm7xx_pci_mbox_read(DEVICE(s)->canonical_path, offset, value, size);
+ return value;
+}
+
+static void npcm7xx_pci_mbox_write(void *opaque, hwaddr offset,
+ uint64_t v, unsigned size)
+{
+ NPCM7xxPCIMBoxState *s = NPCM7XX_PCI_MBOX(opaque);
+
+ trace_npcm7xx_pci_mbox_write(DEVICE(s)->canonical_path, offset, v, size);
+ switch (offset) {
+ case A_NPCM7XX_PCI_MBOX_BMBXSTAT:
+ /* Clear bits that are 1. */
+ s->regs[R_NPCM7XX_PCI_MBOX_BMBXSTAT] &= ~v;
+ break;
+
+ case A_NPCM7XX_PCI_MBOX_BMBXCTL:
+ s->regs[R_NPCM7XX_PCI_MBOX_BMBXCTL] = v;
+ break;
+
+ case A_NPCM7XX_PCI_MBOX_BMBXCMD:
+ /* Set the bits that are 1. */
+ s->regs[R_NPCM7XX_PCI_MBOX_BMBXCMD] |= v;
+ /* TODO: Set interrupt to host. */
+ break;
+
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: offset 0x%04" HWADDR_PRIx " out of range\n",
+ __func__, offset);
+ }
+ npcm7xx_pci_mbox_update_irq(s);
+}
+
+static const struct MemoryRegionOps npcm7xx_pci_mbox_ops = {
+ .read = npcm7xx_pci_mbox_read,
+ .write = npcm7xx_pci_mbox_write,
+ .endianness = DEVICE_LITTLE_ENDIAN,
+ .valid = {
+ .min_access_size = 4,
+ .max_access_size = 4,
+ .unaligned = false,
+ },
+};
+
+static void npcm7xx_pci_mbox_enter_reset(Object *obj, ResetType type)
+{
+ NPCM7xxPCIMBoxState *s = NPCM7XX_PCI_MBOX(obj);
+
+ memset(s->regs, 0, 4 * NPCM7XX_PCI_MBOX_NR_REGS);
+ s->state = NPCM7XX_PCI_MBOX_STATE_IDLE;
+ s->receive_count = 0;
+}
+
+static void npcm7xx_pci_mbox_hold_reset(Object *obj)
+{
+ NPCM7xxPCIMBoxState *s = NPCM7XX_PCI_MBOX(obj);
+
+ qemu_irq_lower(s->irq);
+}
+
+static int can_receive(void *opaque)
+{
+ return 1;
+}
+
+static void receive(void *opaque, const uint8_t *buf, int size)
+{
+ NPCM7xxPCIMBoxState *s = NPCM7XX_PCI_MBOX(opaque);
+ int i;
+
+ for (i = 0; i < size; ++i) {
+ npcm7xx_pci_mbox_receive_char(s, buf[i]);
+ }
+}
+
+static void chr_event(void *opaque, QEMUChrEvent event)
+{
+ switch (event) {
+ case CHR_EVENT_OPENED:
+ case CHR_EVENT_CLOSED:
+ case CHR_EVENT_BREAK:
+ case CHR_EVENT_MUX_IN:
+ case CHR_EVENT_MUX_OUT:
+ /* Ignore */
+ break;
+
+ default:
+ g_assert_not_reached();
+ }
+}
+
+static void npcm7xx_pci_mbox_init(Object *obj)
+{
+ NPCM7xxPCIMBoxState *s = NPCM7XX_PCI_MBOX(obj);
+ SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+
+ memory_region_init_ram_device_ptr(&s->ram, obj, "pci-mbox-ram",
+ NPCM7XX_PCI_MBOX_RAM_SIZE, s->content);
+ memory_region_init_io(&s->iomem, obj, &npcm7xx_pci_mbox_ops, s,
+ "pci-mbox-iomem", 4 * KiB);
+ sysbus_init_mmio(sbd, &s->ram);
+ sysbus_init_mmio(sbd, &s->iomem);
+ sysbus_init_irq(sbd, &s->irq);
+}
+
+static void npcm7xx_pci_mbox_realize(DeviceState *dev, Error **errp)
+{
+ NPCM7xxPCIMBoxState *s = NPCM7XX_PCI_MBOX(dev);
+
+ qemu_chr_fe_set_handlers(&s->chr, can_receive, receive,
+ chr_event, NULL, OBJECT(dev), NULL, true);
+}
+
+static const VMStateDescription vmstate_npcm7xx_pci_mbox = {
+ .name = "npcm7xx-pci-mbox-module",
+ .version_id = 0,
+ .minimum_version_id = 0,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT32_ARRAY(regs, NPCM7xxPCIMBoxState,
+ NPCM7XX_PCI_MBOX_NR_REGS),
+ VMSTATE_END_OF_LIST(),
+ },
+};
+
+// The chardev device is expected to run using Little Endian protocol
+// All requests and responses should be expected to be in LE, and if
+// not should be translated into LE to assure proper working of the device.
