[PATCH v4 0/5] dp8393x: fixes and improvements

[PATCH v4 0/5] dp8393x: fixes and improvements

[Philippe Mathieu-Daudé]

Hi Mark,

This should be the last respin.

Since v3:
- dropped worrying patches
- squashed migration patch
- added tags

Patch #3 (dp8393x: Store CAM registers as 16-bit) still
misses your S-o-b tag.

Based-on mips-next.

Mark Cave-Ayland (1):
  dp8393x: don't force 32-bit register access

Philippe Mathieu-Daudé (4):
  dp8393x: Replace address_space_rw(is_write=1) by address_space_write()
  dp8393x: Replace 0x40 magic value by SONIC_REG16_COUNT definition
  dp8393x: Store CAM registers as 16-bit
  dp8393x: Rewrite dp8393x_get() / dp8393x_put()

 hw/net/dp8393x.c | 206 ++++++++++++++++++++---------------------------
 1 file changed, 87 insertions(+), 119 deletions(-)

-- 
2.31.1

[PATCH v4 1/5] dp8393x: Replace address_space_rw(is_write=1) by address_space_write()

[Philippe Mathieu-Daudé]

Replace address_space_rw(is_write=1) by address_space_write()
and remove pointless cast.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Finn Thain <fthain@linux-m68k.org>
Message-Id: <20210710174954.2577195-2-f4bug@amsat.org>
---
 hw/net/dp8393x.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index 11810c9b600..9118364aa33 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -816,8 +816,8 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
         size = sizeof(uint16_t) * width;
         address = dp8393x_crda(s) + sizeof(uint16_t) * 6 * width;
         dp8393x_put(s, width, 0, 0);
-        address_space_rw(&s->as, address, MEMTXATTRS_UNSPECIFIED,
-                         (uint8_t *)s->data, size, 1);
+        address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
+                            s->data, size);
 
         /* Move to next descriptor */
         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
@@ -846,8 +846,8 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
     /* Pad short packets to keep pointers aligned */
     if (rx_len < padded_len) {
         size = padded_len - rx_len;
-        address_space_rw(&s->as, address, MEMTXATTRS_UNSPECIFIED,
-            (uint8_t *)"\xFF\xFF\xFF", size, 1);
+        address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
+                            "\xFF\xFF\xFF", size);
         address += size;
     }
 
-- 
2.31.1

[PATCH v4 2/5] dp8393x: Replace 0x40 magic value by SONIC_REG16_COUNT definition

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Finn Thain <fthain@linux-m68k.org>
Message-Id: <20210710174954.2577195-3-f4bug@amsat.org>
---
 hw/net/dp8393x.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index 9118364aa33..d1e147a82a6 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -85,6 +85,7 @@ static const char *reg_names[] = {
 #define SONIC_MPT    0x2e
 #define SONIC_MDT    0x2f
 #define SONIC_DCR2   0x3f
+#define SONIC_REG_COUNT  0x40
 
 #define SONIC_CR_HTX     0x0001
 #define SONIC_CR_TXP     0x0002
@@ -158,7 +159,7 @@ struct dp8393xState {
 
     /* Registers */
     uint8_t cam[16][6];
-    uint16_t regs[0x40];
+    uint16_t regs[SONIC_REG_COUNT];
 
     /* Temporaries */
     uint8_t tx_buffer[0x10000];
@@ -972,7 +973,7 @@ static void dp8393x_realize(DeviceState *dev, Error **errp)
 
     address_space_init(&s->as, s->dma_mr, "dp8393x");
     memory_region_init_io(&s->mmio, OBJECT(dev), &dp8393x_ops, s,
-                          "dp8393x-regs", 0x40 << s->it_shift);
+                          "dp8393x-regs", SONIC_REG_COUNT << s->it_shift);
 
     s->nic = qemu_new_nic(&net_dp83932_info, &s->conf,
                           object_get_typename(OBJECT(dev)), dev->id, s);
@@ -987,7 +988,7 @@ static const VMStateDescription vmstate_dp8393x = {
     .minimum_version_id = 0,
     .fields = (VMStateField []) {
         VMSTATE_BUFFER_UNSAFE(cam, dp8393xState, 0, 16 * 6),
-        VMSTATE_UINT16_ARRAY(regs, dp8393xState, 0x40),
+        VMSTATE_UINT16_ARRAY(regs, dp8393xState, SONIC_REG_COUNT),
         VMSTATE_END_OF_LIST()
     }
 };
-- 
2.31.1

