diff options
Diffstat (limited to 'hw/net')
-rw-r--r-- | hw/net/meson.build | 2 | ||||
-rw-r--r-- | hw/net/npcm_gmac.c | 942 | ||||
-rw-r--r-- | hw/net/trace-events | 19 |
3 files changed, 962 insertions, 1 deletions
diff --git a/hw/net/meson.build b/hw/net/meson.build index 2b426d3..b742687 100644 --- a/hw/net/meson.build +++ b/hw/net/meson.build @@ -38,7 +38,7 @@ system_ss.add(when: 'CONFIG_I82596_COMMON', if_true: files('i82596.c')) system_ss.add(when: 'CONFIG_SUNHME', if_true: files('sunhme.c')) system_ss.add(when: 'CONFIG_FTGMAC100', if_true: files('ftgmac100.c')) system_ss.add(when: 'CONFIG_SUNGEM', if_true: files('sungem.c')) -system_ss.add(when: 'CONFIG_NPCM7XX', if_true: files('npcm7xx_emc.c')) +system_ss.add(when: 'CONFIG_NPCM7XX', if_true: files('npcm7xx_emc.c', 'npcm_gmac.c')) system_ss.add(when: 'CONFIG_ETRAXFS', if_true: files('etraxfs_eth.c')) system_ss.add(when: 'CONFIG_COLDFIRE', if_true: files('mcf_fec.c')) diff --git a/hw/net/npcm_gmac.c b/hw/net/npcm_gmac.c new file mode 100644 index 0000000..1b71e25 --- /dev/null +++ b/hw/net/npcm_gmac.c @@ -0,0 +1,942 @@ +/* + * Nuvoton NPCM7xx/8xx GMAC Module + * + * Copyright 2024 Google LLC + * Authors: + * Hao Wu <wuhaotsh@google.com> + * Nabih Estefan <nabihestefan@google.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + * + * Unsupported/unimplemented features: + * - MII is not implemented, MII_ADDR.BUSY and MII_DATA always return zero + * - Precision timestamp (PTP) is not implemented. + */ + +#include "qemu/osdep.h" + +#include "hw/registerfields.h" +#include "hw/net/mii.h" +#include "hw/net/npcm_gmac.h" +#include "migration/vmstate.h" +#include "net/checksum.h" +#include "net/eth.h" +#include "net/net.h" +#include "qemu/cutils.h" +#include "qemu/log.h" +#include "qemu/units.h" +#include "sysemu/dma.h" +#include "trace.h" + +REG32(NPCM_DMA_BUS_MODE, 0x1000) +REG32(NPCM_DMA_XMT_POLL_DEMAND, 0x1004) +REG32(NPCM_DMA_RCV_POLL_DEMAND, 0x1008) +REG32(NPCM_DMA_RX_BASE_ADDR, 0x100c) +REG32(NPCM_DMA_TX_BASE_ADDR, 0x1010) +REG32(NPCM_DMA_STATUS, 0x1014) +REG32(NPCM_DMA_CONTROL, 0x1018) +REG32(NPCM_DMA_INTR_ENA, 0x101c) +REG32(NPCM_DMA_MISSED_FRAME_CTR, 0x1020) +REG32(NPCM_DMA_HOST_TX_DESC, 0x1048) +REG32(NPCM_DMA_HOST_RX_DESC, 0x104c) +REG32(NPCM_DMA_CUR_TX_BUF_ADDR, 0x1050) +REG32(NPCM_DMA_CUR_RX_BUF_ADDR, 0x1054) +REG32(NPCM_DMA_HW_FEATURE, 0x1058) + +REG32(NPCM_GMAC_MAC_CONFIG, 0x0) +REG32(NPCM_GMAC_FRAME_FILTER, 0x4) +REG32(NPCM_GMAC_HASH_HIGH, 0x8) +REG32(NPCM_GMAC_HASH_LOW, 0xc) +REG32(NPCM_GMAC_MII_ADDR, 0x10) +REG32(NPCM_GMAC_MII_DATA, 0x14) +REG32(NPCM_GMAC_FLOW_CTRL, 0x18) +REG32(NPCM_GMAC_VLAN_FLAG, 0x1c) +REG32(NPCM_GMAC_VERSION, 0x20) +REG32(NPCM_GMAC_WAKEUP_FILTER, 0x28) +REG32(NPCM_GMAC_PMT, 0x2c) +REG32(NPCM_GMAC_LPI_CTRL, 0x30) +REG32(NPCM_GMAC_TIMER_CTRL, 0x34) +REG32(NPCM_GMAC_INT_STATUS, 0x38) +REG32(NPCM_GMAC_INT_MASK, 0x3c) +REG32(NPCM_GMAC_MAC0_ADDR_HI, 0x40) +REG32(NPCM_GMAC_MAC0_ADDR_LO, 0x44) +REG32(NPCM_GMAC_MAC1_ADDR_HI, 0x48) +REG32(NPCM_GMAC_MAC1_ADDR_LO, 0x4c) +REG32(NPCM_GMAC_MAC2_ADDR_HI, 0x50) +REG32(NPCM_GMAC_MAC2_ADDR_LO, 