[08/24] hw/arm/mps2-tz: Condition IRQ splitting on number of CPUs, not board type

Commit Message

Peter Maydell Feb. 5, 2021, 5 p.m. UTC

In the mps2-tz board code, we handle devices whose interrupt lines
must be wired to all CPUs by creating IRQ splitter devices for the
AN521, because it has 2 CPUs, but wiring the device IRQ directly to
the SSE/IoTKit input for the AN505, which has only 1 CPU.

We can avoid making an explicit check on the board type constant by
instead creating and using the IRQ splitters for any board with more
than 1 CPU.  This avoids having to add extra cases to the
conditionals every time we add new boards.

Signed-off-by: Peter Maydell <[e-mail]>
---
This removes the only current user of mmc->fpga_type, but we're
going to want it again later in the series.
---
 hw/arm/mps2-tz.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

Comments

Philippe Mathieu-Daudé Feb. 12, 2021, 6:25 p.m. UTC | #1

On 2/5/21 6:00 PM, Peter Maydell wrote:
> In the mps2-tz board code, we handle devices whose interrupt lines
> must be wired to all CPUs by creating IRQ splitter devices for the
> AN521, because it has 2 CPUs, but wiring the device IRQ directly to
> the SSE/IoTKit input for the AN505, which has only 1 CPU.
> 
> We can avoid making an explicit check on the board type constant by
> instead creating and using the IRQ splitters for any board with more
> than 1 CPU.  This avoids having to add extra cases to the
> conditionals every time we add new boards.
> 
> Signed-off-by: Peter Maydell <[e-mail]>
> ---
> This removes the only current user of mmc->fpga_type, but we're
> going to want it again later in the series.
> ---
>  hw/arm/mps2-tz.c | 19 +++++++++----------
>  1 file changed, 9 insertions(+), 10 deletions(-)

Good idea.

Reviewed-by: Philippe Mathieu-Daudé <[e-mail]>

Patch

diff --git a/hw/arm/mps2-tz.c b/hw/arm/mps2-tz.c
index 94618ae54d2..4d8e42fa6b6 100644
--- a/hw/arm/mps2-tz.c
+++ b/hw/arm/mps2-tz.c
@@ -139,17 +139,14 @@  static void make_ram_alias(MemoryRegion *mr, const char *name,
 static qemu_irq get_sse_irq_in(MPS2TZMachineState *mms, int irqno)
 {
     /* Return a qemu_irq which will signal IRQ n to all CPUs in the SSE. */
-    MPS2TZMachineClass *mmc = MPS2TZ_MACHINE_GET_CLASS(mms);
+    MachineClass *mc = MACHINE_GET_CLASS(mms);
 
     assert(irqno < MPS2TZ_NUMIRQ);
 
-    switch (mmc->fpga_type) {
-    case FPGA_AN505:
-        return qdev_get_gpio_in_named(DEVICE(&mms->iotkit), "EXP_IRQ", irqno);
-    case FPGA_AN521:
+    if (mc->max_cpus > 1) {
         return qdev_get_gpio_in(DEVICE(&mms->cpu_irq_splitter[irqno]), 0);
-    default:
-        g_assert_not_reached();
+    } else {
+        return qdev_get_gpio_in_named(DEVICE(&mms->iotkit), "EXP_IRQ", irqno);
     }
 }
 
@@ -437,10 +434,12 @@  static void mps2tz_common_init(MachineState *machine)
     sysbus_realize(SYS_BUS_DEVICE(&mms->iotkit), &error_fatal);
 
     /*
-     * The AN521 needs us to create splitters to feed the IRQ inputs
-     * for each CPU in the SSE-200 from each device in the board.
+     * If this board has more than one CPU, then we need to create splitters
+     * to feed the IRQ inputs for each CPU in the SSE from each device in the
+     * board. If there is only one CPU, we can just wire the device IRQ
+     * directly to the SSE's IRQ input.
      */
-    if (mmc->fpga_type == FPGA_AN521) {
+    if (mc->max_cpus > 1) {
         for (i = 0; i < MPS2TZ_NUMIRQ; i++) {
             char *name = g_strdup_printf("mps2-irq-splitter%d", i);
             SplitIRQ *splitter = &mms->cpu_irq_splitter[i];