On Thu, Mar 1, 2018 at 4:20 PM, Alistair Francis
<alistair.fran...@xilinx.com> wrote:
> The cortex A53 TRM specifices that bits 24 and 25 of the L2CTLR register
> specify the number of cores present and not the number of processors. We
> have correctly been reporting the number of cores, so just fix the
> comment to match the TRM.
>
> Signed-off-by: Alistair Francis <alistair.fran...@xilinx.com>
Ah! This isn't actually what I want, I want something more like this (untested):
commit ce9d9795ebff42e1f742e7dc3786e52524807c65
Author: Alistair Francis <alist...@alistair23.me>
Date: Thu Mar 1 20:19:23 2018 -0800
target/arm: Report the number of cores in the cluster
Previously we assumed that we only has a single cluster, which meant we
could get away with reporting smp_cpus to the guest. There are cases
where we have two clusters (Xilinx's ZynqMP is a good example) so
reporting the number of smp_cpus is incorrect. Instead count the cores
in the cluster.
Signed-off-by: Alistair Francis <alist...@alistair23.me>
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 9743bdc..e7b1f3c 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -42,8 +42,24 @@ static inline void unset_feature(CPUARMState *env,
int feature)
#ifndef CONFIG_USER_ONLY
static uint64_t a57_a53_l2ctlr_read(CPUARMState *env, const ARMCPRegInfo *ri)
{
- /* Number of processors is in [25:24]; otherwise we RAZ */
- return (smp_cpus - 1) << 24;
+ CPUState *cpu;
+ CPUState *cpu_prev = NULL;
+ int num_cores = 0;
+
+ /* Figure out the number of cores in the cluster */
+ for (cpu = first_cpu; cpu; cpu = CPU_NEXT(cpu)) {
+ /* Only increase the core count if the CPU we are on is the same
+ * class as the caller and the previous cpu.
+ */
+ if ((CPU_GET_CLASS(cpu) == CPU_GET_CLASS(cpu_prev)) &&
+ (CPU_GET_CLASS(cpu) == CPU_GET_CLASS(CPU(env)))) {
+ num_cores++;
+ }
+ cpu_prev = cpu;
+ }
+
+ /* Number of cores is in [25:24]; otherwise we RAZ */
+ return num_cores << 24;
}
#endif
I'll send a patch tomorrow after testing.
Alistair
> ---
>
> target/arm/cpu64.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
> index 9743bdc8c3..aac1746efe 100644
> --- a/target/arm/cpu64.c
> +++ b/target/arm/cpu64.c
> @@ -42,7 +42,7 @@ static inline void unset_feature(CPUARMState *env, int
> feature)
> #ifndef CONFIG_USER_ONLY
> static uint64_t a57_a53_l2ctlr_read(CPUARMState *env, const ARMCPRegInfo *ri)
> {
> - /* Number of processors is in [25:24]; otherwise we RAZ */
> + /* Number of cores is in [25:24]; otherwise we RAZ */
> return (smp_cpus - 1) << 24;
> }
> #endif
> --
> 2.14.1
>