0x54) +REG32(NPCM_GMAC_MAC3_ADDR_HI, 0x58) +REG32(NPCM_GMAC_MAC3_ADDR_LO, 0x5c) +REG32(NPCM_GMAC_RGMII_STATUS, 0xd8) +REG32(NPCM_GMAC_WATCHDOG, 0xdc) +REG32(NPCM_GMAC_PTP_TCR, 0x700) +REG32(NPCM_GMAC_PTP_SSIR, 0x704) +REG32(NPCM_GMAC_PTP_STSR, 0x708) +REG32(NPCM_GMAC_PTP_STNSR, 0x70c) +REG32(NPCM_GMAC_PTP_STSUR, 0x710) +REG32(NPCM_GMAC_PTP_STNSUR, 0x714) +REG32(NPCM_GMAC_PTP_TAR, 0x718) +REG32(NPCM_GMAC_PTP_TTSR, 0x71c) + +/* Register Fields */ +#define NPCM_GMAC_MII_ADDR_BUSY BIT(0) +#define NPCM_GMAC_MII_ADDR_WRITE BIT(1) +#define NPCM_GMAC_MII_ADDR_GR(rv) extract16((rv), 6, 5) +#define NPCM_GMAC_MII_ADDR_PA(rv) extract16((rv), 11, 5) + +#define NPCM_GMAC_INT_MASK_LPIIM BIT(10) +#define NPCM_GMAC_INT_MASK_PMTM BIT(3) +#define NPCM_GMAC_INT_MASK_RGIM BIT(0) + +#define NPCM_DMA_BUS_MODE_SWR BIT(0) + +static const uint32_t npcm_gmac_cold_reset_values[NPCM_GMAC_NR_REGS] = { + /* Reduce version to 3.2 so that the kernel can enable interrupt. */ + [R_NPCM_GMAC_VERSION] = 0x00001032, + [R_NPCM_GMAC_TIMER_CTRL] = 0x03e80000, + [R_NPCM_GMAC_MAC0_ADDR_HI] = 0x8000ffff, + [R_NPCM_GMAC_MAC0_ADDR_LO] = 0xffffffff, + [R_NPCM_GMAC_MAC1_ADDR_HI] = 0x0000ffff, + [R_NPCM_GMAC_MAC1_ADDR_LO] = 0xffffffff, + [R_NPCM_GMAC_MAC2_ADDR_HI] = 0x0000ffff, + [R_NPCM_GMAC_MAC2_ADDR_LO] = 0xffffffff, + [R_NPCM_GMAC_MAC3_ADDR_HI] = 0x0000ffff, + [R_NPCM_GMAC_MAC3_ADDR_LO] = 0xffffffff, + [R_NPCM_GMAC_PTP_TCR] = 0x00002000, + [R_NPCM_DMA_BUS_MODE] = 0x00020101, + [R_NPCM_DMA_HW_FEATURE] = 0x100d4f37, +}; + +static const uint16_t phy_reg_init[] = { + [MII_BMCR] = MII_BMCR_AUTOEN | MII_BMCR_FD | MII_BMCR_SPEED1000, + [MII_BMSR] = MII_BMSR_100TX_FD | MII_BMSR_100TX_HD | MII_BMSR_10T_FD | + MII_BMSR_10T_HD | MII_BMSR_EXTSTAT | MII_BMSR_AUTONEG | + MII_BMSR_LINK_ST | MII_BMSR_EXTCAP, + [MII_PHYID1] = 0x0362, + [MII_PHYID2] = 0x5e6a, + [MII_ANAR] = MII_ANAR_TXFD | MII_ANAR_TX | MII_ANAR_10FD | + MII_ANAR_10 | MII_ANAR_CSMACD, + [MII_ANLPAR] = MII_ANLPAR_ACK | MII_ANLPAR_PAUSE | + MII_ANLPAR_TXFD | MII_ANLPAR_TX | MII_ANLPAR_10FD | + MII_ANLPAR_10 | MII_ANLPAR_CSMACD, + [MII_ANER] = 0x64 | MII_ANER_NWAY, + [MII_ANNP] = 0x2001, + [MII_CTRL1000] = MII_CTRL1000_FULL, + [MII_STAT1000] = MII_STAT1000_FULL, + [MII_EXTSTAT] = 0x3000, /* 1000BASTE_T full-duplex capable */ +}; + +static void npcm_gmac_soft_reset(NPCMGMACState *gmac) +{ + memcpy(gmac->regs, npcm_gmac_cold_reset_values, + NPCM_GMAC_NR_REGS * sizeof(uint32_t)); + /* Clear reset bits */ + gmac->regs[R_NPCM_DMA_BUS_MODE] &= ~NPCM_DMA_BUS_MODE_SWR; +} + +static void gmac_phy_set_link(NPCMGMACState *gmac, bool active) +{ + /* Autonegotiation status mirrors link status. */ + if (active) { + gmac->phy_regs[0][MII_BMSR] |= (MII_BMSR_LINK_ST | MII_BMSR_AN_COMP); + } else { + gmac->phy_regs[0][MII_BMSR] &= ~(MII_BMSR_LINK_ST | MII_BMSR_AN_COMP); + } +} + +static bool gmac_can_receive(NetClientState *nc) +{ + NPCMGMACState *gmac = NPCM_GMAC(qemu_get_nic_opaque(nc)); + + /* If GMAC receive is disabled. */ + if (!(gmac->regs[R_NPCM_GMAC_MAC_CONFIG] & NPCM_GMAC_MAC_CONFIG_RX_EN)) { + return false; + } + + /* If GMAC DMA RX is stopped. */ + if (!