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From a3a5c955eb9767e09f62d7d4c1af2f8f5b0fe565 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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 <bigeasy@linutronix.de>
---
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
|
