Re: [PATCH v42 18/98] hw/sd/sdcard: Introduce sd_cmd_to_sendingdata and sd_generic_read_byte

[Philippe Mathieu-Daudé]

On 1/7/24 18:54, Cédric Le Goater wrote:
> On 7/1/24 6:40 PM, Philippe Mathieu-Daudé wrote:
> > On 28/6/24 09:44, Cédric Le Goater wrote:
> > > On 6/28/24 9:00 AM, Philippe Mathieu-Daudé wrote:
> > > > All commands switching from TRANSFER state to (sending)DATA
> > > > do the same: send stream of data on the DAT lines. Instead
> > > > of duplicating the same code many times, introduce 2 helpers:
> > > > - sd_cmd_to_sendingdata() on the I/O line setup the data to
> > > >    be transferred,
> > > > - sd_generic_read_byte() on the DAT lines to fetch the data.
> > > >
> > > > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> > > > ---
> > > >   hw/sd/sd.c | 39 +++++++++++++++++++++++++++++++++++++++
> > > >   1 file changed, 39 insertions(+)

> > > Shouldn't we check for buffer overrun ? sizeof(sd->data)
> >
> > OK if I squash this?
> >
> > -- >8 --
> > diff --git a/hw/sd/sd.c b/hw/sd/sd.c
> > index d292e0adb5..f2d069c2da 100644
> > --- a/hw/sd/sd.c
> > +++ b/hw/sd/sd.c
> > @@ -1123,7 +1123,7 @@ static sd_rsp_type_t 
> > sd_cmd_to_sendingdata(SDState *sd, SDRequest req,
> >       sd->data_start = start;
> >       sd->data_offset = 0;
> >       if (data) {
> > -        assert(size);
> > +        assert(size > 0 && size <= sizeof(sd->data));
> >           memcpy(sd->data, data, size);
> >       }
> > ---
>
> sure.

Great. Can I get your R-b tag? The final patch is:

-- >8 --
Author: Philippe Mathieu-Daudé <philmd@linaro.org>
Date:   Thu Jun 13 16:21:12 2024 +0200

    hw/sd/sdcard: Introduce sd_cmd_to_sendingdata and sd_generic_read_byte

    All commands switching from TRANSFER state to (sending)DATA
    do the same: send stream of data on the DAT lines. Instead
    of duplicating the same code many times, introduce 2 helpers:
    - sd_cmd_to_sendingdata() on the I/O line setup the data to
      be transferred,
    - sd_generic_read_byte() on the DAT lines to fetch the data.

    Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 18bb2f9fd8..60235d3898 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -143,4 +143,6 @@ struct SDState {
     uint32_t blk_written;
+
     uint64_t data_start;
     uint32_t data_offset;
+    size_t data_size;
     uint8_t data[512];
@@ -1080,2 +1082,25 @@ static sd_rsp_type_t sd_cmd_unimplemented(SDState 
*sd, SDRequest req)

+/* Configure fields for following sd_generic_read_byte() calls */
+__attribute__((unused))
+static sd_rsp_type_t sd_cmd_to_sendingdata(SDState *sd, SDRequest req,
+                                           uint64_t start,
+                                           const void *data, size_t size)
+{
+    if (sd->state != sd_transfer_state) {
+        sd_invalid_state_for_cmd(sd, req);
+    }
+
+    sd->state = sd_sendingdata_state;
+    sd->data_start = start;
+    sd->data_offset = 0;
+    if (data) {
+        assert(size > 0 && size <= sizeof(sd->data));
+        memcpy(sd->data, data, size);
+    }
+    if (size) {
+        sd->data_size = size;
+    }
+    return sd_r1;
+}
+
 /* CMD0 */
@@ -1914,2 +1939,16 @@ send_response:

+/* Return true when buffer is consumed. Configured by 
sd_cmd_to_sendingdata() */
+__attribute__((unused))
+static bool sd_generic_read_byte(SDState *sd, uint8_t *value)
+{
+    *value = sd->data[sd->data_offset];
+
+    if (++sd->data_offset >= sd->data_size) {
+        sd->state = sd_transfer_state;
+        return true;
+    }
+
+    return false;
+}
+
 void sd_write_byte(SDState *sd, uint8_t value)
---