[PATCH v3 07/11] net: cadence_gem: Add support for jumbo frames

[Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>]

Add a property "jumbo-max-len", which can be configured for jumbo frame size
up to 16,383 bytes, and also introduce new register GEM_JUMBO_MAX_LEN.

Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
---
 hw/net/cadence_gem.c         | 21 +++++++++++++++++++--
 include/hw/net/cadence_gem.h |  1 +
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
index 5ccec1a..45c50ab 100644
--- a/hw/net/cadence_gem.c
+++ b/hw/net/cadence_gem.c
@@ -61,6 +61,7 @@
 #define GEM_TXPAUSE       (0x0000003C/4) /* TX Pause Time reg */
 #define GEM_TXPARTIALSF   (0x00000040/4) /* TX Partial Store and Forward */
 #define GEM_RXPARTIALSF   (0x00000044/4) /* RX Partial Store and Forward */
+#define GEM_JUMBO_MAX_LEN (0x00000048 / 4) /* Max Jumbo Frame Size */
 #define GEM_HASHLO        (0x00000080/4) /* Hash Low address reg */
 #define GEM_HASHHI        (0x00000084/4) /* Hash High address reg */
 #define GEM_SPADDR1LO     (0x00000088/4) /* Specific addr 1 low reg */
@@ -314,7 +315,8 @@
 
 #define GEM_MODID_VALUE 0x00020118
 
-#define MAX_FRAME_SIZE 2048
+#define MAX_JUMBO_FRAME_SIZE_MASK 0x3FFF
+#define MAX_FRAME_SIZE MAX_JUMBO_FRAME_SIZE_MASK
 
 static inline uint64_t tx_desc_get_buffer(CadenceGEMState *s, uint32_t *desc)
 {
@@ -1343,9 +1345,10 @@ static void gem_reset(DeviceState *d)
     s->regs[GEM_RXPARTIALSF] = 0x000003ff;
     s->regs[GEM_MODID] = s->revision;
     s->regs[GEM_DESCONF] = 0x02500111;
-    s->regs[GEM_DESCONF2] = 0x2ab13fff;
+    s->regs[GEM_DESCONF2] = 0x2ab10000 | s->jumbo_max_len;
     s->regs[GEM_DESCONF5] = 0x002f2045;
     s->regs[GEM_DESCONF6] = GEM_DESCONF6_64B_MASK;
+    s->regs[GEM_JUMBO_MAX_LEN] = s->jumbo_max_len;
 
     if (s->num_priority_queues > 1) {
         queues_mask = MAKE_64BIT_MASK(1, s->num_priority_queues - 1);
@@ -1420,6 +1423,9 @@ static uint64_t gem_read(void *opaque, hwaddr offset, unsigned size)
         DB_PRINT("lowering irqs on ISR read\n");
         /* The interrupts get updated at the end of the function. */
         break;
+    case GEM_JUMBO_MAX_LEN:
+        retval = s->jumbo_max_len;
+        break;
     case GEM_PHYMNTNC:
         if (retval & GEM_PHYMNTNC_OP_R) {
             uint32_t phy_addr, reg_num;
@@ -1516,6 +1522,9 @@ static void gem_write(void *opaque, hwaddr offset, uint64_t val,
         s->regs[GEM_IMR] &= ~val;
         gem_update_int_status(s);
         break;
+    case GEM_JUMBO_MAX_LEN:
+        s->jumbo_max_len = val & MAX_JUMBO_FRAME_SIZE_MASK;
+        break;
     case GEM_INT_Q1_ENABLE ... GEM_INT_Q7_ENABLE:
         s->regs[GEM_INT_Q1_MASK + offset - GEM_INT_Q1_ENABLE] &= ~val;
         gem_update_int_status(s);
@@ -1611,6 +1620,12 @@ static void gem_realize(DeviceState *dev, Error **errp)
     s->nic = qemu_new_nic(&net_gem_info, &s->conf,
                           object_get_typename(OBJECT(dev)), dev->id, s);
 
+    if (s->jumbo_max_len > MAX_FRAME_SIZE) {
+        g_warning("jumbo-max-len is grater than %d",
+                  MAX_FRAME_SIZE);
+        s->jumbo_max_len = MAX_FRAME_SIZE;
+    }
+
     s->tx_packet = g_new0(uint8_t, MAX_FRAME_SIZE);
     s->rx_packet = g_new0(uint8_t, MAX_FRAME_SIZE);
 }
@@ -1670,6 +1685,8 @@ static Property gem_properties[] = {
                       num_type1_screeners, 4),
     DEFINE_PROP_UINT8("num-type2-screeners", CadenceGEMState,
                       num_type2_screeners, 4),
+    DEFINE_PROP_UINT16("jumbo-max-len", CadenceGEMState,
+                       jumbo_max_len, 10240),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/net/cadence_gem.h b/include/hw/net/cadence_gem.h
index 8dbbaa3..ef85737 100644
--- a/include/hw/net/cadence_gem.h
+++ b/include/hw/net/cadence_gem.h
@@ -82,6 +82,7 @@ typedef struct CadenceGEMState {
 
     uint8_t *tx_packet;
     uint8_t *rx_packet;
+    uint16_t jumbo_max_len;
     uint32_t rx_desc[MAX_PRIORITY_QUEUES][DESC_MAX_NUM_WORDS];
 
     bool sar_active[4];
-- 
2.7.4