(gmac->regs[R_NPCM_DMA_CONTROL] & NPCM_DMA_CONTROL_START_STOP_RX)) { + return false; + } + return true; +} + +/* + * Function that updates the GMAC IRQ + * It find the logical OR of the enabled bits for NIS (if enabled) + * It find the logical OR of the enabled bits for AIS (if enabled) + */ +static void gmac_update_irq(NPCMGMACState *gmac) +{ + /* + * Check if the normal interrupts summary is enabled + * if so, add the bits for the summary that are enabled + */ + if (gmac->regs[R_NPCM_DMA_INTR_ENA] & gmac->regs[R_NPCM_DMA_STATUS] & + (NPCM_DMA_INTR_ENAB_NIE_BITS)) { + gmac->regs[R_NPCM_DMA_STATUS] |= NPCM_DMA_STATUS_NIS; + } + /* + * Check if the abnormal interrupts summary is enabled + * if so, add the bits for the summary that are enabled + */ + if (gmac->regs[R_NPCM_DMA_INTR_ENA] & gmac->regs[R_NPCM_DMA_STATUS] & + (NPCM_DMA_INTR_ENAB_AIE_BITS)) { + gmac->regs[R_NPCM_DMA_STATUS] |= NPCM_DMA_STATUS_AIS; + } + + /* Get the logical OR of both normal and abnormal interrupts */ + int level = !!((gmac->regs[R_NPCM_DMA_STATUS] & + gmac->regs[R_NPCM_DMA_INTR_ENA] & + NPCM_DMA_STATUS_NIS) | + (gmac->regs[R_NPCM_DMA_STATUS] & + gmac->regs[R_NPCM_DMA_INTR_ENA] & + NPCM_DMA_STATUS_AIS)); + + /* Set the IRQ */ + trace_npcm_gmac_update_irq(DEVICE(gmac)->canonical_path, + gmac->regs[R_NPCM_DMA_STATUS], + gmac->regs[R_NPCM_DMA_INTR_ENA], + level); + qemu_set_irq(gmac->irq, level); +} + +static int gmac_read_rx_desc(dma_addr_t addr, struct NPCMGMACRxDesc *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->rdes0 = le32_to_cpu(desc->rdes0); + desc->rdes1 = le32_to_cpu(desc->rdes1); + desc->rdes2 = le32_to_cpu(desc->rdes2); + desc->rdes3 = le32_to_cpu(desc->rdes3); + return 0; +} + +static int gmac_write_rx_desc(dma_addr_t addr, struct NPCMGMACRxDesc *desc) +{ + struct NPCMGMACRxDesc le_desc; + le_desc.rdes0 = cpu_to_le32(desc->rdes0); + le_desc.rdes1 = cpu_to_le32(desc->rdes1); + le_desc.rdes2 = cpu_to_le32(desc->rdes2); + le_desc.rdes3 = cpu_to_le32(desc->rdes3); + 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_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, + bool *eof_transferred, + const uint8_t **frame_ptr, + uint16_t *transferred) +{ + uint32_t to_transfer; + /* + * Check that buffer is bigger than the frame being transfered + * If bigger then transfer only whats left of frame + * Else, fill frame with all the content possible + */ + if (rx_buf_len >= *left_frame) { + to_transfer = *left_frame; + *eof_transferred = true; + } else { + to_transfer = rx_buf_len; + } + + /* write frame part to memory */ + if (dma_memory_write(&address_space_memory, (uint64_t) rx_buf_addr, + *frame_ptr, to_transfer, MEMTXATTRS_UNSPECIFIED)) { + return -1; + } + + /* update frame pointer and size of whats left of frame */ + *frame_ptr += to_transfer; + *left_frame -= to_transfer; + *transferred += to_transfer; + + return 0; +} + +static void gmac_dma_set_state(NPCMGMACState *gmac, int shift, uint32_t state) +{ + gmac->regs[R_NPCM_DMA_STATUS] = deposit32(gmac->regs[R_NPCM_DMA_STATUS], + shift, 3, state); +} + +static ssize_t