> From: Allen Hubbe [mailto:alle...@gmail.com] > Sent: Friday, December 18, 2015 12:46 AM > To: Yu, Xiangliang > Cc: jdma...@kudzu.us; dave.ji...@intel.com; linux-...@googlegroups.com; > linux-kernel@vger.kernel.org; SPG_Linux_Kernel > Subject: Re: [PATCH 1/3] NTB: Add AMD PCI-Express NTB driver > > On Thu, Dec 17, 2015 at 3:17 AM, Xiangliang Yu <xiangliang...@amd.com> > wrote: > > AMD NTB support following main features: > > (1) Three memory windows; > > (2) Sixteen 32-bit scratch pad; > > (3) Two 16-bit doorbell interrupt; > > (4) Five event interrupts; > > (5) One system can wake up opposite system of NTB; > > (6) Flush previous request to the opposite system; > > (7) There are reset and PME_TO mechanisms between two systems; > > > > Signed-off-by: Xiangliang Yu <xiangliang...@amd.com> > > Is hardware available on which this can be tested?
No yet. Right now, verified the driver on emulator. > > > +++ b/drivers/ntb/hw/amd/ntb_hw_amd.c > > > +static u64 amd_ntb_db_read(struct ntb_dev *ntb) { > > + struct amd_ntb_dev *ndev = ntb_ndev(ntb); > > + > > + return (u64)NTB_READ_REG(DBSTAT); } > > DBSTAT hides the use of ndev, or ndev is unused. The code should be more > clear, here, and in other places where NTB_READ_REG and NTB_WRITE_REG > are used with a macro argument. Got it, I will add ndev into macro arguments. > > > +static void amd_ack_SMU(struct amd_ntb_dev *ndev, u32 bit) { > > + int reg; > > + > > + reg = NTB_READ_REG(SMUACK); > > + reg |= bit; > > + NTB_WRITE_REG(reg, SMUACK); > > + > > + ndev->peer_sta |= bit; > > +} > > + > > +/* > > + * flush the requests to peer side > > + */ > > +static int amd_flush_peer_requests(struct amd_ntb_dev *ndev) { > > + u32 reg; > > + > > + if (!amd_link_is_up(ndev)) { > > + dev_err(ndev_dev(ndev), "link is down.\n"); > > + return -EINVAL; > > + } > > + > > Add reinit_completion, or this may already be "complete" from a previous > flush. Ok. > > > + reg = NTB_READ_REG(FLUSHTRIG); > > + reg |= 0x1; > > + NTB_WRITE_REG(reg, FLUSHTRIG); > > + > > + wait_for_completion(&ndev->flush_cmpl); > > Because of wait_for_completion, that this can only be called in a thread > context. This is unlike other functions of ntb.h, so there should at least > be a > note in the api documentation. Ok. > > > + > > + return 0; > > +} > > + > > +/* > > + * wake up the peer side > > + */ > > +static int amd_wakeup_peer_side(struct amd_ntb_dev *ndev) { > > + u32 reg; > > + > > + if (!amd_link_is_up(ndev)) { > > + dev_warn(ndev_dev(ndev), "link is down.\n"); > > + return -EINVAL; > > + } > > + > > See previous comment. > > > + NTB_READ_REG(PMSGTRIG); > > + reg |= 0x1; > > + NTB_WRITE_REG(reg, PMSGTRIG); > > + > > + wait_for_completion(&ndev->wakeup_cmpl); > > + > > + return 0; > > +} > > > > +static void amd_handle_event(struct amd_ntb_dev *ndev, int vec) { > > + u32 status; > > + > > + status = NTB_READ_REG(INTSTAT); > > + if (!(status & AMD_EVENT_INTMASK)) > > + return; > > + > > + dev_dbg(ndev_dev(ndev), "status = 0x%x and vec = %d\n", > > + status, vec); > > + > > + status &= AMD_EVENT_INTMASK; > > + switch (status) { > > + case AMD_PEER_FLUSH_EVENT: > > + complete(&ndev->flush_cmpl); > > + break; > > + case AMD_PEER_RESET_EVENT: > > + amd_ack_SMU(ndev, AMD_PEER_RESET_EVENT); > > + > > + /* link down first */ > > + ntb_link_event(&ndev->ntb); > > + /* polling peer status */ > > + schedule_delayed_work(&ndev->hb_timer, > > + AMD_LINK_HB_TIMEOUT); > > + > > + break; > > + case AMD_PEER_D3_EVENT: > > + case AMD_PEER_PMETO_EVENT: > > + amd_ack_SMU(ndev, status); > > + > > + /* link down */ > > + ntb_link_event(&ndev->ntb); > > + > > + break; > > + case AMD_PEER_D0_EVENT: > > + status = NTB_READ_PEER_REG(PMESTAT); > > + /* check if this is WAKEUP event */ > > + if (status & 0x1) > > + complete(&ndev->wakeup_cmpl); > > + > > + amd_ack_SMU(ndev, AMD_PEER_D0_EVENT); > > + > > + if (amd_link_is_up(ndev)) > > + ntb_link_event(&ndev->ntb); > > + else > > + schedule_delayed_work(&ndev->hb_timer, > > + AMD_LINK_HB_TIMEOUT); > > + break; > > + default: > > + pr_err("Unsupported interrupt.\n"); > > + break; > > + } > > +} > > + > > +static irqreturn_t ndev_interrupt(struct amd_ntb_dev *ndev, int vec) > > +{ > > + dev_dbg(ndev_dev(ndev), "vec %d\n", vec); > > + > > + if (vec > 20) { > > This duplicates the "default" case of amd_handle_event. Ok, I'll refine the code. > > > + dev_err(ndev_dev(ndev), "Invalid interrupt.\n"); > > + return IRQ_HANDLED; > > + } > > + > > + if (vec > 16 || (ndev->msix_vec_count == 1)) > > + amd_handle_event(ndev, vec); > > + > > + if (vec < 16) > > + ntb_db_event(&ndev->ntb, vec); > > + > > + return IRQ_HANDLED; > > +}