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* [PATCH v6 0/4] hw/ssi/pnv_spi: Remove PnvXferBuffer and other improvements
@ 2025-03-03 14:13 Chalapathi V
  2025-03-03 14:13 ` [PATCH v6 1/4] hw/ssi/pnv_spi: Replace PnvXferBuffer with Fifo8 structure Chalapathi V
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: Chalapathi V @ 2025-03-03 14:13 UTC (permalink / raw)
  To: qemu-devel
  Cc: qemu-ppc, fbarrat, npiggin, clg, calebs, chalapathi.v,
	chalapathi.v, saif.abrar, dantan, milesg, philmd, alistair

Hello,

In this revision comments from patch V5 are addressed.

Updates in V6:
1. Improve error logging when there is an overflow or underflow of
   Fifo8 structure
2. Add comments about local variable seq_index.
3. Update the bus name to chipX.spi.<busnum>, X = 0..<num_sockets>
4. keep fail_count in PnvSpi so that each instance of spi has its own
   count.

Updates in V5:
1. Use of PnvXferBuffer results in a additional process overhead due to
frequent dynamic allocations and hence use an existing Fifo8 buffer.
2. Use a local variable seq_index and use it with in while loop instead
of repeatedly calling get_seq_index() and make sure s->seq_op doesn't
overrun when seq_index is incremented.
3. Unique bus names are created for each controller in a socket so that
responders are attached to correct SPI controllers via CLI.
4. Enforce a limit on number RDR match failures so that SPI controller
doesn't get caught in an infinite execution loop querying the responder
for RDR match.

Tested:
passed make check and make check-avocado

Chalapathi V (4):
  hw/ssi/pnv_spi: Replace PnvXferBuffer with Fifo8 structure
  hw/ssi/pnv_spi: Use local var seq_index instead of get_seq_index().
  hw/ssi/pnv_spi: Make bus names distinct for each controllers of a
    socket
  hw/ssi/pnv_spi: Put a limit to RDR match failures

 include/hw/ssi/pnv_spi.h           |   7 +-
 hw/ppc/pnv.c                       |   2 +
 hw/ssi/pnv_spi.c                   | 366 +++++++++++++----------------
 tests/qtest/pnv-spi-seeprom-test.c |   2 +-
 4 files changed, 174 insertions(+), 203 deletions(-)

-- 
2.39.5



^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH v6 1/4] hw/ssi/pnv_spi: Replace PnvXferBuffer with Fifo8 structure
  2025-03-03 14:13 [PATCH v6 0/4] hw/ssi/pnv_spi: Remove PnvXferBuffer and other improvements Chalapathi V
@ 2025-03-03 14:13 ` Chalapathi V
  2025-03-03 14:13 ` [PATCH v6 2/4] hw/ssi/pnv_spi: Use local var seq_index instead of get_seq_index() Chalapathi V
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 5+ messages in thread
From: Chalapathi V @ 2025-03-03 14:13 UTC (permalink / raw)
  To: qemu-devel
  Cc: qemu-ppc, fbarrat, npiggin, clg, calebs, chalapathi.v,
	chalapathi.v, saif.abrar, dantan, milesg, philmd, alistair

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         | 264 ++++++++++++++++-----------------------
 2 files changed, 108 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..388b425157 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]))) {
@@ -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 +85,24 @@ 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;
+    int i;
 
