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From: Chalapathi V <chalapathi.v@linux.ibm.com>
To: Nicholas Piggin <npiggin@gmail.com>, qemu-devel@nongnu.org
Cc: qemu-ppc@nongnu.org, fbarrat@linux.ibm.com, clg@kaod.org,
	calebs@linux.ibm.com, chalapathi.v@ibm.com,
	saif.abrar@linux.ibm.com, dantan@linux.vnet.ibm.com,
	milesg@linux.ibm.com, philmd@linaro.org, alistair@alistair23.me
Subject: Re: [PATCH v5 1/4] hw/ssi/pnv_spi: Replace PnvXferBuffer with Fifo8 structure
Date: Fri, 28 Feb 2025 08:29:48 +0530	[thread overview]
Message-ID: <a4e1e393-4f12-4242-848b-e67a9a55dc0f@linux.ibm.com> (raw)
In-Reply-To: <D82UFOB22C3K.31271R5VWD0LU@gmail.com>

[-- Attachment #1: Type: text/plain, Size: 26753 bytes --]

Hello Nick,

Thank You for reviewing this series.

On 27-02-2025 07:09, Nicholas Piggin wrote:
> On Sat Jan 4, 2025 at 2:18 AM AEST, Chalapathi V wrote:
>> In PnvXferBuffer dynamically allocating and freeing is a
>> process overhead. Hence used an existing Fifo8 buffer with
>> capacity of 16 bytes.
>>
>> Signed-off-by: Chalapathi V<chalapathi.v@linux.ibm.com>
>> ---
>>   include/hw/ssi/pnv_spi.h |   3 +
>>   hw/ssi/pnv_spi.c         | 237 +++++++++++++--------------------------
>>   2 files changed, 81 insertions(+), 159 deletions(-)
>>
>> diff --git a/include/hw/ssi/pnv_spi.h b/include/hw/ssi/pnv_spi.h
>> index 8815f67d45..9878d9a25f 100644
>> --- a/include/hw/ssi/pnv_spi.h
>> +++ b/include/hw/ssi/pnv_spi.h
>> @@ -23,6 +23,7 @@
>>   
>>   #include "hw/ssi/ssi.h"
>>   #include "hw/sysbus.h"
>> +#include "qemu/fifo8.h"
>>   
>>   #define TYPE_PNV_SPI "pnv-spi"
>>   OBJECT_DECLARE_SIMPLE_TYPE(PnvSpi, PNV_SPI)
>> @@ -37,6 +38,8 @@ typedef struct PnvSpi {
>>       SSIBus *ssi_bus;
>>       qemu_irq *cs_line;
>>       MemoryRegion    xscom_spic_regs;
>> +    Fifo8 tx_fifo;
>> +    Fifo8 rx_fifo;
>>       /* SPI object number */
>>       uint32_t        spic_num;
>>       uint8_t         transfer_len;
>> diff --git a/hw/ssi/pnv_spi.c b/hw/ssi/pnv_spi.c
>> index 15e25bd1be..63d298980d 100644
>> --- a/hw/ssi/pnv_spi.c
>> +++ b/hw/ssi/pnv_spi.c
>> @@ -19,6 +19,7 @@
>>   
>>   #define PNV_SPI_OPCODE_LO_NIBBLE(x) (x & 0x0F)
>>   #define PNV_SPI_MASKED_OPCODE(x) (x & 0xF0)
>> +#define PNV_SPI_FIFO_SIZE 16
>>   
>>   /*
>>    * Macro from include/hw/ppc/fdt.h
>> @@ -35,48 +36,14 @@
>>           }                                                          \
>>       } 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)
>> -{
>> -    g_free(payload->data);
>> -    g_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]);
>> +    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]))) {
> Usually try to avoid unrelated / cleanup in the same patch that acually
> changes things. In this case it's quite minor but it helps with review
> and rebasing to avoid.
>
> If it's on the same line or very close line to your change, or
> occasional ones I don't mind so much, but you have quite a few
> more further down the patch.
Sorry about that!. Should I create a new patch in v6 or keep it as is 
for now?

Going forward will create new patches for distinct changes.

Thank You.

