[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v2 6/7] hw/net/stellaris_enet: Get rid of rx_fif
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [PATCH v2 6/7] hw/net/stellaris_enet: Get rid of rx_fifo pointer |
Date: |
Wed, 2 Apr 2014 17:19:01 +0100 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
* Peter Maydell (address@hidden) wrote:
> The rx_fifo pointer is awkward to migrate, and is actually
> redundant since it is always possible to determine it from
> the current rx[].len/.data and rx_fifo_len. Remove both
> rx_fifo and rx_fifo_len from the state, replacing them with
> a simple rx_fifo_offset which points at the current location
> in the RX fifo.
>
> Signed-off-by: Peter Maydell <address@hidden>
> ---
> hw/net/stellaris_enet.c | 42 ++++++++++++++++++++----------------------
> 1 file changed, 20 insertions(+), 22 deletions(-)
>
> diff --git a/hw/net/stellaris_enet.c b/hw/net/stellaris_enet.c
> index e818b9d..af1c3ef 100644
> --- a/hw/net/stellaris_enet.c
> +++ b/hw/net/stellaris_enet.c
> @@ -67,8 +67,7 @@ typedef struct {
> uint8_t data[2048];
> int len;
> } rx[31];
> - uint8_t *rx_fifo;
> - int rx_fifo_len;
> + int rx_fifo_offset;
> int next_packet;
> NICState *nic;
> NICConf conf;
> @@ -216,21 +215,21 @@ static uint64_t stellaris_enet_read(void *opaque,
> hwaddr offset,
> case 0x0c: /* TCTL */
> return s->tctl;
> case 0x10: /* DATA */
> - if (s->rx_fifo_len == 0) {
> - if (s->np == 0) {
> - BADF("RX underflow\n");
> - return 0;
> - }
> - s->rx_fifo_len = s->rx[s->next_packet].len;
> - s->rx_fifo = s->rx[s->next_packet].data;
> - DPRINTF("RX FIFO start packet len=%d\n", s->rx_fifo_len);
> + {
> + uint8_t *rx_fifo;
> +
> + if (s->np == 0) {
> + BADF("RX underflow\n");
> + return 0;
> }
> - val = s->rx_fifo[0] | (s->rx_fifo[1] << 8) | (s->rx_fifo[2] << 16)
> - | (s->rx_fifo[3] << 24);
> - s->rx_fifo += 4;
> - s->rx_fifo_len -= 4;
> - if (s->rx_fifo_len <= 0) {
> - s->rx_fifo_len = 0;
> +
> + rx_fifo = s->rx[s->next_packet].data + s->rx_fifo_offset;
> +
> + val = rx_fifo[0] | (rx_fifo[1] << 8) | (rx_fifo[2] << 16)
> + | (rx_fifo[3] << 24);
> + s->rx_fifo_offset += 4;
> + if (s->rx_fifo_offset >= s->rx[s->next_packet].len) {
> + s->rx_fifo_offset = 0;
> s->next_packet++;
> if (s->next_packet >= 31)
> s->next_packet = 0;
> @@ -238,6 +237,7 @@ static uint64_t stellaris_enet_read(void *opaque, hwaddr
> offset,
> DPRINTF("RX done np=%d\n", s->np);
> }
> return val;
> + }
> case 0x14: /* IA0 */
> return s->conf.macaddr.a[0] | (s->conf.macaddr.a[1] << 8)
> | (s->conf.macaddr.a[2] << 16)
> @@ -291,8 +291,8 @@ static void stellaris_enet_write(void *opaque, hwaddr
> offset,
> case 0x08: /* RCTL */
> s->rctl = value;
> if (value & SE_RCTL_RSTFIFO) {
> - s->rx_fifo_len = 0;
> s->np = 0;
> + s->rx_fifo_offset = 0;
> stellaris_enet_update(s);
> }
> break;
> @@ -402,8 +402,7 @@ static void stellaris_enet_save(QEMUFile *f, void *opaque)
>
> }
> qemu_put_be32(f, s->next_packet);
> - qemu_put_be32(f, s->rx_fifo - s->rx[s->next_packet].data);
> - qemu_put_be32(f, s->rx_fifo_len);
> + qemu_put_be32(f, s->rx_fifo_offset);
> }
>
> static int stellaris_enet_load(QEMUFile *f, void *opaque, int version_id)
> @@ -432,8 +431,7 @@ static int stellaris_enet_load(QEMUFile *f, void *opaque,
> int version_id)
>
> }
> s->next_packet = qemu_get_be32(f);
> - s->rx_fifo = s->rx[s->next_packet].data + qemu_get_be32(f);
> - s->rx_fifo_len = qemu_get_be32(f);
> + s->rx_fifo_offset = qemu_get_be32(f);
Hmm, yes with the proviso that this of course is still as insecure as the
original,
but you're about to fix that.
> return 0;
> }
> @@ -469,7 +467,7 @@ static int stellaris_enet_init(SysBusDevice *sbd)
> qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
>
> stellaris_enet_reset(s);
> - register_savevm(dev, "stellaris_enet", -1, 2,
> + register_savevm(dev, "stellaris_enet", -1, 3,
> stellaris_enet_save, stellaris_enet_load, s);
> return 0;
> }
Same comment as the tx patch, need to change the matching value in the _load(
However, now that you've got the VMState conversion in there I think it's
perfectly
reasonable to skip these version inc's; it doesn't seem to make sense to inc a
version by 3 in one small patchset.
Reviewed-by: Dr. David Alan Gilbert <address@hidden>
> --
> 1.9.0
>
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
- [Qemu-devel] [PATCH v2 0/7] stellaris_enet: overhaul tx/rx, convert to vmstate, Peter Maydell, 2014/04/01
- [Qemu-devel] [PATCH v2 7/7] hw/net/stellaris_enet: Convert to vmstate, Peter Maydell, 2014/04/01
- [Qemu-devel] [PATCH v2 4/7] hw/net/stellaris_enet: Correctly implement the TR and THR registers, Peter Maydell, 2014/04/01
- [Qemu-devel] [PATCH v2 3/7] hw/net/stellaris_enet: Rewrite tx fifo handling code, Peter Maydell, 2014/04/01
- [Qemu-devel] [PATCH v2 6/7] hw/net/stellaris_enet: Get rid of rx_fifo pointer, Peter Maydell, 2014/04/01
- Re: [Qemu-devel] [PATCH v2 6/7] hw/net/stellaris_enet: Get rid of rx_fifo pointer,
Dr. David Alan Gilbert <=
- [Qemu-devel] [PATCH v2 1/7] hw/net/stellaris_enet: Restructure tx_fifo code to avoid buffer overrun, Peter Maydell, 2014/04/01
- [Qemu-devel] [PATCH v2 5/7] hw/net/stellaris_enet: Fix debug format strings, Peter Maydell, 2014/04/01
- [Qemu-devel] [PATCH v2 2/7] hw/net/stellaris_enet: Correct handling of packet padding, Peter Maydell, 2014/04/01
- Re: [Qemu-devel] [PATCH v2 0/7] stellaris_enet: overhaul tx/rx, convert to vmstate, Michael S. Tsirkin, 2014/04/28