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Re: [Qemu-arm] [PATCH v4 1/8] bcm2835_mbox: add BCM2835 mailboxes
From: |
Peter Crosthwaite |
Subject: |
Re: [Qemu-arm] [PATCH v4 1/8] bcm2835_mbox: add BCM2835 mailboxes |
Date: |
Mon, 25 Jan 2016 21:54:35 -0800 |
On Fri, Jan 15, 2016 at 3:58 PM, Andrew Baumann
<address@hidden> wrote:
> This adds the system mailboxes which are used to communicate with a
> number of GPU peripherals on Pi/Pi2.
>
> Signed-off-by: Andrew Baumann <address@hidden>
> ---
>
> Notes:
> v3:
> * #define register offsets
> * rename mbox_init -> mbox_reset
> * s/_/-/ in property and type names
> * avoid hw_error
> * minor style tweaks
>
> v2:
> * renamed bcm2835_sbm to bcm2835_mbox
> * dropped bcm2835_arm_control.h (needed defs moved to bcm2835_mbox.c)
> * documented use of private address space through defines in
> bcm2835_mbox_defs.h
> * remove unused fields from BCM2835Mbox
> * s/int/bool/ where appropriate
> * cleaned up logic in _update and _mbox_update_status for
> clarity/simplicity
> * added vmstate
> * misc cleanup
>
> default-configs/arm-softmmu.mak | 1 +
> hw/misc/Makefile.objs | 1 +
> hw/misc/bcm2835_mbox.c | 333
> ++++++++++++++++++++++++++++++++++++
> include/hw/misc/bcm2835_mbox.h | 37 ++++
> include/hw/misc/bcm2835_mbox_defs.h | 27 +++
> 5 files changed, 399 insertions(+)
> create mode 100644 hw/misc/bcm2835_mbox.c
> create mode 100644 include/hw/misc/bcm2835_mbox.h
> create mode 100644 include/hw/misc/bcm2835_mbox_defs.h
>
> diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak
> index d9b90a5..a9f82a1 100644
> --- a/default-configs/arm-softmmu.mak
> +++ b/default-configs/arm-softmmu.mak
> @@ -79,6 +79,7 @@ CONFIG_TUSB6010=y
> CONFIG_IMX=y
> CONFIG_MAINSTONE=y
> CONFIG_NSERIES=y
> +CONFIG_RASPI=y
> CONFIG_REALVIEW=y
> CONFIG_ZAURUS=y
> CONFIG_ZYNQ=y
> diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
> index d4765c2..d0ea105 100644
> --- a/hw/misc/Makefile.objs
> +++ b/hw/misc/Makefile.objs
> @@ -36,6 +36,7 @@ obj-$(CONFIG_OMAP) += omap_gpmc.o
> obj-$(CONFIG_OMAP) += omap_l4.o
> obj-$(CONFIG_OMAP) += omap_sdrc.o
> obj-$(CONFIG_OMAP) += omap_tap.o
> +obj-$(CONFIG_RASPI) += bcm2835_mbox.o
> obj-$(CONFIG_SLAVIO) += slavio_misc.o
> obj-$(CONFIG_ZYNQ) += zynq_slcr.o
> obj-$(CONFIG_ZYNQ) += zynq-xadc.o
> diff --git a/hw/misc/bcm2835_mbox.c b/hw/misc/bcm2835_mbox.c
> new file mode 100644
> index 0000000..167bf59
> --- /dev/null
> +++ b/hw/misc/bcm2835_mbox.c
> @@ -0,0 +1,333 @@
> +/*
> + * Raspberry Pi emulation (c) 2012 Gregory Estrade
> + * This code is licensed under the GNU GPLv2 and later.
