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@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Zenghui Yu <yuzenghui@huawei.com>
Cc: wanghaibin.wang@huawei.com
Tested-by: Kunkun Jiang <jiangkunkun@huawei.com>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20230617073242.3199746-1-maz@kernel.org

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 1994541eaef841cb0ffcdcec01b9692af4918c6e..5365bc3b1c497ea87e7fdbad0c0f6f2d70fb0444 100644 (file)
--- 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)
@@ -3953,18 +3978,10 @@ 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)