+static Property npcm7xx_pci_mbox_properties[] = {
+ DEFINE_PROP_CHR("chardev", NPCM7xxPCIMBoxState, chr),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void npcm7xx_pci_mbox_class_init(ObjectClass *klass, void *data)
+{
+ ResettableClass *rc = RESETTABLE_CLASS(klass);
+ DeviceClass *dc = DEVICE_CLASS(klass);
+
+ dc->desc = "NPCM7xx PCI Mailbox Controller";
+ dc->vmsd = &vmstate_npcm7xx_pci_mbox;
+ dc->realize = npcm7xx_pci_mbox_realize;
+ rc->phases.enter = npcm7xx_pci_mbox_enter_reset;
+ rc->phases.hold = npcm7xx_pci_mbox_hold_reset;
+ device_class_set_props(dc, npcm7xx_pci_mbox_properties);
+}
+
+static const TypeInfo npcm7xx_pci_mbox_info = {
+ .name = TYPE_NPCM7XX_PCI_MBOX,
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(NPCM7xxPCIMBoxState),
+ .class_init = npcm7xx_pci_mbox_class_init,
+ .instance_init = npcm7xx_pci_mbox_init,
+};
+
+static void npcm7xx_pci_mbox_register_type(void)
+{
+ type_register_static(&npcm7xx_pci_mbox_info);
+}
+type_init(npcm7xx_pci_mbox_register_type);
diff --git a/hw/misc/trace-events b/hw/misc/trace-events
index 85725506bf..72e72210cb 100644
--- a/hw/misc/trace-events
+++ b/hw/misc/trace-events
@@ -152,6 +152,11 @@ npcm7xx_pwm_write(const char *id, uint64_t offset, uint32_t value) "%s offset: 0
npcm7xx_pwm_update_freq(const char *id, uint8_t index, uint32_t old_value, uint32_t new_value) "%s pwm[%u] Update Freq: old_freq: %u, new_freq: %u"
npcm7xx_pwm_update_duty(const char *id, uint8_t index, uint32_t old_value, uint32_t new_value) "%s pwm[%u] Update Duty: old_duty: %u, new_duty: %u"
+# npcm7xx_pci_mbox.c
+npcm7xx_pci_mbox_read(const char *id, uint64_t offset, uint64_t value, unsigned size) "%s offset: 0x%04" PRIx64 " value: 0x%02" PRIx64 " size: %u"
+npcm7xx_pci_mbox_write(const char *id, uint64_t offset, uint64_t value, unsigned size) "%s offset: 0x%04" PRIx64 " value: 0x%02" PRIx64 " size: %u"
+npcm7xx_pci_mbox_irq(int irq_level) "irq level: %d"
+
# stm32f4xx_syscfg.c
stm32f4xx_syscfg_set_irq(int gpio, int line, int level) "Interrupt: GPIO: %d, Line: %d; Level: %d"
stm32f4xx_pulse_exti(int irq) "Pulse EXTI: %d"
diff --git a/include/hw/misc/npcm7xx_pci_mbox.h b/include/hw/misc/npcm7xx_pci_mbox.h
new file mode 100644
index 0000000000..e595fbcc70
--- /dev/null
+++ b/include/hw/misc/npcm7xx_pci_mbox.h
@@ -0,0 +1,81 @@
+/*
+ * Nuvoton NPCM7xx PCI Mailbox Module
+ *
+ * Copyright 2021 Google LLC
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+#ifndef NPCM7XX_PCI_MBOX_H
+#define NPCM7XX_PCI_MBOX_H
+
+#include "chardev/char-fe.h"
+#include "exec/memory.h"
+#include "hw/clock.h"
+#include "hw/irq.h"
+#include "hw/pci/pci.h"
+#include "hw/sysbus.h"
