qemu/hw/dma/pl080.c
Markus Armbruster efec3dd631 qdev: Replace no_user by cannot_instantiate_with_device_add_yet
In an ideal world, machines can be built by wiring devices together
with configuration, not code.  Unfortunately, that's not the world we
live in right now.  We still have quite a few devices that need to be
wired up by code.  If you try to device_add such a device, it'll fail
in sometimes mysterious ways.  If you're lucky, you get an
unmysterious immediate crash.

To protect users from such badness, DeviceClass member no_user used to
make device models unavailable with -device / device_add, but that
regressed in commit 18b6dad.  The device model is still omitted from
help, but is available anyway.

Attempts to fix the regression have been rejected with the argument
that the purpose of no_user isn't clear, and it's prone to misuse.

This commit clarifies no_user's purpose.  Anthony suggested to rename
it cannot_instantiate_with_device_add_yet_due_to_internal_bugs, which
I shorten somewhat to keep checkpatch happy.  While there, make it
bool.

Every use of cannot_instantiate_with_device_add_yet gets a FIXME
comment asking for rationale.  The next few commits will clean them
all up, either by providing a rationale, or by getting rid of the use.

With that done, the regression fix is hopefully acceptable.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel.a@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2013-12-23 00:27:22 +01:00

411 lines
11 KiB
C

/*
* Arm PrimeCell PL080/PL081 DMA controller
*
* Copyright (c) 2006 CodeSourcery.
* Written by Paul Brook
*
* This code is licensed under the GPL.
*/
#include "hw/sysbus.h"
#define PL080_MAX_CHANNELS 8
#define PL080_CONF_E 0x1
#define PL080_CONF_M1 0x2
#define PL080_CONF_M2 0x4
#define PL080_CCONF_H 0x40000
#define PL080_CCONF_A 0x20000
#define PL080_CCONF_L 0x10000
#define PL080_CCONF_ITC 0x08000
#define PL080_CCONF_IE 0x04000
#define PL080_CCONF_E 0x00001
#define PL080_CCTRL_I 0x80000000
#define PL080_CCTRL_DI 0x08000000
#define PL080_CCTRL_SI 0x04000000
#define PL080_CCTRL_D 0x02000000
#define PL080_CCTRL_S 0x01000000
typedef struct {
uint32_t src;
uint32_t dest;
uint32_t lli;
uint32_t ctrl;
uint32_t conf;
} pl080_channel;
#define TYPE_PL080 "pl080"
#define PL080(obj) OBJECT_CHECK(PL080State, (obj), TYPE_PL080)
typedef struct PL080State {
SysBusDevice parent_obj;
MemoryRegion iomem;
uint8_t tc_int;
uint8_t tc_mask;
uint8_t err_int;
uint8_t err_mask;
uint32_t conf;
uint32_t sync;
uint32_t req_single;
uint32_t req_burst;
pl080_channel chan[PL080_MAX_CHANNELS];
int nchannels;
/* Flag to avoid recursive DMA invocations. */
int running;
qemu_irq irq;
} PL080State;
static const VMStateDescription vmstate_pl080_channel = {
.name = "pl080_channel",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT32(src, pl080_channel),
VMSTATE_UINT32(dest, pl080_channel),
VMSTATE_UINT32(lli, pl080_channel),
VMSTATE_UINT32(ctrl, pl080_channel),
VMSTATE_UINT32(conf, pl080_channel),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription vmstate_pl080 = {
.name = "pl080",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT8(tc_int, PL080State),
VMSTATE_UINT8(tc_mask, PL080State),
VMSTATE_UINT8(err_int, PL080State),
VMSTATE_UINT8(err_mask, PL080State),
VMSTATE_UINT32(conf, PL080State),
VMSTATE_UINT32(sync, PL080State),
VMSTATE_UINT32(req_single, PL080State),
VMSTATE_UINT32(req_burst, PL080State),
VMSTATE_UINT8(tc_int, PL080State),
