| /* |
| * RX ucode for the Intel IXP2400 in POS-PHY mode. |
| * Copyright (C) 2004, 2005 Lennert Buytenhek |
| * Dedicated to Marija Kulikova. |
| * |
| * 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. |
| * |
| * Assumptions made in this code: |
| * - The IXP2400 MSF is configured for POS-PHY mode, in a mode where |
| * only one full element list is used. This includes, for example, |
| * 1x32 SPHY and 1x32 MPHY32, but not 4x8 SPHY or 1x32 MPHY4. (This |
| * is not an exhaustive list.) |
| * - The RBUF uses 64-byte mpackets. |
| * - RX descriptors reside in SRAM, and have the following format: |
| * struct rx_desc |
| * { |
| * // to uengine |
| * u32 buf_phys_addr; |
| * u32 buf_length; |
| * |
| * // from uengine |
| * u32 channel; |
| * u32 pkt_length; |
| * }; |
| * - Packet data resides in DRAM. |
| * - Packet buffer addresses are 8-byte aligned. |
| * - Scratch ring 0 is rx_pending. |
| * - Scratch ring 1 is rx_done, and has status condition 'full'. |
| * - The host triggers rx_done flush and rx_pending refill on seeing INTA. |
| * - This code is run on all eight threads of the microengine it runs on. |
| * |
| * Local memory is used for per-channel RX state. |
| */ |
| |
| #define RX_THREAD_FREELIST_0 0x0030 |
| #define RBUF_ELEMENT_DONE 0x0044 |
| |
| #define CHANNEL_FLAGS *l$index0[0] |
| #define CHANNEL_FLAG_RECEIVING 1 |
| #define PACKET_LENGTH *l$index0[1] |
| #define PACKET_CHECKSUM *l$index0[2] |
| #define BUFFER_HANDLE *l$index0[3] |
| #define BUFFER_START *l$index0[4] |
| #define BUFFER_LENGTH *l$index0[5] |
| |
| #define CHANNEL_STATE_SIZE 24 // in bytes |
| #define CHANNEL_STATE_SHIFT 5 // ceil(log2(state size)) |
| |
| |
| .sig volatile sig1 |
| .sig volatile sig2 |
| .sig volatile sig3 |
| |
| .sig mpacket_arrived |
| .reg add_to_rx_freelist |
| .reg read $rsw0, $rsw1 |
| .xfer_order $rsw0 $rsw1 |
| |
| .reg zero |
| |
| /* |
| * Initialise add_to_rx_freelist. |
| */ |
| .begin |
| .reg temp |
| .reg temp2 |
| |
| immed[add_to_rx_freelist, RX_THREAD_FREELIST_0] |
| immed_w1[add_to_rx_freelist, (&$rsw0 | (&mpacket_arrived << 12))] |
| |
| local_csr_rd[ACTIVE_CTX_STS] |
| immed[temp, 0] |
| alu[temp2, temp, and, 0x1f] |
| alu_shf[add_to_rx_freelist, add_to_rx_freelist, or, temp2, <<20] |
| alu[temp2, temp, and, 0x80] |
| alu_shf[add_to_rx_freelist, add_to_rx_freelist, or, temp2, <<18] |
| .end |
| |
| immed[zero, 0] |
| |
| /* |
| * Skip context 0 initialisation? |
| */ |
| .begin |
| br!=ctx[0, mpacket_receive_loop#] |
| .end |
| |
| /* |
| * Initialise local memory. |
| */ |
| .begin |
| .reg addr |
| .reg temp |
| |
| immed[temp, 0] |
| init_local_mem_loop#: |
| alu_shf[addr, --, b, temp, <<CHANNEL_STATE_SHIFT] |
| local_csr_wr[ACTIVE_LM_ADDR_0, addr] |
| nop |
| nop |
| nop |
| |
| immed[CHANNEL_FLAGS, 0] |
| |
| alu[temp, temp, +, 1] |
| alu[--, temp, and, 0x20] |
| beq[init_local_mem_loop#] |
| .end |
| |
| /* |
| * Initialise signal pipeline. |
| */ |
| .begin |
| local_csr_wr[SAME_ME_SIGNAL, (&sig1 << 3)] |
| .set_sig sig1 |
| |
| local_csr_wr[SAME_ME_SIGNAL, (&sig2 << 3)] |
| .set_sig sig2 |
| |
