Commit 02cfe21f6a for qemu.org
commit 02cfe21f6a251df1229077af3b1c5583020a33bf
Author: Peter Maydell <peter.maydell@linaro.org>
Date: Mon Jul 20 19:05:30 2026 +0100
hw/dma/soc_dma: Remove soc_dma_port_fifo support
Our current single OMAP SoC doesn't call the soc_dma_port_add_fifo(),
soc_dma_port_add_fifo_in() or soc_dma_port_add_fifo_out() functions.
Remove them, plus the soc_dma_port_fifo handling that only those
functions needed.
The motivation for this is that it removes a lot of code that is
careless about the fact that the largest possible DMA transfer is
more bits than will fit into an "int" variable, and which does direct
accesses to host memory pointers into guest backing RAM without doing
bounds checks. Deleting this code means we don't have to audit and
update it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
Message-id: 20260710105907.2570621-2-peter.maydell@linaro.org
diff --git a/hw/dma/soc_dma.c b/hw/dma/soc_dma.c
index d5c52b804f..8ba531feea 100644
--- a/hw/dma/soc_dma.c
+++ b/hw/dma/soc_dma.c
@@ -29,33 +29,6 @@ static void transfer_mem2mem(struct soc_dma_ch_s *ch)
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;
@@ -67,11 +40,6 @@ struct dma_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;
@@ -129,20 +97,7 @@ static inline enum soc_dma_port_type soc_dma_ch_update_type(
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->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;
@@ -173,15 +128,8 @@ void soc_dma_ch_update(struct soc_dma_ch_s *ch)
}
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;
@@ -251,61 +199,10 @@ struct soc_dma_s *soc_dma_init(int n)
}
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)
{
diff --git a/include/hw/arm/soc_dma.h b/include/hw/arm/soc_dma.h
index bcdb91425a..e1d75bb3ba 100644
--- a/include/hw/arm/soc_dma.h
+++ b/include/hw/arm/soc_dma.h
@@ -25,12 +25,10 @@
struct soc_dma_s;
struct soc_dma_ch_s;
-typedef void (*soc_dma_io_t)(void *opaque, uint8_t *buf, int len);
typedef void (*soc_dma_transfer_t)(struct soc_dma_ch_s *ch);
enum soc_dma_port_type {
soc_dma_port_mem,
- soc_dma_port_fifo,
soc_dma_port_other,
};
@@ -57,8 +55,6 @@ struct soc_dma_ch_s {
hwaddr vaddr[2]; /* Updated by .transfer_fn(). */
/* Private */
void *paddr[2];
- soc_dma_io_t io_fn[2];
- void *io_opaque[2];
int running;
soc_dma_transfer_t transfer_fn;
@@ -82,33 +78,21 @@ struct soc_dma_s {
/* Call to activate or stop a DMA channel. */
void soc_dma_set_request(struct soc_dma_ch_s *ch, int level);
-/* Call after every write to one of the following fields and before
+/*
+ * Call after every write to one of the following fields and before
* calling soc_dma_set_request(ch, 1):
* ch->type[0...1],
* ch->vaddr[0...1],
* ch->paddr[0...1],
- * or after a soc_dma_port_add_fifo() or soc_dma_port_add_mem(). */
+ * or after a soc_dma_port_add_mem().
+ */
void soc_dma_ch_update(struct soc_dma_ch_s *ch);
/* The SoC should call this when the DMA module is being reset. */
void soc_dma_reset(struct soc_dma_s *s);
struct soc_dma_s *soc_dma_init(int n);
-void soc_dma_port_add_fifo(struct soc_dma_s *dma, hwaddr virt_base,
- soc_dma_io_t fn, void *opaque, int out);
void soc_dma_port_add_mem(struct soc_dma_s *dma, uint8_t *phys_base,
hwaddr virt_base, size_t size);
-static inline void soc_dma_port_add_fifo_in(struct soc_dma_s *dma,
- hwaddr virt_base, soc_dma_io_t fn, void *opaque)
-{
- return soc_dma_port_add_fifo(dma, virt_base, fn, opaque, 0);
-}
-
-static inline void soc_dma_port_add_fifo_out(struct soc_dma_s *dma,
- hwaddr virt_base, soc_dma_io_t fn, void *opaque)
-{
- return soc_dma_port_add_fifo(dma, virt_base, fn, opaque, 1);
-}
-
#endif