     /*
      * Processing here must handle:
@@ -144,13 +115,14 @@ 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 +147,23 @@ 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) {
+            /* pop out N1_bytes from rx_fifo if not already */
+            if (s->N1_rx == 0) {
+                for (i = 0; i < s->N1_bytes; i++) {
+                    if (!fifo8_is_empty(&s->rx_fifo)) {
+                        fifo8_pop(&s->rx_fifo);
+                    } else {
+                        qemu_log_mask(LOG_GUEST_ERROR, "pnv_spi: Reading empty"
+                                                       " RX_FIFO\n");
+                    }
+                }
+            }
             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 +190,41 @@ 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) {
+                break;
+            }
+            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);
+            } else {
+                qemu_log_mask(LOG_GUEST_ERROR, "pnv_spi: RX_FIFO is full\n");
                 break;
             }
-            *(pnv_spi_xfer_buffer_write_ptr(rsp_payload, rsp_payload->len, 1)) =
-                    (rx >> (8 * (s->transfer_len - 1) - i * 8)) & 0xFF;
         }
     }
-    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 +295,11 @@ 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 +311,7 @@ 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 +322,7 @@ 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 +331,10 @@ 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 +385,13 @@ 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 {
+                    qemu_log_mask(LOG_GUEST_ERROR, "pnv_spi: TX_FIFO is full\n");
+                    break;
+                }
             } else {
                 /*
                  * We hit a shift_n1 opcode TX but the TDR is empty, tell the
@@ -436,16 +412,17 @@ 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);
+            } else {
+                qemu_log_mask(LOG_GUEST_ERROR, "pnv_spi: TX_FIFO is full\n");
+                break;
             }
         }
         n1_count++;
@@ -486,15 +463,13 @@ 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 +527,11 @@ 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 +544,7 @@ 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 +562,10 @@ 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 +592,47 @@ 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 {
+                qemu_log_mask(LOG_GUEST_ERROR, "pnv_spi: TX_FIFO is full\n");
+                break;
+            }
+        } 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);
+        } else {
+            qemu_log_mask(LOG_GUEST_ERROR, "pnv_spi: TX_FIFO is full\n");
+            break;
         }
         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 +648,6 @@ 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 +665,6 @@ 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 +726,8 @@ 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 +789,8 @@ 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 +806,7 @@ 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 +814,7 @@ 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 +837,18 @@ 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 +932,7 @@ 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 +1152,9 @@ 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);
-- 
2.39.5



^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH v6 2/4] hw/ssi/pnv_spi: Use local var seq_index instead of get_seq_index().
  2025-03-03 14:13 [PATCH v6 0/4] hw/ssi/pnv_spi: Remove PnvXferBuffer and other improvements Chalapathi V
  2025-03-03 14:13 ` [PATCH v6 1/4] hw/ssi/pnv_spi: Replace PnvXferBuffer with Fifo8 structure Chalapathi V
@ 2025-03-03 14:13 ` Chalapathi V
  2025-03-03 14:13 ` [PATCH v6 3/4] hw/ssi/pnv_spi: Make bus names distinct for each controllers of a socket Chalapathi V
  2025-03-03 14:13 ` [PATCH v6 4/4] hw/ssi/pnv_spi: Put a limit to RDR match failures Chalapathi V
  3 siblings, 0 replies; 5+ messages in thread
From: Chalapathi V @ 2025-03-03 14:13 UTC (permalink / raw)
  To: qemu-devel
  Cc: qemu-ppc, fbarrat, npiggin, clg, calebs, chalapathi.v,
	chalapathi.v, saif.abrar, dantan, milesg, philmd, alistair

Use a local variable seq_index instead of repeatedly calling
get_seq_index() method and open-code next_sequencer_fsm().

Signed-off-by: Chalapathi V <chalapathi.v@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
---
 hw/ssi/pnv_spi.c | 97 ++++++++++++++++++++++++++----------------------
 1 file changed, 52 insertions(+), 45 deletions(-)

diff --git a/hw/ssi/pnv_spi.c b/hw/ssi/pnv_spi.c
index 388b425157..de33542c35 100644
--- a/hw/ssi/pnv_spi.c
+++ b/hw/ssi/pnv_spi.c
@@ -227,18 +227,6 @@ static void transfer(PnvSpi *s)
     fifo8_reset(&s->rx_fifo);
 }
 
-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.
@@ -664,6 +652,7 @@ static void operation_sequencer(PnvSpi *s)
     bool stop = false; /* Flag to stop the sequencer */
     uint8_t opcode = 0;
     uint8_t masked_opcode = 0;
+    uint8_t seq_index;
 