VMSTATE_UINT8(tc_int, PL080State),
VMSTATE_UINT8(tc_int, PL080State),
VMSTATE_STRUCT_ARRAY(chan, PL080State, PL080_MAX_CHANNELS,
1, vmstate_pl080_channel, pl080_channel),
VMSTATE_INT32(running, PL080State),
VMSTATE_END_OF_LIST()
}
};
static const unsigned char pl080_id[] =
{ 0x80, 0x10, 0x04, 0x0a, 0x0d, 0xf0, 0x05, 0xb1 };
static const unsigned char pl081_id[] =
{ 0x81, 0x10, 0x04, 0x0a, 0x0d, 0xf0, 0x05, 0xb1 };
static void pl080_update(PL080State *s)
{
if ((s->tc_int & s->tc_mask)
|| (s->err_int & s->err_mask))
qemu_irq_raise(s->irq);
else
qemu_irq_lower(s->irq);
}
static void pl080_run(PL080State *s)
{
int c;
int flow;
pl080_channel *ch;
int swidth;
int dwidth;
int xsize;
int n;
int src_id;
int dest_id;
int size;
uint8_t buff[4];
uint32_t req;
s->tc_mask = 0;
for (c = 0; c < s->nchannels; c++) {
if (s->chan[c].conf & PL080_CCONF_ITC)
s->tc_mask |= 1 << c;
if (s->chan[c].conf & PL080_CCONF_IE)
s->err_mask |= 1 << c;
}
if ((s->conf & PL080_CONF_E) == 0)
return;
hw_error("DMA active\n");
/* If we are already in the middle of a DMA operation then indicate that
there may be new DMA requests and return immediately. */
if (s->running) {
s->running++;
return;
}
s->running = 1;
while (s->running) {
for (c = 0; c < s->nchannels; c++) {
ch = &s->chan[c];
again:
/* Test if thiws channel has any pending DMA requests. */
if ((ch->conf & (PL080_CCONF_H | PL080_CCONF_E))
!= PL080_CCONF_E)
continue;
flow = (ch->conf >> 11) & 7;
if (flow >= 4) {
hw_error(
"pl080_run: Peripheral flow control not implemented\n");
}
src_id = (ch->conf >> 1) & 0x1f;
dest_id = (ch->conf >> 6) & 0x1f;
size = ch->ctrl & 0xfff;
req = s->req_single | s->req_burst;
switch (flow) {
case 0:
break;
case 1:
if ((req & (1u << dest_id)) == 0)
size = 0;
break;
case 2:
if ((req & (1u << src_id)) == 0)
size = 0;
break;
case 3:
if ((req & (1u << src_id)) == 0
|| (req & (1u << dest_id)) == 0)
size = 0;
break;
}
if (!size)
continue;
/* Transfer one element. */
/* ??? Should transfer multiple elements for a burst request. */
/* ??? Unclear what the proper behavior is when source and
destination widths are different. */
swidth = 1 << ((ch->ctrl >> 18) & 7);
dwidth = 1 << ((ch->ctrl >> 21) & 7);
for (n = 0; n < dwidth; n+= swidth) {
cpu_physical_memory_read(ch->src, buff + n, swidth);
if (ch->ctrl & PL080_CCTRL_SI)
ch->src += swidth;
}
xsize = (dwidth < swidth) ? swidth : dwidth;
/* ??? This may pad the value incorrectly for dwidth < 32. */
for (n = 0; n < xsize; n += dwidth) {
cpu_physical_memory_write(ch->dest + n, buff + n, dwidth);
if (ch->ctrl & PL080_CCTRL_DI)
ch->dest += swidth;
}
size--;
ch->ctrl = (ch->ctrl & 0xfffff000) | size;
if (size == 0) {
/* Transfer complete. */
if (ch->lli) {
ch->src = ldl_le_phys(ch->lli);
ch->dest = ldl_le_phys(ch->lli + 4);
ch->ctrl = ldl_le_phys(ch->lli + 12);
ch->lli = ldl_le_phys(ch->lli + 8);
} else {
ch->conf &= ~PL080_CCONF_E;
}
if (ch->ctrl & PL080_CCTRL_I) {
s->tc_int |= 1 << c;
}
}
goto again;
}
if (--s->running)
s->running = 1;
}
}
static uint64_t pl080_read(void *opaque, hwaddr offset,
unsigned size)
{
PL080State *s = (PL080State *)opaque;
uint32_t i;
uint32_t mask;
if (offset >= 0xfe0 && offset < 0x1000) {
if (s->nchannels == 8) {
return pl080_id[(offset - 0xfe0) >> 2];
} else {
return pl081_id[(offset - 0xfe0) >> 2];
}
}
if (offset >= 0x100 && offset < 0x200) {
i = (offset & 0xe0) >> 5;
if (i >= s->nchannels)
goto bad_offset;
switch (offset >> 2) {