Re: [PATCH v4 2/5] dp8393x: Replace 0x40 magic value by SONIC_REG16_COUNT definition

[Mark Cave-Ayland]

On 11/07/2021 11:36, Philippe Mathieu-Daudé wrote:

> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> Tested-by: Finn Thain <fthain@linux-m68k.org>
> Message-Id: <20210710174954.2577195-3-f4bug@amsat.org>
> ---
>   hw/net/dp8393x.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
> index 9118364aa33..d1e147a82a6 100644
> --- a/hw/net/dp8393x.c
> +++ b/hw/net/dp8393x.c
> @@ -85,6 +85,7 @@ static const char *reg_names[] = {
>   #define SONIC_MPT    0x2e
>   #define SONIC_MDT    0x2f
>   #define SONIC_DCR2   0x3f
> +#define SONIC_REG_COUNT  0x40
>   
>   #define SONIC_CR_HTX     0x0001
>   #define SONIC_CR_TXP     0x0002
> @@ -158,7 +159,7 @@ struct dp8393xState {
>   
>       /* Registers */
>       uint8_t cam[16][6];
> -    uint16_t regs[0x40];
> +    uint16_t regs[SONIC_REG_COUNT];
>   
>       /* Temporaries */
>       uint8_t tx_buffer[0x10000];
> @@ -972,7 +973,7 @@ static void dp8393x_realize(DeviceState *dev, Error **errp)
>   
>       address_space_init(&s->as, s->dma_mr, "dp8393x");
>       memory_region_init_io(&s->mmio, OBJECT(dev), &dp8393x_ops, s,
> -                          "dp8393x-regs", 0x40 << s->it_shift);
> +                          "dp8393x-regs", SONIC_REG_COUNT << s->it_shift);
>   
>       s->nic = qemu_new_nic(&net_dp83932_info, &s->conf,
>                             object_get_typename(OBJECT(dev)), dev->id, s);
> @@ -987,7 +988,7 @@ static const VMStateDescription vmstate_dp8393x = {
>       .minimum_version_id = 0,
>       .fields = (VMStateField []) {
>           VMSTATE_BUFFER_UNSAFE(cam, dp8393xState, 0, 16 * 6),
> -        VMSTATE_UINT16_ARRAY(regs, dp8393xState, 0x40),
> +        VMSTATE_UINT16_ARRAY(regs, dp8393xState, SONIC_REG_COUNT),
>           VMSTATE_END_OF_LIST()
>       }
>   };

I just noticed that the subject line is wrong here: the subject line mentions 
SONIC_REG16_COUNT whereas the variable name in the patch is SONIC_REG_COUNT. This is 
trivial enough to fix without resending the series though.


ATB,

Mark.

[PATCH v4 3/5] dp8393x: Store CAM registers as 16-bit

[Philippe Mathieu-Daudé]

Per the DP83932C datasheet from July 1995:

  4.0 SONIC Registers
  4.1 THE CAM UNIT

    The Content Addressable Memory (CAM) consists of sixteen
    48-bit entries for complete address filtering of network
    packets. Each entry corresponds to a 48-bit destination
    address that is user programmable and can contain any
    combination of Multicast or Physical addresses. Each entry
    is partitioned into three 16-bit CAM cells accessible
    through CAM Address Ports (CAP 2, CAP 1 and CAP 0) with
    CAP0 corresponding to the least significant 16 bits of
    the Destination Address and CAP2 corresponding to the
    most significant bits.

Store the CAM registers as 16-bit as it simplifies the code.

Having now the CAM registers as arrays of 3 uint16_t, we can avoid
using the VMSTATE_BUFFER_UNSAFE macro by using VMSTATE_UINT16_2DARRAY
which is more appropriate. This breaks the migration stream however.

