From a3a5c955eb9767e09f62d7d4c1af2f8f5b0fe565 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Tue, 2 Feb 2021 18:01:03 +0100 Subject: [PATCH 152/323] chelsio: cxgb: Replace the workqueue with threaded interrupt Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz The external interrupt (F_PL_INTR_EXT) needs to be handled in a process context and this is accomplished by utilizing a workqueue. The process context can also be provided by a threaded interrupt instead of a workqueue. The threaded interrupt can be used later for other interrupt related processing which require non-atomic context without using yet another workqueue. free_irq() also ensures that the thread is done which is currently missing (the worker could continue after the module has been removed). Save pending flags in pending_thread_intr. Use the same mechanism to disable F_PL_INTR_EXT as interrupt source like it is used before the worker is scheduled. Enable the interrupt again once t1_elmer0_ext_intr_handler() is done. Signed-off-by: Sebastian Andrzej Siewior --- drivers/net/ethernet/chelsio/cxgb/common.h | 5 +-- drivers/net/ethernet/chelsio/cxgb/cxgb2.c | 44 ++-------------------- drivers/net/ethernet/chelsio/cxgb/sge.c | 33 ++++++++++++++-- drivers/net/ethernet/chelsio/cxgb/sge.h | 1 + drivers/net/ethernet/chelsio/cxgb/subr.c | 26 +++++++++---- 5 files changed, 55 insertions(+), 54 deletions(-) diff --git a/drivers/net/ethernet/chelsio/cxgb/common.h b/drivers/net/ethernet/chelsio/cxgb/common.h index 6475060649e9..e999a9b9fe6c 100644 --- a/drivers/net/ethernet/chelsio/cxgb/common.h +++ b/drivers/net/ethernet/chelsio/cxgb/common.h @@ -238,7 +238,6 @@ struct adapter { int msg_enable; u32 mmio_len; - struct work_struct ext_intr_handler_task; struct adapter_params params; /* Terminator modules. */ @@ -257,6 +256,7 @@ struct adapter { /* guards async operations */ spinlock_t async_lock ____cacheline_aligned; + u32 pending_thread_intr; u32 slow_intr_mask; int t1powersave; }; @@ -334,8 +334,7 @@ void t1_interrupts_enable(adapter_t *adapter); void t1_interrupts_disable(adapter_t *adapter); void t1_interrupts_clear(adapter_t *adapter); int t1_elmer0_ext_intr_handler(adapter_t *adapter); -void t1_elmer0_ext_intr(adapter_t *adapter); -int t1_slow_intr_handler(adapter_t *adapter); +irqreturn_t t1_slow_intr_handler(adapter_t *adapter); int t1_link_start(struct cphy *phy, struct cmac *mac, struct link_config *lc); const struct board_info *t1_get_board_info(unsigned int board_id); diff --git a/drivers/net/ethernet/chelsio/cxgb/cxgb2.c b/drivers/net/ethernet/chelsio/cxgb/cxgb2.c index c6db85fe1629..737c24136e2f 100644 --- a/drivers/net/ethernet/chelsio/cxgb/cxgb2.c +++ b/drivers/net/ethernet/chelsio/cxgb/cxgb2.c @@ -211,9 +211,10 @@ static int cxgb_up(struct adapter *adapter) t1_interrupts_clear(adapter); adapter->params.has_msi = !disable_msi && !pci_enable_msi(adapter->pdev); - err = request_irq(adapter->pdev->irq, t1_interrupt, - adapter->params.has_msi ? 0 : IRQF_SHARED, - adapter->name, adapter); + err = request_threaded_irq(adapter->pdev->irq, t1_interrupt, + t1_interrupt_thread, + adapter->params.has_msi ? 0 : IRQF_SHARED, + adapter->name, adapter); if (err) { if (adapter->params.has_msi) pci_disable_msi(adapter->pdev); @@ -916,41 +917,6 @@ static void mac_stats_task(struct work_struct *work) spin_unlock(&adapter->work_lock); } -/* - * Processes elmer0 external interrupts in process context. - */ -static void ext_intr_task(struct work_struct *work) -{ - struct adapter *adapter = - container_of(work, struct adapter, ext_intr_handler_task); - - t1_elmer0_ext_intr_handler(adapter); - - /* Now reenable external interrupts */ - spin_lock_irq(&adapter->async_lock); - adapter->slow_intr_mask |= F_PL_INTR_EXT; - writel(F_PL_INTR_EXT, adapter->regs + A_PL_CAUSE); - writel(adapter->slow_intr_mask | F_PL_INTR_SGE_DATA, - adapter->regs + A_PL_ENABLE); - spin_unlock_irq(&adapter->async_lock); -} - -/* - * Interrupt-context handler for elmer0 external interrupts. - */ -void t1_elmer0_ext_intr(struct adapter *adapter) -{ - /* - * Schedule a task to handle external interrupts as we require - * a process context. We disable EXT interrupts in the interim - * and let the task reenable them when it's done. - */ - adapter->slow_intr_mask &= ~F_PL_INTR_EXT; - writel(adapter->slow_intr_mask | F_PL_INTR_SGE_DATA, - adapter->regs + A_PL_ENABLE); - schedule_work(&adapter->ext_intr_handler_task); -} - void t1_fatal_err(struct adapter *adapter) { if (adapter->flags & FULL_INIT_DONE) { @@ -1062,8 +1028,6 @@ static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent) spin_lock_init(&adapter->async_lock); spin_lock_init(&adapter->mac_lock); - INIT_WORK(&adapter->ext_intr_handler_task, - ext_intr_task); INIT_DELAYED_WORK(&adapter->stats_update_task, mac_stats_task); diff --git a/drivers/net/ethernet/chelsio/cxgb/sge.c b/drivers/net/ethernet/chelsio/cxgb/sge.c index 2d9c2b5a690a..5aef9ae1ecfe 100644 --- a/drivers/net/ethernet/chelsio/cxgb/sge.c +++ b/drivers/net/ethernet/chelsio/cxgb/sge.c @@ -1619,11 +1619,38 @@ int t1_poll(struct napi_struct *napi, int budget) return work_done; } +irqreturn_t t1_interrupt_thread(int irq, void *data) +{ + struct adapter *adapter = data; + u32 pending_thread_intr; + + spin_lock_irq(&adapter->async_lock); + pending_thread_intr = adapter->pending_thread_intr; + adapter->pending_thread_intr = 0; + spin_unlock_irq(&adapter->async_lock); + + if (!pending_thread_intr) + return IRQ_NONE; + + if (pending_thread_intr & F_PL_INTR_EXT) + t1_elmer0_ext_intr_handler(adapter); + + spin_lock_irq(&adapter->async_lock); + adapter->slow_intr_mask |= F_PL_INTR_EXT; + + writel(F_PL_INTR_EXT, adapter->regs + A_PL_CAUSE); + writel(adapter->slow_intr_mask | F_PL_INTR_SGE_DATA, + adapter->regs + A_PL_ENABLE); + spin_unlock_irq(&adapter->async_lock); + + return IRQ_HANDLED; +} + irqreturn_t t1_interrupt(int irq, void *data) { struct adapter *adapter = data; struct sge *sge = adapter->sge; - int handled; + irqreturn_t handled; if (likely(responses_pending(adapter))) { writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE); @@ -1645,10 +1672,10 @@ irqreturn_t t1_interrupt(int irq, void *data) handled = t1_slow_intr_handler(adapter); spin_unlock(&adapter->async_lock); - if (!handled) + if (handled == IRQ_NONE) sge->stats.unhandled_irqs++; - return IRQ_RETVAL(handled != 0); + return handled; } /* diff --git a/drivers/net/ethernet/chelsio/cxgb/sge.h b/drivers/net/ethernet/chelsio/cxgb/sge.h index a1ba591b3431..76516d2a8aa9 100644 --- a/drivers/net/ethernet/chelsio/cxgb/sge.h +++ b/drivers/net/ethernet/chelsio/cxgb/sge.h @@ -74,6 +74,7 @@ struct sge *t1_sge_create(struct adapter *, struct sge_params *); int t1_sge_configure(struct sge *, struct sge_params *); int t1_sge_set_coalesce_params(struct sge *, struct sge_params *); void t1_sge_destroy(struct sge *); +irqreturn_t t1_interrupt_thread(int irq, void *data); irqreturn_t t1_interrupt(int irq, void *cookie); int t1_poll(struct napi_struct *, int); diff --git a/drivers/net/ethernet/chelsio/cxgb/subr.c b/drivers/net/ethernet/chelsio/cxgb/subr.c index ea0f8741d7cf..d90ad07ff1a4 100644 --- a/drivers/net/ethernet/chelsio/cxgb/subr.c +++ b/drivers/net/ethernet/chelsio/cxgb/subr.c @@ -210,7 +210,7 @@ static int fpga_phy_intr_handler(adapter_t *adapter) /* * Slow path interrupt handler for FPGAs. */ -static int fpga_slow_intr(adapter_t *adapter) +static irqreturn_t fpga_slow_intr(adapter_t *adapter) { u32 cause = readl(adapter->regs + A_PL_CAUSE); @@ -238,7 +238,7 @@ static int fpga_slow_intr(adapter_t *adapter) if (cause) writel(cause, adapter->regs + A_PL_CAUSE); - return cause != 0; + return cause == 0 ? IRQ_NONE : IRQ_HANDLED; } #endif @@ -842,13 +842,14 @@ void t1_interrupts_clear(adapter_t* adapter) /* * Slow path interrupt handler for ASICs. */ -static int asic_slow_intr(adapter_t *adapter) +static irqreturn_t asic_slow_intr(adapter_t *adapter) { u32 cause = readl(adapter->regs + A_PL_CAUSE); + irqreturn_t ret = IRQ_HANDLED; cause &= adapter->slow_intr_mask; if (!cause) - return 0; + return IRQ_NONE; if (cause & F_PL_INTR_SGE_ERR) t1_sge_intr_error_handler(adapter->sge); if (cause & F_PL_INTR_TP) @@ -857,16 +858,25 @@ static int asic_slow_intr(adapter_t *adapter) t1_espi_intr_handler(adapter->espi); if (cause & F_PL_INTR_PCIX) t1_pci_intr_handler(adapter); - if (cause & F_PL_INTR_EXT) - t1_elmer0_ext_intr(adapter); + if (cause & F_PL_INTR_EXT) { + /* Wake the threaded interrupt to handle external interrupts as + * we require a process context. We disable EXT interrupts in + * the interim and let the thread reenable them when it's done. + */ + adapter->pending_thread_intr |= F_PL_INTR_EXT; + adapter->slow_intr_mask &= ~F_PL_INTR_EXT; + writel(adapter->slow_intr_mask | F_PL_INTR_SGE_DATA, + adapter->regs + A_PL_ENABLE); + ret = IRQ_WAKE_THREAD; + } /* Clear the interrupts just processed. */ writel(cause, adapter->regs + A_PL_CAUSE); readl(adapter->regs + A_PL_CAUSE); /* flush writes */ - return 1; + return ret; } -int t1_slow_intr_handler(adapter_t *adapter) +irqreturn_t t1_slow_intr_handler(adapter_t *adapter) { #ifdef CONFIG_CHELSIO_T1_1G if (!t1_is_asic(adapter)) -- 2.43.0