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hw/net: GMAC Tx Implementation
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- Implementation of Transmit function for packets
- Implementation for reading and writing from and to descriptors in
  memory for Tx

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

Added relevant trace-events

Change-Id: Icf14f9fcc6cc7808a41acd872bca67c9832087e6
Signed-off-by: Nabih Estefan <nabihestefan@google.com>
Reviewed-by: Tyrone Ting <kfting@nuvoton.com>
Message-id: 20240110234232.4116804-10-nabihestefan@google.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
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@pm215
Nabih Estefan Diaz authored and pm215 committed Jan 15, 2024
1 parent 71cce75 commit d42cf41
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203 changes: 203 additions & 0 deletions hw/net/npcm_gmac.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand Down Expand Up @@ -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. */
Expand Down Expand Up @@ -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)) {
Expand Down
2 changes: 2 additions & 0 deletions hw/net/trace-events
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down

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