Co-developed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Co-developed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Finn Thain <fthain@linux-m68k.org>
Message-Id: <20210710174954.2577195-5-f4bug@amsat.org>
---
Missing:
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
 hw/net/dp8393x.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index d1e147a82a6..283de9db0bf 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -158,7 +158,7 @@ struct dp8393xState {
     MemoryRegion mmio;
 
     /* Registers */
-    uint8_t cam[16][6];
+    uint16_t cam[16][3];
     uint16_t regs[SONIC_REG_COUNT];
 
     /* Temporaries */
@@ -281,15 +281,13 @@ static void dp8393x_do_load_cam(dp8393xState *s)
         address_space_read(&s->as, dp8393x_cdp(s),
                            MEMTXATTRS_UNSPECIFIED, s->data, size);
         index = dp8393x_get(s, width, 0) & 0xf;
-        s->cam[index][0] = dp8393x_get(s, width, 1) & 0xff;
-        s->cam[index][1] = dp8393x_get(s, width, 1) >> 8;
-        s->cam[index][2] = dp8393x_get(s, width, 2) & 0xff;
-        s->cam[index][3] = dp8393x_get(s, width, 2) >> 8;
-        s->cam[index][4] = dp8393x_get(s, width, 3) & 0xff;
-        s->cam[index][5] = dp8393x_get(s, width, 3) >> 8;
-        trace_dp8393x_load_cam(index, s->cam[index][0], s->cam[index][1],
-                               s->cam[index][2], s->cam[index][3],
-                               s->cam[index][4], s->cam[index][5]);
+        s->cam[index][0] = dp8393x_get(s, width, 1);
+        s->cam[index][1] = dp8393x_get(s, width, 2);
+        s->cam[index][2] = dp8393x_get(s, width, 3);
+        trace_dp8393x_load_cam(index,
+                               s->cam[index][0] >> 8, s->cam[index][0] & 0xff,
+                               s->cam[index][1] >> 8, s->cam[index][1] & 0xff,
+                               s->cam[index][2] >> 8, s->cam[index][2] & 0xff);
         /* Move to next entry */
         s->regs[SONIC_CDC]--;
         s->regs[SONIC_CDP] += size;
@@ -592,8 +590,7 @@ static uint64_t dp8393x_read(void *opaque, hwaddr addr, unsigned int size)
     case SONIC_CAP1:
     case SONIC_CAP0:
         if (s->regs[SONIC_CR] & SONIC_CR_RST) {
-            val = s->cam[s->regs[SONIC_CEP] & 0xf][2 * (SONIC_CAP0 - reg) + 1] << 8;
-            val |= s->cam[s->regs[SONIC_CEP] & 0xf][2 * (SONIC_CAP0 - reg)];
+            val = s->cam[s->regs[SONIC_CEP] & 0xf][SONIC_CAP0 - reg];
         }
         break;
     /* All other registers have no special contraints */
@@ -984,10 +981,10 @@ static void dp8393x_realize(DeviceState *dev, Error **errp)
 
 static const VMStateDescription vmstate_dp8393x = {
     .name = "dp8393x",
-    .version_id = 0,
-    .minimum_version_id = 0,
+    .version_id = 1,
+    .minimum_version_id = 1,
     .fields = (VMStateField []) {
-        VMSTATE_BUFFER_UNSAFE(cam, dp8393xState, 0, 16 * 6),
+        VMSTATE_UINT16_2DARRAY(cam, dp8393xState, 16, 3),
         VMSTATE_UINT16_ARRAY(regs, dp8393xState, SONIC_REG_COUNT),
         VMSTATE_END_OF_LIST()
     }
-- 
2.31.1

[PATCH v4 4/5] dp8393x: Rewrite dp8393x_get() / dp8393x_put()

[Philippe Mathieu-Daudé]

Instead of accessing N registers via a single address_space API
call using a temporary buffer (stored in the device state) and
updating each register, move the address_space call in the
register put/get. The load/store and word size checks are moved
to put/get too. This simplifies a bit, making the code easier
to read.