> + *
> + * This file models the system mailboxes, which are used for
> + * communication with low-bandwidth GPU peripherals. Refs:
> + * https://github.com/raspberrypi/firmware/wiki/Mailboxes
> + * https://github.com/raspberrypi/firmware/wiki/Accessing-mailboxes
> + */
> +
> +#include "hw/misc/bcm2835_mbox.h"
> +
> +#define MAIL0_PEEK 0x90
> +#define MAIL0_SENDER 0x94
> +#define MAIL1_STATUS 0xb8
> +
> +/* Mailbox status register */
> +#define MAIL0_STATUS 0x98
> +#define ARM_MS_FULL 0x80000000
> +#define ARM_MS_EMPTY 0x40000000
> +#define ARM_MS_LEVEL 0x400000FF /* Max. value depends on mailbox depth
> */
> +
> +/* MAILBOX config/status register */
> +#define MAIL0_CONFIG 0x9c
> +/* ANY write to this register clears the error bits! */
> +#define ARM_MC_IHAVEDATAIRQEN 0x00000001 /* mbox irq enable: has data */
> +#define ARM_MC_IHAVESPACEIRQEN 0x00000002 /* mbox irq enable: has space */
> +#define ARM_MC_OPPISEMPTYIRQEN 0x00000004 /* mbox irq enable: Opp is empty
> */
> +#define ARM_MC_MAIL_CLEAR 0x00000008 /* mbox clear write 1, then 0 */
> +#define ARM_MC_IHAVEDATAIRQPEND 0x00000010 /* mbox irq pending: has space
> */
> +#define ARM_MC_IHAVESPACEIRQPEND 0x00000020 /* mbox irq pending: Opp is
> empty */
> +#define ARM_MC_OPPISEMPTYIRQPEND 0x00000040 /* mbox irq pending */
> +/* Bit 7 is unused */
> +#define ARM_MC_ERRNOOWN 0x00000100 /* error : none owner read from mailbox
> */
> +#define ARM_MC_ERROVERFLW 0x00000200 /* error : write to fill mailbox */
> +#define ARM_MC_ERRUNDRFLW 0x00000400 /* error : read from empty mailbox */
> +
> +static void mbox_update_status(BCM2835Mbox *mb)
> +{
> + mb->status &= ~(ARM_MS_EMPTY | ARM_MS_FULL);
> + if (mb->count == 0) {
> + mb->status |= ARM_MS_EMPTY;
> + } else if (mb->count == MBOX_SIZE) {
> + mb->status |= ARM_MS_FULL;
> + }
> +}
> +
> +static void mbox_reset(BCM2835Mbox *mb)
> +{
> + int n;
> +
> + mb->count = 0;
> + mb->config = 0;
> + for (n = 0; n < MBOX_SIZE; n++) {
> + mb->reg[n] = MBOX_INVALID_DATA;
> + }
> + mbox_update_status(mb);
> +}
> +
> +static uint32_t mbox_pull(BCM2835Mbox *mb, int index)
> +{
> + int n;
> + uint32_t val;
> +
> + assert(mb->count > 0);
> + assert(index < mb->count);
> +
> + val = mb->reg[index];
> + for (n = index + 1; n < mb->count; n++) {
> + mb->reg[n - 1] = mb->reg[n];
> + }
> + mb->count--;
> + mb->reg[mb->count] = MBOX_INVALID_DATA;
> +
> + mbox_update_status(mb);
> +
> + return val;
> +}
> +
> +static void mbox_push(BCM2835Mbox *mb, uint32_t val)
> +{
> + assert(mb->count < MBOX_SIZE);
> + mb->reg[mb->count++] = val;
> + mbox_update_status(mb);
> +}
> +
> +static void bcm2835_mbox_update(BCM2835MboxState *s)
> +{
> + uint32_t value;
> + bool set;
> + int n;
> +
> + s->mbox_irq_disabled = true;
> +
> + /* Get pending responses and put them in the vc->arm mbox,
> + * as long as it's not full */
newline before */
(sorry I missed your clarification question on this earlier)
> + for (n = 0; n < MBOX_CHAN_COUNT; n++) {
> + while (s->available[n] && !(s->mbox[0].status & ARM_MS_FULL)) {
> + value = ldl_phys(&s->mbox_as, n << MBOX_AS_CHAN_SHIFT);
> + assert(value != MBOX_INVALID_DATA); /* Pending interrupt but no
> data */
> + mbox_push(&s->mbox[0], value);
> + }
> + }
> +
> + /* Try to push pending requests from the arm->vc mbox */
> + /* TODO (?) */
same.