     /*
      * Clear the sequencer FSM error bit - general_SPI_status[3]
@@ -677,12 +666,17 @@ static void operation_sequencer(PnvSpi *s)
     if (GETFIELD(SPI_STS_SEQ_FSM, s->status) == SEQ_STATE_IDLE) {
         s->status = SETFIELD(SPI_STS_SEQ_INDEX, s->status, 0);
     }
+    /*
+     * SPI_STS_SEQ_INDEX of status register is kept in seq_index variable and
+     * updated back to status register at the end of operation_sequencer().
+     */
+    seq_index = GETFIELD(SPI_STS_SEQ_INDEX, s->status);
     /*
      * 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)];
+    while (seq_index < NUM_SEQ_OPS) {
+        opcode = s->seq_op[seq_index];
         /* Set sequencer state to decode */
         s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_DECODE);
         /*
@@ -699,7 +693,7 @@ static void operation_sequencer(PnvSpi *s)
         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));
+            trace_pnv_spi_sequencer_op("STOP", seq_index);
 
             stop = true;
             s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_IDLE);
@@ -710,7 +704,7 @@ static void operation_sequencer(PnvSpi *s)
 
         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));
+            trace_pnv_spi_sequencer_op("SELECT_SLAVE", seq_index);
             /*
              * This device currently only supports a single responder
              * connection at position 0.  De-selecting a responder is fine
@@ -721,8 +715,7 @@ static void operation_sequencer(PnvSpi *s)
             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));
+                seq_index++;
                 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 "
@@ -747,13 +740,15 @@ static void operation_sequencer(PnvSpi *s)
                  * applies once a valid responder select has occurred.
                  */
                 s->shift_n1_done = false;
-                next_sequencer_fsm(s);
+                seq_index++;
+                s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status,
+                                SEQ_STATE_INDEX_INCREMENT);
             }
             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));
+            trace_pnv_spi_sequencer_op("SHIFT_N1", seq_index);
             /*
              * 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
@@ -785,8 +780,9 @@ static void operation_sequencer(PnvSpi *s)
                  * 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) {
+                if ((seq_index != 7) &&
+                    PNV_SPI_MASKED_OPCODE(s->seq_op[(seq_index + 1)]) ==
+                    SEQ_OP_SHIFT_N2) {
                     send_n1_alone = false;
                 }
                 s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_SHIFT_N1);
@@ -806,9 +802,8 @@ 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);
-                        s->status = SETFIELD(SPI_STS_SEQ_INDEX, s->status,
-                                        (get_seq_index(s) + 1));
+                                                  FSM_SHIFT_N2);
+                        seq_index++;
                     } else {
                         /*
                          * This is case (1) or (2) so the sequencer needs to
@@ -819,14 +814,16 @@ static void operation_sequencer(PnvSpi *s)
                 } else {
                     /* Ok to move on to the next index */
                     s->shift_n1_done = true;
-                    next_sequencer_fsm(s);
+                    seq_index++;
+                    s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status,
+                                    SEQ_STATE_INDEX_INCREMENT);
                 }
             }
             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));
+            trace_pnv_spi_sequencer_op("SHIFT_N2", seq_index);
             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",
@@ -851,14 +848,16 @@ static void operation_sequencer(PnvSpi *s)
                     s->status = SETFIELD(SPI_STS_SHIFTER_FSM, s->status, FSM_WAIT);
                 } else {
                     /* Ok to move on to the next index */
-                    next_sequencer_fsm(s);
+                    seq_index++;
+                    s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status,
+                                    SEQ_STATE_INDEX_INCREMENT);
                 }
             }
             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));
+            trace_pnv_spi_sequencer_op("BRANCH_IFNEQ_RDR", seq_index);
             /*
              * The memory mapping register RDR match value is compared against
              * the 16 rightmost bytes of the RDR (potentially with masking).
@@ -874,15 +873,16 @@ static void operation_sequencer(PnvSpi *s)
                 if (rdr_matched) {
                     trace_pnv_spi_RDR_match("success");
                     /* A match occurred, increment the sequencer index. */
-                    next_sequencer_fsm(s);
+                    seq_index++;
+                    s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status,
+                                    SEQ_STATE_INDEX_INCREMENT);
                 } 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));
+                    seq_index = PNV_SPI_OPCODE_LO_NIBBLE(opcode);
                 }
                 /*
                  * Regardless of where the branch ended up we want the
@@ -901,12 +901,13 @@ static void operation_sequencer(PnvSpi *s)
         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);
+            seq_index++;
+            s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_INDEX_INCREMENT);
             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));
+            trace_pnv_spi_sequencer_op("BRANCH_IFNEQ_INC_1", seq_index);
             /*
              * The spec says the loop should execute count compare + 1 times.
              * However we learned from engineering that we really only loop
@@ -920,19 +921,21 @@ static void operation_sequencer(PnvSpi *s)
                  * 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));
+                seq_index = PNV_SPI_OPCODE_LO_NIBBLE(opcode);
                 s->loop_counter_1++;
             } else {
                 /* Continue to next index if loop counter is reached */
-                next_sequencer_fsm(s);
+                seq_index++;
+                s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status,
+                                SEQ_STATE_INDEX_INCREMENT);
             }
             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]);
+            trace_pnv_spi_sequencer_op("BRANCH_IFNEQ_INC_2", seq_index);
+            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
@@ -945,19 +948,21 @@ static void operation_sequencer(PnvSpi *s)
                  * 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));
+                seq_index = PNV_SPI_OPCODE_LO_NIBBLE(opcode);
                 s->loop_counter_2++;
             } else {
                 /* Continue to next index if loop counter is reached */
-                next_sequencer_fsm(s);
+                seq_index++;
+                s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status,
+                                SEQ_STATE_INDEX_INCREMENT);
             }
             break;
 
