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[Qemu-devel] [PATCH v3 2/4] util/fifo: Generalise for common integer wid
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From: |
Peter Crosthwaite |
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Subject: |
[Qemu-devel] [PATCH v3 2/4] util/fifo: Generalise for common integer widths |
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Date: |
Wed, 9 Apr 2014 23:42:31 -0700 |
Add support for 16, 32 and 64 bit width FIFOs. The push and pop
functions are replicated to accept all four different integer types.
The element width of the FIFO is set at creation time.
The backing storage for all element types is still uint8_t regardless of
element width so some save-load logic is needed to handle endianness
issue WRT VMSD.
Signed-off-by: Peter Crosthwaite <address@hidden>
---
changed since v2:
replicated (and glueified) the push/pop functions (Don Slutz review).
Fix "each each" typo (Beniamino review).
Done use "Case(n):" (Beniamino review).
hw/char/serial.c | 4 +-
hw/net/allwinner_emac.c | 6 +--
hw/ssi/xilinx_spi.c | 4 +-
hw/ssi/xilinx_spips.c | 4 +-
include/qemu/fifo.h | 33 ++++++++++---
util/fifo.c | 120 +++++++++++++++++++++++++++++++++++++-----------
6 files changed, 127 insertions(+), 44 deletions(-)
diff --git a/hw/char/serial.c b/hw/char/serial.c
index c7a1841..c53db13 100644
--- a/hw/char/serial.c
+++ b/hw/char/serial.c
@@ -659,8 +659,8 @@ void serial_realize_core(SerialState *s, Error **errp)
qemu_chr_add_handlers(s->chr, serial_can_receive1, serial_receive1,
serial_event, s);
- fifo_create(&s->recv_fifo, UART_FIFO_LENGTH);
- fifo_create(&s->xmit_fifo, UART_FIFO_LENGTH);
+ fifo_create(&s->recv_fifo, UART_FIFO_LENGTH, 8);
+ fifo_create(&s->xmit_fifo, UART_FIFO_LENGTH, 8);
}
void serial_exit_core(SerialState *s)
diff --git a/hw/net/allwinner_emac.c b/hw/net/allwinner_emac.c
index 860cb5e..669b54a 100644
--- a/hw/net/allwinner_emac.c
+++ b/hw/net/allwinner_emac.c
@@ -455,9 +455,9 @@ static void aw_emac_realize(DeviceState *dev, Error **errp)
object_get_typename(OBJECT(dev)), dev->id, s);
qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
- fifo_create(&s->rx_fifo, RX_FIFO_SIZE);
- fifo_create(&s->tx_fifo[0], TX_FIFO_SIZE);
- fifo_create(&s->tx_fifo[1], TX_FIFO_SIZE);
+ fifo_create(&s->rx_fifo, RX_FIFO_SIZE, 8);
+ fifo_create(&s->tx_fifo[0], TX_FIFO_SIZE, 8);
+ fifo_create(&s->tx_fifo[1], TX_FIFO_SIZE, 8);
}
static Property aw_emac_properties[] = {
diff --git a/hw/ssi/xilinx_spi.c b/hw/ssi/xilinx_spi.c
index ca19e47..017331d 100644
--- a/hw/ssi/xilinx_spi.c
+++ b/hw/ssi/xilinx_spi.c
@@ -341,8 +341,8 @@ static int xilinx_spi_init(SysBusDevice *sbd)
s->irqline = -1;
- fifo_create(&s->tx_fifo, FIFO_CAPACITY);
- fifo_create(&s->rx_fifo, FIFO_CAPACITY);
+ fifo_create(&s->tx_fifo, FIFO_CAPACITY, 8);
+ fifo_create(&s->rx_fifo, FIFO_CAPACITY, 8);
return 0;
}
diff --git a/hw/ssi/xilinx_spips.c b/hw/ssi/xilinx_spips.c
index 5633209..0777f5c 100644
--- a/hw/ssi/xilinx_spips.c
+++ b/hw/ssi/xilinx_spips.c
@@ -669,8 +669,8 @@ static void xilinx_spips_realize(DeviceState *dev, Error
**errp)
s->irqline = -1;
- fifo_create(&s->rx_fifo, xsc->rx_fifo_size);
- fifo_create(&s->tx_fifo, xsc->tx_fifo_size);
+ fifo_create(&s->rx_fifo, xsc->rx_fifo_size, 8);
+ fifo_create(&s->tx_fifo, xsc->tx_fifo_size, 8);
}
static void xilinx_qspips_realize(DeviceState *dev, Error **errp)
diff --git a/include/qemu/fifo.h b/include/qemu/fifo.h
index a704bd4..d15964d 100644
--- a/include/qemu/fifo.h
+++ b/include/qemu/fifo.h
@@ -5,8 +5,12 @@
typedef struct {
/* All fields are private */
+ int width; /* byte width of each element */
+ uint32_t capacity; /* number of elements */
+
uint8_t *data;
- uint32_t capacity;
+ uint32_t buffer_size;
+
uint32_t head;
uint32_t num;
} Fifo;
@@ -14,13 +18,14 @@ typedef struct {
/**
* fifo_create:
* @fifo: struct Fifo to initialise with new FIFO
- * @capacity: capacity of the newly created FIFO
+ * @capacity: capacity (number of elements) of the newly created FIFO
+ * @width: integer width of each element. Must be 8, 16, 32 or 64.
