6.12-stable review patch. If anyone has any objections, please let me know.
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From: Anup Patel apatel@ventanamicro.com
[ Upstream commit 0f67911e821c67ecfccc365a2103ce276a9a56fe ]
Currently, there is only one "move" pointer in struct imsic_vector so during vector movement the old vector points to the new vector and new vector points to itself.
To support forced cleanup of the old vector, add separate "move_next" and "move_prev" pointers to struct imsic_vector, where during vector movement the "move_next" pointer of the old vector points to the new vector and the "move_prev" pointer of the new vector points to the old vector.
Both "move_next" and "move_prev" pointers are cleared separately by __imsic_local_sync() with a restriction that "move_prev" on the new CPU is cleared only after the old CPU has cleared "move_next".
Signed-off-by: Anup Patel apatel@ventanamicro.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Link: https://lore.kernel.org/all/20250217085657.789309-8-apatel@ventanamicro.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/irqchip/irq-riscv-imsic-early.c | 8 ++- drivers/irqchip/irq-riscv-imsic-state.c | 96 +++++++++++++++++-------- drivers/irqchip/irq-riscv-imsic-state.h | 7 +- 3 files changed, 78 insertions(+), 33 deletions(-)
diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c index c5c2e6929a2f5..b5def6268936e 100644 --- a/drivers/irqchip/irq-riscv-imsic-early.c +++ b/drivers/irqchip/irq-riscv-imsic-early.c @@ -77,6 +77,12 @@ static void imsic_handle_irq(struct irq_desc *desc) struct imsic_vector *vec; unsigned long local_id;
+ /* + * Process pending local synchronization instead of waiting + * for per-CPU local timer to expire. + */ + imsic_local_sync_all(false); + chained_irq_enter(chip, desc);
while ((local_id = csr_swap(CSR_TOPEI, 0))) { @@ -120,7 +126,7 @@ static int imsic_starting_cpu(unsigned int cpu) * Interrupts identities might have been enabled/disabled while * this CPU was not running so sync-up local enable/disable state. */ - imsic_local_sync_all(); + imsic_local_sync_all(true);
/* Enable local interrupt delivery */ imsic_local_delivery(true); diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c index b97e6cd89ed74..1aeba76d72795 100644 --- a/drivers/irqchip/irq-riscv-imsic-state.c +++ b/drivers/irqchip/irq-riscv-imsic-state.c @@ -124,10 +124,11 @@ void __imsic_eix_update(unsigned long base_id, unsigned long num_id, bool pend, } }
-static void __imsic_local_sync(struct imsic_local_priv *lpriv) +static bool __imsic_local_sync(struct imsic_local_priv *lpriv) { struct imsic_local_config *mlocal; struct imsic_vector *vec, *mvec; + bool ret = true; int i;
lockdep_assert_held(&lpriv->lock); @@ -143,35 +144,75 @@ static void __imsic_local_sync(struct imsic_local_priv *lpriv) __imsic_id_clear_enable(i);
/* - * If the ID was being moved to a new ID on some other CPU - * then we can get a MSI during the movement so check the - * ID pending bit and re-trigger the new ID on other CPU - * using MMIO write. + * Clear the previous vector pointer of the new vector only + * after the movement is complete on the old CPU. */ - mvec = READ_ONCE(vec->move); - WRITE_ONCE(vec->move, NULL); - if (mvec && mvec != vec) { + mvec = READ_ONCE(vec->move_prev); + if (mvec) { + /* + * If the old vector has not been updated then + * try again in the next sync-up call. + */ + if (READ_ONCE(mvec->move_next)) { + ret = false; + continue; + } + + WRITE_ONCE(vec->move_prev, NULL); + } + + /* + * If a vector was being moved to a new vector on some other + * CPU then we can get a MSI during the movement so check the + * ID pending bit and re-trigger the new ID on other CPU using + * MMIO write. + */ + mvec = READ_ONCE(vec->move_next); + if (mvec) { if (__imsic_id_read_clear_pending(i)) { mlocal = per_cpu_ptr(imsic->global.local, mvec->cpu); writel_relaxed(mvec->local_id, mlocal->msi_va); }
+ WRITE_ONCE(vec->move_next, NULL); imsic_vector_free(&lpriv->vectors[i]); }
skip: bitmap_clear(lpriv->dirty_bitmap, i, 1); } + + return ret; }