Co-developed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Co-developed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Finn Thain <fthain@linux-m68k.org>
Message-Id: <20210710174954.2577195-8-f4bug@amsat.org>
---
 hw/net/dp8393x.c | 160 +++++++++++++++++++----------------------------
 1 file changed, 63 insertions(+), 97 deletions(-)

diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index 283de9db0bf..4057a263de3 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -163,7 +163,6 @@ struct dp8393xState {
 
     /* Temporaries */
     uint8_t tx_buffer[0x10000];
-    uint16_t data[12];
     int loopback_packet;
 
     /* Memory access */
@@ -220,34 +219,48 @@ static uint32_t dp8393x_wt(dp8393xState *s)
     return s->regs[SONIC_WT1] << 16 | s->regs[SONIC_WT0];
 }
 
-static uint16_t dp8393x_get(dp8393xState *s, int width, int offset)
+static uint16_t dp8393x_get(dp8393xState *s, hwaddr addr, int offset)
 {
+    const MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
     uint16_t val;
 
-    if (s->big_endian) {
-        val = be16_to_cpu(s->data[offset * width + width - 1]);
+    if (s->regs[SONIC_DCR] & SONIC_DCR_DW) {
+        addr += offset << 2;
+        if (s->big_endian) {
+            val = address_space_ldl_be(&s->as, addr, attrs, NULL);
+        } else {
+            val = address_space_ldl_le(&s->as, addr, attrs, NULL);
+        }
     } else {
-        val = le16_to_cpu(s->data[offset * width]);
+        addr += offset << 1;
+        if (s->big_endian) {
+            val = address_space_lduw_be(&s->as, addr, attrs, NULL);
+        } else {
+            val = address_space_lduw_le(&s->as, addr, attrs, NULL);
+        }
     }
+
     return val;
 }
 
-static void dp8393x_put(dp8393xState *s, int width, int offset,
-                        uint16_t val)
+static void dp8393x_put(dp8393xState *s,
+                        hwaddr addr, int offset, uint16_t val)
 {
-    if (s->big_endian) {
-        if (width == 2) {
-            s->data[offset * 2] = 0;
-            s->data[offset * 2 + 1] = cpu_to_be16(val);
+    const MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
+
+    if (s->regs[SONIC_DCR] & SONIC_DCR_DW) {
+        addr += offset << 2;
+        if (s->big_endian) {
+            address_space_stl_be(&s->as, addr, val, attrs, NULL);
         } else {
-            s->data[offset] = cpu_to_be16(val);
+            address_space_stl_le(&s->as, addr, val, attrs, NULL);
         }
     } else {
-        if (width == 2) {
-            s->data[offset * 2] = cpu_to_le16(val);
-            s->data[offset * 2 + 1] = 0;
+        addr += offset << 1;
+        if (s->big_endian) {
+            address_space_stw_be(&s->as, addr, val, attrs, NULL);
         } else {
-            s->data[offset] = cpu_to_le16(val);
+            address_space_stw_le(&s->as, addr, val, attrs, NULL);
         }
     }
 }
@@ -278,12 +291,10 @@ static void dp8393x_do_load_cam(dp8393xState *s)
 
     while (s->regs[SONIC_CDC] & 0x1f) {
         /* Fill current entry */
-        address_space_read(&s->as, dp8393x_cdp(s),
-                           MEMTXATTRS_UNSPECIFIED, s->data, size);
-        index = dp8393x_get(s, width, 0) & 0xf;
-        s->cam[index][0] = dp8393x_get(s, width, 1);
-        s->cam[index][1] = dp8393x_get(s, width, 2);
-        s->cam[index][2] = dp8393x_get(s, width, 3);
+        index = dp8393x_get(s, dp8393x_cdp(s), 0) & 0xf;
+        s->cam[index][0] = dp8393x_get(s, dp8393x_cdp(s), 1);
+        s->cam[index][1] = dp8393x_get(s, dp8393x_cdp(s), 2);
+        s->cam[index][2] = dp8393x_get(s, dp8393x_cdp(s), 3);
         trace_dp8393x_load_cam(index,
                                s->cam[index][0] >> 8, s->cam[index][0] & 0xff,
                                s->cam[index][1] >> 8, s->cam[index][1] & 0xff,
@@ -294,9 +305,7 @@ static void dp8393x_do_load_cam(dp8393xState *s)
     }
 
