diff options
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/quirks.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index f439de848658..e249676fbf04 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -25,6 +25,7 @@ #include <linux/sched.h> #include <linux/ktime.h> #include <linux/mm.h> +#include <linux/nvme.h> #include <linux/platform_data/x86/apple.h> #include <linux/pm_runtime.h> #include <asm/dma.h> /* isa_dma_bridge_buggy */ @@ -3664,6 +3665,87 @@ static int reset_chelsio_generic_dev(struct pci_dev *dev, int probe) #define PCI_DEVICE_ID_INTEL_IVB_M_VGA 0x0156 #define PCI_DEVICE_ID_INTEL_IVB_M2_VGA 0x0166 +/* + * The Samsung SM961/PM961 controller can sometimes enter a fatal state after + * FLR where config space reads from the device return -1. We seem to be + * able to avoid this condition if we disable the NVMe controller prior to + * FLR. This quirk is generic for any NVMe class device requiring similar + * assistance to quiesce the device prior to FLR. + * + * NVMe specification: https://nvmexpress.org/resources/specifications/ + * Revision 1.0e: + * Chapter 2: Required and optional PCI config registers + * Chapter 3: NVMe control registers + * Chapter 7.3: Reset behavior + */ +static int nvme_disable_and_flr(struct pci_dev *dev, int probe) +{ + void __iomem *bar; + u16 cmd; + u32 cfg; + + if (dev->class != PCI_CLASS_STORAGE_EXPRESS || + !pcie_has_flr(dev) || !pci_resource_start(dev, 0)) + return -ENOTTY; + + if (probe) + return 0; + + bar = pci_iomap(dev, 0, NVME_REG_CC + sizeof(cfg)); + if (!bar) + return -ENOTTY; + + pci_read_config_word(dev, PCI_COMMAND, &cmd); + pci_write_config_word(dev, PCI_COMMAND, cmd | PCI_COMMAND_MEMORY); + + cfg = readl(bar + NVME_REG_CC); + + /* Disable controller if enabled */ + if (cfg & NVME_CC_ENABLE) { + u32 cap = readl(bar + NVME_REG_CAP); + unsigned long timeout; + + /* + * Per nvme_disable_ctrl() skip shutdown notification as it + * could complete commands to the admin queue. We only intend + * to quiesce the device before reset. + */ + cfg &= ~(NVME_CC_SHN_MASK | NVME_CC_ENABLE); + + writel(cfg, bar + NVME_REG_CC); + + /* + * Some controllers require an additional delay here, see + * NVME_QUIRK_DELAY_BEFORE_CHK_RDY. None of those are yet + * supported by this quirk. + */ + + /* Cap register provides max timeout in 500ms increments */ + timeout = ((NVME_CAP_TIMEOUT(cap) + 1) * HZ / 2) + jiffies; + + for (;;) { + u32 status = readl(bar + NVME_REG_CSTS); + + /* Ready status becomes zero on disable complete */ + if (!(status & NVME_CSTS_RDY)) + break; + + msleep(100); + + if (time_after(jiffies, timeout)) { + pci_warn(dev, "Timeout waiting for NVMe ready status to clear after disable\n"); + break; + } + } + } + + pci_iounmap(dev, bar); + + pcie_flr(dev); + + return 0; +} + static const struct pci_dev_reset_methods pci_dev_reset_methods[] = { { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82599_SFP_VF, reset_intel_82599_sfp_virtfn }, @@ -3671,6 +3753,7 @@ static const struct pci_dev_reset_methods pci_dev_reset_methods[] = { reset_ivb_igd }, { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IVB_M2_VGA, reset_ivb_igd }, + { PCI_VENDOR_ID_SAMSUNG, 0xa804, nvme_disable_and_flr }, { PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID, reset_chelsio_generic_dev }, { 0 } |