>> @@ -107,8 +74,8 @@ static uint8_t get_from_offset(PnvSpi *s, uint8_t offset)
>>       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)
>> +static uint8_t read_from_frame(PnvSpi *s, uint8_t nr_bytes, uint8_t ecc_count,
>> +                uint8_t shift_in_count)
>>   {
>>       uint8_t byte;
>>       int count = 0;
>> @@ -118,20 +85,23 @@ static uint8_t read_from_frame(PnvSpi *s, uint8_t *read_buf, uint8_t nr_bytes,
>>           if ((ecc_count != 0) &&
>>               (shift_in_count == (PNV_SPI_REG_SIZE + ecc_count))) {
>>               shift_in_count = 0;
>> -        } else {
>> -            byte = read_buf[count];
>> +        } else if (!fifo8_is_empty(&s->rx_fifo)) {
>> +            byte = fifo8_pop(&s->rx_fifo);
>>               trace_pnv_spi_shift_rx(byte, count);
>>               s->regs[SPI_RCV_DATA_REG] = (s->regs[SPI_RCV_DATA_REG] << 8) | byte;
>> +        } else {
>> +            qemu_log_mask(LOG_GUEST_ERROR, "pnv_spi: Reading empty RX_FIFO\n");
>>           }
>>           count++;
>>       } /* end of while */
>>       return shift_in_count;
>>   }
>>   
>> -static void spi_response(PnvSpi *s, int bits, PnvXferBuffer *rsp_payload)
>> +static void spi_response(PnvSpi *s)
>>   {
>>       uint8_t ecc_count;
>>       uint8_t shift_in_count;
>> +    uint32_t rx_len;
>>   
>>       /*
>>        * Processing here must handle:
>> @@ -144,13 +114,14 @@ static void spi_response(PnvSpi *s, int bits, PnvXferBuffer *rsp_payload)
>>        * 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)) {
>> +    rx_len = fifo8_num_used(&s->rx_fifo);
>> +    if (rx_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);
>> +                       (s->N1_bytes + s->N2_bytes), rx_len);
>>       } else {
>>           uint8_t ecc_control;
>> -        trace_pnv_spi_rx_received(rsp_payload->len);
>> +        trace_pnv_spi_rx_received(rx_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);
>>           /*
>> @@ -175,15 +146,12 @@ static void spi_response(PnvSpi *s, int bits, PnvXferBuffer *rsp_payload)
>>           /* 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);
>> +            shift_in_count = read_from_frame(s, 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);
>> +            shift_in_count = read_from_frame(s, s->N2_bytes, ecc_count, shift_in_count);
>>           }
>>           if ((s->N1_rx + s->N2_rx) > 0) {
>>               /*
>> @@ -210,36 +178,38 @@ static void spi_response(PnvSpi *s, int bits, PnvXferBuffer *rsp_payload)
>>       } /* end of else */
>>   } /* end of spi_response() */
>>   
>> -static void transfer(PnvSpi *s, PnvXferBuffer *payload)
>> +static void transfer(PnvSpi *s)
>>   {
>> -    uint32_t tx;
>> -    uint32_t rx;
>> -    PnvXferBuffer *rsp_payload = NULL;
>> +    uint32_t tx, rx, payload_len;
>> +    uint8_t rx_byte;
>>   
>> -    rsp_payload = pnv_spi_xfer_buffer_new();
>> -    if (!rsp_payload) {
>> -        return;
>> -    }
>> -    for (int offset = 0; offset < payload->len; offset += s->transfer_len) {
>> +    payload_len = fifo8_num_used(&s->tx_fifo);
>> +    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) {
>> +            if ((offset + i) >= payload_len) {
>>                   tx <<= 8;
>> +            } else if (!fifo8_is_empty(&s->tx_fifo)) {
>> +                tx = (tx << 8) | fifo8_pop(&s->tx_fifo);
>>               } else {
>> -                tx = (tx << 8) | payload->data[offset + i];
>> +                qemu_log_mask(LOG_GUEST_ERROR, "pnv_spi: TX_FIFO underflow\n");
>>               }
>>           }
>>           rx = ssi_transfer(s->ssi_bus, tx);
>>           for (int i = 0; i < s->transfer_len; i++) {
>> -            if ((offset + i) >= payload->len) {
>> +            if (((offset + i) >= payload_len) || fifo8_is_full(&s->rx_fifo)) {
>>                   break;
>>               }
>> -            *(pnv_spi_xfer_buffer_write_ptr(rsp_payload, rsp_payload->len, 1)) =
>> -                    (rx >> (8 * (s->transfer_len - 1) - i * 8)) & 0xFF;
>> +            rx_byte = (rx >> (8 * (s->transfer_len - 1) - i * 8)) & 0xFF;
>> +            if (!fifo8_is_full(&s->rx_fifo)) {
>> +                fifo8_push(&s->rx_fifo, rx_byte);
>> +            }
>>           }
>>       }
>> -    spi_response(s, s->N1_bits, rsp_payload);
>> -    pnv_spi_xfer_buffer_free(rsp_payload);
>> +    spi_response(s);
>> +    /* Reset fifo for next frame */
>> +    fifo8_reset(&s->tx_fifo);
>> +    fifo8_reset(&s->rx_fifo);
>>   }
>>   
>>   static inline uint8_t get_seq_index(PnvSpi *s)
>> @@ -310,13 +280,11 @@ static void calculate_N1(PnvSpi *s, uint8_t opcode)
>>                * 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) {
>> +            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) {
>> +            if (GETFIELD(SPI_CTR_CFG_N1_CTRL_B3, s->regs[SPI_CTR_CFG_REG]) == 1) {
>>                   s->N1_rx = s->N1_bytes;
>>               }
>>           }
>> @@ -328,8 +296,7 @@ static void calculate_N1(PnvSpi *s, uint8_t opcode)
>>        * 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]);
>> +    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 "
>> @@ -340,8 +307,7 @@ static void calculate_N1(PnvSpi *s, uint8_t opcode)
>>           }
>>       } 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);
>> +                      "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;
>>       }
>> @@ -350,19 +316,10 @@ static void calculate_N1(PnvSpi *s, uint8_t opcode)
>>   /*
>>    * Shift_N1 operation handler method
>>    */
>> -static bool operation_shiftn1(PnvSpi *s, uint8_t opcode,
>> -                       PnvXferBuffer **payload, bool send_n1_alone)
>> +static bool operation_shiftn1(PnvSpi *s, uint8_t opcode, 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.
>> @@ -413,9 +370,10 @@ static bool operation_shiftn1(PnvSpi *s, uint8_t opcode,
>>                    */
>>                   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;
>> +                if (!fifo8_is_full(&s->tx_fifo)) {
>> +                    trace_pnv_spi_tx_append("n1_byte", n1_byte, n1_count);
>> +                    fifo8_push(&s->tx_fifo, n1_byte);
>> +                }
>>               } else {
>>                   /*
>>                    * We hit a shift_n1 opcode TX but the TDR is empty, tell the
>> @@ -436,16 +394,14 @@ static bool operation_shiftn1(PnvSpi *s, uint8_t opcode,
