diff mbox series

[v15,8/9] hw/net: GMAC Tx Implementation

Message ID 20240125194247.1589037-9-nabihestefan@google.com (mailing list archive)
State New, archived
Headers show
Series Implementation of NPI Mailbox and GMAC Networking Module | expand

Commit Message

Nabih Estefan Jan. 25, 2024, 7:42 p.m. UTC 
From: Nabih Estefan Diaz <nabihestefan@google.com>

- Implementation of Transmit function for packets
- Implementation for reading and writing from and to descriptors in
  memory for Tx

Added relevant trace-events

NOTE: This function implements the steps detailed in the datasheet for
transmitting messages from the GMAC.

Change-Id: Icf14f9fcc6cc7808a41acd872bca67c9832087e6
Signed-off-by: Nabih Estefan <nabihestefan@google.com>
Reviewed-by: Tyrone Ting <kfting@nuvoton.com>
---
 hw/net/npcm_gmac.c  | 203 ++++++++++++++++++++++++++++++++++++++++++++
 hw/net/trace-events |   2 +
 2 files changed, 205 insertions(+)
diff mbox series

Patch

diff --git a/hw/net/npcm_gmac.c b/hw/net/npcm_gmac.c
index b2b9314f5e..a0b1cd9356 100644
--- a/hw/net/npcm_gmac.c
+++ b/hw/net/npcm_gmac.c
@@ -235,6 +235,37 @@  static int gmac_write_rx_desc(dma_addr_t addr, struct NPCMGMACRxDesc *desc)
     return 0;
 }
 
+static int gmac_read_tx_desc(dma_addr_t addr, struct NPCMGMACTxDesc *desc)
+{
+    if (dma_memory_read(&address_space_memory, addr, desc,
+                        sizeof(*desc), MEMTXATTRS_UNSPECIFIED)) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: Failed to read descriptor @ 0x%"
+                      HWADDR_PRIx "\n", __func__, addr);
+        return -1;
+    }
+    desc->tdes0 = le32_to_cpu(desc->tdes0);
+    desc->tdes1 = le32_to_cpu(desc->tdes1);
+    desc->tdes2 = le32_to_cpu(desc->tdes2);
+    desc->tdes3 = le32_to_cpu(desc->tdes3);
+    return 0;
+}
+
+static int gmac_write_tx_desc(dma_addr_t addr, struct NPCMGMACTxDesc *desc)
+{
+    struct NPCMGMACTxDesc le_desc;
+    le_desc.tdes0 = cpu_to_le32(desc->tdes0);
+    le_desc.tdes1 = cpu_to_le32(desc->tdes1);
+    le_desc.tdes2 = cpu_to_le32(desc->tdes2);
+    le_desc.tdes3 = cpu_to_le32(desc->tdes3);
+    if (dma_memory_write(&address_space_memory, addr, &le_desc,
+                        sizeof(le_desc), MEMTXATTRS_UNSPECIFIED)) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: Failed to write descriptor @ 0x%"
+                      HWADDR_PRIx "\n", __func__, addr);
+        return -1;
+    }
+    return 0;
+}
+
 static int gmac_rx_transfer_frame_to_buffer(uint32_t rx_buf_len,
                                             uint32_t *left_frame,
                                             uint32_t rx_buf_addr,
@@ -456,6 +487,155 @@  static ssize_t gmac_receive(NetClientState *nc, const uint8_t *buf, size_t len)
     return len;
 }
 
