hw/intc/arm_gicv5: Implement IRS_SPI_{SELR, STATUSR, CFGR, DOMAINR}

Implement the IRS registers IRS_SPI_{SELR,STATUSR,CFGR,DOMAINR} which
form the config access for setting the trigger mode and domain of an
SPI.  The way these work is that the guest writes the ID of the
interrupt it wants to configure to IRS_SPI_SELR, and then it can read
and write the trigger mode of that SPI via IRS_SPI_CFGR and the
domain via IRS_SPI_DOMAINR.  IRS_SPI_STATUSR has a bit to indicate
whether the SPI is valid, and the usual IDLE bit to allow for
non-instantaneous updates (which QEMU doesn't do).

Since the only domain which can configure the domain of an SPI is EL3
and our initial implementation is NS-only, technically the DOMAINR
handling is unused code.  However it is straightforward, being almost
the same as the CFGR handling, and we'll need it later on.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Message-id: 20260327111700.795099-28-peter.maydell@linaro.org

diff --git a/hw/intc/arm_gicv5.c b/hw/intc/arm_gicv5.c
index 04d4391ae56cac04943eb6e4a4bfd86cd3ced4b2..6ff3a797454757491ea90d11329c7b6e13e55729 100644 (file)
--- a/hw/intc/arm_gicv5.c
+++ b/hw/intc/arm_gicv5.c
@@ -310,6 +310,22 @@ FIELD(ICSR, HM, 5, 1)
 FIELD(ICSR, PRIORITY, 11, 5)
 FIELD(ICSR, IAFFID, 32, 16)
 
+static GICv5SPIState *spi_for_selr(GICv5Common *cs, GICv5Domain domain)
+{
+    /*
+     * If the IRS_SPI_SELR value specifies an SPI that can be managed in
+     * this domain, return a pointer to its GICv5SPIState; otherwise
+     * return NULL.
+     */
+    uint32_t id = FIELD_EX32(cs->irs_spi_selr[domain], IRS_SPI_SELR, ID);
+    GICv5SPIState *spi = gicv5_raw_spi_state(cs, id);
+
+    if (spi && (domain == GICV5_ID_EL3 || domain == spi->domain)) {
+        return spi;
+    }
+    return NULL;
+}
+
 static MemTxAttrs irs_txattrs(GICv5Common *cs, GICv5Domain domain)
 {
     /*
@@ -1010,6 +1026,38 @@ static bool config_readl(GICv5 *s, GICv5Domain domain, hwaddr offset,
     case A_IRS_IST_CFGR:
         *data = cs->irs_ist_cfgr[domain];
         return true;
+
+    case A_IRS_SPI_STATUSR:
+        /*
+         * QEMU writes to IRS_SPI_{CFGR,DOMAINR,SELR,VMR} take effect
+         * instantaneously, so the guest can never see the IDLE bit as 0.
+         */
+        v = FIELD_DP32(v, IRS_SPI_STATUSR, V,
+                       spi_for_selr(cs, domain) != NULL);
+        v = FIELD_DP32(v, IRS_SPI_STATUSR, IDLE, 1);
+        *data = v;
+        return true;
+
+    case A_IRS_SPI_CFGR:
+    {
+        GICv5SPIState *spi = spi_for_selr(cs, domain);
+
+        if (spi) {
+            v = FIELD_DP32(v, IRS_SPI_CFGR, TM, spi->tm);
+        }
+        *data = v;
+        return true;
+    }
+    case A_IRS_SPI_DOMAINR:
+        if (domain == GICV5_ID_EL3) {
+            /* This is RAZ/WI except for the EL3 domain */
+            GICv5SPIState *spi = spi_for_selr(cs, domain);
+            if (spi) {
+                v = FIELD_DP32(v, IRS_SPI_DOMAINR, DOMAIN, spi->domain);
+            }
+        }
+        *data = v;
+        return true;
     }
 
     return false;
@@ -1041,6 +1089,26 @@ static bool config_writel(GICv5 *s, GICv5Domain domain, hwaddr offset,
     case A_IRS_MAP_L2_ISTR:
         irs_map_l2_istr_write(s, domain, data);
         return true;
+    case A_IRS_SPI_SELR:
+        cs->irs_spi_selr[domain] = data;
+        return true;
+    case A_IRS_SPI_CFGR:
+    {
+        GICv5SPIState *spi = spi_for_selr(cs, domain);
+        if (spi) {
+            spi->tm = FIELD_EX32(data, IRS_SPI_CFGR, TM);
+        }
+        return true;
+    }
+    case A_IRS_SPI_DOMAINR:
+        if (domain == GICV5_ID_EL3) {
+            /* this is RAZ/WI except for the EL3 domain */
+            GICv5SPIState *spi = spi_for_selr(cs, domain);
+            if (spi) {
+                spi->domain = FIELD_EX32(data, IRS_SPI_DOMAINR, DOMAIN);
+            }
+        }
+        return true;
     }
 
     return false;

diff --git a/hw/intc/arm_gicv5_common.c b/hw/intc/arm_gicv5_common.c
index aa5877ee055106e37949337f96f1b33e7739f79b..607b99c2ac52f88330530a103c5321b253e4f47c 100644 (file)
--- a/hw/intc/arm_gicv5_common.c
+++ b/hw/intc/arm_gicv5_common.c
@@ -92,6 +92,15 @@ static void gicv5_common_reset_hold(Object *obj, ResetType type)
             cs->spi[i].domain = mp_domain;
         }
     }
+
+    for (int i = 0; i < NUM_GICV5_DOMAINS; i++) {
+        /*
+         * We reset irs_spi_selr to an invalid value so that our reset
+         * value for IRS_SPI_STATUSR.V is correctly 0. The guest can
+         * never read IRS_SPI_SELR directly.
+         */
+        cs->irs_spi_selr[i] = cs->spi_base + cs->spi_irs_range;
+    }
 }
 
 static void gicv5_common_init(Object *obj)

diff --git a/include/hw/intc/arm_gicv5_common.h b/include/hw/intc/arm_gicv5_common.h
index 6897f941178d4d4021f19ead2dacba5970d2b327..c5a64bf86d024a23cacbf52497f5c3ec8de19a5c 100644 (file)
--- a/include/hw/intc/arm_gicv5_common.h
+++ b/include/hw/intc/arm_gicv5_common.h
@@ -85,6 +85,7 @@ struct GICv5Common {
 
     uint64_t irs_ist_baser[NUM_GICV5_DOMAINS];
     uint32_t irs_ist_cfgr[NUM_GICV5_DOMAINS];
+    uint32_t irs_spi_selr[NUM_GICV5_DOMAINS];
 
     /*
      * Pointer to an array of state information for the SPIs.  Array