gmac_receive(NetClientState *nc, const uint8_t *buf, size_t len) +{ + /* + * Comments have steps that relate to the + * receiving process steps in pg 386 + */ + NPCMGMACState *gmac = NPCM_GMAC(qemu_get_nic_opaque(nc)); + uint32_t left_frame = len; + const uint8_t *frame_ptr = buf; + uint32_t desc_addr; + uint32_t rx_buf_len, rx_buf_addr; + struct NPCMGMACRxDesc rx_desc; + uint16_t transferred = 0; + bool eof_transferred = false; + + trace_npcm_gmac_packet_receive(DEVICE(gmac)->canonical_path, len); + if (!gmac_can_receive(nc)) { + qemu_log_mask(LOG_GUEST_ERROR, "GMAC Currently is not able for Rx"); + return -1; + } + if (!gmac->regs[R_NPCM_DMA_HOST_RX_DESC]) { + gmac->regs[R_NPCM_DMA_HOST_RX_DESC] = + NPCM_DMA_HOST_RX_DESC_MASK(gmac->regs[R_NPCM_DMA_RX_BASE_ADDR]); + } + desc_addr = NPCM_DMA_HOST_RX_DESC_MASK(gmac->regs[R_NPCM_DMA_HOST_RX_DESC]); + + /* step 1 */ + gmac_dma_set_state(gmac, NPCM_DMA_STATUS_RX_PROCESS_STATE_SHIFT, + NPCM_DMA_STATUS_RX_RUNNING_FETCHING_STATE); + trace_npcm_gmac_packet_desc_read(DEVICE(gmac)->canonical_path, desc_addr); + if (gmac_read_rx_desc(desc_addr, &rx_desc)) { + qemu_log_mask(LOG_GUEST_ERROR, "RX Descriptor @ 0x%x cant be read\n", + desc_addr); + gmac_dma_set_state(gmac, NPCM_DMA_STATUS_RX_PROCESS_STATE_SHIFT, + NPCM_DMA_STATUS_RX_SUSPENDED_STATE); + return -1; + } + + /* step 2 */ + if (!(rx_desc.rdes0 & RX_DESC_RDES0_OWN)) { + qemu_log_mask(LOG_GUEST_ERROR, + "RX Descriptor @ 0x%x is owned by software\n", + desc_addr); + gmac->regs[R_NPCM_DMA_STATUS] |= NPCM_DMA_STATUS_RU; + gmac->regs[R_NPCM_DMA_STATUS] |= NPCM_DMA_STATUS_RI; + gmac_dma_set_state(gmac, NPCM_DMA_STATUS_RX_PROCESS_STATE_SHIFT, + NPCM_DMA_STATUS_RX_SUSPENDED_STATE); + gmac_update_irq(gmac); + return len; + } + /* step 3 */ + /* + * TODO -- + * Implement all frame filtering and processing (with its own interrupts) + */ + trace_npcm_gmac_debug_desc_data(DEVICE(gmac)->canonical_path, &rx_desc, + rx_desc.rdes0, rx_desc.rdes1, rx_desc.rdes2, + rx_desc.rdes3); + /* Clear rdes0 for the incoming descriptor and set FS in first descriptor.*/ + rx_desc.rdes0 = RX_DESC_RDES0_FIRST_DESC_MASK; + + gmac_dma_set_state(gmac, NPCM_DMA_STATUS_RX_PROCESS_STATE_SHIFT, + NPCM_DMA_STATUS_RX_RUNNING_TRANSFERRING_STATE); + + /* Pad the frame with FCS as the kernel driver will strip it away. */ + left_frame += ETH_FCS_LEN; + + /* repeat while we still have frame to transfer to memory */ + while (!eof_transferred) { + /* Return descriptor no matter what happens */ + rx_desc.rdes0 &= ~RX_DESC_RDES0_OWN; + /* Set the frame to be an IPv4/IPv6 frame. */ + rx_desc.rdes0 |= RX_DESC_RDES0_FRM_TYPE_MASK; + + /* step 4 */ + rx_buf_len = RX_DESC_RDES1_BFFR1_SZ_MASK(rx_desc.rdes1); + rx_buf_addr = rx_desc.rdes2; + gmac->regs[R_NPCM_DMA_CUR_RX_BUF_ADDR] = rx_buf_addr; + gmac_rx_transfer_frame_to_buffer(rx_buf_len, &left_frame, rx_buf_addr, + &eof_transferred, &frame_ptr, + &transferred); + + trace_npcm_gmac_packet_receiving_buffer(DEVICE(gmac)->canonical_path, + rx_buf_len, rx_buf_addr); + /* if we still have frame left and the second buffer is not chained */ + if (!