+static int gmac_tx_get_csum(uint32_t tdes1)
+{
+    uint32_t mask = TX_DESC_TDES1_CHKSM_INS_CTRL_MASK(tdes1);
+    int csum = 0;
+
+    if (likely(mask > 0)) {
+        csum |= CSUM_IP;
+    }
+    if (likely(mask > 1)) {
+        csum |= CSUM_TCP | CSUM_UDP;
+    }
+
+    return csum;
+}
+
+static void gmac_try_send_next_packet(NPCMGMACState *gmac)
+{
+    /*
+     * Comments about steps refer to steps for
+     * transmitting in page 384 of datasheet
+     */
+    uint16_t tx_buffer_size = 2048;
+    g_autofree uint8_t *tx_send_buffer = g_malloc(tx_buffer_size);
+    uint32_t desc_addr;
+    struct NPCMGMACTxDesc tx_desc;
+    uint32_t tx_buf_addr, tx_buf_len;
+    uint16_t length = 0;
+    uint8_t *buf = tx_send_buffer;
+    uint32_t prev_buf_size = 0;
+    int csum = 0;
+
+    /* steps 1&2 */
+    if (!gmac->regs[R_NPCM_DMA_HOST_TX_DESC]) {
+        gmac->regs[R_NPCM_DMA_HOST_TX_DESC] =
+            NPCM_DMA_HOST_TX_DESC_MASK(gmac->regs[R_NPCM_DMA_TX_BASE_ADDR]);
+    }
+    desc_addr = gmac->regs[R_NPCM_DMA_HOST_TX_DESC];
+
+    while (true) {
+        gmac_dma_set_state(gmac, NPCM_DMA_STATUS_TX_PROCESS_STATE_SHIFT,
+            NPCM_DMA_STATUS_TX_RUNNING_FETCHING_STATE);
+        if (gmac_read_tx_desc(desc_addr, &tx_desc)) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "TX Descriptor @ 0x%x can't be read\n",
+                          desc_addr);
+            return;
+        }
+        /* step 3 */
+
+        trace_npcm_gmac_packet_desc_read(DEVICE(gmac)->canonical_path,
+            desc_addr);
+        trace_npcm_gmac_debug_desc_data(DEVICE(gmac)->canonical_path, &tx_desc,
+            tx_desc.tdes0, tx_desc.tdes1, tx_desc.tdes2, tx_desc.tdes3);
+
+        /* 1 = DMA Owned, 0 = Software Owned */
+        if (!(tx_desc.tdes0 & TX_DESC_TDES0_OWN)) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "TX Descriptor @ 0x%x is owned by software\n",
+                          desc_addr);
+            gmac->regs[R_NPCM_DMA_STATUS] |= NPCM_DMA_STATUS_TU;
+            gmac_dma_set_state(gmac, NPCM_DMA_STATUS_TX_PROCESS_STATE_SHIFT,
+                NPCM_DMA_STATUS_TX_SUSPENDED_STATE);
+            gmac_update_irq(gmac);
+            return;
+        }
+
+        gmac_dma_set_state(gmac, NPCM_DMA_STATUS_TX_PROCESS_STATE_SHIFT,
+            NPCM_DMA_STATUS_TX_RUNNING_READ_STATE);
+        /* Give the descriptor back regardless of what happens. */
+        tx_desc.tdes0 &= ~TX_DESC_TDES0_OWN;
+
+        if (tx_desc.tdes1 & TX_DESC_TDES1_FIRST_SEG_MASK) {
+            csum = gmac_tx_get_csum(tx_desc.tdes1);
+        }
+
+        /* step 4 */
+        tx_buf_addr = tx_desc.tdes2;
+        gmac->regs[R_NPCM_DMA_CUR_TX_BUF_ADDR] = tx_buf_addr;
+        tx_buf_len = TX_DESC_TDES1_BFFR1_SZ_MASK(tx_desc.tdes1);
+        buf = &tx_send_buffer[prev_buf_size];
+
+        if ((prev_buf_size + tx_buf_len) > sizeof(buf)) {
+            tx_buffer_size = prev_buf_size + tx_buf_len;
+            tx_send_buffer = g_realloc(tx_send_buffer, tx_buffer_size);
+            buf = &tx_send_buffer[prev_buf_size];
+        }
+
+        /* step 5 */
+        if (dma_memory_read(&address_space_memory, tx_buf_addr, buf,
+                            tx_buf_len, MEMTXATTRS_UNSPECIFIED)) {
+            qemu_log_mask(LOG_GUEST_ERROR, "%s: Failed to read packet @ 0x%x\n",
+                        __func__, tx_buf_addr);
+            return;
+        }
+        length += tx_buf_len;
+        prev_buf_size += tx_buf_len;
+
+        /* If not chained we'll have a second buffer. */
+        if (!(tx_desc.tdes1 & TX_DESC_TDES1_SEC_ADDR_CHND_MASK)) {
+            tx_buf_addr = tx_desc.tdes3;
+            gmac->regs[R_NPCM_DMA_CUR_TX_BUF_ADDR] = tx_buf_addr;
+            tx_buf_len = TX_DESC_TDES1_BFFR2_SZ_MASK(tx_desc.tdes1);
+            buf = &tx_send_buffer[prev_buf_size];
+
+            if ((prev_buf_size + tx_buf_len) > sizeof(buf)) {
+                tx_buffer_size = prev_buf_size + tx_buf_len;
+                tx_send_buffer = g_realloc(tx_send_buffer, tx_buffer_size);
+                buf = &tx_send_buffer[prev_buf_size];
+            }
+
+            if (dma_memory_read(&address_space_memory, tx_buf_addr, buf,
+                                tx_buf_len, MEMTXATTRS_UNSPECIFIED)) {
+                qemu_log_mask(LOG_GUEST_ERROR,
+                              "%s: Failed to read packet @ 0x%x\n",
+                              __func__, tx_buf_addr);
+                return;
+            }
+            length += tx_buf_len;
+            prev_buf_size += tx_buf_len;
+        }
+        if (tx_desc.tdes1 & TX_DESC_TDES1_LAST_SEG_MASK) {
+            net_checksum_calculate(tx_send_buffer, length, csum);
+            qemu_send_packet(qemu_get_queue(gmac->nic), tx_send_buffer, length);
+            trace_npcm_gmac_packet_sent(DEVICE(gmac)->canonical_path, length);
+            buf = tx_send_buffer;
+            length = 0;
+        }
+
+        /* step 6 */
+        gmac_dma_set_state(gmac, NPCM_DMA_STATUS_TX_PROCESS_STATE_SHIFT,
+            NPCM_DMA_STATUS_TX_RUNNING_CLOSING_STATE);
+        gmac_write_tx_desc(desc_addr, &tx_desc);
+        if (tx_desc.tdes1 & TX_DESC_TDES1_TX_END_RING_MASK) {
+            desc_addr = gmac->regs[R_NPCM_DMA_TX_BASE_ADDR];
+        } else if (tx_desc.tdes1 & TX_DESC_TDES1_SEC_ADDR_CHND_MASK) {
+            desc_addr = tx_desc.tdes3;
+        } else {
+            desc_addr += sizeof(tx_desc);
+        }
+        gmac->regs[R_NPCM_DMA_HOST_TX_DESC] = desc_addr;
+
+        /* step 7 */
+        if (tx_desc.tdes1 & TX_DESC_TDES1_INTERR_COMP_MASK) {
+            gmac->regs[R_NPCM_DMA_STATUS] |= NPCM_DMA_STATUS_TI;
+            gmac_update_irq(gmac);
+        }
+    }
+}
+
 static void gmac_cleanup(NetClientState *nc)
 {
     /* Nothing to do yet. */
@@ -610,6 +790,29 @@  static void npcm_gmac_write(void *opaque, hwaddr offset,
             NPCM_DMA_STATUS_RX_RUNNING_WAITING_STATE);
         break;
 