>>                * - 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)) {
>> +            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 {
>> +            } else if (!fifo8_is_full(&s->tx_fifo)) {
>>                   trace_pnv_spi_tx_append_FF("n1_byte");
>> -                *(pnv_spi_xfer_buffer_write_ptr(*payload, (*payload)->len, 1))
>> -                        = 0xff;
>> +                fifo8_push(&s->tx_fifo, 0xff);
>>               }
> Is there any problem or overrun that needs to be logged if the
> fifo is full in the above two places?
Will add a error log upon hitting the overflow. Thank You.
>>           }
>>           n1_count++;
>> @@ -486,15 +442,13 @@ static bool operation_shiftn1(PnvSpi *s, uint8_t opcode,
>>        */
>>       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);
>> +        trace_pnv_spi_tx_request("Shifting N1 frame", fifo8_num_used(&s->tx_fifo));
>> +        transfer(s);
>>           /* 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() */
>> @@ -552,13 +506,11 @@ static void calculate_N2(PnvSpi *s, uint8_t opcode)
>>                * 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) {
>> +            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) {
>> +            if (GETFIELD(SPI_CTR_CFG_N2_CTRL_B2, s->regs[SPI_CTR_CFG_REG]) == 1) {
>>                   s->N2_tx = s->N2_bytes;
>>               }
>>           }
>> @@ -571,8 +523,7 @@ static void calculate_N2(PnvSpi *s, uint8_t opcode)
>>        * 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]);
>> +    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 */
>> @@ -590,19 +541,10 @@ static void calculate_N2(PnvSpi *s, uint8_t opcode)
>>    * Shift_N2 operation handler method
>>    */
>>   
>> -static bool operation_shiftn2(PnvSpi *s, uint8_t opcode,
>> -                       PnvXferBuffer **payload)
>> +static bool operation_shiftn2(PnvSpi *s, uint8_t opcode)
>>   {
>>       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.
>> @@ -629,44 +571,41 @@ static bool operation_shiftn2(PnvSpi *s, uint8_t opcode,
>>            * 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)) {
>> +        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)) {
>> +        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 {
>> +            if (!fifo8_is_full(&s->tx_fifo)) {
>> +                trace_pnv_spi_tx_append("n2_byte", n2_byte, (s->N1_tx + n2_count));
>> +                fifo8_push(&s->tx_fifo, n2_byte);
>> +            }
>> +        } else if (!fifo8_is_full(&s->tx_fifo)) {
>>               /*
>>                * 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;
>> +            fifo8_push(&s->tx_fifo, 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);
>> +        trace_pnv_spi_tx_request("Shifting N2 frame", fifo8_num_used(&s->tx_fifo));
>> +        transfer(s);
>>           /*
>>            * 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)) {
>> +        if ((s->N2_tx != 0) && (GETFIELD(SPI_STS_TDR_FULL, s->status) == 1)) {
>>               s->status = SETFIELD(SPI_STS_TDR_FULL, s->status, 0);
>>           }
>>           /*
>> @@ -682,8 +621,6 @@ static bool operation_shiftn2(PnvSpi *s, uint8_t opcode,
>>           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()*/
>> @@ -701,19 +638,6 @@ static void operation_sequencer(PnvSpi *s)
>>       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.
>> @@ -775,10 +699,8 @@ static void operation_sequencer(PnvSpi *s)
>>                   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");
>> +                              "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 {
>> @@ -840,9 +762,8 @@ static void operation_sequencer(PnvSpi *s)
>>                                   == 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);
>> +                s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_SHIFT_N1);
>> +                stop = operation_shiftn1(s, opcode, send_n1_alone);
>>                   if (stop) {
>>                       /*
>>                        *  The operation code says to stop, this can occur if:
>> @@ -858,7 +779,7 @@ static void operation_sequencer(PnvSpi *s)
>>                       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);
>> +                                        FSM_SHIFT_N2);
>>                           s->status = SETFIELD(SPI_STS_SEQ_INDEX, s->status,
>>                                           (get_seq_index(s) + 1));
>>                       } else {
>> @@ -866,8 +787,7 @@ static void operation_sequencer(PnvSpi *s)
>>                            * 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);
>> +                        s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_WAIT);
>>                       }
>>                   } else {
>>                       /* Ok to move on to the next index */
>> @@ -890,21 +810,18 @@ static void operation_sequencer(PnvSpi *s)
>>                    * 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");
>> +                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);
>> +                s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_SHIFT_N2);
>> +                stop = operation_shiftn2(s, opcode);
>>                   /*
>>                    * 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);
>> +                    s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_WAIT);
>>                   } else {
>>                       /* Ok to move on to the next index */
>>                       next_sequencer_fsm(s);
>> @@ -988,8 +905,7 @@ static void operation_sequencer(PnvSpi *s)
>>           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]);
>> +            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
>> @@ -1209,6 +1125,9 @@ static void pnv_spi_realize(DeviceState *dev, Error **errp)
>>       s->cs_line = g_new0(qemu_irq, 1);
>>       qdev_init_gpio_out_named(DEVICE(s), s->cs_line, "cs", 1);
>>   
>> +    fifo8_create(&s->tx_fifo, PNV_SPI_FIFO_SIZE);
>> +    fifo8_create(&s->rx_fifo, PNV_SPI_FIFO_SIZE);
>> +
>>       /* spi scoms */
>>       pnv_xscom_region_init(&s->xscom_spic_regs, OBJECT(s), &pnv_spi_xscom_ops,
>>                             s, "xscom-spi", PNV10_XSCOM_PIB_SPIC_SIZE);
> Aside from those small nits, it looks like a good cleanup and
> improvement with more error logging.
>
> Thanks,
> Nick