*
* Create a FIFO of the specified size. Clients should call fifo_destroy()
* when finished using the fifo. The FIFO is initially empty.
*/
-void fifo_create(Fifo *fifo, uint32_t capacity);
+void fifo_create(Fifo *fifo, uint32_t capacity, int width);
/**
* fifo_destroy:
@@ -33,15 +38,22 @@ void fifo_create(Fifo *fifo, uint32_t capacity);
void fifo_destroy(Fifo *fifo);
/**
- * fifo_push:
+ * fifo_pushX:
* @fifo: FIFO to push to
* @data: data value to push
*
* Push a data value to the FIFO. Behaviour is undefined if the FIFO is full.
* Clients are responsible for checking for fullness using fifo_is_full().
+ *
+ * 8, 16, 32 and 64 bit variants are available. Behaviour is undefined if a
+ * variant mismatched to the FIFO width used (e.g. you cannot use fifo_push8
+ * with a FIFO created with width == 16).
*/
void fifo_push8(Fifo *fifo, uint8_t data);
+void fifo_push16(Fifo *fifo, uint16_t data);
+void fifo_push32(Fifo *fifo, uint32_t data);
+void fifo_push64(Fifo *fifo, uint64_t data);
/**
* fifo_push_all:
@@ -54,19 +66,26 @@ void fifo_push8(Fifo *fifo, uint8_t data);
* fifo_num_free().
*/
-void fifo_push_all(Fifo *fifo, const uint8_t *data, uint32_t num);
+void fifo_push_all(Fifo *fifo, const void *data, uint32_t num);
/**
- * fifo_pop:
+ * fifo_popX:
* @fifo: fifo to pop from
*
* Pop a data value from the FIFO. Behaviour is undefined if the FIFO is empty.
* Clients are responsible for checking for emptyness using fifo_is_empty().
*
+ * 8, 16, 32 and 64 bit variants are available. Behaviour is undefined if a
+ * variant mismatched to the FIFO width is used (e.g. you cannot use fifo_pop8
+ * with a FIFO created with width == 16).
+ *
* Returns: The popped data value.
*/
uint8_t fifo_pop8(Fifo *fifo);
+uint16_t fifo_pop16(Fifo *fifo);
+uint32_t fifo_pop32(Fifo *fifo);
+uint64_t fifo_pop64(Fifo *fifo);
/**
* fifo_pop_buf:
@@ -93,7 +112,7 @@ uint8_t fifo_pop8(Fifo *fifo);
* Returns: A pointer to popped data.
*/
-const uint8_t *fifo_pop_buf(Fifo *fifo, uint32_t max, uint32_t *num);
+const void *fifo_pop_buf(Fifo *fifo, uint32_t max, uint32_t *num);
/**
* fifo_reset:
diff --git a/util/fifo.c b/util/fifo.c
index 4ee6c85..a52e920 100644
--- a/util/fifo.c
+++ b/util/fifo.c
@@ -15,9 +15,11 @@
#include "qemu-common.h"
#include "qemu/fifo.h"
-void fifo_create(Fifo *fifo, uint32_t capacity)
+void fifo_create(Fifo *fifo, uint32_t capacity, int width)
{
- fifo->data = g_new(uint8_t, capacity);
+ assert(width == 8 || width == 16 || width == 32 || width == 64);
+ fifo->width = width / 8;
+ fifo->data = g_new(uint8_t, capacity * fifo->width);
fifo->capacity = capacity;
fifo->head = 0;
fifo->num = 0;
@@ -28,16 +30,25 @@ void fifo_destroy(Fifo *fifo)
g_free(fifo->data);
}
-void fifo_push8(Fifo *fifo, uint8_t data)
-{
- if (fifo->num == fifo->capacity) {
- abort();
- }
- fifo->data[(fifo->head + fifo->num) % fifo->capacity] = data;
- fifo->num++;
+#define FIFO_PUSH_FN(n) \
+void fifo_push ## n(Fifo *fifo, uint ## n ## _t data) \
+{ \
+ uint32_t next_idx = (fifo->head + fifo->num) % fifo->capacity; \
+ \
+ assert(n == fifo->width * 8); \
+ if (fifo->num == fifo->capacity) { \
+ abort(); \
+ } \
+ ((uint ## n ## _t *)fifo->data)[next_idx] = data; \