     /* Read CAM enable */
-    address_space_read(&s->as, dp8393x_cdp(s),
-                       MEMTXATTRS_UNSPECIFIED, s->data, size);
-    s->regs[SONIC_CE] = dp8393x_get(s, width, 0);
+    s->regs[SONIC_CE] = dp8393x_get(s, dp8393x_cdp(s), 0);
     trace_dp8393x_load_cam_done(s->regs[SONIC_CE]);
 
     /* Done */
@@ -312,14 +321,12 @@ static void dp8393x_do_read_rra(dp8393xState *s)
     /* Read memory */
     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
     size = sizeof(uint16_t) * 4 * width;
-    address_space_read(&s->as, dp8393x_rrp(s),
-                       MEMTXATTRS_UNSPECIFIED, s->data, size);
 
     /* Update SONIC registers */
-    s->regs[SONIC_CRBA0] = dp8393x_get(s, width, 0);
-    s->regs[SONIC_CRBA1] = dp8393x_get(s, width, 1);
-    s->regs[SONIC_RBWC0] = dp8393x_get(s, width, 2);
-    s->regs[SONIC_RBWC1] = dp8393x_get(s, width, 3);
+    s->regs[SONIC_CRBA0] = dp8393x_get(s, dp8393x_rrp(s), 0);
+    s->regs[SONIC_CRBA1] = dp8393x_get(s, dp8393x_rrp(s), 1);
+    s->regs[SONIC_RBWC0] = dp8393x_get(s, dp8393x_rrp(s), 2);
+    s->regs[SONIC_RBWC1] = dp8393x_get(s, dp8393x_rrp(s), 3);
     trace_dp8393x_read_rra_regs(s->regs[SONIC_CRBA0], s->regs[SONIC_CRBA1],
                                 s->regs[SONIC_RBWC0], s->regs[SONIC_RBWC1]);
 
@@ -415,28 +422,22 @@ static void dp8393x_do_receiver_disable(dp8393xState *s)
 static void dp8393x_do_transmit_packets(dp8393xState *s)
 {
     NetClientState *nc = qemu_get_queue(s->nic);
-    int width, size;
     int tx_len, len;
     uint16_t i;
 
-    width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
-
     while (1) {
         /* Read memory */
-        size = sizeof(uint16_t) * 6 * width;
         s->regs[SONIC_TTDA] = s->regs[SONIC_CTDA];
         trace_dp8393x_transmit_packet(dp8393x_ttda(s));
-        address_space_read(&s->as, dp8393x_ttda(s) + sizeof(uint16_t) * width,
-                           MEMTXATTRS_UNSPECIFIED, s->data, size);
         tx_len = 0;
 
         /* Update registers */
-        s->regs[SONIC_TCR] = dp8393x_get(s, width, 0) & 0xf000;
-        s->regs[SONIC_TPS] = dp8393x_get(s, width, 1);
-        s->regs[SONIC_TFC] = dp8393x_get(s, width, 2);
-        s->regs[SONIC_TSA0] = dp8393x_get(s, width, 3);
-        s->regs[SONIC_TSA1] = dp8393x_get(s, width, 4);
-        s->regs[SONIC_TFS] = dp8393x_get(s, width, 5);
+        s->regs[SONIC_TCR] = dp8393x_get(s, dp8393x_ttda(s), 1) & 0xf000;
+        s->regs[SONIC_TPS] = dp8393x_get(s, dp8393x_ttda(s), 2);
+        s->regs[SONIC_TFC] = dp8393x_get(s, dp8393x_ttda(s), 3);
+        s->regs[SONIC_TSA0] = dp8393x_get(s, dp8393x_ttda(s), 4);
+        s->regs[SONIC_TSA1] = dp8393x_get(s, dp8393x_ttda(s), 5);
+        s->regs[SONIC_TFS] = dp8393x_get(s, dp8393x_ttda(s), 6);
 
