From 3aa52da4f470e475e6c4caa76255e3911e83ffa8 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Mon, 27 Jul 2020 11:10:53 -0400 Subject: [PATCH] PCI/AER: Use kfifo for tracking events instead of reimplementing it task #29600094 commit 27c1ce8bbed7e7f0e4a87cf4a93f09be26d62ada upstream. Backport summary: for 4.19 kernel ICX PCIe Gen4 support. 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 Signed-off-by: Bjorn Helgaas (cherry picked from commit 27c1ce8bbed7e7f0e4a87cf4a93f09be26d62ada) Signed-off-by: Ethan Zhao Signed-off-by: Artie Ding Acked-by: Caspar Zhang --- drivers/pci/pcie/aer.c | 88 ++++++------------------------------------ 1 file changed, 11 insertions(+), 77 deletions(-) diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c index 85c713f6cfdb..122a78197172 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 @@ -1217,35 +1211,6 @@ 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; - - 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); + struct pci_dev *rp = rpc->rpd; + struct aer_err_source e_src = {}; + int pos = rp->aer_cap; - /* 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); -- GitLab