> +
> + /* Re-enable calls from the IRQ routine */
> + s->mbox_irq_disabled = false;
> +
> + /* Update ARM IRQ status */
> + set = false;
> + s->mbox[0].config &= ~ARM_MC_IHAVEDATAIRQPEND;
> + if (!(s->mbox[0].status & ARM_MS_EMPTY)) {
> + s->mbox[0].config |= ARM_MC_IHAVEDATAIRQPEND;
> + if (s->mbox[0].config & ARM_MC_IHAVEDATAIRQEN) {
> + set = true;
> + }
> + }
> + qemu_set_irq(s->arm_irq, set);
> +}
> +
> +static void bcm2835_mbox_set_irq(void *opaque, int irq, int level)
> +{
> + BCM2835MboxState *s = opaque;
> +
> + s->available[irq] = level;
> +
> + /* avoid recursively calling bcm2835_mbox_update when the interrupt
> + * status changes due to the ldl_phys call within that function
> + */
> + if (!s->mbox_irq_disabled) {
> + bcm2835_mbox_update(s);
> + }
> +}
> +
> +static uint64_t bcm2835_mbox_read(void *opaque, hwaddr offset, unsigned size)
> +{
> + BCM2835MboxState *s = opaque;
> + uint32_t res = 0;
> +
> + offset &= 0xff;
> +
> + switch (offset) {
> + case 0x80 ... 0x8c: /* MAIL0_READ */
> + if (s->mbox[0].status & ARM_MS_EMPTY) {
> + res = MBOX_INVALID_DATA;
> + } else {
> + res = mbox_pull(&s->mbox[0], 0);
> + }
> + break;
> +
> + case MAIL0_PEEK:
> + res = s->mbox[0].reg[0];
> + break;
> +
> + case MAIL0_SENDER:
> + break;
> +
> + case MAIL0_STATUS:
> + res = s->mbox[0].status;
> + break;
> +
> + case MAIL0_CONFIG:
> + res = s->mbox[0].config;
> + break;
> +
> + case MAIL1_STATUS:
> + res = s->mbox[1].status;
> + break;
> +
> + default:
> + qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
> + __func__, offset);
> + return 0;
> + }
> +
> + bcm2835_mbox_update(s);
> +
> + return res;
> +}
> +
> +static void bcm2835_mbox_write(void *opaque, hwaddr offset,
> + uint64_t value, unsigned size)
> +{
> + BCM2835MboxState *s = opaque;
> + hwaddr childaddr;
> + uint8_t ch;
> +
> + offset &= 0xff;
> +
> + switch (offset) {
> + case MAIL0_SENDER:
> + break;
> +
> + case MAIL0_CONFIG:
> + s->mbox[0].config &= ~ARM_MC_IHAVEDATAIRQEN;
> + s->mbox[0].config |= value & ARM_MC_IHAVEDATAIRQEN;
> + break;
> +
> + case 0xa0 ... 0xac: /* MAIL1_WRITE */
> + if (s->mbox[1].status & ARM_MS_FULL) {
> + /* Mailbox full */
> + qemu_log_mask(LOG_GUEST_ERROR, "%s: mailbox full\n", __func__);
> + } else {
> + ch = value & 0xf;
> + if (ch < MBOX_CHAN_COUNT) {
> + childaddr = ch << MBOX_AS_CHAN_SHIFT;
> + if (ldl_phys(&s->mbox_as, childaddr + MBOX_AS_PENDING)) {
> + /* Child busy, push delayed. Push it in the arm->vc mbox
> */
> + mbox_push(&s->mbox[1], value);
> + } else {
> + /* Push it directly to the child device */
> + stl_phys(&s->mbox_as, childaddr, value);
> + }
> + } else {
> + /* Invalid channel number */
> + qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid channel %u\n",
> + __func__, ch);
> + }
> + }
> + break;
> +
> + default:
> + qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
> + __func__, offset);
> + return;
> + }
> +
> + bcm2835_mbox_update(s);
> +}
> +
> +static const MemoryRegionOps bcm2835_mbox_ops = {
> + .read = bcm2835_mbox_read,
> + .write = bcm2835_mbox_write,
> + .endianness = DEVICE_NATIVE_ENDIAN,
> + .valid.min_access_size = 4,