         /* Handle programmable interrupt */
         if (s->regs[SONIC_TCR] & SONIC_TCR_PINT) {
@@ -458,15 +459,12 @@ static void dp8393x_do_transmit_packets(dp8393xState *s)
             i++;
             if (i != s->regs[SONIC_TFC]) {
                 /* Read next fragment details */
-                size = sizeof(uint16_t) * 3 * width;
-                address_space_read(&s->as,
-                                   dp8393x_ttda(s)
-                                   + sizeof(uint16_t) * width * (4 + 3 * i),
-                                   MEMTXATTRS_UNSPECIFIED, s->data,
-                                   size);
-                s->regs[SONIC_TSA0] = dp8393x_get(s, width, 0);
-                s->regs[SONIC_TSA1] = dp8393x_get(s, width, 1);
-                s->regs[SONIC_TFS] = dp8393x_get(s, width, 2);
+                s->regs[SONIC_TSA0] = dp8393x_get(s, dp8393x_ttda(s),
+                                                  4 + 3 * i);
+                s->regs[SONIC_TSA1] = dp8393x_get(s, dp8393x_ttda(s),
+                                                  5 + 3 * i);
+                s->regs[SONIC_TFS] = dp8393x_get(s, dp8393x_ttda(s),
+                                                 6 + 3 * i);
             }
         }
 
@@ -499,22 +497,12 @@ static void dp8393x_do_transmit_packets(dp8393xState *s)
         s->regs[SONIC_TCR] |= SONIC_TCR_PTX;
 
         /* Write status */
-        dp8393x_put(s, width, 0,
-                    s->regs[SONIC_TCR] & 0x0fff); /* status */
-        size = sizeof(uint16_t) * width;
-        address_space_write(&s->as, dp8393x_ttda(s),
-                            MEMTXATTRS_UNSPECIFIED, s->data, size);
+        dp8393x_put(s, dp8393x_ttda(s), 0, s->regs[SONIC_TCR] & 0x0fff);
 
         if (!(s->regs[SONIC_CR] & SONIC_CR_HTX)) {
             /* Read footer of packet */
-            size = sizeof(uint16_t) * width;
-            address_space_read(&s->as,
-                               dp8393x_ttda(s)
-                               + sizeof(uint16_t) * width
-                                 * (4 + 3 * s->regs[SONIC_TFC]),
-                               MEMTXATTRS_UNSPECIFIED, s->data,
-                               size);
-            s->regs[SONIC_CTDA] = dp8393x_get(s, width, 0);
+            s->regs[SONIC_CTDA] = dp8393x_get(s, dp8393x_ttda(s),
+                                              4 + 3 * s->regs[SONIC_TFC]);
             if (s->regs[SONIC_CTDA] & SONIC_DESC_EOL) {
                 /* EOL detected */
                 break;
@@ -762,7 +750,7 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
     dp8393xState *s = qemu_get_nic_opaque(nc);
     int packet_type;
     uint32_t available, address;
-    int width, rx_len, padded_len;
+    int rx_len, padded_len;
     uint32_t checksum;
     int size;
 
@@ -775,10 +763,8 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
 
     rx_len = pkt_size + sizeof(checksum);
     if (s->regs[SONIC_DCR] & SONIC_DCR_DW) {
-        width = 2;
         padded_len = ((rx_len - 1) | 3) + 1;
     } else {
-        width = 1;
         padded_len = ((rx_len - 1) | 1) + 1;
     }
 
@@ -799,11 +785,7 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
     /* Check for EOL */
     if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
         /* Are we still in resource exhaustion? */
-        size = sizeof(uint16_t) * 1 * width;
-        address = dp8393x_crda(s) + sizeof(uint16_t) * 5 * width;
-        address_space_read(&s->as, address, MEMTXATTRS_UNSPECIFIED,
-                           s->data, size);
-        s->regs[SONIC_LLFA] = dp8393x_get(s, width, 0);
+        s->regs[SONIC_LLFA] = dp8393x_get(s, dp8393x_crda(s), 5);
         if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
             /* Still EOL ; stop reception */
             return -1;
@@ -811,11 +793,7 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
         /* Link has been updated by host */
 