-void imsic_local_sync_all(void) +#ifdef CONFIG_SMP +static void __imsic_local_timer_start(struct imsic_local_priv *lpriv) +{ + lockdep_assert_held(&lpriv->lock); + + if (!timer_pending(&lpriv->timer)) { + lpriv->timer.expires = jiffies + 1; + add_timer_on(&lpriv->timer, smp_processor_id()); + } +} +#else +static inline void __imsic_local_timer_start(struct imsic_local_priv *lpriv) +{ +} +#endif + +void imsic_local_sync_all(bool force_all) { struct imsic_local_priv *lpriv = this_cpu_ptr(imsic->lpriv); unsigned long flags;
raw_spin_lock_irqsave(&lpriv->lock, flags); - bitmap_fill(lpriv->dirty_bitmap, imsic->global.nr_ids + 1); - __imsic_local_sync(lpriv); + + if (force_all) + bitmap_fill(lpriv->dirty_bitmap, imsic->global.nr_ids + 1); + if (!__imsic_local_sync(lpriv)) + __imsic_local_timer_start(lpriv); + raw_spin_unlock_irqrestore(&lpriv->lock, flags); }
@@ -190,12 +231,7 @@ void imsic_local_delivery(bool enable) #ifdef CONFIG_SMP static void imsic_local_timer_callback(struct timer_list *timer) { - struct imsic_local_priv *lpriv = this_cpu_ptr(imsic->lpriv); - unsigned long flags; - - raw_spin_lock_irqsave(&lpriv->lock, flags); - __imsic_local_sync(lpriv); - raw_spin_unlock_irqrestore(&lpriv->lock, flags); + imsic_local_sync_all(false); }
static void __imsic_remote_sync(struct imsic_local_priv *lpriv, unsigned int cpu) @@ -216,14 +252,11 @@ static void __imsic_remote_sync(struct imsic_local_priv *lpriv, unsigned int cpu */ if (cpu_online(cpu)) { if (cpu == smp_processor_id()) { - __imsic_local_sync(lpriv); - return; + if (__imsic_local_sync(lpriv)) + return; }
- if (!timer_pending(&lpriv->timer)) { - lpriv->timer.expires = jiffies + 1; - add_timer_on(&lpriv->timer, cpu); - } + __imsic_local_timer_start(lpriv); } } #else @@ -278,8 +311,9 @@ void imsic_vector_unmask(struct imsic_vector *vec) raw_spin_unlock(&lpriv->lock); }
-static bool imsic_vector_move_update(struct imsic_local_priv *lpriv, struct imsic_vector *vec, - bool new_enable, struct imsic_vector *new_move) +static bool imsic_vector_move_update(struct imsic_local_priv *lpriv, + struct imsic_vector *vec, bool is_old_vec, + bool new_enable, struct imsic_vector *move_vec) { unsigned long flags; bool enabled; @@ -289,7 +323,10 @@ static bool imsic_vector_move_update(struct imsic_local_priv *lpriv, struct imsi /* Update enable and move details */ enabled = READ_ONCE(vec->enable); WRITE_ONCE(vec->enable, new_enable); - WRITE_ONCE(vec->move, new_move); + if (is_old_vec) + WRITE_ONCE(vec->move_next, move_vec); + else + WRITE_ONCE(vec->move_prev, move_vec);
/* Mark the vector as dirty and synchronize */ bitmap_set(lpriv->dirty_bitmap, vec->local_id, 1); @@ -322,8 +359,8 @@ void imsic_vector_move(struct imsic_vector *old_vec, struct imsic_vector *new_ve * interrupt on the old vector while device was being moved * to the new vector. */ - enabled = imsic_vector_move_update(old_lpriv, old_vec, false, new_vec); - imsic_vector_move_update(new_lpriv, new_vec, enabled, new_vec); + enabled = imsic_vector_move_update(old_lpriv, old_vec, true, false, new_vec); + imsic_vector_move_update(new_lpriv, new_vec, false, enabled, old_vec); }
#ifdef CONFIG_GENERIC_IRQ_DEBUGFS @@ -386,7 +423,8 @@ struct imsic_vector *imsic_vector_alloc(unsigned int hwirq, const struct cpumask vec = &lpriv->vectors[local_id]; vec->hwirq = hwirq; vec->enable = false; - vec->move = NULL; + vec->move_next = NULL; + vec->move_prev = NULL;
return vec; } diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h index 391e442808275..f02842b84ed58 100644 --- a/drivers/irqchip/irq-riscv-imsic-state.h +++ b/drivers/irqchip/irq-riscv-imsic-state.h @@ -23,7 +23,8 @@ struct imsic_vector { unsigned int hwirq; /* Details accessed using local lock held */ bool enable; - struct imsic_vector *move; + struct imsic_vector *move_next; + struct imsic_vector *move_prev; };
struct imsic_local_priv { @@ -74,7 +75,7 @@ static inline void __imsic_id_clear_enable(unsigned long id) __imsic_eix_update(id, 1, false, false); }
-void imsic_local_sync_all(void); +void imsic_local_sync_all(bool force_all); void imsic_local_delivery(bool enable);
void imsic_vector_mask(struct imsic_vector *vec); @@ -87,7 +88,7 @@ static inline bool imsic_vector_isenabled(struct imsic_vector *vec)
static inline struct imsic_vector *imsic_vector_get_move(struct imsic_vector *vec) { - return READ_ONCE(vec->move); + return READ_ONCE(vec->move_prev); }
void imsic_vector_move(struct imsic_vector *old_vec, struct imsic_vector *new_vec);