| local_csr_wr[SAME_ME_SIGNAL, (&sig3 << 3)] |
| .set_sig sig3 |
| .end |
| |
| mpacket_receive_loop#: |
| /* |
| * Synchronise and wait for mpacket. |
| */ |
| .begin |
| ctx_arb[sig1] |
| local_csr_wr[SAME_ME_SIGNAL, (0x80 | (&sig1 << 3))] |
| |
| msf[fast_wr, --, add_to_rx_freelist, 0] |
| .set_sig mpacket_arrived |
| ctx_arb[mpacket_arrived] |
| .set $rsw0 $rsw1 |
| .end |
| |
| /* |
| * We halt if we see {inbparerr,parerr,null,soperror}. |
| */ |
| .begin |
| alu_shf[--, 0x1b, and, $rsw0, >>8] |
| bne[abort_rswerr#] |
| .end |
| |
| /* |
| * Point local memory pointer to this channel's state area. |
| */ |
| .begin |
| .reg chanaddr |
| |
| alu[chanaddr, $rsw0, and, 0x1f] |
| alu_shf[chanaddr, --, b, chanaddr, <<CHANNEL_STATE_SHIFT] |
| local_csr_wr[ACTIVE_LM_ADDR_0, chanaddr] |
| nop |
| nop |
| nop |
| .end |
| |
| /* |
| * Check whether we received a SOP mpacket while we were already |
| * working on a packet, or a non-SOP mpacket while there was no |
| * packet pending. (SOP == RECEIVING -> abort) If everything's |
| * okay, update the RECEIVING flag to reflect our new state. |
| */ |
| .begin |
| .reg temp |
| .reg eop |
| |
| #if CHANNEL_FLAG_RECEIVING != 1 |
| #error CHANNEL_FLAG_RECEIVING is not 1 |
| #endif |
| |
| alu_shf[temp, 1, and, $rsw0, >>15] |
| alu[temp, temp, xor, CHANNEL_FLAGS] |
| alu[--, temp, and, CHANNEL_FLAG_RECEIVING] |
| beq[abort_proterr#] |
| |
| alu_shf[eop, 1, and, $rsw0, >>14] |
| alu[CHANNEL_FLAGS, temp, xor, eop] |
| .end |
| |
| /* |
| * Copy the mpacket into the right spot, and in case of EOP, |
| * write back the descriptor and pass the packet on. |
| */ |
| .begin |
| .reg buffer_offset |
| .reg _packet_length |
| .reg _packet_checksum |
| .reg _buffer_handle |
| .reg _buffer_start |
| .reg _buffer_length |
| |
| /* |
| * Determine buffer_offset, _packet_length and |
| * _packet_checksum. |
| */ |
| .begin |
| .reg temp |
| |
| alu[--, 1, and, $rsw0, >>15] |
| beq[not_sop#] |
| |
| immed[PACKET_LENGTH, 0] |
| immed[PACKET_CHECKSUM, 0] |
| |
| not_sop#: |
| alu[buffer_offset, --, b, PACKET_LENGTH] |
| alu_shf[temp, 0xff, and, $rsw0, >>16] |
| alu[_packet_length, buffer_offset, +, temp] |
| alu[PACKET_LENGTH, --, b, _packet_length] |
| |
| immed[temp, 0xffff] |
| alu[temp, $rsw1, and, temp] |
| alu[_packet_checksum, PACKET_CHECKSUM, +, temp] |
| alu[PACKET_CHECKSUM, --, b, _packet_checksum] |
| .end |
| |
| /* |
| * Allocate buffer in case of SOP. |
| */ |
| .begin |
| .reg temp |
| |
| alu[temp, 1, and, $rsw0, >>15] |
| beq[skip_buffer_alloc#] |
| |
| .begin |
| .sig zzz |
| .reg read $stemp $stemp2 |
| .xfer_order $stemp $stemp2 |
| |
| rx_nobufs#: |
| scratch[get, $stemp, zero, 0, 1], ctx_swap[zzz] |
| alu[_buffer_handle, --, b, $stemp] |
| beq[rx_nobufs#] |
| |
| sram[read, $stemp, _buffer_handle, 0, 2], |
| ctx_swap[zzz] |
| alu[_buffer_start, --, b, $stemp] |
| alu[_buffer_length, --, b, $stemp2] |
| .end |
| |
| skip_buffer_alloc#: |
| .end |
| |
| /* |
| * Resynchronise. |
| */ |
| .begin |
| ctx_arb[sig2] |
| local_csr_wr[SAME_ME_SIGNAL, (0x80 | (&sig2 << 3))] |
| .end |
| |
| /* |
| * Synchronise buffer state. |
| */ |
