[PATCH 2/3] irqchip/gic-v3-its: Spin off GICv4 init into a separate function

From: Oliver Upton
Date: Mon Feb 19 2024 - 13:59:15 EST


Burying the GICv4 redistributor initialization into the routine for LPIs
is a bit confusing, and can lead to sillies where unexpected codepaths
may not fully initialize the RD.

Hoist it out of its_cpu_init_lpis() into a dedicated function.

Signed-off-by: Oliver Upton <oliver.upton@xxxxxxxxx>
---
drivers/irqchip/irq-gic-v3-its.c | 32 +++++++++++++++++++++-----------
1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 0022852ce494..63d1743f08cc 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3173,8 +3173,25 @@ static void its_cpu_init_lpis(void)
writel_relaxed(val, rbase + GICR_CTLR);

out:
- if (gic_rdists->has_vlpis && !gic_rdists->has_rvpeid) {
+ /* Make sure the GIC has seen the above */
+ dsb(sy);
+ gic_data_rdist()->flags |= RD_LOCAL_LPI_ENABLED;
+ pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n",
+ smp_processor_id(),
+ gic_data_rdist()->flags & RD_LOCAL_PENDTABLE_PREALLOCATED ?
+ "reserved" : "allocated",
+ &paddr);
+}
+
+static void its_cpu_init_vlpis(void)
+{
+ /* No vLPIs? No problem. */
+ if (!gic_rdists->has_vlpis)
+ return;
+
+ if (!gic_rdists->has_rvpeid) {
void __iomem *vlpi_base = gic_data_rdist_vlpi_base();
+ u64 val;

/*
* It's possible for CPU to receive VLPIs before it is
@@ -3193,7 +3210,8 @@ static void its_cpu_init_lpis(void)
* ancient programming gets left in and has possibility of
* corrupting memory.
*/
- val = its_clear_vpend_valid(vlpi_base, 0, 0);
+ its_clear_vpend_valid(vlpi_base, 0, 0);
+ return;
}

if (allocate_vpe_l1_table()) {
@@ -3205,15 +3223,6 @@ static void its_cpu_init_lpis(void)
gic_rdists->has_rvpeid = false;
gic_rdists->has_vlpis = false;
}
-
- /* Make sure the GIC has seen the above */
- dsb(sy);
- gic_data_rdist()->flags |= RD_LOCAL_LPI_ENABLED;
- pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n",
- smp_processor_id(),
- gic_data_rdist()->flags & RD_LOCAL_PENDTABLE_PREALLOCATED ?
- "reserved" : "allocated",
- &paddr);
}

static void its_cpu_init_collection(struct its_node *its)
@@ -5265,6 +5274,7 @@ int its_cpu_init(void)
return ret;

its_cpu_init_lpis();
+ its_cpu_init_vlpis();
its_cpu_init_collections();
}

--
2.44.0.rc0.258.g7320e95886-goog