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  reply	other threads:[~2025-02-28  3:01 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-03 16:18 [PATCH v5 0/4] hw/ssi/pnv_spi: Remove PnvXferBuffer and fix CID 1558827 Chalapathi V
2025-01-03 16:18 ` [PATCH v5 1/4] hw/ssi/pnv_spi: Replace PnvXferBuffer with Fifo8 structure Chalapathi V
2025-02-27  1:39   ` Nicholas Piggin
2025-02-28  2:59     ` Chalapathi V [this message]
2025-01-03 16:18 ` [PATCH v5 2/4] hw/ssi/pnv_spi: Coverity CID 1558827: Use local var seq_index instead of get_seq_index() Chalapathi V
2025-02-27  1:43   ` Nicholas Piggin
2025-02-27  1:44   ` Nicholas Piggin
2025-01-03 16:18 ` [PATCH v5 3/4] hw/ssi/pnv_spi: Make bus names distinct for each controllers of a socket Chalapathi V
2025-02-27  1:54   ` Nicholas Piggin
2025-02-28  3:03     ` Chalapathi V
2025-02-28  7:45       ` Cédric Le Goater
2025-02-28 11:00         ` Chalapathi V
2025-02-28 16:15           ` Cédric Le Goater
2025-01-03 16:18 ` [PATCH v5 4/4] hw/ssi/pnv_spi: Put a limit to RDR match failures Chalapathi V
2025-02-27  1:56   ` Nicholas Piggin
2025-02-28  3:04     ` Chalapathi V

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