         /* Clear in_use */
-        size = sizeof(uint16_t) * width;
-        address = dp8393x_crda(s) + sizeof(uint16_t) * 6 * width;
-        dp8393x_put(s, width, 0, 0);
-        address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
-                            s->data, size);
+        dp8393x_put(s, dp8393x_crda(s), 6, 0x0000);
 
         /* Move to next descriptor */
         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
@@ -869,32 +847,20 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
 
     /* Write status to memory */
     trace_dp8393x_receive_write_status(dp8393x_crda(s));
-    dp8393x_put(s, width, 0, s->regs[SONIC_RCR]); /* status */
-    dp8393x_put(s, width, 1, rx_len); /* byte count */
-    dp8393x_put(s, width, 2, s->regs[SONIC_TRBA0]); /* pkt_ptr0 */
-    dp8393x_put(s, width, 3, s->regs[SONIC_TRBA1]); /* pkt_ptr1 */
-    dp8393x_put(s, width, 4, s->regs[SONIC_RSC]); /* seq_no */
-    size = sizeof(uint16_t) * 5 * width;
-    address_space_write(&s->as, dp8393x_crda(s),
-                        MEMTXATTRS_UNSPECIFIED,
-                        s->data, size);
+    dp8393x_put(s, dp8393x_crda(s), 0, s->regs[SONIC_RCR]); /* status */
+    dp8393x_put(s, dp8393x_crda(s), 1, rx_len); /* byte count */
+    dp8393x_put(s, dp8393x_crda(s), 2, s->regs[SONIC_TRBA0]); /* pkt_ptr0 */
+    dp8393x_put(s, dp8393x_crda(s), 3, s->regs[SONIC_TRBA1]); /* pkt_ptr1 */
+    dp8393x_put(s, dp8393x_crda(s), 4, s->regs[SONIC_RSC]); /* seq_no */
 
     /* Check link field */
-    size = sizeof(uint16_t) * width;
-    address_space_read(&s->as,
-                       dp8393x_crda(s) + sizeof(uint16_t) * 5 * width,
-                       MEMTXATTRS_UNSPECIFIED, s->data, size);
-    s->regs[SONIC_LLFA] = dp8393x_get(s, width, 0);
+    s->regs[SONIC_LLFA] = dp8393x_get(s, dp8393x_crda(s), 5);
     if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
         /* EOL detected */
         s->regs[SONIC_ISR] |= SONIC_ISR_RDE;
     } else {
         /* Clear in_use */
-        size = sizeof(uint16_t) * width;
-        address = dp8393x_crda(s) + sizeof(uint16_t) * 6 * width;
-        dp8393x_put(s, width, 0, 0);
-        address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
-                            s->data, size);
+        dp8393x_put(s, dp8393x_crda(s), 6, 0x0000);
 
         /* Move to next descriptor */
         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
-- 
2.31.1

[PATCH v4 5/5] dp8393x: don't force 32-bit register access

[Philippe Mathieu-Daudé]

From: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

Commit 3fe9a838ec "dp8393x: Always use 32-bit accesses" set .impl.min_access_size
and .impl.max_access_size to 4 to try and fix the Linux jazzsonic driver which uses
32-bit accesses.

The problem with forcing the register access to 32-bit in this way is that since the
dp8393x uses 16-bit registers, a manual endian swap is required for devices on big
endian machines with 32-bit accesses.

For both access sizes and machine endians the QEMU memory API can do the right thing
automatically: all that is needed is to set .impl.min_access_size to 2 to declare that
the dp8393x implements 16-bit registers.

Normally .impl.max_access_size should also be set to 2, however that doesn't quite
work in this case since the register stride is specified using a (dynamic) it_shift
property which is applied during the MMIO access itself. The effect of this is that
for a 32-bit access the memory API performs 2 x 16-bit accesses, but the use of
it_shift within the MMIO access itself causes the register value to be repeated in both
the top 16-bits and bottom 16-bits. The Linux jazzsonic driver expects the stride to be
zero-extended up to access size and therefore fails to correctly detect the dp8393x
device due to the extra data in the top 16-bits.