> + .valid.max_access_size = 4,
> +};
> +
> +/* vmstate of a single mailbox */
> +static const VMStateDescription vmstate_bcm2835_mbox_box = {
> + .name = TYPE_BCM2835_MBOX "_box",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .fields = (VMStateField[]) {
> + VMSTATE_UINT32_ARRAY(reg, BCM2835Mbox, MBOX_SIZE),
> + VMSTATE_UINT32(count, BCM2835Mbox),
> + VMSTATE_UINT32(status, BCM2835Mbox),
> + VMSTATE_UINT32(config, BCM2835Mbox),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> +/* vmstate of the entire device */
> +static const VMStateDescription vmstate_bcm2835_mbox = {
> + .name = TYPE_BCM2835_MBOX,
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .minimum_version_id_old = 1,
> + .fields = (VMStateField[]) {
> + VMSTATE_BOOL_ARRAY(available, BCM2835MboxState, MBOX_CHAN_COUNT),
> + VMSTATE_STRUCT_ARRAY(mbox, BCM2835MboxState, 2, 1,
> + vmstate_bcm2835_mbox_box, BCM2835Mbox),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> +static void bcm2835_mbox_init(Object *obj)
> +{
> + BCM2835MboxState *s = BCM2835_MBOX(obj);
> +
> + memory_region_init_io(&s->iomem, obj, &bcm2835_mbox_ops, s,
> + TYPE_BCM2835_MBOX, 0x400);
> + sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
> + sysbus_init_irq(SYS_BUS_DEVICE(s), &s->arm_irq);
> + qdev_init_gpio_in(DEVICE(s), bcm2835_mbox_set_irq, MBOX_CHAN_COUNT);
> +}
> +
> +static void bcm2835_mbox_reset(DeviceState *dev)
> +{
> + BCM2835MboxState *s = BCM2835_MBOX(dev);
> + int n;
> +
> + mbox_reset(&s->mbox[0]);
> + mbox_reset(&s->mbox[1]);
> + s->mbox_irq_disabled = false;
> + for (n = 0; n < MBOX_CHAN_COUNT; n++) {
> + s->available[n] = false;
> + }
> +}
> +
> +static void bcm2835_mbox_realize(DeviceState *dev, Error **errp)
> +{
> + BCM2835MboxState *s = BCM2835_MBOX(dev);
> + Object *obj;
> + Error *err = NULL;
> +
> + obj = object_property_get_link(OBJECT(dev), "mbox-mr", &err);
> + if (obj == NULL) {
> + error_setg(errp, "%s: required mbox-mr link not found: %s",
> + __func__, error_get_pretty(err));
> + return;
> + }
> +
> + s->mbox_mr = MEMORY_REGION(obj);
> + address_space_init(&s->mbox_as, s->mbox_mr, NULL);
> + bcm2835_mbox_reset(dev);
> +}
> +
> +static void bcm2835_mbox_class_init(ObjectClass *klass, void *data)
> +{
> + DeviceClass *dc = DEVICE_CLASS(klass);
> +
> + dc->realize = bcm2835_mbox_realize;
> + dc->reset = bcm2835_mbox_reset;
> + dc->vmsd = &vmstate_bcm2835_mbox;
> +}
> +
> +static TypeInfo bcm2835_mbox_info = {
> + .name = TYPE_BCM2835_MBOX,
> + .parent = TYPE_SYS_BUS_DEVICE,
> + .instance_size = sizeof(BCM2835MboxState),
> + .class_init = bcm2835_mbox_class_init,
> + .instance_init = bcm2835_mbox_init,
> +};
> +
> +static void bcm2835_mbox_register_types(void)
> +{
> + type_register_static(&bcm2835_mbox_info);
> +}
> +
> +type_init(bcm2835_mbox_register_types)
> diff --git a/include/hw/misc/bcm2835_mbox.h b/include/hw/misc/bcm2835_mbox.h
> new file mode 100644
> index 0000000..32ae077
> --- /dev/null
> +++ b/include/hw/misc/bcm2835_mbox.h
> @@ -0,0 +1,37 @@
> +/*
> + * Raspberry Pi emulation (c) 2012 Gregory Estrade
> + * This code is licensed under the GNU GPLv2 and later.
