qemu/hw/dma/soc_dma.c
Philippe Mathieu-Daudé f7795e4096 misc: Replace zero-length arrays with flexible array member (automatic)
Description copied from Linux kernel commit from Gustavo A. R. Silva
(see [3]):

--v-- description start --v--

  The current codebase makes use of the zero-length array language
  extension to the C90 standard, but the preferred mechanism to
  declare variable-length types such as these ones is a flexible
  array member [1], introduced in C99:

  struct foo {
      int stuff;
      struct boo array[];
  };

  By making use of the mechanism above, we will get a compiler
  warning in case the flexible array does not occur last in the
  structure, which will help us prevent some kind of undefined
  behavior bugs from being unadvertenly introduced [2] to the
  Linux codebase from now on.

--^-- description end --^--

Do the similar housekeeping in the QEMU codebase (which uses
C99 since commit 7be41675f7).

All these instances of code were found with the help of the
following Coccinelle script:

  @@
  identifier s, m, a;
  type t, T;
  @@
   struct s {
      ...
      t m;
  -   T a[0];
  +   T a[];
  };
  @@
  identifier s, m, a;
  type t, T;
  @@
   struct s {
      ...
      t m;
  -   T a[0];
  +   T a[];
   } QEMU_PACKED;

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76497732932f
[3] https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/commit/?id=17642a2fbd2c1