The solution here is to remove .impl.max_access_size so that the memory API will
correctly zero-extend the 16-bit registers to the access size up to and including
it_shift. Since it_shift is never greater than 2 than this will always do the right
thing for both 16-bit and 32-bit accesses regardless of the machine endian, allowing
the manual endian swap code to be removed.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Fixes: 3fe9a838ec ("dp8393x: Always use 32-bit accesses")
Message-Id: <20210705214929.17222-2-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Finn Thain <fthain@linux-m68k.org>
---
 hw/net/dp8393x.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index 4057a263de3..45b954e46c2 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -588,15 +588,14 @@ static uint64_t dp8393x_read(void *opaque, hwaddr addr, unsigned int size)
 
     trace_dp8393x_read(reg, reg_names[reg], val, size);
 
-    return s->big_endian ? val << 16 : val;
+    return val;
 }
 
-static void dp8393x_write(void *opaque, hwaddr addr, uint64_t data,
+static void dp8393x_write(void *opaque, hwaddr addr, uint64_t val,
                           unsigned int size)
 {
     dp8393xState *s = opaque;
     int reg = addr >> s->it_shift;
-    uint32_t val = s->big_endian ? data >> 16 : data;
 
     trace_dp8393x_write(reg, reg_names[reg], val, size);
 
@@ -677,11 +676,16 @@ static void dp8393x_write(void *opaque, hwaddr addr, uint64_t data,
     }
 }
 
+/*
+ * Since .impl.max_access_size is effectively controlled by the it_shift
+ * property, leave it unspecified for now to allow the memory API to
+ * correctly zero extend the 16-bit register values to the access size up to and
+ * including it_shift.
+ */
 static const MemoryRegionOps dp8393x_ops = {
     .read = dp8393x_read,
     .write = dp8393x_write,
-    .impl.min_access_size = 4,
-    .impl.max_access_size = 4,
+    .impl.min_access_size = 2,
     .endianness = DEVICE_NATIVE_ENDIAN,
 };
 
-- 
2.31.1

Re: [PATCH v4 0/5] dp8393x: fixes and improvements

[Mark Cave-Ayland]

On 11/07/2021 11:36, Philippe Mathieu-Daudé wrote:

> Hi Mark,
> 
> This should be the last respin.
> 
> Since v3:
> - dropped worrying patches
> - squashed migration patch
> - added tags
> 
> Patch #3 (dp8393x: Store CAM registers as 16-bit) still
> misses your S-o-b tag.
> 
> Based-on mips-next.
> 
> Mark Cave-Ayland (1):
>    dp8393x: don't force 32-bit register access
> 
> Philippe Mathieu-Daudé (4):
>    dp8393x: Replace address_space_rw(is_write=1) by address_space_write()
>    dp8393x: Replace 0x40 magic value by SONIC_REG16_COUNT definition
>    dp8393x: Store CAM registers as 16-bit
>    dp8393x: Rewrite dp8393x_get() / dp8393x_put()
> 
>   hw/net/dp8393x.c | 206 ++++++++++++++++++++---------------------------
>   1 file changed, 87 insertions(+), 119 deletions(-)

Thanks Phil. A small typo in the subject line of patch 2, but otherwise this series 
passes my local tests (assuming "dp8393x: fix CAM descriptor entry index" is already 
applied to mips-next).

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>


ATB,

Mark.

Re: [PATCH v4 0/5] dp8393x: fixes and improvements

[Philippe Mathieu-Daudé]

On 7/11/21 12:36 PM, Philippe Mathieu-Daudé wrote:
> Hi Mark,
> 
> This should be the last respin.
> 
> Since v3:
> - dropped worrying patches
> - squashed migration patch
> - added tags
> 
> Patch #3 (dp8393x: Store CAM registers as 16-bit) still
> misses your S-o-b tag.
> 
> Based-on mips-next.
> 
> Mark Cave-Ayland (1):
>   dp8393x: don't force 32-bit register access
> 
> Philippe Mathieu-Daudé (4):
>   dp8393x: Replace address_space_rw(is_write=1) by address_space_write()
>   dp8393x: Replace 0x40 magic value by SONIC_REG16_COUNT definition
>   dp8393x: Store CAM registers as 16-bit
>   dp8393x: Rewrite dp8393x_get() / dp8393x_put()

Series applied to mips-next.