case 0: /* SrcAddr */
return s->chan[i].src;
case 1: /* DestAddr */
return s->chan[i].dest;
case 2: /* LLI */
return s->chan[i].lli;
case 3: /* Control */
return s->chan[i].ctrl;
case 4: /* Configuration */
return s->chan[i].conf;
default:
goto bad_offset;
}
}
switch (offset >> 2) {
case 0: /* IntStatus */
return (s->tc_int & s->tc_mask) | (s->err_int & s->err_mask);
case 1: /* IntTCStatus */
return (s->tc_int & s->tc_mask);
case 3: /* IntErrorStatus */
return (s->err_int & s->err_mask);
case 5: /* RawIntTCStatus */
return s->tc_int;
case 6: /* RawIntErrorStatus */
return s->err_int;
case 7: /* EnbldChns */
mask = 0;
for (i = 0; i < s->nchannels; i++) {
if (s->chan[i].conf & PL080_CCONF_E)
mask |= 1 << i;
}
return mask;
case 8: /* SoftBReq */
case 9: /* SoftSReq */
case 10: /* SoftLBReq */
case 11: /* SoftLSReq */
/* ??? Implement these. */
return 0;
case 12: /* Configuration */
return s->conf;
case 13: /* Sync */
return s->sync;
default:
bad_offset:
qemu_log_mask(LOG_GUEST_ERROR,
"pl080_read: Bad offset %x\n", (int)offset);
return 0;
}
}
static void pl080_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
PL080State *s = (PL080State *)opaque;
int i;
if (offset >= 0x100 && offset < 0x200) {
i = (offset & 0xe0) >> 5;
if (i >= s->nchannels)
goto bad_offset;
switch (offset >> 2) {
case 0: /* SrcAddr */
s->chan[i].src = value;
break;
case 1: /* DestAddr */
s->chan[i].dest = value;
break;
case 2: /* LLI */
s->chan[i].lli = value;
break;
case 3: /* Control */
s->chan[i].ctrl = value;
break;
case 4: /* Configuration */
s->chan[i].conf = value;
pl080_run(s);
break;
}
}
switch (offset >> 2) {
case 2: /* IntTCClear */
s->tc_int &= ~value;
break;
case 4: /* IntErrorClear */
s->err_int &= ~value;
break;
case 8: /* SoftBReq */
case 9: /* SoftSReq */
case 10: /* SoftLBReq */
case 11: /* SoftLSReq */
/* ??? Implement these. */
qemu_log_mask(LOG_UNIMP, "pl080_write: Soft DMA not implemented\n");
break;
case 12: /* Configuration */
s->conf = value;
if (s->conf & (PL080_CONF_M1 | PL080_CONF_M1)) {
qemu_log_mask(LOG_UNIMP,
"pl080_write: Big-endian DMA not implemented\n");
}
pl080_run(s);
break;
case 13: /* Sync */
s->sync = value;
break;
default:
bad_offset:
qemu_log_mask(LOG_GUEST_ERROR,
"pl080_write: Bad offset %x\n", (int)offset);
}
pl080_update(s);
}
static const MemoryRegionOps pl080_ops = {
.read = pl080_read,
.write = pl080_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static void pl080_init(Object *obj)
{
SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
PL080State *s = PL080(obj);
memory_region_init_io(&s->iomem, OBJECT(s), &pl080_ops, s, "pl080", 0x1000);
sysbus_init_mmio(sbd, &s->iomem);
sysbus_init_irq(sbd, &s->irq);
s->nchannels = 8;
}
static void pl081_init(Object *obj)
{
PL080State *s = PL080(obj);
s->nchannels = 2;
}
static void pl080_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
dc->vmsd = &vmstate_pl080;
}
static const TypeInfo pl080_info = {
.name = TYPE_PL080,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(PL080State),
.instance_init = pl080_init,
.class_init = pl080_class_init,
};
static const TypeInfo pl081_info = {
.name = "pl081",
.parent = TYPE_PL080,
.instance_init = pl081_init,
};
/* The PL080 and PL081 are the same except for the number of channels
they implement (8 and 2 respectively). */
static void pl080_register_types(void)
{
type_register_static(&pl080_info);
type_register_static(&pl081_info);
}
type_init(pl080_register_types)