> + */
> +
> +#ifndef BCM2835_MBOX_H
> +#define BCM2835_MBOX_H
> +
> +#include "bcm2835_mbox_defs.h"
> +#include "hw/sysbus.h"
> +#include "exec/address-spaces.h"
> +
> +#define TYPE_BCM2835_MBOX "bcm2835-mbox"
> +#define BCM2835_MBOX(obj) \
> + OBJECT_CHECK(BCM2835MboxState, (obj), TYPE_BCM2835_MBOX)
> +
> +typedef struct {
> + uint32_t reg[MBOX_SIZE];
> + uint32_t count;
> + uint32_t status;
> + uint32_t config;
> +} BCM2835Mbox;
> +
> +typedef struct {
> + /*< private >*/
> + SysBusDevice busdev;
> + /*< public >*/
> + MemoryRegion *mbox_mr;
> + AddressSpace mbox_as;
> + MemoryRegion iomem;
> + qemu_irq arm_irq;
A nit, but a blank line here to separate the external interfaces from
the internal state.
I haven'y rechecked the logic line-over-line this time, but it was
good last time and the stylistic comments are all addressed. So
otherwise:
Reviewed-by: Peter Crosthwaite <address@hidden>
Regards,
Peter
> + bool mbox_irq_disabled;
> + bool available[MBOX_CHAN_COUNT];
> + BCM2835Mbox mbox[2];
> +} BCM2835MboxState;
> +
> +#endif
> diff --git a/include/hw/misc/bcm2835_mbox_defs.h
> b/include/hw/misc/bcm2835_mbox_defs.h
> new file mode 100644
> index 0000000..a18e520
> --- /dev/null
> +++ b/include/hw/misc/bcm2835_mbox_defs.h
> @@ -0,0 +1,27 @@
> +/*
> + * Raspberry Pi emulation (c) 2012 Gregory Estrade
> + * This code is licensed under the GNU GPLv2 and later.
> + */
> +
> +#ifndef BCM2835_MBOX_DEFS_H
> +#define BCM2835_MBOX_DEFS_H
> +
> +/* Constants shared with the ARM identifying separate mailbox channels */
> +#define MBOX_CHAN_POWER 0 /* for use by the power management interface */
> +#define MBOX_CHAN_FB 1 /* for use by the frame buffer */
> +#define MBOX_CHAN_VCHIQ 3 /* for use by the VCHIQ interface */
> +#define MBOX_CHAN_PROPERTY 8 /* for use by the property channel */
> +#define MBOX_CHAN_COUNT 9
> +
> +#define MBOX_SIZE 32
> +#define MBOX_INVALID_DATA 0x0f
> +
> +/* Layout of the private address space used for communication between
> + * the mbox device emulation, and child devices: each channel occupies
> + * 16 bytes of address space, but only two registers are presently defined.
> + */
> +#define MBOX_AS_CHAN_SHIFT 4
> +#define MBOX_AS_DATA 0 /* request / response data (RW at offset 0) */
> +#define MBOX_AS_PENDING 4 /* pending response status (RO at offset 4) */
> +
> +#endif /* BCM2835_MBOX_DEFS_H */
> --
> 2.5.3
>
- [Qemu-arm] [PATCH v4 0/8] Raspberry Pi 2 support, Andrew Baumann, 2016/01/15
- [Qemu-arm] [PATCH v4 1/8] bcm2835_mbox: add BCM2835 mailboxes, Andrew Baumann, 2016/01/15
- Re: [Qemu-arm] [PATCH v4 1/8] bcm2835_mbox: add BCM2835 mailboxes,
Peter Crosthwaite <=
- [Qemu-arm] [PATCH v4 2/8] bcm2835_property: add bcm2835 property channel, Andrew Baumann, 2016/01/15
- [Qemu-arm] [PATCH v4 3/8] bcm2835_ic: add bcm2835 interrupt controller, Andrew Baumann, 2016/01/15
- [Qemu-arm] [PATCH v4 6/8] bcm2836: add bcm2836 soc device, Andrew Baumann, 2016/01/15
- [Qemu-arm] [PATCH v4 4/8] bcm2835_peripherals: add rollup device for bcm2835 peripherals, Andrew Baumann, 2016/01/15