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Message-Id: <20230617073242.3199746-1-maz@kernel.org>
Date: Sat, 17 Jun 2023 08:32:42 +0100
From: Marc Zyngier <maz@...nel.org>
To: linux-kernel@...r.kernel.org
Cc: Thomas Gleixner <tglx@...utronix.de>,
Kunkun Jiang <jiangkunkun@...wei.com>,
Zenghui Yu <yuzenghui@...wei.com>, wanghaibin.wang@...wei.com
Subject: [PATCH] irqchip/gic-v4.1: Properly lock VPEs when doing a directLPI invalidation
We normally rely on the irq_to_cpuid_[un]lock() primitives to make
sure nothing will change col->idx while performing a LPI invalidation.
However, these primitives do not cover VPE doorbells, and we have
some open-coded locking for that. Unfortunately, this locking is
pretty bogus.
Instead, extend the above primitives to cover VPE doorbells and
convert the whole thing to it.
Fixes: f3a059219bc7 ("irqchip/gic-v4.1: Ensure mutual exclusion between vPE affinity change and RD access")
Reported-by: Kunkun Jiang <jiangkunkun@...wei.com>
Signed-off-by: Marc Zyngier <maz@...nel.org>
Cc: Zenghui Yu <yuzenghui@...wei.com>
Cc: wanghaibin.wang@...wei.com
---
drivers/irqchip/irq-gic-v3-its.c | 75 ++++++++++++++++++++------------
1 file changed, 46 insertions(+), 29 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 0ec2b1e1df75..c5cb2830e853 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -273,13 +273,23 @@ static void vpe_to_cpuid_unlock(struct its_vpe *vpe, unsigned long flags)
raw_spin_unlock_irqrestore(&vpe->vpe_lock, flags);
}
+static struct irq_chip its_vpe_irq_chip;
+
static int irq_to_cpuid_lock(struct irq_data *d, unsigned long *flags)
{
- struct its_vlpi_map *map = get_vlpi_map(d);
+ struct its_vpe *vpe = NULL;
int cpu;
- if (map) {
- cpu = vpe_to_cpuid_lock(map->vpe, flags);
+ if (d->chip == &its_vpe_irq_chip) {
+ vpe = irq_data_get_irq_chip_data(d);
+ } else {
+ struct its_vlpi_map *map = get_vlpi_map(d);
+ if (map)
+ vpe = map->vpe;
+ }
+
+ if (vpe) {
+ cpu = vpe_to_cpuid_lock(vpe, flags);
} else {
/* Physical LPIs are already locked via the irq_desc lock */
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
@@ -293,10 +303,18 @@ static int irq_to_cpuid_lock(struct irq_data *d, unsigned long *flags)
static void irq_to_cpuid_unlock(struct irq_data *d, unsigned long flags)
{
- struct its_vlpi_map *map = get_vlpi_map(d);
+ struct its_vpe *vpe = NULL;
+
+ if (d->chip == &its_vpe_irq_chip) {
+ vpe = irq_data_get_irq_chip_data(d);
+ } else {
+ struct its_vlpi_map *map = get_vlpi_map(d);
+ if (map)
+ vpe = map->vpe;
+ }
- if (map)
- vpe_to_cpuid_unlock(map->vpe, flags);
+ if (vpe)
+ vpe_to_cpuid_unlock(vpe, flags);
}
static struct its_collection *valid_col(struct its_collection *col)
@@ -1433,14 +1451,29 @@ static void wait_for_syncr(void __iomem *rdbase)
cpu_relax();
}
-static void direct_lpi_inv(struct irq_data *d)
+static void __direct_lpi_inv(struct irq_data *d, u64 val)
{
- struct its_vlpi_map *map = get_vlpi_map(d);
void __iomem *rdbase;
unsigned long flags;
- u64 val;
int cpu;
+ /* Target the redistributor this LPI is currently routed to */
+ cpu = irq_to_cpuid_lock(d, &flags);
+ raw_spin_lock(&gic_data_rdist_cpu(cpu)->rd_lock);
+
+ rdbase = per_cpu_ptr(gic_rdists->rdist, cpu)->rd_base;
+ gic_write_lpir(val, rdbase + GICR_INVLPIR);
+ wait_for_syncr(rdbase);
+
+ raw_spin_unlock(&gic_data_rdist_cpu(cpu)->rd_lock);
+ irq_to_cpuid_unlock(d, flags);
+}
+
+static void direct_lpi_inv(struct irq_data *d)
+{
+ struct its_vlpi_map *map = get_vlpi_map(d);
+ u64 val;
+
if (map) {
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
@@ -1453,15 +1486,7 @@ static void direct_lpi_inv(struct irq_data *d)
val = d->hwirq;
}
- /* Target the redistributor this LPI is currently routed to */
- cpu = irq_to_cpuid_lock(d, &flags);
- raw_spin_lock(&gic_data_rdist_cpu(cpu)->rd_lock);
- rdbase = per_cpu_ptr(gic_rdists->rdist, cpu)->rd_base;
- gic_write_lpir(val, rdbase + GICR_INVLPIR);
-
- wait_for_syncr(rdbase);
- raw_spin_unlock(&gic_data_rdist_cpu(cpu)->rd_lock);
- irq_to_cpuid_unlock(d, flags);
+ __direct_lpi_inv(d, val);
}
static void lpi_update_config(struct irq_data *d, u8 clr, u8 set)
@@ -3952,18 +3977,10 @@ static void its_vpe_send_inv(struct irq_data *d)
{
struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
- if (gic_rdists->has_direct_lpi) {
- void __iomem *rdbase;
-
- /* Target the redistributor this VPE is currently known on */
- raw_spin_lock(&gic_data_rdist_cpu(vpe->col_idx)->rd_lock);
- rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
- gic_write_lpir(d->parent_data->hwirq, rdbase + GICR_INVLPIR);
- wait_for_syncr(rdbase);
- raw_spin_unlock(&gic_data_rdist_cpu(vpe->col_idx)->rd_lock);
- } else {
+ if (gic_rdists->has_direct_lpi)
+ __direct_lpi_inv(d, d->parent_data->hwirq);
+ else
its_vpe_send_cmd(vpe, its_send_inv);
- }
}
static void its_vpe_mask_irq(struct irq_data *d)
--
2.34.1
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