         default:
             s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_EXECUTE);
             /* Ignore unsupported operations. */
-            next_sequencer_fsm(s);
+            seq_index++;
+            s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_INDEX_INCREMENT);
             break;
         } /* end of switch */
         /*
@@ -965,10 +970,10 @@ static void operation_sequencer(PnvSpi *s)
          * 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) {
+        if (seq_index == 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);
+            seq_index = 0;
             s->loop_counter_1 = 0;
             s->loop_counter_2 = 0;
             s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status, SEQ_STATE_IDLE);
@@ -979,6 +984,8 @@ static void operation_sequencer(PnvSpi *s)
             break;
         }
     } /* end of while */
+    /* Update sequencer index field in status.*/
+    s->status = SETFIELD(SPI_STS_SEQ_INDEX, s->status, seq_index);
     return;
 } /* end of operation_sequencer() */
 
-- 
2.39.5



^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH v6 3/4] hw/ssi/pnv_spi: Make bus names distinct for each controllers of a socket
  2025-03-03 14:13 [PATCH v6 0/4] hw/ssi/pnv_spi: Remove PnvXferBuffer and other improvements Chalapathi V
  2025-03-03 14:13 ` [PATCH v6 1/4] hw/ssi/pnv_spi: Replace PnvXferBuffer with Fifo8 structure Chalapathi V
  2025-03-03 14:13 ` [PATCH v6 2/4] hw/ssi/pnv_spi: Use local var seq_index instead of get_seq_index() Chalapathi V
@ 2025-03-03 14:13 ` Chalapathi V
  2025-03-03 14:13 ` [PATCH v6 4/4] hw/ssi/pnv_spi: Put a limit to RDR match failures Chalapathi V
  3 siblings, 0 replies; 5+ messages in thread
From: Chalapathi V @ 2025-03-03 14:13 UTC (permalink / raw)
  To: qemu-devel
  Cc: qemu-ppc, fbarrat, npiggin, clg, calebs, chalapathi.v,
	chalapathi.v, saif.abrar, dantan, milesg, philmd, alistair

Create a spi buses with distinct names on each socket so that responders
are attached to correct SPI controllers.

Change the bus name to chipX.spi.<busnum> where X = 0..<num_sockets>

QOM tree on a 2 socket machine:
(qemu) info qom-tree
/machine (powernv10-machine)
  /chip[0] (power10_v2.0-pnv-chip)
    /pib_spic[0] (pnv-spi)
      /chip0.spi.0 (SSI)
      /xscom-spi[0] (memory-region)
  /chip[1] (power10_v2.0-pnv-chip)
    /pib_spic[0] (pnv-spi)
      /chip1.spi.0 (SSI)
      /xscom-spi[0] (memory-region)

Signed-off-by: Chalapathi V <chalapathi.v@linux.ibm.com>
---
 include/hw/ssi/pnv_spi.h           | 3 ++-
 hw/ppc/pnv.c                       | 2 ++
 hw/ssi/pnv_spi.c                   | 5 +++--
 tests/qtest/pnv-spi-seeprom-test.c | 2 +-
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/hw/ssi/pnv_spi.h b/include/hw/ssi/pnv_spi.h
index 9878d9a25f..6adb72dbb2 100644
--- a/include/hw/ssi/pnv_spi.h
+++ b/include/hw/ssi/pnv_spi.h
@@ -31,7 +31,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(PnvSpi, PNV_SPI)
 #define PNV_SPI_REG_SIZE 8
 #define PNV_SPI_REGS 7
 