+    case A_NPCM_DMA_XMT_POLL_DEMAND:
+        /* We dont actually care about the value */
+        gmac_try_send_next_packet(gmac);
+        break;
+
+    case A_NPCM_DMA_CONTROL:
+        gmac->regs[offset / sizeof(uint32_t)] = v;
+        if (v & NPCM_DMA_CONTROL_START_STOP_TX) {
+            gmac_try_send_next_packet(gmac);
+        } else {
+            gmac_dma_set_state(gmac, NPCM_DMA_STATUS_TX_PROCESS_STATE_SHIFT,
+                NPCM_DMA_STATUS_TX_STOPPED_STATE);
+        }
+        if (v & NPCM_DMA_CONTROL_START_STOP_RX) {
+            gmac_dma_set_state(gmac, NPCM_DMA_STATUS_RX_PROCESS_STATE_SHIFT,
+                NPCM_DMA_STATUS_RX_RUNNING_WAITING_STATE);
+            qemu_flush_queued_packets(qemu_get_queue(gmac->nic));
+        } else {
+            gmac_dma_set_state(gmac, NPCM_DMA_STATUS_RX_PROCESS_STATE_SHIFT,
+                NPCM_DMA_STATUS_RX_STOPPED_STATE);
+        }
+        break;
+
     case A_NPCM_DMA_STATUS:
         /* Check that RO bits are not written to */
         if (NPCM_DMA_STATUS_RO_MASK(v)) {
diff --git a/hw/net/trace-events b/hw/net/trace-events
index f91b1a4a3d..78efa2ec2c 100644
--- a/hw/net/trace-events
+++ b/hw/net/trace-events
@@ -478,7 +478,9 @@  npcm_gmac_packet_desc_read(const char* name, uint32_t desc_addr) "%s: attempting
 npcm_gmac_packet_receive(const char* name, uint32_t len) "%s: RX packet length: 0x%04" PRIX32
 npcm_gmac_packet_receiving_buffer(const char* name, uint32_t buf_len, uint32_t rx_buf_addr) "%s: Receiving into Buffer size: 0x%04" PRIX32 " at address 0x%04" PRIX32
 npcm_gmac_packet_received(const char* name, uint32_t len) "%s: Reception finished, packet left: 0x%04" PRIX32
+npcm_gmac_packet_sent(const char* name, uint16_t len) "%s: TX packet sent!, length: 0x%04" PRIX16
 npcm_gmac_debug_desc_data(const char* name, void* addr, uint32_t des0, uint32_t des1, uint32_t des2, uint32_t des3)"%s: Address: %p Descriptor 0: 0x%04" PRIX32 " Descriptor 1: 0x%04" PRIX32 "Descriptor 2: 0x%04" PRIX32 " Descriptor 3: 0x%04" PRIX32
+npcm_gmac_packet_tx_desc_data(const char* name, uint32_t tdes0, uint32_t tdes1) "%s: Tdes0: 0x%04" PRIX32 " Tdes1: 0x%04" PRIX32
 
 # npcm_pcs.c
 npcm_pcs_reg_read(const char *name, uint16_t indirect_access_baes, uint64_t offset, uint16_t value) "%s: IND: 0x%02" PRIx16 " offset: 0x%04" PRIx64 " value: 0x%04" PRIx16