+#include "qom/object.h"
+
+#define NPCM7XX_PCI_MBOX_RAM_SIZE 0x4000
+
+#define NPCM7XX_PCI_VENDOR_ID 0x1050
+#define NPCM7XX_PCI_DEVICE_ID 0x0750
+#define NPCM7XX_PCI_REVISION 0
+#define NPCM7XX_PCI_CLASS_CODE 0xff
+
+typedef enum NPCM7xxPCIMBoxHostState {
+ NPCM7XX_PCI_MBOX_STATE_IDLE,
+ NPCM7XX_PCI_MBOX_STATE_OFFSET,
+ NPCM7XX_PCI_MBOX_STATE_SIZE,
+ NPCM7XX_PCI_MBOX_STATE_DATA,
+} NPCM7xxPCIMBoxHostState ;
+
+/*
+ * Maximum amount of control registers in PCI Mailbox module. Do not increase
+ * this value without bumping vm version.
+ */
+#define NPCM7XX_PCI_MBOX_NR_REGS 3
+
+/**
+ * struct NPCM7xxPciMboxState - PCI Mailbox Device
+ * @parent: System bus device.
+ * @ram: the mailbox RAM memory space
+ * @iomem: Memory region through which registers are accessed.
+ * @content: The content of the PCI mailbox, initialized to 0.
+ * @regs: The MMIO registers.
+ * @chr: The chardev backend used to communicate with core CPU.
+ * @offset: The offset to start transfer.
+ */
+typedef struct NPCM7xxPCIMBoxState {
+ SysBusDevice parent;
+
+ MemoryRegion ram;
+ MemoryRegion iomem;
+
+ qemu_irq irq;
+ uint8_t content[NPCM7XX_PCI_MBOX_RAM_SIZE];
+ uint32_t regs[NPCM7XX_PCI_MBOX_NR_REGS];
+ CharBackend chr;
+
+ /* aux data for receiving host commands. */
+ NPCM7xxPCIMBoxHostState state;
+ uint8_t op;
+ hwaddr offset;
+ uint8_t size;
+ uint64_t data;
+ int receive_count;
+} NPCM7xxPCIMBoxState;
+
+#define TYPE_NPCM7XX_PCI_MBOX "npcm7xx-pci-mbox"
+#define NPCM7XX_PCI_MBOX(obj) \
+ OBJECT_CHECK(NPCM7xxPCIMBoxState, (obj), TYPE_NPCM7XX_PCI_MBOX)
+
+#endif /* NPCM7XX_PCI_MBOX_H */
--
2.43.0.429.g432eaa2c6b-googOn Mon, 22 Jan 2024 at 17:37, Nabih Estefan <nabihestefan@google.com> wrote: > > From: Hao Wu <wuhaotsh@google.com> > > The PCI Mailbox Module is a high-bandwidth communcation module > between a Nuvoton BMC and CPU. It features 16KB RAM that are both > accessible by the BMC and core CPU. and supports interrupt for > both sides. > > This patch implements the BMC side of the PCI mailbox module. > Communication with the core CPU is emulated via a chardev and > will be in a follow-up patch. > +// The device is using a Little Endian Protocol. > +// If running into errors, please check what protocol is being expected. (1) This is not the right format for a comment in our coding style. (2) This is not sufficient to count as protocol documentation. The protocol should be documented in enough detail that I could, by reading *only the comment and not the code at all*, implement something that connects to the chardev and talks to the device. thanks -- PMM
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