-#define TYPE_PNV_SPI_BUS "pnv-spi-bus"
+#define TYPE_PNV_SPI_BUS "spi"
 typedef struct PnvSpi {
     SysBusDevice parent_obj;
 
@@ -42,6 +42,7 @@ typedef struct PnvSpi {
     Fifo8 rx_fifo;
     /* SPI object number */
     uint32_t        spic_num;
+    uint32_t        chip_id;
     uint8_t         transfer_len;
     uint8_t         responder_select;
     /* To verify if shift_n1 happens prior to shift_n2 */
diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index 11fd477b71..ce23892fdf 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -2226,6 +2226,8 @@ static void pnv_chip_power10_realize(DeviceState *dev, Error **errp)
         /* pib_spic[2] connected to 25csm04 which implements 1 byte transfer */
         object_property_set_int(OBJECT(&chip10->pib_spic[i]), "transfer_len",
                                 (i == 2) ? 1 : 4, &error_fatal);
+        object_property_set_int(OBJECT(&chip10->pib_spic[i]), "chip-id",
+                                chip->chip_id, &error_fatal);
         if (!sysbus_realize(SYS_BUS_DEVICE(OBJECT
                                         (&chip10->pib_spic[i])), errp)) {
             return;
diff --git a/hw/ssi/pnv_spi.c b/hw/ssi/pnv_spi.c
index de33542c35..83221607c9 100644
--- a/hw/ssi/pnv_spi.c
+++ b/hw/ssi/pnv_spi.c
@@ -1147,14 +1147,15 @@ static const MemoryRegionOps pnv_spi_xscom_ops = {
 
 static const Property pnv_spi_properties[] = {
     DEFINE_PROP_UINT32("spic_num", PnvSpi, spic_num, 0),
+    DEFINE_PROP_UINT32("chip-id", PnvSpi, chip_id, 0),
     DEFINE_PROP_UINT8("transfer_len", PnvSpi, transfer_len, 4),
 };
 
 static void pnv_spi_realize(DeviceState *dev, Error **errp)
 {
     PnvSpi *s = PNV_SPI(dev);
-    g_autofree char *name = g_strdup_printf(TYPE_PNV_SPI_BUS ".%d",
-                    s->spic_num);
+    g_autofree char *name = g_strdup_printf("chip%d." TYPE_PNV_SPI_BUS ".%d",
+                    s->chip_id, s->spic_num);
     s->ssi_bus = ssi_create_bus(dev, name);
     s->cs_line = g_new0(qemu_irq, 1);
     qdev_init_gpio_out_named(DEVICE(s), s->cs_line, "cs", 1);
diff --git a/tests/qtest/pnv-spi-seeprom-test.c b/tests/qtest/pnv-spi-seeprom-test.c
index 57f20af76e..600493c425 100644
--- a/tests/qtest/pnv-spi-seeprom-test.c
+++ b/tests/qtest/pnv-spi-seeprom-test.c
@@ -92,7 +92,7 @@ static void test_spi_seeprom(const void *data)
     qts = qtest_initf("-machine powernv10 -smp 2,cores=2,"
                       "threads=1 -accel tcg,thread=single -nographic "
                       "-blockdev node-name=pib_spic2,driver=file,"
-                      "filename=%s -device 25csm04,bus=pnv-spi-bus.2,cs=0,"
+                      "filename=%s -device 25csm04,bus=chip0.spi.2,cs=0,"
                       "drive=pib_spic2", tmp_path);
     spi_seeprom_transaction(qts, chip);
     qtest_quit(qts);
-- 
2.39.5



