diff options
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/ssi/pnv_spi.c | 1045 | ||||
| -rw-r--r-- | hw/ssi/trace-events | 15 |
2 files changed, 1060 insertions, 0 deletions
diff --git a/hw/ssi/pnv_spi.c b/hw/ssi/pnv_spi.c index 468afdad07..cdff3f9621 100644 --- a/hw/ssi/pnv_spi.c +++ b/hw/ssi/pnv_spi.c @@ -17,6 +17,9 @@ #include "hw/irq.h" #include "trace.h" +#define PNV_SPI_OPCODE_LO_NIBBLE(x) (x & 0x0F) +#define PNV_SPI_MASKED_OPCODE(x) (x & 0xF0) + /* * Macro from include/hw/ppc/fdt.h * fdt.h cannot be included here as it contain ppc target specific dependency. @@ -32,6 +35,1040 @@ } \ } while (0) +/* PnvXferBuffer */ +typedef struct PnvXferBuffer { + + uint32_t len; + uint8_t *data; + +} PnvXferBuffer; + +/* pnv_spi_xfer_buffer_methods */ +static PnvXferBuffer *pnv_spi_xfer_buffer_new(void) +{ + PnvXferBuffer *payload = g_malloc0(sizeof(*payload)); + + return payload; +} + +static void pnv_spi_xfer_buffer_free(PnvXferBuffer *payload) +{ + free(payload->data); + free(payload); +} + +static uint8_t *pnv_spi_xfer_buffer_write_ptr(PnvXferBuffer *payload, + uint32_t offset, uint32_t length) +{ + if (payload->len < (offset + length)) { + payload->len = offset + length; + payload->data = g_realloc(payload->data, payload->len); + } + return &payload->data[offset]; +} + +static bool does_rdr_match(PnvSpi *s) +{ + /* + * According to spec, the mask bits that are 0 are compared and the + * bits that are 1 are ignored. + */ + uint16_t rdr_match_mask = GETFIELD(SPI_MM_RDR_MATCH_MASK, + s->regs[SPI_MM_REG]); + uint16_t rdr_match_val = GETFIELD(SPI_MM_RDR_MATCH_VAL, + s->regs[SPI_MM_REG]); + + if ((~rdr_match_mask & rdr_match_val) == ((~rdr_match_mask) & + GETFIELD(PPC_BITMASK(48, 63), s->regs[SPI_RCV_DATA_REG]))) { + return true; + } + return false; +} + +static uint8_t get_from_offset(PnvSpi *s, uint8_t offset) +{ + uint8_t byte; + + /* + * Offset is an index between 0 and PNV_SPI_REG_SIZE - 1 + * Check the offset before using it. + */ + if (offset < PNV_SPI_REG_SIZE) { + byte = (s->regs[SPI_XMIT_DATA_REG] >> (56 - offset * 8)) & 0xFF; + } else { + /* + * Log an error and return a 0xFF since we have to assign something + * to byte before returning. + */ + qemu_log_mask(LOG_GUEST_ERROR, "Invalid offset = %d used to get byte " + "from TDR\n", offset); + byte = 0xff; + } + return byte; +} + +static uint8_t read_from_frame(PnvSpi *s, uint8_t *read_buf, uint8_t nr_bytes, + uint8_t ecc_count, uint8_t shift_in_count) +{ + uint8_t byte; + int count = 0; + + while (count < nr_bytes) { + shift_in_count++; + if ((ecc_count != 0) && + (shift_in_count == (PNV_SPI_REG_SIZE + ecc_count))) { + shift_in_count = 0; + } else { + byte = read_buf[count]; + trace_pnv_spi_shift_rx(byte, count); + s->regs[SPI_RCV_DATA_REG] = (s->regs[SPI_RCV_DATA_REG] << 8) | byte; + } + count++; + } /* end of while */ + return shift_in_count; +} + +static void spi_response(PnvSpi *s, int bits, PnvXferBuffer *rsp_payload) +{ + uint8_t ecc_count; + uint8_t shift_in_count; + + /* + * Processing here must handle: + * - Which bytes in the payload we should move to the RDR + * - Explicit mode counter configuration settings + * - RDR full and RDR overrun status + */ + + /* + * First check that the response payload is the exact same + * number of bytes as the request payload was + */ + if (rsp_payload->len != (s->N1_bytes + s->N2_bytes)) { + qemu_log_mask(LOG_GUEST_ERROR, "Invalid response payload size in " + "bytes, expected %d, got %d\n", + (s->N1_bytes + s->N2_bytes), rsp_payload->len); + } else { + uint8_t ecc_control; + trace_pnv_spi_rx_received(rsp_payload->len); + trace_pnv_spi_log_Ncounts(s->N1_bits, s->N1_bytes, s->N1_tx, + s->N1_rx, s->N2_bits, s->N2_bytes, s->N2_tx, s->N2_rx); + /* + * Adding an ECC count let's us know when we have found a payload byte + * that was shifted in but cannot be loaded into RDR. Bits 29-30 of + * clock_config_reset_control register equal to either 0b00 or 0b10 + * indicate that we are taking in data with ECC and either applying + * the ECC or discarding it. + */ + ecc_count = 0; + ecc_control = GETFIELD(SPI_CLK_CFG_ECC_CTRL, s->regs[SPI_CLK_CFG_REG]); + if (ecc_control == 0 || ecc_control == 2) { + ecc_count = 1; + } + /* + * Use the N1_rx and N2_rx counts to control shifting data from the + * payload into the RDR. Keep an overall count of the number of bytes + * shifted into RDR so we can discard every 9th byte when ECC is + * enabled. + */ + shift_in_count = 0; + /* Handle the N1 portion of the frame first */ + if (s->N1_rx != 0) { + trace_pnv_spi_rx_read_N1frame(); + shift_in_count = read_from_frame(s, &rsp_payload->data[0], + s->N1_bytes, ecc_count, shift_in_count); + } + /* Handle the N2 portion of the frame */ + if (s->N2_rx != 0) { + trace_pnv_spi_rx_read_N2frame(); + shift_in_count = read_from_frame(s, + &rsp_payload->data[s->N1_bytes], s->N2_bytes, + ecc_count, shift_in_count); + } + if ((s->N1_rx + s->N2_rx) > 0) { + /* + * Data was received so handle RDR status. + * It is easier to handle RDR_full and RDR_overrun status here + * since the RDR register's shift_byte_in method is called + * multiple times in a row. Controlling RDR status is done here + * instead of in the RDR scoped methods for that reason. + */ + if (GETFIELD(SPI_STS_RDR_FULL, s->status) == 1) { + /* + * Data was shifted into the RDR before having been read + * causing previous data to have been overrun. + */ + s->status = SETFIELD(SPI_STS_RDR_OVERRUN, s->status, 1); + } else { + /* + * Set status to indicate that the received data register is + * full. This flag is only cleared once the RDR is unloaded. + */ + s->status = SETFIELD(SPI_STS_RDR_FULL, s->status, 1); + } + } + } /* end of else */ +} /* end of spi_response() */ + +static void transfer(PnvSpi *s, PnvXferBuffer *payload) +{ + uint32_t tx; + uint32_t rx; + PnvXferBuffer *rsp_payload = NULL; + + rsp_payload = pnv_spi_xfer_buffer_new(); + for (int offset = 0; offset < payload->len; offset += s->transfer_len) { + tx = 0; + for (int i = 0; i < s->transfer_len; i++) { + if ((offset + i) >= payload->len) { + tx <<= 8; + } else { + tx = (tx << 8) | payload->data[offset + i]; + } + } + rx = ssi_transfer(s->ssi_bus, tx); + for (int i = 0; i < s->transfer_len; i++) { + if ((offset + i) >= payload->len) { + break; + } + *(pnv_spi_xfer_buffer_write_ptr(rsp_payload, rsp_payload->len, 1)) = + (rx >> (8 * (s->transfer_len - 1) - i * 8)) & 0xFF; + } + } + if (rsp_payload != NULL) { + spi_response(s, s->N1_bits, rsp_payload); + } +} + +static inline uint8_t get_seq_index(PnvSpi *s) +{ + return GETFIELD(SPI_STS_SEQ_INDEX, s->status); +} + +static inline void next_sequencer_fsm(PnvSpi *s) +{ + uint8_t seq_index = get_seq_index(s); + s->status = SETFIELD(SPI_STS_SEQ_INDEX, s->status, (seq_index + 1)); + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_INDEX_INCREMENT); +} + +/* + * Calculate the N1 counters based on passed in opcode and + * internal register values. + * The method assumes that the opcode is a Shift_N1 opcode + * and doesn't test it. + * The counters returned are: + * N1 bits: Number of bits in the payload data that are significant + * to the responder. + * N1_bytes: Total count of payload bytes for the N1 (portion of the) frame. + * N1_tx: Total number of bytes taken from TDR for N1 + * N1_rx: Total number of bytes taken from the payload for N1 + */ +static void calculate_N1(PnvSpi *s, uint8_t opcode) +{ + /* + * Shift_N1 opcode form: 0x3M + * Implicit mode: + * If M != 0 the shift count is M bytes and M is the number of tx bytes. + * Forced Implicit mode: + * M is the shift count but tx and rx is determined by the count control + * register fields. Note that we only check for forced Implicit mode when + * M != 0 since the mode doesn't make sense when M = 0. + * Explicit mode: + * If M == 0 then shift count is number of bits defined in the + * Counter Configuration Register's shift_count_N1 field. + */ + if (PNV_SPI_OPCODE_LO_NIBBLE(opcode) == 0) { + /* Explicit mode */ + s->N1_bits = GETFIELD(SPI_CTR_CFG_N1, s->regs[SPI_CTR_CFG_REG]); + s->N1_bytes = (s->N1_bits + 7) / 8; + s->N1_tx = 0; + s->N1_rx = 0; + /* If tx count control for N1 is set, load the tx value */ + if (GETFIELD(SPI_CTR_CFG_N1_CTRL_B2, s->regs[SPI_CTR_CFG_REG]) == 1) { + s->N1_tx = s->N1_bytes; + } + /* If rx count control for N1 is set, load the rx value */ + if (GETFIELD(SPI_CTR_CFG_N1_CTRL_B3, s->regs[SPI_CTR_CFG_REG]) == 1) { + s->N1_rx = s->N1_bytes; + } + } else { + /* Implicit mode/Forced Implicit mode, use M field from opcode */ + s->N1_bytes = PNV_SPI_OPCODE_LO_NIBBLE(opcode); + s->N1_bits = s->N1_bytes * 8; + /* + * Assume that we are going to transmit the count + * (pure Implicit only) + */ + s->N1_tx = s->N1_bytes; + s->N1_rx = 0; + /* Let Forced Implicit mode have an effect on the counts */ + if (GETFIELD(SPI_CTR_CFG_N1_CTRL_B1, s->regs[SPI_CTR_CFG_REG]) == 1) { + /* + * If Forced Implicit mode and count control doesn't + * indicate transmit then reset the tx count to 0 + */ + if (GETFIELD(SPI_CTR_CFG_N1_CTRL_B2, + s->regs[SPI_CTR_CFG_REG]) == 0) { + s->N1_tx = 0; + } + /* If rx count control for N1 is set, load the rx value */ + if (GETFIELD(SPI_CTR_CFG_N1_CTRL_B3, + s->regs[SPI_CTR_CFG_REG]) == 1) { + s->N1_rx = s->N1_bytes; + } + } + } + /* + * Enforce an upper limit on the size of N1 that is equal to the known size + * of the shift register, 64 bits or 72 bits if ECC is enabled. + * If the size exceeds 72 bits it is a user error so log an error, + * cap the size at a max of 64 bits or 72 bits and set the sequencer FSM + * error bit. + */ + uint8_t ecc_control = GETFIELD(SPI_CLK_CFG_ECC_CTRL, + s->regs[SPI_CLK_CFG_REG]); + if (ecc_control == 0 || ecc_control == 2) { + if (s->N1_bytes > (PNV_SPI_REG_SIZE + 1)) { + qemu_log_mask(LOG_GUEST_ERROR, "Unsupported N1 shift size when " + "ECC enabled, bytes = 0x%x, bits = 0x%x\n", + s->N1_bytes, s->N1_bits); + s->N1_bytes = PNV_SPI_REG_SIZE + 1; + s->N1_bits = s->N1_bytes * 8; + } + } else if (s->N1_bytes > PNV_SPI_REG_SIZE) { + qemu_log_mask(LOG_GUEST_ERROR, "Unsupported N1 shift size, " + "bytes = 0x%x, bits = 0x%x\n", + s->N1_bytes, s->N1_bits); + s->N1_bytes = PNV_SPI_REG_SIZE; + s->N1_bits = s->N1_bytes * 8; + } +} /* end of calculate_N1 */ + +/* + * Shift_N1 operation handler method + */ +static bool operation_shiftn1(PnvSpi *s, uint8_t opcode, + PnvXferBuffer **payload, bool send_n1_alone) +{ + uint8_t n1_count; + bool stop = false; + + /* + * If there isn't a current payload left over from a stopped sequence + * create a new one. + */ + if (*payload == NULL) { + *payload = pnv_spi_xfer_buffer_new(); + } + /* + * Use a combination of N1 counters to build the N1 portion of the + * transmit payload. + * We only care about transmit at this time since the request payload + * only represents data going out on the controller output line. + * Leave mode specific considerations in the calculate function since + * all we really care about are counters that tell use exactly how + * many bytes are in the payload and how many of those bytes to + * include from the TDR into the payload. + */ + calculate_N1(s, opcode); + trace_pnv_spi_log_Ncounts(s->N1_bits, s->N1_bytes, s->N1_tx, + s->N1_rx, s->N2_bits, s->N2_bytes, s->N2_tx, s->N2_rx); + /* + * Zero out the N2 counters here in case there is no N2 operation following + * the N1 operation in the sequencer. This keeps leftover N2 information + * from interfering with spi_response logic. + */ + s->N2_bits = 0; + s->N2_bytes = 0; + s->N2_tx = 0; + s->N2_rx = 0; + /* + * N1_bytes is the overall size of the N1 portion of the frame regardless of + * whether N1 is used for tx, rx or both. Loop over the size to build a + * payload that is N1_bytes long. + * N1_tx is the count of bytes to take from the TDR and "shift" into the + * frame which means append those bytes to the payload for the N1 portion + * of the frame. + * If N1_tx is 0 or if the count exceeds the size of the TDR append 0xFF to + * the frame until the overall N1 count is reached. + */ + n1_count = 0; + while (n1_count < s->N1_bytes) { + /* + * Assuming that if N1_tx is not equal to 0 then it is the same as + * N1_bytes. + */ + if ((s->N1_tx != 0) && (n1_count < PNV_SPI_REG_SIZE)) { + + if (GETFIELD(SPI_STS_TDR_FULL, s->status) == 1) { + /* + * Note that we are only appending to the payload IF the TDR + * is full otherwise we don't touch the payload because we are + * going to NOT send the payload and instead tell the sequencer + * that called us to stop and wait for a TDR write so we have + * data to load into the payload. + */ + uint8_t n1_byte = 0x00; + n1_byte = get_from_offset(s, n1_count); + trace_pnv_spi_tx_append("n1_byte", n1_byte, n1_count); + *(pnv_spi_xfer_buffer_write_ptr(*payload, (*payload)->len, 1)) = + n1_byte; + } else { + /* + * We hit a shift_n1 opcode TX but the TDR is empty, tell the + * sequencer to stop and break this loop. + */ + trace_pnv_spi_sequencer_stop_requested("Shift N1" + "set for transmit but TDR is empty"); + stop = true; + break; + } + } else { + /* + * Cases here: + * - we are receiving during the N1 frame segment and the RDR + * is full so we need to stop until the RDR is read + * - we are transmitting and we don't care about RDR status + * since we won't be loading RDR during the frame segment. + * - we are receiving and the RDR is empty so we allow the operation + * to proceed. + */ + if ((s->N1_rx != 0) && (GETFIELD(SPI_STS_RDR_FULL, + s->status) == 1)) { + trace_pnv_spi_sequencer_stop_requested("shift N1" + "set for receive but RDR is full"); + stop = true; + break; + } else { + trace_pnv_spi_tx_append_FF("n1_byte"); + *(pnv_spi_xfer_buffer_write_ptr(*payload, (*payload)->len, 1)) + = 0xff; + } + } + n1_count++; + } /* end of while */ + /* + * If we are not stopping due to an empty TDR and we are doing an N1 TX + * and the TDR is full we need to clear the TDR_full status. + * Do this here instead of up in the loop above so we don't log the message + * in every loop iteration. + * Ignore the send_n1_alone flag, all that does is defer the TX until the N2 + * operation, which was found immediately after the current opcode. The TDR + * was unloaded and will be shifted so we have to clear the TDR_full status. + */ + if (!stop && (s->N1_tx != 0) && + (GETFIELD(SPI_STS_TDR_FULL, s->status) == 1)) { + s->status = SETFIELD(SPI_STS_TDR_FULL, s->status, 0); + } + /* + * There are other reasons