Hi Zenghui,

On 2020-02-06 07:57, Zenghui Yu wrote:
In GICv4, we will ensure that level2 vPE table memory is allocated
for the specified vpe_id on all v4 ITS, in its_alloc_vpe_table().
This still works well for the typical GICv4.1 implementation, where
the new vPE table is shared between the ITSs and the RDs.

To make it explicit, let us introduce allocate_vpe_l2_table() to
make sure that the L2 tables are allocated on all v4.1 RDs. We're
likely not need to allocate memory in it because the vPE table is
shared and (L2 table is) already allocated at ITS level, except
for the case where the ITS doesn't share anything (say SVPET == 0,
practically unlikely but architecturally allowed).

The implementation of allocate_vpe_l2_table() is mostly copied from
its_alloc_table_entry().

Signed-off-by: Zenghui Yu <yuzeng...@huawei.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 80 ++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 0f1fe56ce0af..ae4e7b355b46 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2443,6 +2443,72 @@ static u64 inherit_vpe_l1_table_from_rd(cpumask_t **mask)
        return 0;
 }

+static bool allocate_vpe_l2_table(int cpu, u32 id)
+{
+       void __iomem *base = gic_data_rdist_cpu(cpu)->rd_base;
+       u64 val, gpsz, npg;
+       unsigned int psz, esz, idx;
+       struct page *page;
+       __le64 *table;
+
+       if (!gic_rdists->has_rvpeid)
+               return true;
+
+       val  = gits_read_vpropbaser(base + SZ_128K + GICR_VPROPBASER);

Having rebased the rest of the GICv4.1 series on top of -rc1, I've hit a small issue right here. I run a FVP model that only spawns 4 CPUs, while the DT has
8 of them. This means that online_cpus = 4, and possible_cpus = 8.

So in my case, half of the RDs have base == NULL, and things stop quickly.

I plan to queue the following:

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index d85dc8dcb0ad..7656b353a95f 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2526,6 +2526,10 @@ static bool allocate_vpe_l2_table(int cpu, u32 id)
        if (!gic_rdists->has_rvpeid)
                return true;

+       /* Skip non-present CPUs */
+       if (!base)
+               return true;
+
        val  = gicr_read_vpropbaser(base + SZ_128K + GICR_VPROPBASER);

        esz  = FIELD_GET(GICR_VPROPBASER_4_1_ENTRY_SIZE, val) + 1;


Thanks,

        M.
--
Jazz is not dead. It just smells funny...
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