PCI/AER: Use kfifo for tracking events instead of reimplementing it
The kernel provides a generic FIFO implementation, so no need to reinvent
that capability in a driver. Replace the AER-specific implementation with
the kernel-provided kfifo. Since the interrupt handler producer and work
queue consumer run single threaded, there is no need for additional
locking, so remove that lock, too.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 85c713f..122a781 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -30,7 +30,7 @@
#include "../pci.h"
#include "portdrv.h"
-#define AER_ERROR_SOURCES_MAX 100
+#define AER_ERROR_SOURCES_MAX 128
#define AER_MAX_TYPEOF_COR_ERRS 16 /* as per PCI_ERR_COR_STATUS */
#define AER_MAX_TYPEOF_UNCOR_ERRS 26 /* as per PCI_ERR_UNCOR_STATUS*/
@@ -43,14 +43,8 @@ struct aer_err_source {
struct aer_rpc {
struct pci_dev *rpd; /* Root Port device */
struct work_struct dpc_handler;
- struct aer_err_source e_sources[AER_ERROR_SOURCES_MAX];
- unsigned short prod_idx; /* Error Producer Index */
- unsigned short cons_idx; /* Error Consumer Index */
+ DECLARE_KFIFO(aer_fifo, struct aer_err_source, AER_ERROR_SOURCES_MAX);
int isr;
- spinlock_t e_lock; /*
- * Lock access to Error Status/ID Regs
- * and error producer/consumer index
- */
struct mutex rpc_mutex; /*
* only one thread could do
* recovery on the same
@@ -1218,35 +1212,6 @@ static void aer_isr_one_error(struct aer_rpc *rpc,
}
/**
- * get_e_source - retrieve an error source
- * @rpc: pointer to the root port which holds an error
- * @e_src: pointer to store retrieved error source
- *
- * Return 1 if an error source is retrieved, otherwise 0.
- *
- * Invoked by DPC handler to consume an error.
- */
-static int get_e_source(struct aer_rpc *rpc, struct aer_err_source *e_src)
-{
- unsigned long flags;
-
- /* Lock access to Root error producer/consumer index */
- spin_lock_irqsave(&rpc->e_lock, flags);
- if (rpc->prod_idx == rpc->cons_idx) {
- spin_unlock_irqrestore(&rpc->e_lock, flags);
- return 0;
- }
-
- *e_src = rpc->e_sources[rpc->cons_idx];
- rpc->cons_idx++;
- if (rpc->cons_idx == AER_ERROR_SOURCES_MAX)
- rpc->cons_idx = 0;
- spin_unlock_irqrestore(&rpc->e_lock, flags);
-
- return 1;
-}
-
-/**
* aer_isr - consume errors detected by root port
* @work: definition of this work item
*
@@ -1258,7 +1223,7 @@ static void aer_isr(struct work_struct *work)
struct aer_err_source uninitialized_var(e_src);
mutex_lock(&rpc->rpc_mutex);
- while (get_e_source(rpc, &e_src))
+ while (kfifo_get(&rpc->aer_fifo, &e_src))
aer_isr_one_error(rpc, &e_src);
mutex_unlock(&rpc->rpc_mutex);
}
@@ -1272,51 +1237,23 @@ static void aer_isr(struct work_struct *work)
*/
irqreturn_t aer_irq(int irq, void *context)
{
- unsigned int status, id;
struct pcie_device *pdev = (struct pcie_device *)context;
struct aer_rpc *rpc = get_service_data(pdev);
- int next_prod_idx;
- unsigned long flags;
- int pos;
+ struct pci_dev *rp = rpc->rpd;
+ struct aer_err_source e_src = {};
+ int pos = rp->aer_cap;
- pos = pdev->port->aer_cap;
- /*
- * Must lock access to Root Error Status Reg, Root Error ID Reg,
- * and Root error producer/consumer index
- */
- spin_lock_irqsave(&rpc->e_lock, flags);
-
- /* Read error status */
- pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
- if (!(status & (PCI_ERR_ROOT_UNCOR_RCV|PCI_ERR_ROOT_COR_RCV))) {
- spin_unlock_irqrestore(&rpc->e_lock, flags);
+ pci_read_config_dword(rp, pos + PCI_ERR_ROOT_STATUS, &e_src.status);
+ if (!(e_src.status & (PCI_ERR_ROOT_UNCOR_RCV|PCI_ERR_ROOT_COR_RCV)))
return IRQ_NONE;
- }
- /* Read error source and clear error status */
- pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_ERR_SRC, &id);
- pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);
+ pci_read_config_dword(rp, pos + PCI_ERR_ROOT_ERR_SRC, &e_src.id);
+ pci_write_config_dword(rp, pos + PCI_ERR_ROOT_STATUS, e_src.status);
- /* Store error source for later DPC handler */
- next_prod_idx = rpc->prod_idx + 1;
- if (next_prod_idx == AER_ERROR_SOURCES_MAX)
- next_prod_idx = 0;
- if (next_prod_idx == rpc->cons_idx) {
- /*
- * Error Storm Condition - possibly the same error occurred.
- * Drop the error.
- */
- spin_unlock_irqrestore(&rpc->e_lock, flags);
+ if (!kfifo_put(&rpc->aer_fifo, e_src))
return IRQ_HANDLED;
- }
- rpc->e_sources[rpc->prod_idx].status = status;
- rpc->e_sources[rpc->prod_idx].id = id;
- rpc->prod_idx = next_prod_idx;
- spin_unlock_irqrestore(&rpc->e_lock, flags);
- /* Invoke DPC handler */
schedule_work(&rpc->dpc_handler);
-
return IRQ_HANDLED;
}
EXPORT_SYMBOL_GPL(aer_irq);
@@ -1441,9 +1378,6 @@ static struct aer_rpc *aer_alloc_rpc(struct pcie_device *dev)
if (!rpc)
return NULL;
- /* Initialize Root lock access, e_lock, to Root Error Status Reg */
- spin_lock_init(&rpc->e_lock);
-
rpc->rpd = dev->port;
INIT_WORK(&rpc->dpc_handler, aer_isr);
mutex_init(&rpc->rpc_mutex);