Inspired-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 22:07:42 +01:00

362 lines
11 KiB
C

/*
* On-chip DMA controller framework.
*
* Copyright (C) 2008 Nokia Corporation
* Written by Andrzej Zaborowski <andrew@openedhand.com>
*
* 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 or
* (at your option) version 3 of the License.
*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "qemu/timer.h"
#include "hw/arm/soc_dma.h"
static void transfer_mem2mem(struct soc_dma_ch_s *ch)
{
memcpy(ch->paddr[0], ch->paddr[1], ch->bytes);
ch->paddr[0] += ch->bytes;
ch->paddr[1] += ch->bytes;
}
static void transfer_mem2fifo(struct soc_dma_ch_s *ch)
{
ch->io_fn[1](ch->io_opaque[1], ch->paddr[0], ch->bytes);
ch->paddr[0] += ch->bytes;
}
static void transfer_fifo2mem(struct soc_dma_ch_s *ch)
{
ch->io_fn[0](ch->io_opaque[0], ch->paddr[1], ch->bytes);
ch->paddr[1] += ch->bytes;
}
/* This is further optimisable but isn't very important because often
* DMA peripherals forbid this kind of transfers and even when they don't,
* oprating systems may not need to use them. */
static void *fifo_buf;
static int fifo_size;
static void transfer_fifo2fifo(struct soc_dma_ch_s *ch)
{
if (ch->bytes > fifo_size)
fifo_buf = g_realloc(fifo_buf, fifo_size = ch->bytes);
/* Implement as transfer_fifo2linear + transfer_linear2fifo. */
ch->io_fn[0](ch->io_opaque[0], fifo_buf, ch->bytes);
ch->io_fn[1](ch->io_opaque[1], fifo_buf, ch->bytes);
}
struct dma_s {
struct soc_dma_s soc;
int chnum;
uint64_t ch_enable_mask;
int64_t channel_freq;
int enabled_count;
struct memmap_entry_s {
enum soc_dma_port_type type;
hwaddr addr;
union {
struct {
void *opaque;
soc_dma_io_t fn;
int out;
} fifo;
struct {
void *base;
size_t size;
} mem;
} u;
} *memmap;
int memmap_size;
struct soc_dma_ch_s ch[];
};
static void soc_dma_ch_schedule(struct soc_dma_ch_s *ch, int delay_bytes)
{
int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
struct dma_s *dma = (struct dma_s *) ch->dma;
timer_mod(ch->timer, now + delay_bytes / dma->channel_freq);
}
static void soc_dma_ch_run(void *opaque)
{
struct soc_dma_ch_s *ch = (struct soc_dma_ch_s *) opaque;
ch->running = 1;
ch->dma->setup_fn(ch);
ch->transfer_fn(ch);
ch->running = 0;
if (ch->enable)
soc_dma_ch_schedule(ch, ch->bytes);
ch->bytes = 0;
}
static inline struct memmap_entry_s *soc_dma_lookup(struct dma_s *dma,
hwaddr addr)
{
struct memmap_entry_s *lo;
int hi;
lo = dma->memmap;
hi = dma->memmap_size;
while (hi > 1) {
hi /= 2;
if (lo[hi].addr <= addr)
lo += hi;
}
return lo;
}
static inline enum soc_dma_port_type soc_dma_ch_update_type(
struct soc_dma_ch_s *ch, int port)
{
struct dma_s *dma = (struct dma_s *) ch->dma;
struct memmap_entry_s *entry = soc_dma_lookup(dma, ch->vaddr[port]);
if (entry->type == soc_dma_port_fifo) {
while (entry < dma->memmap + dma->memmap_size &&
entry->u.fifo.out != port)
entry ++;
if (entry->addr != ch->vaddr[port] || entry->u.fifo.out != port)
return soc_dma_port_other;
if (ch->type[port] != soc_dma_access_const)
return soc_dma_port_other;
ch->io_fn[port] = entry->u.fifo.fn;
ch->io_opaque[port] = entry->u.fifo.opaque;
return soc_dma_port_fifo;
} else if (entry->type == soc_dma_port_mem) {
if (entry->addr > ch->vaddr[port] ||
entry->addr + entry->u.mem.size <= ch->vaddr[port])
return soc_dma_port_other;
/* TODO: support constant memory address for source port as used for
* drawing solid rectangles by PalmOS(R). */
if (ch->type[port] != soc_dma_access_const)
return soc_dma_port_other;
ch->paddr[port] = (uint8_t *) entry->u.mem.base +
(ch->vaddr[port] - entry->addr);
/* TODO: save bytes left to the end of the mapping somewhere so we
* can check we're not reading beyond it. */
return soc_dma_port_mem;
} else
return soc_dma_port_other;
}
void soc_dma_ch_update(struct soc_dma_ch_s *ch)
{
enum soc_dma_port_type src, dst;
src = soc_dma_ch_update_type(ch, 0);
if (src == soc_dma_port_other) {
ch->update = 0;
ch->transfer_fn = ch->dma->transfer_fn;
return;
}
dst = soc_dma_ch_update_type(ch, 1);
/* TODO: use src and dst as array indices. */
if (src == soc_dma_port_mem && dst == soc_dma_port_mem)
ch->transfer_fn = transfer_mem2mem;
else if (src == soc_dma_port_mem && dst == soc_dma_port_fifo)
ch->transfer_fn = transfer_mem2fifo;
else if (src == soc_dma_port_fifo && dst == soc_dma_port_mem)