(rx_desc.rdes1 & RX_DESC_RDES1_SEC_ADDR_CHND_MASK) && \ + !eof_transferred) { + /* repeat process from above on buffer 2 */ + rx_buf_len = RX_DESC_RDES1_BFFR2_SZ_MASK(rx_desc.rdes1); + rx_buf_addr = rx_desc.rdes3; + gmac->regs[R_NPCM_DMA_CUR_RX_BUF_ADDR] = rx_buf_addr; + gmac_rx_transfer_frame_to_buffer(rx_buf_len, &left_frame, + rx_buf_addr, &eof_transferred, + &frame_ptr, &transferred); + trace_npcm_gmac_packet_receiving_buffer( \ + DEVICE(gmac)->canonical_path, + rx_buf_len, rx_buf_addr); + } + /* update address for descriptor */ + gmac->regs[R_NPCM_DMA_HOST_RX_DESC] = rx_buf_addr; + /* Return descriptor */ + rx_desc.rdes0 &= ~RX_DESC_RDES0_OWN; + /* Update frame length transferred */ + rx_desc.rdes0 |= ((uint32_t)transferred) + << RX_DESC_RDES0_FRAME_LEN_SHIFT; + trace_npcm_gmac_debug_desc_data(DEVICE(gmac)->canonical_path, &rx_desc, + rx_desc.rdes0, rx_desc.rdes1, + rx_desc.rdes2, rx_desc.rdes3); + + /* step 5 */ + gmac_write_rx_desc(desc_addr, &rx_desc); + trace_npcm_gmac_debug_desc_data(DEVICE(gmac)->canonical_path, + &rx_desc, rx_desc.rdes0, + rx_desc.rdes1, rx_desc.rdes2, + rx_desc.rdes3); + /* read new descriptor into rx_desc if needed*/ + if (!eof_transferred) { + /* Get next descriptor address (chained or sequential) */ + if (rx_desc.rdes1 & RX_DESC_RDES1_RC_END_RING_MASK) { + desc_addr = gmac->regs[R_NPCM_DMA_RX_BASE_ADDR]; + } else if (rx_desc.rdes1 & RX_DESC_RDES1_SEC_ADDR_CHND_MASK) { + desc_addr = rx_desc.rdes3; + } else { + desc_addr += sizeof(rx_desc); + } + trace_npcm_gmac_packet_desc_read(DEVICE(gmac)->canonical_path, + desc_addr); + if (gmac_read_rx_desc(desc_addr, &rx_desc)) { + qemu_log_mask(LOG_GUEST_ERROR, + "RX Descriptor @ 0x%x cant be read\n", + desc_addr); + gmac->regs[R_NPCM_DMA_STATUS] |= NPCM_DMA_STATUS_RU; + gmac_update_irq(gmac); + return len; + } + + /* step 6 */ + if (!(rx_desc.rdes0 & RX_DESC_RDES0_OWN)) { + if (!(gmac->regs[R_NPCM_DMA_CONTROL] & \ + NPCM_DMA_CONTROL_FLUSH_MASK)) { + rx_desc.rdes0 |= RX_DESC_RDES0_DESC_ERR_MASK; + } + eof_transferred = true; + } + /* Clear rdes0 for the incoming descriptor */ + rx_desc.rdes0 = 0; + } + } + gmac_dma_set_state(gmac, NPCM_DMA_STATUS_RX_PROCESS_STATE_SHIFT, + NPCM_DMA_STATUS_RX_RUNNING_CLOSING_STATE); + + rx_desc.rdes0 |= RX_DESC_RDES0_LAST_DESC_MASK; + if (!(rx_desc.rdes1 & RX_DESC_RDES1_DIS_INTR_COMP_MASK)) { + gmac->regs[R_NPCM_DMA_STATUS] |= NPCM_DMA_STATUS_RI; + gmac_update_irq(gmac); + } + trace_npcm_gmac_debug_desc_data(DEVICE(gmac)->canonical_path, &rx_desc, + rx_desc.rdes0, rx_desc.rdes1, rx_desc.rdes2, + rx_desc.rdes3); + + /* step 8 */ + gmac->regs[R_NPCM_DMA_CONTROL] |= NPCM_DMA_CONTROL_FLUSH_MASK; + + /* step 9 */ + trace_npcm_gmac_packet_received(DEVICE(gmac)->canonical_path, left_frame); + gmac_dma_set_state(gmac, NPCM_DMA_STATUS_RX_PROCESS_STATE_SHIFT, + NPCM_DMA_STATUS_RX_RUNNING_WAITING_STATE); + gmac_write_rx_desc(desc_addr, &rx_desc); + + /* Get next descriptor address (chained or sequential) */ + if (rx_desc.rdes1 & RX_DESC_RDES1_RC_END_RING_MASK) { + desc_addr = gmac->regs[R_NPCM_DMA_RX_BASE_ADDR]; + } else if (rx_desc.rdes1 & RX_DESC_RDES1_SEC_ADDR_CHND_MASK) { + desc_addr = rx_desc.rdes3; + } else { + desc_addr += sizeof(rx_desc); + } + gmac->regs[R_NPCM_DMA_HOST_RX_DESC] = desc_addr; + 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. */ +} + +static void gmac_set_link(NetClientState *nc) +{ + NPCMGMACState *gmac = qemu_get_nic_opaque(nc); + + trace_npcm_gmac_set_link(!nc->link_down); + gmac_phy_set_link(gmac, !nc->link_down); +} + +static void npcm_gmac_mdio_access(NPCMGMACState *gmac, uint16_t v) +{ + bool busy = v & NPCM_GMAC_MII_ADDR_BUSY; + uint8_t is_write; + uint8_t pa, gr; + uint16_t data; + + if (busy) { + is_write = v & NPCM_GMAC_MII_ADDR_WRITE; + pa = NPCM_GMAC_MII_ADDR_PA(v); + gr = NPCM_GMAC_MII_ADDR_GR(v); + /* Both pa and gr are 5 bits, so they are less than 32. */ + g_assert(pa < NPCM_GMAC_MAX_PHYS); + g_assert(gr < NPCM_GMAC_MAX_PHY_REGS); + + + if (v & NPCM_GMAC_MII_ADDR_WRITE) { + data = gmac->regs[R_NPCM_GMAC_MII_DATA]; + /* Clear reset bit for BMCR register */ + switch (gr) { + case MII_BMCR: + data &= ~MII_BMCR_RESET; + /* Autonegotiation is a W1C bit*/ + if (data & MII_BMCR_ANRESTART) { + /* Tells autonegotiation to not restart again */ + data &= ~MII_BMCR_ANRESTART; + } + if ((data & MII_BMCR_AUTOEN) && + !(gmac->phy_regs[pa][MII_BMSR] & MII_BMSR_AN_COMP)) { + /* sets autonegotiation as complete */ + gmac->phy_regs[pa][MII_BMSR] |= MII_BMSR_AN_COMP; + /* Resolve AN automatically->need to set this */ + gmac->phy_regs[0][MII_ANLPAR] = 0x0000; + } + } + gmac->phy_regs[pa][gr] = data; + } else { + data = gmac->phy_regs[pa][gr]; + gmac->regs[R_NPCM_GMAC_MII_DATA] = data; + } + trace_npcm_gmac_mdio_access(DEVICE(gmac)->canonical_path, is_write, pa, + gr, data); + } + gmac->regs[R_NPCM_GMAC_MII_ADDR] = v & ~NPCM_GMAC_MII_ADDR_BUSY; +} + +static uint64_t npcm_gmac_read(void *opaque, hwaddr offset, unsigned size) +{ + NPCMGMACState *gmac = opaque; + uint32_t v = 0; + + switch (offset) { + /* Write only registers */ + case A_NPCM_DMA_XMT_POLL_DEMAND: + case A_NPCM_DMA_RCV_POLL_DEMAND: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Read of write-only reg: offset: 0x%04" HWADDR_PRIx + "\n", DEVICE(gmac)->canonical_path, offset); + break; + + default: + v = gmac->regs[offset / sizeof(uint32_t)]; + } + + trace_npcm_gmac_reg_read(DEVICE(gmac)->canonical_path, offset, v); + return v; +} + +static void npcm_gmac_write(void *opaque, hwaddr offset, + uint64_t v, unsigned size) +{ + NPCMGMACState *gmac = opaque; + + trace_npcm_gmac_reg_write(DEVICE(gmac)->canonical_path, offset, v); + + switch (offset) { + /* Read only registers */ + case A_NPCM_GMAC_VERSION: + case A_NPCM_GMAC_INT_STATUS: + case A_NPCM_GMAC_RGMII_STATUS: + case A_NPCM_GMAC_PTP_STSR: + case A_NPCM_GMAC_PTP_STNSR: + case A_NPCM_DMA_MISSED_FRAME_CTR: + case A_NPCM_DMA_HOST_TX_DESC: + case A_NPCM_DMA_HOST_RX_DESC: + case A_NPCM_DMA_CUR_TX_BUF_ADDR: + case A_NPCM_DMA_CUR_RX_BUF_ADDR: + case A_NPCM_DMA_HW_FEATURE: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Write of read-only reg: offset: 0x%04" HWADDR_PRIx + ", value: 0x%04" PRIx64 "\n", + DEVICE(gmac)->canonical_path, offset, v); + break; + + case A_NPCM_GMAC_MAC_CONFIG: + gmac->regs[offset / sizeof(uint32_t)] = v; + break; + + case A_NPCM_GMAC_MII_ADDR: + npcm_gmac_mdio_access(gmac, v); + break; + + case A_NPCM_GMAC_MAC0_ADDR_HI: + gmac->regs[offset / sizeof(uint32_t)] = v; + gmac->conf.macaddr.a[0] = v >> 8; + gmac->conf.macaddr.a[1] = v >> 0; + break; + + case A_NPCM_GMAC_MAC0_ADDR_LO: + gmac->regs[offset / sizeof(uint32_t)] = v; + gmac->conf.macaddr.a[2] = v >> 24; + gmac->conf.macaddr.a[3] = v >> 16; + gmac->conf.macaddr.a[4] = v >> 8; + gmac->conf.macaddr.a[5] = v >> 0; + break; + + case A_NPCM_GMAC_MAC1_ADDR_HI: + case A_NPCM_GMAC_MAC1_ADDR_LO: + case A_NPCM_GMAC_MAC2_ADDR_HI: + case A_NPCM_GMAC_MAC2_ADDR_LO: + case A_NPCM_GMAC_MAC3_ADDR_HI: + case A_NPCM_GMAC_MAC3_ADDR_LO: + gmac->regs[offset / sizeof(uint32_t)] = v; + qemu_log_mask(LOG_UNIMP, + "%s: Only MAC Address 0 is supported. This request " + "is ignored.\n", DEVICE(gmac)->canonical_path); + break; + + case A_NPCM_DMA_BUS_MODE: + gmac->regs[offset / sizeof(uint32_t)] = v; + if (v & NPCM_DMA_BUS_MODE_SWR) { + npcm_gmac_soft_reset(gmac); + } + break; + + case A_NPCM_DMA_RCV_POLL_DEMAND: + /* We dont actually care about the value */ + gmac_dma_set_state(gmac, NPCM_DMA_STATUS_RX_PROCESS_STATE_SHIFT, + 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)) { + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Write of read-only bits of reg: offset: 0x%04" + HWADDR_PRIx ", value: 0x%04" PRIx64 "\n", + DEVICE(gmac)->canonical_path, offset, v); + } + /* for W1C bits, implement W1C */ + gmac->regs[offset / sizeof(uint32_t)] &= ~NPCM_DMA_STATUS_W1C_MASK(v); + if (v & NPCM_DMA_STATUS_RU) { + /* Clearing RU bit indicates descriptor is owned by DMA again. */ + 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)); + } + break; + + default: + gmac->regs[offset / sizeof(uint32_t)] = v; + break; + } + + gmac_update_irq(gmac); +} + +static void npcm_gmac_reset(DeviceState *dev) +{ + NPCMGMACState *gmac = NPCM_GMAC(dev); + + npcm_gmac_soft_reset(gmac); + memcpy(gmac->phy_regs[0], phy_reg_init, sizeof(phy_reg_init)); + + trace_npcm_gmac_reset(DEVICE(gmac)->canonical_path, + gmac->phy_regs[0][MII_BMSR]); +} + +static NetClientInfo net_npcm_gmac_info = { + .type = NET_CLIENT_DRIVER_NIC, + .size = sizeof(NICState), + .can_receive = gmac_can_receive, + .receive = gmac_receive, + .cleanup = gmac_cleanup, + .link_status_changed = gmac_set_link, +}; + +static const struct MemoryRegionOps npcm_gmac_ops = { + .read = npcm_gmac_read, + .write = npcm_gmac_write, + .endianness = DEVICE_LITTLE_ENDIAN, + .valid = { + .min_access_size = 4, + .max_access_size = 4, + .unaligned = false, + }, +}; + +static void npcm_gmac_realize(DeviceState *dev, Error **errp) +{ + NPCMGMACState *gmac = NPCM_GMAC(dev); + SysBusDevice *sbd = SYS_BUS_DEVICE(dev); + + memory_region_init_io(&gmac->iomem, OBJECT(gmac), &npcm_gmac_ops, gmac, + TYPE_NPCM_GMAC, 8 * KiB); + sysbus_init_mmio(sbd, &gmac->iomem); + sysbus_init_irq(sbd, &gmac->irq); + + qemu_macaddr_default_if_unset(&gmac->conf.macaddr); + + gmac->nic = qemu_new_nic(&net_npcm_gmac_info, &gmac->conf, TYPE_NPCM_GMAC, + dev->id, &dev->mem_reentrancy_guard, gmac); + qemu_format_nic_info_str(qemu_get_queue(gmac->nic), gmac->conf.macaddr.a); + gmac->regs[R_NPCM_GMAC_MAC0_ADDR_HI] = (gmac->conf.macaddr.a[0] << 8) + \ + gmac->conf.macaddr.a[1]; + gmac->regs[R_NPCM_GMAC_MAC0_ADDR_LO] = (gmac->conf.macaddr.a[2] << 24) + \ + (gmac->conf.macaddr.a[3] << 16) + \ + (gmac->conf.macaddr.a[4] << 8) + \ + gmac->conf.macaddr.a[5]; +} + +static void npcm_gmac_unrealize(DeviceState *dev) +{ + NPCMGMACState *gmac = NPCM_GMAC(dev); + + qemu_del_nic(gmac->nic); +} + +static const VMStateDescription vmstate_npcm_gmac = { + .name = TYPE_NPCM_GMAC, + .version_id = 0, + .minimum_version_id = 0, + .fields = (VMStateField[]) { + VMSTATE_UINT32_ARRAY(regs, NPCMGMACState, NPCM_GMAC_NR_REGS), + VMSTATE_END_OF_LIST(), + }, +}; + +static Property npcm_gmac_properties[] = { + DEFINE_NIC_PROPERTIES(NPCMGMACState, conf), + DEFINE_PROP_END_OF_LIST(), +}; + +static void npcm_gmac_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + set_bit(DEVICE_CATEGORY_NETWORK, dc->categories); + dc->desc = "NPCM GMAC Controller"; + dc->realize = npcm_gmac_realize; + dc->unrealize = npcm_gmac_unrealize; + dc->reset = npcm_gmac_reset; + dc->vmsd = &vmstate_npcm_gmac; + device_class_set_props(dc, npcm_gmac_properties); +} + +static const TypeInfo npcm_gmac_types[] = { + { + .name = TYPE_NPCM_GMAC, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(NPCMGMACState), + .class_init = npcm_gmac_class_init, + }, +}; +DEFINE_TYPES(npcm_gmac_types) diff --git a/hw/net/trace-events b/hw/net/trace-events index 387e32e..78efa2e 100644 --- a/hw/net/trace-events +++ b/hw/net/trace-events @@ -467,6 +467,25 @@ npcm7xx_emc_rx_done(uint32_t crxdsa) "RX done, CRXDSA=0x%x" npcm7xx_emc_reg_read(int emc_num, uint32_t result, const char *name, int regno) "emc%d: 0x%x = reg[%s/%d]" npcm7xx_emc_reg_write(int emc_num, const char *name, int regno, uint32_t value) "emc%d: reg[%s/%d] = 0x%x" +# npcm_gmac.c +npcm_gmac_reg_read(const char *name, uint64_t offset, uint32_t value) "%s: offset: 0x%04" PRIx64 " value: 0x%04" PRIx32 +npcm_gmac_reg_write(const char *name, uint64_t offset, uint32_t value) "%s: offset: 0x%04" PRIx64 " value: 0x%04" PRIx32 +npcm_gmac_mdio_access(const char *name, uint8_t is_write, uint8_t pa, uint8_t gr, uint16_t val) "%s: is_write: %" PRIu8 " pa: %" PRIu8 " gr: %" PRIu8 " val: 0x%04" PRIx16 +npcm_gmac_reset(const char *name, uint16_t value) "%s: phy_regs[0][1]: 0x%04" PRIx16 +npcm_gmac_set_link(bool active) "Set link: active=%u" +npcm_gmac_update_irq(const char *name, uint32_t status, uint32_t intr_en, int level) "%s: Status Reg: 0x%04" PRIX32 " Interrupt Enable Reg: 0x%04" PRIX32 " IRQ Set: %d" +npcm_gmac_packet_desc_read(const char* name, uint32_t desc_addr) "%s: attempting to read descriptor @0x%04" PRIX32 +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 +npcm_pcs_reg_write(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 + # dp8398x.c dp8393x_raise_irq(int isr) "raise irq, isr is 0x%04x" dp8393x_lower_irq(void) "lower irq" |