diff options
Diffstat (limited to 'drivers/ntb/ntb_hw.c')
| -rw-r--r-- | drivers/ntb/ntb_hw.c | 110 |
1 files changed, 107 insertions, 3 deletions
diff --git a/drivers/ntb/ntb_hw.c b/drivers/ntb/ntb_hw.c index 226f82b..3493e95 100644 --- a/drivers/ntb/ntb_hw.c +++ b/drivers/ntb/ntb_hw.c @@ -46,10 +46,12 @@ * Jon Mason <jon.mason@intel.com> */ #include <linux/debugfs.h> +#include <linux/delay.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/pci.h> +#include <linux/random.h> #include <linux/slab.h> #include "ntb_hw.h" #include "ntb_regs.h" @@ -84,6 +86,8 @@ enum { static struct dentry *debugfs_dir; +#define BWD_LINK_RECOVERY_TIME 500 + /* Translate memory window 0,1 to BAR 2,4 */ #define MW_TO_BAR(mw) (mw * NTB_MAX_NUM_MW + 2) @@ -425,6 +429,49 @@ void ntb_ring_sdb(struct ntb_device *ndev, unsigned int db) (db * ndev->bits_per_vector), ndev->reg_ofs.sdb); } +static void bwd_recover_link(struct ntb_device *ndev) +{ + u32 status; + + /* Driver resets the NTB ModPhy lanes - magic! */ + writeb(0xe0, ndev->reg_base + BWD_MODPHY_PCSREG6); + writeb(0x40, ndev->reg_base + BWD_MODPHY_PCSREG4); + writeb(0x60, ndev->reg_base + BWD_MODPHY_PCSREG4); + writeb(0x60, ndev->reg_base + BWD_MODPHY_PCSREG6); + + /* Driver waits 100ms to allow the NTB ModPhy to settle */ + msleep(100); + + /* Clear AER Errors, write to clear */ + status = readl(ndev->reg_base + BWD_ERRCORSTS_OFFSET); + dev_dbg(&ndev->pdev->dev, "ERRCORSTS = %x\n", status); + status &= PCI_ERR_COR_REP_ROLL; + writel(status, ndev->reg_base + BWD_ERRCORSTS_OFFSET); + + /* Clear unexpected electrical idle event in LTSSM, write to clear */ + status = readl(ndev->reg_base + BWD_LTSSMERRSTS0_OFFSET); + dev_dbg(&ndev->pdev->dev, "LTSSMERRSTS0 = %x\n", status); + status |= BWD_LTSSMERRSTS0_UNEXPECTEDEI; + writel(status, ndev->reg_base + BWD_LTSSMERRSTS0_OFFSET); + + /* Clear DeSkew Buffer error, write to clear */ + status = readl(ndev->reg_base + BWD_DESKEWSTS_OFFSET); + dev_dbg(&ndev->pdev->dev, "DESKEWSTS = %x\n", status); + status |= BWD_DESKEWSTS_DBERR; + writel(status, ndev->reg_base + BWD_DESKEWSTS_OFFSET); + + status = readl(ndev->reg_base + BWD_IBSTERRRCRVSTS0_OFFSET); + dev_dbg(&ndev->pdev->dev, "IBSTERRRCRVSTS0 = %x\n", status); + status &= BWD_IBIST_ERR_OFLOW; + writel(status, ndev->reg_base + BWD_IBSTERRRCRVSTS0_OFFSET); + + /* Releases the NTB state machine to allow the link to retrain */ + status = readl(ndev->reg_base + BWD_LTSSMSTATEJMP_OFFSET); + dev_dbg(&ndev->pdev->dev, "LTSSMSTATEJMP = %x\n", status); + status &= ~BWD_LTSSMSTATEJMP_FORCEDETECT; + writel(status, ndev->reg_base + BWD_LTSSMSTATEJMP_OFFSET); +} + static void ntb_link_event(struct ntb_device *ndev, int link_state) { unsigned int event; @@ -448,13 +495,16 @@ static void ntb_link_event(struct ntb_device *ndev, int link_state) if (rc) return; } + + ndev->link_width = (status & NTB_LINK_WIDTH_MASK) >> 4; + ndev->link_speed = (status & NTB_LINK_SPEED_MASK); dev_info(&ndev->pdev->dev, "Link Width %d, Link Speed %d\n", - (status & NTB_LINK_WIDTH_MASK) >> 4, - (status & NTB_LINK_SPEED_MASK)); + ndev->link_width, ndev->link_speed); } else { dev_info(&ndev->pdev->dev, "Link Down\n"); ndev->link_status = NTB_LINK_DOWN; event = NTB_EVENT_HW_LINK_DOWN; + /* Don't modify link width/speed, we need it in link recovery */ } /* notify the upper layer if we have an event change */ @@ -494,6 +544,47 @@ static int ntb_link_status(struct ntb_device *ndev) return 0; } +static void bwd_link_recovery(struct work_struct *work) +{ + struct ntb_device *ndev = container_of(work, struct ntb_device, + lr_timer.work); + u32 status32; + + bwd_recover_link(ndev); + /* There is a potential race between the 2 NTB devices recovering at the + * same time. If the times are the same, the link will not recover and + * the driver will be stuck in this loop forever. Add a random interval + * to the recovery time to prevent this race. + */ + msleep(BWD_LINK_RECOVERY_TIME + prandom_u32() % BWD_LINK_RECOVERY_TIME); + + status32 = readl(ndev->reg_base + BWD_LTSSMSTATEJMP_OFFSET); + if (status32 & BWD_LTSSMSTATEJMP_FORCEDETECT) + goto retry; + + status32 = readl(ndev->reg_base + BWD_IBSTERRRCRVSTS0_OFFSET); + if (status32 & BWD_IBIST_ERR_OFLOW) + goto retry; + + status32 = readl(ndev->reg_ofs.lnk_cntl); + if (!(status32 & BWD_CNTL_LINK_DOWN)) { + unsigned char speed, width; + u16 status16; + + status16 = readw(ndev->reg_ofs.lnk_stat); + width = (status16 & NTB_LINK_WIDTH_MASK) >> 4; + speed = (status16 & NTB_LINK_SPEED_MASK); + if (ndev->link_width != width || ndev->link_speed != speed) + goto retry; + } + + schedule_delayed_work(&ndev->hb_timer, NTB_HB_TIMEOUT); + return; + +retry: + schedule_delayed_work(&ndev->lr_timer, NTB_HB_TIMEOUT); +} + /* BWD doesn't have link status interrupt, poll on that platform */ static void bwd_link_poll(struct work_struct *work) { @@ -509,6 +600,16 @@ static void bwd_link_poll(struct work_struct *work) if (rc) dev_err(&ndev->pdev->dev, "Error determining link status\n"); + + /* Check to see if a link error is the cause of the link down */ + if (ndev->link_status == NTB_LINK_DOWN) { + u32 status32 = readl(ndev->reg_base + + BWD_LTSSMSTATEJMP_OFFSET); + if (status32 & BWD_LTSSMSTATEJMP_FORCEDETECT) { + schedule_delayed_work(&ndev->lr_timer, 0); + return; + } + } } schedule_delayed_work(&ndev->hb_timer, NTB_HB_TIMEOUT); @@ -703,6 +804,7 @@ static int ntb_bwd_setup(struct ntb_device *ndev) /* Since bwd doesn't have a link interrupt, setup a poll timer */ INIT_DELAYED_WORK(&ndev->hb_timer, bwd_link_poll); + INIT_DELAYED_WORK(&ndev->lr_timer, bwd_link_recovery); schedule_delayed_work(&ndev->hb_timer, NTB_HB_TIMEOUT); return 0; @@ -743,8 +845,10 @@ static int ntb_device_setup(struct ntb_device *ndev) static void ntb_device_free(struct ntb_device *ndev) { - if (ndev->hw_type == BWD_HW) + if (ndev->hw_type == BWD_HW) { cancel_delayed_work_sync(&ndev->hb_timer); + cancel_delayed_work_sync(&ndev->lr_timer); + } } static irqreturn_t bwd_callback_msix_irq(int irq, void *data) |
