On 2020-06-25 19:25, Valentin Schneider wrote:
On 24/06/20 20:57, Marc Zyngier wrote:
@@ -696,9 +696,76 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
if ((unsigned)ipinr < NR_IPI)
trace_ipi_exit_rcuidle(ipi_types[ipinr]);
+}
+
+/* Legacy version, should go away once all irqchips have been
converted */
+void handle_IPI(int ipinr, struct pt_regs *regs)
+{
+ struct pt_regs *old_regs = set_irq_regs(regs);
+
+ irq_enter();
+ do_handle_IPI(ipinr);
+ irq_exit();
+
set_irq_regs(old_regs);
}
+static irqreturn_t ipi_handler(int irq, void *data)
+{
+ do_handle_IPI(irq - ipi_irq_base);
+ return IRQ_HANDLED;
+}
+
+static void ipi_send(const struct cpumask *target, unsigned int ipi)
+{
+ __ipi_send_mask(ipi_desc[ipi], target);
+}
+
+static void ipi_setup(int cpu)
+{
+ if (ipi_irq_base) {
+ int i;
+
+ for (i = 0; i < nr_ipi; i++)
+ enable_percpu_irq(ipi_irq_base + i, 0);
+ }
+}
+
+static void ipi_teardown(int cpu)
+{
+ if (ipi_irq_base) {
+ int i;
+
+ for (i = 0; i < nr_ipi; i++)
+ disable_percpu_irq(ipi_irq_base + i);
+ }
+}
+
+void __init set_smp_ipi_range(int ipi_base, int n)
+{
+ int i;
+
+ WARN_ON(n < MAX_IPI);
+ nr_ipi = min(n, MAX_IPI);
I got confused by that backtrace thing and NR_IPI vs MAX_IPI.
I think I got it now : we don't want to call trace_ipi_raise() for
IPI_CPU_BACKTRACE *but* we still need to alloc the desc and route it
through the generic IPI layers.
Indeed, and I didn't want to have a bizarre "+ 1" hanging about.
The only difference I can tell is that now we will get some trace
events
for it via the handler entry/exit tracepoints - that shouldn't cause
any
issue.
I hope so. I don't see how you can avoid all tracepoints anyway (if that
was the intention).
Thanks,
M.
--
Jazz is not dead. It just smells funny...