| .begin |
| .reg temp |
| |
| alu[temp, 1, and, $rsw0, >>15] |
| beq[copy_from_local_mem#] |
| |
| alu[BUFFER_HANDLE, --, b, _buffer_handle] |
| alu[BUFFER_START, --, b, _buffer_start] |
| alu[BUFFER_LENGTH, --, b, _buffer_length] |
| br[sync_state_done#] |
| |
| copy_from_local_mem#: |
| alu[_buffer_handle, --, b, BUFFER_HANDLE] |
| alu[_buffer_start, --, b, BUFFER_START] |
| alu[_buffer_length, --, b, BUFFER_LENGTH] |
| |
| sync_state_done#: |
| .end |
| |
| #if 0 |
| /* |
| * Debug buffer state management. |
| */ |
| .begin |
| .reg temp |
| |
| alu[temp, 1, and, $rsw0, >>14] |
| beq[no_poison#] |
| immed[BUFFER_HANDLE, 0xdead] |
| immed[BUFFER_START, 0xdead] |
| immed[BUFFER_LENGTH, 0xdead] |
| no_poison#: |
| |
| immed[temp, 0xdead] |
| alu[--, _buffer_handle, -, temp] |
| beq[state_corrupted#] |
| alu[--, _buffer_start, -, temp] |
| beq[state_corrupted#] |
| alu[--, _buffer_length, -, temp] |
| beq[state_corrupted#] |
| .end |
| #endif |
| |
| /* |
| * Check buffer length. |
| */ |
| .begin |
| alu[--, _buffer_length, -, _packet_length] |
| blo[buffer_overflow#] |
| .end |
| |
| /* |
| * Copy the mpacket and give back the RBUF element. |
| */ |
| .begin |
| .reg element |
| .reg xfer_size |
| .reg temp |
| .sig copy_sig |
| |
| alu_shf[element, 0x7f, and, $rsw0, >>24] |
| alu_shf[xfer_size, 0xff, and, $rsw0, >>16] |
| |
| alu[xfer_size, xfer_size, -, 1] |
| alu_shf[xfer_size, 0x10, or, xfer_size, >>3] |
| alu_shf[temp, 0x10, or, xfer_size, <<21] |
| alu_shf[temp, temp, or, element, <<11] |
| alu_shf[--, temp, or, 1, <<18] |
| |
| dram[rbuf_rd, --, _buffer_start, buffer_offset, max_8], |
| indirect_ref, sig_done[copy_sig] |
| ctx_arb[copy_sig] |
| |
| alu[temp, RBUF_ELEMENT_DONE, or, element, <<16] |
| msf[fast_wr, --, temp, 0] |
| .end |
| |
| /* |
| * If EOP, write back the packet descriptor. |
| */ |
| .begin |
| .reg write $stemp $stemp2 |
| .xfer_order $stemp $stemp2 |
| .sig zzz |
| |
| alu_shf[--, 1, and, $rsw0, >>14] |
| beq[no_writeback#] |
| |
| alu[$stemp, $rsw0, and, 0x1f] |
| alu[$stemp2, --, b, _packet_length] |
| sram[write, $stemp, _buffer_handle, 8, 2], ctx_swap[zzz] |
| |
| no_writeback#: |
| .end |
| |
| /* |
| * Resynchronise. |
| */ |
| .begin |
| ctx_arb[sig3] |
| local_csr_wr[SAME_ME_SIGNAL, (0x80 | (&sig3 << 3))] |
| .end |
| |
| /* |
| * If EOP, put the buffer back onto the scratch ring. |
| */ |
| .begin |
| .reg write $stemp |
| .sig zzz |
| |
| br_inp_state[SCR_Ring1_Status, rx_done_ring_overflow#] |
| |
| alu_shf[--, 1, and, $rsw0, >>14] |
| beq[mpacket_receive_loop#] |
| |
| alu[--, 1, and, $rsw0, >>10] |
| bne[rxerr#] |
| |
| alu[$stemp, --, b, _buffer_handle] |
| scratch[put, $stemp, zero, 4, 1], ctx_swap[zzz] |
| cap[fast_wr, 0, XSCALE_INT_A] |
| br[mpacket_receive_loop#] |
| |
| rxerr#: |
| alu[$stemp, --, b, _buffer_handle] |
| scratch[put, $stemp, zero, 0, 1], ctx_swap[zzz] |
| br[mpacket_receive_loop#] |
| .end |
| .end |
| |
| |
| abort_rswerr#: |
| halt |
| |
| abort_proterr#: |
| halt |
| |
| state_corrupted#: |
| halt |
| |
| buffer_overflow#: |
| halt |
| |
| rx_done_ring_overflow#: |
| halt |
| |
| |