ch->transfer_fn = transfer_fifo2mem;
else if (src == soc_dma_port_fifo && dst == soc_dma_port_fifo)
ch->transfer_fn = transfer_fifo2fifo;
else
ch->transfer_fn = ch->dma->transfer_fn;
ch->update = (dst != soc_dma_port_other);
}
static void soc_dma_ch_freq_update(struct dma_s *s)
{
if (s->enabled_count)
/* We completely ignore channel priorities and stuff */
s->channel_freq = s->soc.freq / s->enabled_count;
else {
/* TODO: Signal that we want to disable the functional clock and let
* the platform code decide what to do with it, i.e. check that
* auto-idle is enabled in the clock controller and if we are stopping
* the clock, do the same with any parent clocks that had only one
* user keeping them on and auto-idle enabled. */
}
}
void soc_dma_set_request(struct soc_dma_ch_s *ch, int level)
{
struct dma_s *dma = (struct dma_s *) ch->dma;
dma->enabled_count += level - ch->enable;
if (level)
dma->ch_enable_mask |= 1 << ch->num;
else
dma->ch_enable_mask &= ~(1 << ch->num);
if (level != ch->enable) {
soc_dma_ch_freq_update(dma);
ch->enable = level;
if (!ch->enable)
timer_del(ch->timer);
else if (!ch->running)
soc_dma_ch_run(ch);
else
soc_dma_ch_schedule(ch, 1);
}
}
void soc_dma_reset(struct soc_dma_s *soc)
{
struct dma_s *s = (struct dma_s *) soc;
s->soc.drqbmp = 0;
s->ch_enable_mask = 0;
s->enabled_count = 0;
soc_dma_ch_freq_update(s);
}
/* TODO: take a functional-clock argument */
struct soc_dma_s *soc_dma_init(int n)
{
int i;
struct dma_s *s = g_malloc0(sizeof(*s) + n * sizeof(*s->ch));
s->chnum = n;
s->soc.ch = s->ch;
for (i = 0; i < n; i ++) {
s->ch[i].dma = &s->soc;
s->ch[i].num = i;
s->ch[i].timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, soc_dma_ch_run, &s->ch[i]);
}
soc_dma_reset(&s->soc);
fifo_size = 0;
return &s->soc;
}
void soc_dma_port_add_fifo(struct soc_dma_s *soc, hwaddr virt_base,
soc_dma_io_t fn, void *opaque, int out)
{
struct memmap_entry_s *entry;
struct dma_s *dma = (struct dma_s *) soc;
dma->memmap = g_realloc(dma->memmap, sizeof(*entry) *
(dma->memmap_size + 1));
entry = soc_dma_lookup(dma, virt_base);
if (dma->memmap_size) {
if (entry->type == soc_dma_port_mem) {
if (entry->addr <= virt_base &&
entry->addr + entry->u.mem.size > virt_base) {
error_report("%s: FIFO at %"PRIx64
" collides with RAM region at %"PRIx64
"-%"PRIx64, __func__,
virt_base, entry->addr,
(entry->addr + entry->u.mem.size));
exit(-1);
}
if (entry->addr <= virt_base)
entry ++;
} else
while (entry < dma->memmap + dma->memmap_size &&
entry->addr <= virt_base) {
if (entry->addr == virt_base && entry->u.fifo.out == out) {
error_report("%s: FIFO at %"PRIx64
" collides FIFO at %"PRIx64,
__func__, virt_base, entry->addr);
exit(-1);
}
entry ++;
}
memmove(entry + 1, entry,
(uint8_t *) (dma->memmap + dma->memmap_size ++) -
(uint8_t *) entry);
} else
dma->memmap_size ++;
entry->addr = virt_base;
entry->type = soc_dma_port_fifo;
entry->u.fifo.fn = fn;
entry->u.fifo.opaque = opaque;
entry->u.fifo.out = out;
}
void soc_dma_port_add_mem(struct soc_dma_s *soc, uint8_t *phys_base,
hwaddr virt_base, size_t size)
{
struct memmap_entry_s *entry;
struct dma_s *dma = (struct dma_s *) soc;
dma->memmap = g_realloc(dma->memmap, sizeof(*entry) *
(dma->memmap_size + 1));
entry = soc_dma_lookup(dma, virt_base);
if (dma->memmap_size) {
if (entry->type == soc_dma_port_mem) {
if ((entry->addr >= virt_base && entry->addr < virt_base + size) ||
(entry->addr <= virt_base &&
entry->addr + entry->u.mem.size > virt_base)) {
error_report("%s: RAM at %"PRIx64 "-%"PRIx64
" collides with RAM region at %"PRIx64
"-%"PRIx64, __func__,
virt_base, virt_base + size,
entry->addr, entry->addr + entry->u.mem.size);
exit(-1);
}
if (entry->addr <= virt_base)
entry ++;
} else {
if (entry->addr >= virt_base &&
entry->addr < virt_base + size) {
error_report("%s: RAM at %"PRIx64 "-%"PRIx64
" collides with FIFO at %"PRIx64,
__func__, virt_base, virt_base + size,
entry->addr);
exit(-1);
}
while (entry < dma->memmap + dma->memmap_size &&
entry->addr <= virt_base)
entry ++;
}
memmove(entry + 1, entry,
(uint8_t *) (dma->memmap + dma->memmap_size ++) -
(uint8_t *) entry);
} else
dma->memmap_size ++;
entry->addr = virt_base;
entry->type = soc_dma_port_mem;
entry->u.mem.base = phys_base;
entry->u.mem.size = size;
}
/* TODO: port removal for ports like PCMCIA memory */