why the shifter would stop, such as a TDR empty + * or RDR full condition with N1 set to receive. If we haven't stopped due + * to either one of those conditions then check if the send_n1_alone flag is + * equal to False, indicating the next opcode is an N2 operation, AND if + * the N2 counter reload switch (bit 0 of the N2 count control field) is + * set. This condition requires a pacing write to "kick" off the N2 + * shift which includes the N1 shift as well when send_n1_alone is False. + */ + if (!stop && !send_n1_alone && + (GETFIELD(SPI_CTR_CFG_N2_CTRL_B0, s->regs[SPI_CTR_CFG_REG]) == 1)) { + trace_pnv_spi_sequencer_stop_requested("N2 counter reload " + "active, stop N1 shift, TDR_underrun set to 1"); + stop = true; + s->status = SETFIELD(SPI_STS_TDR_UNDERRUN, s->status, 1); + } + /* + * If send_n1_alone is set AND we have a full TDR then this is the first and + * last payload to send and we don't have an N2 frame segment to add to the + * payload. + */ + if (send_n1_alone && !stop) { + /* We have a TX and a full TDR or an RX and an empty RDR */ + trace_pnv_spi_tx_request("Shifting N1 frame", (*payload)->len); + transfer(s, *payload); + /* The N1 frame shift is complete so reset the N1 counters */ + s->N2_bits = 0; + s->N2_bytes = 0; + s->N2_tx = 0; + s->N2_rx = 0; + pnv_spi_xfer_buffer_free(*payload); + *payload = NULL; + } + return stop; +} /* end of operation_shiftn1() */ + +/* + * Calculate the N2 counters based on passed in opcode and + * internal register values. + * The method assumes that the opcode is a Shift_N2 opcode + * and doesn't test it. + * The counters returned are: + * N2 bits: Number of bits in the payload data that are significant + * to the responder. + * N2_bytes: Total count of payload bytes for the N2 frame. + * N2_tx: Total number of bytes taken from TDR for N2 + * N2_rx: Total number of bytes taken from the payload for N2 + */ +static void calculate_N2(PnvSpi *s, uint8_t opcode) +{ + /* + * Shift_N2 opcode form: 0x4M + * Implicit mode: + * If M!=0 the shift count is M bytes and M is the number of rx bytes. + * Forced Implicit mode: + * M is the shift count but tx and rx is determined by the count control + * register fields. Note that we only check for Forced Implicit mode when + * M != 0 since the mode doesn't make sense when M = 0. + * Explicit mode: + * If M==0 then shift count is number of bits defined in the + * Counter Configuration Register's shift_count_N1 field. + */ + if (PNV_SPI_OPCODE_LO_NIBBLE(opcode) == 0) { + /* Explicit mode */ + s->N2_bits = GETFIELD(SPI_CTR_CFG_N2, s->regs[SPI_CTR_CFG_REG]); + s->N2_bytes = (s->N2_bits + 7) / 8; + s->N2_tx = 0; + s->N2_rx = 0; + /* If tx count control for N2 is set, load the tx value */ + if (GETFIELD(SPI_CTR_CFG_N2_CTRL_B2, s->regs[SPI_CTR_CFG_REG]) == 1) { + s->N2_tx = s->N2_bytes; + } + /* If rx count control for N2 is set, load the rx value */ + if (GETFIELD(SPI_CTR_CFG_N2_CTRL_B3, s->regs[SPI_CTR_CFG_REG]) == 1) { + s->N2_rx = s->N2_bytes; + } + } else { + /* Implicit mode/Forced Implicit mode, use M field from opcode */ + s->N2_bytes = PNV_SPI_OPCODE_LO_NIBBLE(opcode); + s->N2_bits = s->N2_bytes * 8; + /* Assume that we are going to receive the count */ + s->N2_rx = s->N2_bytes; + s->N2_tx = 0; + /* Let Forced Implicit mode have an effect on the counts */ + if (GETFIELD(SPI_CTR_CFG_N2_CTRL_B1, s->regs[SPI_CTR_CFG_REG]) == 1) { + /* + * If Forced Implicit mode and count control doesn't + * indicate a receive then reset the rx count to 0 + */ + if (GETFIELD(SPI_CTR_CFG_N2_CTRL_B3, + s->regs[SPI_CTR_CFG_REG]) == 0) { + s->N2_rx = 0; + } + /* If tx count control for N2 is set, load the tx value */ + if (GETFIELD(SPI_CTR_CFG_N2_CTRL_B2, + s->regs[SPI_CTR_CFG_REG]) == 1) { + s->N2_tx = s->N2_bytes; + } + } + } + /* + * Enforce an upper limit on the size of N1 that is equal to the + * known size of the shift register, 64 bits or 72 bits if ECC + * is enabled. + * If the size exceeds 72 bits it is a user error so log an error, + * cap the size at a max of 64 bits or 72 bits and set the sequencer FSM + * error bit. + */ + uint8_t ecc_control = GETFIELD(SPI_CLK_CFG_ECC_CTRL, + s->regs[SPI_CLK_CFG_REG]); + if (ecc_control == 0 || ecc_control == 2) { + if (s->N2_bytes > (PNV_SPI_REG_SIZE + 1)) { + /* Unsupported N2 shift size when ECC enabled */ + s->N2_bytes = PNV_SPI_REG_SIZE + 1; + s->N2_bits = s->N2_bytes * 8; + } + } else if (s->N2_bytes > PNV_SPI_REG_SIZE) { + /* Unsupported N2 shift size */ + s->N2_bytes = PNV_SPI_REG_SIZE; + s->N2_bits = s->N2_bytes * 8; + } +} /* end of calculate_N2 */ + +/* + * Shift_N2 operation handler method + */ + +static bool operation_shiftn2(PnvSpi *s, uint8_t opcode, + PnvXferBuffer **payload) +{ + uint8_t n2_count; + bool stop = false; + + /* + * If there isn't a current payload left