+ fifo->num++; \
}
-void fifo_push_all(Fifo *fifo, const uint8_t *data, uint32_t num)
+FIFO_PUSH_FN(8)
+FIFO_PUSH_FN(16)
+FIFO_PUSH_FN(32)
+FIFO_PUSH_FN(64)
+
+void fifo_push_all(Fifo *fifo, const void *data, uint32_t num)
{
uint32_t start, avail;
@@ -48,38 +59,46 @@ void fifo_push_all(Fifo *fifo, const uint8_t *data,
uint32_t num)
start = (fifo->head + fifo->num) % fifo->capacity;
if (start + num <= fifo->capacity) {
- memcpy(&fifo->data[start], data, num);
+ memcpy(&fifo->data[start * fifo->width], data, num * fifo->width);
} else {
avail = fifo->capacity - start;
- memcpy(&fifo->data[start], data, avail);
- memcpy(&fifo->data[0], &data[avail], num - avail);
+ memcpy(&fifo->data[start * fifo->width], data, avail * fifo->width);
+ memcpy(&fifo->data[0], data + avail * fifo->width,
+ (num - avail) * fifo->width);
}
fifo->num += num;
}
-uint8_t fifo_pop8(Fifo *fifo)
-{
- uint8_t ret;
-
- if (fifo->num == 0) {
- abort();
- }
- ret = fifo->data[fifo->head++];
- fifo->head %= fifo->capacity;
- fifo->num--;
- return ret;
+#define FIFO_POP_FN(n) \
+uint ## n ## _t fifo_pop ## n(Fifo *fifo) \
+{ \
+ uint32_t next_idx; \
+ \
+ assert(n == fifo->width * 8); \
+ if (fifo->num == 0) { \
+ abort(); \
+ } \
+ next_idx = fifo->head++; \
+ fifo->head %= fifo->capacity; \
+ fifo->num--; \
+ return ((uint ## n ## _t *)fifo->data)[next_idx]; \
}
-const uint8_t *fifo_pop_buf(Fifo *fifo, uint32_t max, uint32_t *num)
+FIFO_POP_FN(8)
+FIFO_POP_FN(16)
+FIFO_POP_FN(32)
+FIFO_POP_FN(64)
+
+const void *fifo_pop_buf(Fifo *fifo, uint32_t max, uint32_t *num)
{
- uint8_t *ret;
+ void *ret;
if (max == 0 || max > fifo->num) {
abort();
}
*num = MIN(fifo->capacity - fifo->head, max);
- ret = &fifo->data[fifo->head];
+ ret = &fifo->data[fifo->head * fifo->width];
fifo->head += *num;
fifo->head %= fifo->capacity;
fifo->num -= *num;
@@ -112,13 +131,58 @@ uint32_t fifo_num_used(Fifo *fifo)
return fifo->num;
}
+/* Always store buffer data in little (arbitrarily chosen) endian format to
+ * allow for migration to/from BE <-> LE hosts.
+ */
+
+static inline void fifo_save_load_swap(Fifo *fifo)
+{
+#ifdef HOST_WORDS_BIGENDIAN
+ int i;
+ uint16_t *d16 = (uint16_t *)fifo->data;
+ uint32_t *d32 = (uint32_t *)fifo->data;
+ uint64_t *d64 = (uint64_t *)fifo->data;
+
+ for (i = 0; i < fifo->capacity; ++i) {
+ switch (fifo->width) {
+ case 1:
+ return;
+ case 2:
+ d16[i] = bswap16(d16[i]);
+ break;
+ case 4:
+ d32[i] = bswap32(d32[i]);
+ break;
+ case 8:
+ d64[i] = bswap64(d64[i]);
+ break;
+ default:
+ abort();
+ }
+ }
+#endif
+}
+
+static void fifo_pre_save(void *opaque)
+{
+ fifo_save_load_swap((Fifo *)opaque);
+}
+
+static int fifo_post_load(void *opaque, int version_id)
+{
+ fifo_save_load_swap((Fifo *)opaque);
+ return 0;
+}
+
const VMStateDescription vmstate_fifo = {
.name = "Fifo8",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
+ .pre_save = fifo_pre_save,
+ .post_load = fifo_post_load,
.fields = (VMStateField[]) {
- VMSTATE_VBUFFER_UINT32(data, Fifo, 1, NULL, 0, capacity),
+ VMSTATE_VBUFFER_UINT32(data, Fifo, 1, NULL, 0, buffer_size),
VMSTATE_UINT32(head, Fifo),
VMSTATE_UINT32(num, Fifo),
VMSTATE_END_OF_LIST()
--
1.9.1.1.gbb9f595