^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH v6 4/4] hw/ssi/pnv_spi: Put a limit to RDR match failures
  2025-03-03 14:13 [PATCH v6 0/4] hw/ssi/pnv_spi: Remove PnvXferBuffer and other improvements Chalapathi V
                   ` (2 preceding siblings ...)
  2025-03-03 14:13 ` [PATCH v6 3/4] hw/ssi/pnv_spi: Make bus names distinct for each controllers of a socket Chalapathi V
@ 2025-03-03 14:13 ` Chalapathi V
  3 siblings, 0 replies; 5+ messages in thread
From: Chalapathi V @ 2025-03-03 14:13 UTC (permalink / raw)
  To: qemu-devel
  Cc: qemu-ppc, fbarrat, npiggin, clg, calebs, chalapathi.v,
	chalapathi.v, saif.abrar, dantan, milesg, philmd, alistair

There is a possibility that SPI controller can get into loop due to indefinite
RDR match failures. Hence put a limit to failures and stop the sequencer.

Signed-off-by: Chalapathi V <chalapathi.v@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
---
 include/hw/ssi/pnv_spi.h |  1 +
 hw/ssi/pnv_spi.c         | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/include/hw/ssi/pnv_spi.h b/include/hw/ssi/pnv_spi.h
index 6adb72dbb2..c591a0663d 100644
--- a/include/hw/ssi/pnv_spi.h
+++ b/include/hw/ssi/pnv_spi.h
@@ -40,6 +40,7 @@ typedef struct PnvSpi {
     MemoryRegion    xscom_spic_regs;
     Fifo8 tx_fifo;
     Fifo8 rx_fifo;
+    uint8_t fail_count; /* RDR Match failure counter */
     /* SPI object number */
     uint32_t        spic_num;
     uint32_t        chip_id;
diff --git a/hw/ssi/pnv_spi.c b/hw/ssi/pnv_spi.c
index 83221607c9..126070393e 100644
--- a/hw/ssi/pnv_spi.c
+++ b/hw/ssi/pnv_spi.c
@@ -20,6 +20,7 @@
 #define PNV_SPI_OPCODE_LO_NIBBLE(x) (x & 0x0F)
 #define PNV_SPI_MASKED_OPCODE(x) (x & 0xF0)
 #define PNV_SPI_FIFO_SIZE 16
+#define RDR_MATCH_FAILURE_LIMIT 16
 
 /*
  * Macro from include/hw/ppc/fdt.h
@@ -872,18 +873,27 @@ static void operation_sequencer(PnvSpi *s)
                 rdr_matched = does_rdr_match(s);
                 if (rdr_matched) {
                     trace_pnv_spi_RDR_match("success");
+                    s->fail_count = 0;
                     /* A match occurred, increment the sequencer index. */
                     seq_index++;
                     s->status = SETFIELD(SPI_STS_SEQ_FSM, s->status,
                                     SEQ_STATE_INDEX_INCREMENT);
                 } else {
                     trace_pnv_spi_RDR_match("failed");
+                    s->fail_count++;
                     /*
                      * Branch the sequencer to the index coded into the op
                      * code.
                      */
                     seq_index = PNV_SPI_OPCODE_LO_NIBBLE(opcode);
                 }
+                if (s->fail_count >= RDR_MATCH_FAILURE_LIMIT) {
+                    qemu_log_mask(LOG_GUEST_ERROR, "pnv_spi: RDR match failure"
+                                  " limit crossed %d times hence requesting "
+                                  "sequencer to stop.\n",
+                                  RDR_MATCH_FAILURE_LIMIT);
+                    stop = true;
+                }
                 /*
                  * Regardless of where the branch ended up we want the
                  * sequencer to continue shifting so we have to clear
-- 
2.39.5



^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2025-03-03 14:16 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-03-03 14:13 [PATCH v6 0/4] hw/ssi/pnv_spi: Remove PnvXferBuffer and other improvements Chalapathi V
2025-03-03 14:13 ` [PATCH v6 1/4] hw/ssi/pnv_spi: Replace PnvXferBuffer with Fifo8 structure Chalapathi V
2025-03-03 14:13 ` [PATCH v6 2/4] hw/ssi/pnv_spi: Use local var seq_index instead of get_seq_index() Chalapathi V
2025-03-03 14:13 ` [PATCH v6 3/4] hw/ssi/pnv_spi: Make bus names distinct for each controllers of a socket Chalapathi V
2025-03-03 14:13 ` [PATCH v6 4/4] hw/ssi/pnv_spi: Put a limit to RDR match failures Chalapathi V

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