over from a stopped sequence + * create a new one. + */ + if (*payload == NULL) { + *payload = pnv_spi_xfer_buffer_new(); + } + /* + * Use a combination of N2 counters to build the N2 portion of the + * transmit payload. + */ + calculate_N2(s, opcode); + trace_pnv_spi_log_Ncounts(s->N1_bits, s->N1_bytes, s->N1_tx, + s->N1_rx, s->N2_bits, s->N2_bytes, s->N2_tx, s->N2_rx); + /* + * The only difference between this code and the code for shift N1 is + * that this code has to account for the possible presence of N1 transmit + * bytes already taken from the TDR. + * If there are bytes to be transmitted for the N2 portion of the frame + * and there are still bytes in TDR that have not been copied into the + * TX data of the payload, this code will handle transmitting those + * remaining bytes. + * If for some reason the transmit count(s) add up to more than the size + * of the TDR we will just append 0xFF to the transmit payload data until + * the payload is N1 + N2 bytes long. + */ + n2_count = 0; + while (n2_count < s->N2_bytes) { + /* + * If the RDR is full and we need to RX just bail out, letting the + * code continue will end up building the payload twice in the same + * buffer since RDR full causes a sequence stop and restart. + */ + if ((s->N2_rx != 0) && + (GETFIELD(SPI_STS_RDR_FULL, s->status) == 1)) { + trace_pnv_spi_sequencer_stop_requested("shift N2 set" + "for receive but RDR is full"); + stop = true; + break; + } + if ((s->N2_tx != 0) && ((s->N1_tx + n2_count) < + PNV_SPI_REG_SIZE)) { + /* Always append data for the N2 segment if it is set for TX */ + uint8_t n2_byte = 0x00; + n2_byte = get_from_offset(s, (s->N1_tx + n2_count)); + trace_pnv_spi_tx_append("n2_byte", n2_byte, (s->N1_tx + n2_count)); + *(pnv_spi_xfer_buffer_write_ptr(*payload, (*payload)->len, 1)) + = n2_byte; + } else { + /* + * Regardless of whether or not N2 is set for TX or RX, we need + * the number of bytes in the payload to match the overall length + * of the operation. + */ + trace_pnv_spi_tx_append_FF("n2_byte"); + *(pnv_spi_xfer_buffer_write_ptr(*payload, (*payload)->len, 1)) + = 0xff; + } + n2_count++; + } /* end of while */ + if (!stop) { + /* We have a TX and a full TDR or an RX and an empty RDR */ + trace_pnv_spi_tx_request("Shifting N2 frame", (*payload)->len); + transfer(s, *payload); + /* + * If we are doing an N2 TX and the TDR is full we need to clear the + * TDR_full status. Do this here instead of up in the loop above so we + * don't log the message in every loop iteration. + */ + if ((s->N2_tx != 0) && + (GETFIELD(SPI_STS_TDR_FULL, s->status) == 1)) { + s->status = SETFIELD(SPI_STS_TDR_FULL, s->status, 0); + } + /* + * The N2 frame shift is complete so reset the N2 counters. + * Reset the N1 counters also in case the frame was a combination of + * N1 and N2 segments. + */ + s->N2_bits = 0; + s->N2_bytes = 0; + s->N2_tx = 0; + s->N2_rx = 0; + s->N1_bits = 0; + s->N1_bytes = 0; + s->N1_tx = 0; + s->N1_rx = 0; + pnv_spi_xfer_buffer_free(*payload); + *payload = NULL; + } + return stop; +} /* end of operation_shiftn2()*/ + +static void operation_sequencer(PnvSpi *s) +{ + /* + * Loop through each sequencer operation ID and perform the requested + * operations. + * Flag for indicating if we should send the N1 frame or wait to combine + * it with a preceding N2 frame. + */ + bool send_n1_alone = true; + bool stop = false; /* Flag to stop the sequencer */ + uint8_t opcode = 0; + uint8_t masked_opcode = 0; + + /* + * PnvXferBuffer for containing the payload of the SPI frame. + * This is a static because there are cases where a sequence has to stop + * and wait for the target application to unload the RDR. If this occurs + * during a sequence where N1 is not sent alone and instead combined with + * N2 since the N1 tx length + the N2 tx length is less than the size of + * the TDR. + */ + static PnvXferBuffer *payload; + + if (payload == NULL) { + payload = pnv_spi_xfer_buffer_new(); + } + /* + * Clear the sequencer FSM error bit - general_SPI_status[3] + * before starting a sequence. + */ + s->status = SETFIELD(SPI_STS_GEN_STATUS_B3, s->status, 0); + /* + * If the FSM is idle set the sequencer index to 0 + * (new/restarted sequence) + */ + if (GETFIELD(SPI_STS_SEQ_FSM, s->status) == SEQ_STATE_IDLE) { + s->status = SETFIELD(SPI_STS_SEQ_INDEX, s->status, 0); + } + /* + * There are only 8 possible operation IDs to iterate through though + * some operations may cause more than one frame to be sequenced. + */ + while (get_seq_index(s) < NUM_SEQ_OPS) { + opcode = s->seq_op[get_seq_index(s)]; + /* Set sequencer state to decode */ + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_DECODE); + /* + * Only the upper nibble of the operation ID is needed to know what + * kind of operation is requested. + */ + masked_opcode = PNV_SPI_MASKED_OPCODE(opcode); + switch (masked_opcode) { + /* + * Increment the operation index in each case instead of just + * once at the end in case an operation like the branch + * operation needs to change the index. + */ + case SEQ_OP_STOP: + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_EXECUTE); + /* A stop operation in any position stops the sequencer */ + trace_pnv_spi_sequencer_op("STOP", get_seq_index(s)); + + stop = true; + s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_IDLE); + s->loop_counter_1 = 0; + s->loop_counter_2 = 0; + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_IDLE); + break; + + case SEQ_OP_SELECT_SLAVE: + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_EXECUTE); + trace_pnv_spi_sequencer_op("SELECT_SLAVE", get_seq_index(s)); + /* + * This device currently only supports a single responder + * connection at position 0. De-selecting a responder is fine + * and expected at the end of a sequence but selecting any + * responder other than 0 should cause an error. + */ + s->responder_select = PNV_SPI_OPCODE_LO_NIBBLE(opcode); + if (s->responder_select == 0) { + trace_pnv_spi_shifter_done(); + qemu_set_irq(s->cs_line[0], 1); + s->status = SETFIELD(SPI_STS_SEQ_INDEX, s->status, + (get_seq_index(s) + 1)); + s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_DONE); + } else if (s->responder_select != 1) { + qemu_log_mask(LOG_GUEST_ERROR, "Slave selection other than 1 " + "not supported, select = 0x%x\n", + s->responder_select); + trace_pnv_spi_sequencer_stop_requested("invalid " + "responder select"); + s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_IDLE); + stop = true; + } else { + /* + * Only allow an FSM_START state when a responder is + * selected + */ + s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_START); + trace_pnv_spi_shifter_stating(); + qemu_set_irq(s->cs_line[0], 0); + /* + * A Shift_N2 operation is only valid after a Shift_N1 + * according to the spec. The spec doesn't say if that means + * immediately after or just after at any point. We will track + * the occurrence of a Shift_N1 to enforce this requirement in + * the most generic way possible by assuming that the rule + * applies once a valid responder select has occurred. + */ + s->shift_n1_done = false; + next_sequencer_fsm(s); + } + break; + + case SEQ_OP_SHIFT_N1: + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_EXECUTE); + trace_pnv_spi_sequencer_op("SHIFT_N1", get_seq_index(s)); + /* + * Only allow a shift_n1 when the state is not IDLE or DONE. + * In either of those two cases the sequencer is not in a proper + * state to perform shift operations because the sequencer has: + * - processed a responder deselect (DONE) + * - processed a stop opcode (IDLE) + * - encountered an error (IDLE) + */ + if ((GETFIELD(SPI_STS_SHIFTER_FSM, s->status) == FSM_IDLE) || + (GETFIELD(SPI_STS_SHIFTER_FSM, s->status) == FSM_DONE)) { + qemu_log_mask(LOG_GUEST_ERROR, "Shift_N1 not allowed in " + "shifter state = 0x%llx", GETFIELD( + SPI_STS_SHIFTER_FSM, s->status)); + /* + * Set sequencer FSM error bit 3 (general_SPI_status[3]) + * in status reg. + */ + s->status = SETFIELD(SPI_STS_GEN_STATUS_B3, s->status, 1); + trace_pnv_spi_sequencer_stop_requested("invalid shifter state"); + stop = true; + } else { + /* + * Look for the special case where there is a shift_n1 set for + * transmit and it is followed by a shift_n2 set for transmit + * AND the combined transmit length of the two operations is + * less than or equal to the size of the TDR register. In this + * case we want to use both this current shift_n1 opcode and the + * following shift_n2 opcode to assemble the frame for + * transmission to the responder without requiring a refill of + * the TDR between the two operations. + */ + if (PNV_SPI_MASKED_OPCODE(s->seq_op[get_seq_index(s) + 1]) + == SEQ_OP_SHIFT_N2) { + send_n1_alone = false; + } + s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, + FSM_SHIFT_N1); + stop = operation_shiftn1(s, opcode, &payload, send_n1_alone); + if (stop) { + /* + * The operation code says to stop, this can occur if: + * (1) RDR is full and the N1 shift is set for receive + * (2) TDR was empty at the time of the N1 shift so we need + * to wait for data. + * (3) Neither 1 nor 2 are occurring and we aren't sending + * N1 alone and N2 counter reload is set (bit 0 of the N2 + * counter reload field). In this case TDR_underrun will + * will be set and the Payload has been loaded so it is + * ok to advance the sequencer. + */ + if (GETFIELD(SPI_STS_TDR_UNDERRUN, s->status)) { + s->shift_n1_done = true; + s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, + FSM_SHIFT_N2); + s->status = SETFIELD(SPI_STS_SEQ_INDEX, s->status, + (get_seq_index(s) + 1)); + } else { + /* + * This is case (1) or (2) so the sequencer needs to + * wait and NOT go to the next sequence yet. + */ + s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, + FSM_WAIT); + } + } else { + /* Ok to move on to the next index */ + s->shift_n1_done = true; + next_sequencer_fsm(s); + } + } + break; + + case SEQ_OP_SHIFT_N2: + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_EXECUTE); + trace_pnv_spi_sequencer_op("SHIFT_N2", get_seq_index(s)); + if (!s->shift_n1_done) { + qemu_log_mask(LOG_GUEST_ERROR, "Shift_N2 is not allowed if a " + "Shift_N1 is not done, shifter state = 0x%llx", + GETFIELD(SPI_STS_SHIFTER_FSM, s->status)); + /* + * In case the sequencer actually stops if an N2 shift is + * requested before any N1 shift is done. Set sequencer FSM + * error bit 3 (general_SPI_status[3]) in status reg. + */ + s->status = SETFIELD(SPI_STS_GEN_STATUS_B3, s->status, 1); + trace_pnv_spi_sequencer_stop_requested("shift_n2 " + "w/no shift_n1 done"); + stop = true; + } else { + /* Ok to do a Shift_N2 */ + s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, + FSM_SHIFT_N2); + stop = operation_shiftn2(s, opcode, &payload); + /* + * If the operation code says to stop set the shifter state to + * wait and stop + */ + if (stop) { + s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, + FSM_WAIT); + } else { + /* Ok to move on to the next index */ + next_sequencer_fsm(s); + } + } + break; + + case SEQ_OP_BRANCH_IFNEQ_RDR: + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_EXECUTE); + trace_pnv_spi_sequencer_op("BRANCH_IFNEQ_RDR", get_seq_index(s)); + /* + * The memory mapping register RDR match value is compared against + * the 16 rightmost bytes of the RDR (potentially with masking). + * Since this comparison is performed against the contents of the + * RDR then a receive must have previously occurred otherwise + * there is no data to compare and the operation cannot be + * completed and will stop the sequencer until RDR full is set to + * 1. + */ + if (GETFIELD(SPI_STS_RDR_FULL, s->status) == 1) { + bool rdr_matched = false; + rdr_matched = does_rdr_match(s); + if (rdr_matched) { + trace_pnv_spi_RDR_match("success"); + /* A match occurred, increment the sequencer index. */ + next_sequencer_fsm(s); + } else { + trace_pnv_spi_RDR_match("failed"); + /* + * Branch the sequencer to the index coded into the op + * code. + */ + s->status = SETFIELD(SPI_STS_SEQ_INDEX, s->status, + PNV_SPI_OPCODE_LO_NIBBLE(opcode)); + } + /* + * Regardless of where the branch ended up we want the + * sequencer to continue shifting so we have to clear + * RDR_full. + */ + s->status = SETFIELD(SPI_STS_RDR_FULL, s->status, 0); + } else { + trace_pnv_spi_sequencer_stop_requested("RDR not" + "full for 0x6x opcode"); + stop = true; + s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_WAIT); + } + break; + + case SEQ_OP_TRANSFER_TDR: + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_EXECUTE); + qemu_log_mask(LOG_GUEST_ERROR, "Transfer TDR is not supported\n"); + next_sequencer_fsm(s); + break; + + case SEQ_OP_BRANCH_IFNEQ_INC_1: + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_EXECUTE); + trace_pnv_spi_sequencer_op("BRANCH_IFNEQ_INC_1", get_seq_index(s)); + /* + * The spec says the loop should execute count compare + 1 times. + * However we learned from engineering that we really only loop + * count_compare times, count compare = 0 makes this op code a + * no-op + */ + if (s->loop_counter_1 != + GETFIELD(SPI_CTR_CFG_CMP1, s->regs[SPI_CTR_CFG_REG])) { + /* + * Next index is the lower nibble of the branch operation ID, + * mask off all but the first three bits so we don't try to + * access beyond the sequencer_operation_reg boundary. + */ + s->status = SETFIELD(SPI_STS_SEQ_INDEX, s->status, + PNV_SPI_OPCODE_LO_NIBBLE(opcode)); + s->loop_counter_1++; + } else { + /* Continue to next index if loop counter is reached */ + next_sequencer_fsm(s); + } + break; + + case SEQ_OP_BRANCH_IFNEQ_INC_2: + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_EXECUTE); + trace_pnv_spi_sequencer_op("BRANCH_IFNEQ_INC_2", get_seq_index(s)); + uint8_t condition2 = GETFIELD(SPI_CTR_CFG_CMP2, + s->regs[SPI_CTR_CFG_REG]); + /* + * The spec says the loop should execute count compare + 1 times. + * However we learned from engineering that we really only loop + * count_compare times, count compare = 0 makes this op code a + * no-op + */ + if (s->loop_counter_2 != condition2) { + /* + * Next index is the lower nibble of the branch operation ID, + * mask off all but the first three bits so we don't try to + * access beyond the sequencer_operation_reg boundary. + */ + s->status = SETFIELD(SPI_STS_SEQ_INDEX, + s->status, PNV_SPI_OPCODE_LO_NIBBLE(opcode)); + s->loop_counter_2++; + } else { + /* Continue to next index if loop counter is reached */ + next_sequencer_fsm(s); + } + break; + + default: + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_EXECUTE); + /* Ignore unsupported operations. */ + next_sequencer_fsm(s); + break; + } /* end of switch */ + /* + * If we used all 8 opcodes without seeing a 00 - STOP in the sequence + * we need to go ahead and end things as if there was a STOP at the + * end. + */ + if (get_seq_index(s) == NUM_SEQ_OPS) { + /* All 8 opcodes completed, sequencer idling */ + s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_IDLE); + s->status = SETFIELD(SPI_STS_SEQ_INDEX, s->status, 0); + s->loop_counter_1 = 0; + s->loop_counter_2 = 0; + s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_IDLE); + break; + } + /* Break the loop if a stop was requested */ + if (stop) { + break; + } + } /* end of while */ + return; +} /* end of operation_sequencer() */ + +/* + * The SPIC engine and its internal sequencer can be interrupted and reset by + * a hardware signal, the sbe_spicst_hard_reset bits from Pervasive + * Miscellaneous Register of sbe_register_bo device. + * Reset immediately aborts any SPI transaction in progress and returns the + * sequencer and state machines to idle state. + * The configuration register values are not changed. The status register is + * not reset. The engine registers are not reset. + * The SPIC engine reset does not have any affect on the attached devices. + * Reset handling of any attached devices is beyond the scope of the engine. + */ +static void do_reset(DeviceState *dev) +{ + PnvSpi *s = PNV_SPI(dev); + + trace_pnv_spi_reset(); + + /* Reset all N1 and N2 counters, and other constants */ + s->N2_bits = 0; + s->N2_bytes = 0; + s->N2_tx = 0; + s->N2_rx = 0; + s->N1_bits = 0; + s->N1_bytes = 0; + s->N1_tx = 0; + s->N1_rx = 0; + s->loop_counter_1 = 0; + s->loop_counter_2 = 0; + /* Disconnected from responder */ + qemu_set_irq(s->cs_line[0], 1); +} + static uint64_t pnv_spi_xscom_read(void *opaque, hwaddr addr, unsigned size) { PnvSpi *s = PNV_SPI(opaque); @@ -51,6 +1088,10 @@ static uint64_t pnv_spi_xscom_read(void *opaque, hwaddr addr, unsigned size) val = s->regs[reg]; trace_pnv_spi_read_RDR(val); s->status = SETFIELD(SPI_STS_RDR_FULL, s->status, 0); + if (GETFIELD(SPI_STS_SHIFTER_FSM, s->status) == FSM_WAIT) { + trace_pnv_spi_start_sequencer(); + operation_sequencer(s); + } break; case SPI_SEQ_OP_REG: val = 0; @@ -112,6 +1153,8 @@ static void pnv_spi_xscom_write(void *opaque, hwaddr addr, trace_pnv_spi_write_TDR(val); s->status = SETFIELD(SPI_STS_TDR_FULL, s->status, 1); s->status = SETFIELD(SPI_STS_TDR_UNDERRUN, s->status, 0); + trace_pnv_spi_start_sequencer(); + operation_sequencer(s); break; case SPI_SEQ_OP_REG: for (int i = 0; i < PNV_SPI_REG_SIZE; i++) { @@ -144,6 +1187,7 @@ static const MemoryRegionOps pnv_spi_xscom_ops = { static Property pnv_spi_properties[] = { DEFINE_PROP_UINT32("spic_num", PnvSpi, spic_num, 0), + DEFINE_PROP_UINT8("transfer_len", PnvSpi, transfer_len, 4), DEFINE_PROP_END_OF_LIST(), }; @@ -193,6 +1237,7 @@ static void pnv_spi_class_init(ObjectClass *klass, void *data) dc->desc = "PowerNV SPI"; dc->realize = pnv_spi_realize; + dc->reset = do_reset; device_class_set_props(dc, pnv_spi_properties); } diff --git a/hw/ssi/trace-events b/hw/ssi/trace-events index 2cc29e1284..089d269994 100644 --- a/hw/ssi/trace-events +++ b/hw/ssi/trace-events @@ -38,3 +38,18 @@ pnv_spi_read(uint64_t addr, uint64_t val) "addr 0x%" PRIx64 " val 0x%" PRIx64 pnv_spi_write(uint64_t addr, uint64_t val) "addr 0x%" PRIx64 " val 0x%" PRIx64 pnv_spi_read_RDR(uint64_t val) "data extracted = 0x%" PRIx64 pnv_spi_write_TDR(uint64_t val) "being written, data written = 0x%" PRIx64 +pnv_spi_start_sequencer(void) "" +pnv_spi_reset(void) "spic engine sequencer configuration and spi communication" +pnv_spi_sequencer_op(const char* op, uint8_t index) "%s at index = 0x%x" +pnv_spi_shifter_stating(void) "pull CS line low" +pnv_spi_shifter_done(void) "pull the CS line high" +pnv_spi_log_Ncounts(uint8_t N1_bits, uint8_t N1_bytes, uint8_t N1_tx, uint8_t N1_rx, uint8_t N2_bits, uint8_t N2_bytes, uint8_t N2_tx, uint8_t N2_rx) "N1_bits = %d, N1_bytes = %d, N1_tx = %d, N1_rx = %d, N2_bits = %d, N2_bytes = %d, N2_tx = %d, N2_rx = %d" +pnv_spi_tx_append(const char* frame, uint8_t byte, uint8_t tdr_index) "%s = 0x%2.2x to payload from TDR at index %d" +pnv_spi_tx_append_FF(const char* frame) "%s to Payload" +pnv_spi_tx_request(const char* frame, uint32_t payload_len) "%s, payload len = %d" +pnv_spi_rx_received(uint32_t payload_len) "payload len = %d" +pnv_spi_rx_read_N1frame(void) "" +pnv_spi_rx_read_N2frame(void) "" +pnv_spi_shift_rx(uint8_t byte, uint32_t index) "byte = 0x%2.2x into RDR from payload index %d" +pnv_spi_sequencer_stop_requested(const char* reason) "due to %s" +pnv_spi_RDR_match(const char* result) "%s" |