RE: [PATCH net-next] net: mana: Add handler for hardware servicing events

[Haiyang Zhang]

> -----Original Message-----
> From: Shradha Gupta <shradhagupta@xxxxxxxxxxxxxxxxxxx>
> Sent: Thursday, May 8, 2025 5:29 AM
> To: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> Cc: linux-hyperv@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; Dexuan Cui
> <decui@xxxxxxxxxxxxx>; stephen@xxxxxxxxxxxxxxxxxx; KY Srinivasan
> <kys@xxxxxxxxxxxxx>; Paul Rosswurm <paulros@xxxxxxxxxxxxx>;
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> wei.liu@xxxxxxxxxx; edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx;
> pabeni@xxxxxxxxxx; leon@xxxxxxxxxx; Long Li <longli@xxxxxxxxxxxxx>;
> ssengar@xxxxxxxxxxxxxxxxxxx; linux-rdma@xxxxxxxxxxxxxxx;
> daniel@xxxxxxxxxxxxx; john.fastabend@xxxxxxxxx; bpf@xxxxxxxxxxxxxxx;
> ast@xxxxxxxxxx; hawk@xxxxxxxxxx; tglx@xxxxxxxxxxxxx;
> andrew+netdev@xxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH net-next] net: mana: Add handler for hardware
> servicing events
> 
> On Wed, May 07, 2025 at 08:58:39AM -0700, Haiyang Zhang wrote:
> > To collaborate with hardware servicing events, upon receiving the
> special
> > EQE notification from the HW channel, remove the devices on this bus.
> > Then, after a waiting period based on the device specs, rescan the
> parent
> > bus to recover the devices.
> >
> > Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> > ---
> >  .../net/ethernet/microsoft/mana/gdma_main.c   | 61 +++++++++++++++++++
> >  include/net/mana/gdma.h                       |  5 +-
> >  2 files changed, 65 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c
> b/drivers/net/ethernet/microsoft/mana/gdma_main.c
> > index 4ffaf7588885..aa2ccf4d0ec6 100644
> > --- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
> > +++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
> > @@ -352,11 +352,52 @@ void mana_gd_ring_cq(struct gdma_queue *cq, u8
> arm_bit)
> >  }
> >  EXPORT_SYMBOL_NS(mana_gd_ring_cq, "NET_MANA");
> >
> > +#define MANA_SERVICE_PERIOD 10
> > +
> > +struct mana_serv_work {
> > +	struct work_struct serv_work;
> > +	struct pci_dev *pdev;
> > +};
> > +
> > +static void mana_serv_func(struct work_struct *w)
> > +{
> > +	struct mana_serv_work *mns_wk = container_of(w, struct
> mana_serv_work, serv_work);
> > +	struct pci_dev *pdev = mns_wk->pdev;
> > +	struct pci_bus *bus, *parent;
> > +
> > +	if (!pdev)
> > +		goto out;
> > +
> > +	bus = pdev->bus;
> > +	if (!bus) {
> > +		dev_err(&pdev->dev, "MANA service: no bus\n");
> > +		goto out;
> > +	}
> > +
> > +	parent = bus->parent;
> > +	if (!parent) {
> > +		dev_err(&pdev->dev, "MANA service: no parent bus\n");
> > +		goto out;
> > +	}
> > +
> > +	pci_stop_and_remove_bus_device_locked(bus->self);
> > +
> > +	msleep(MANA_SERVICE_PERIOD * 1000);
> > +
> > +	pci_lock_rescan_remove();
> > +	pci_rescan_bus(parent);
> > +	pci_unlock_rescan_remove();
> > +
> > +out:
> > +	kfree(mns_wk);
> 
> Shouldn't gc->in_service be set to false again?
> 
> > +}
> > +
> >  static void mana_gd_process_eqe(struct gdma_queue *eq)
> >  {
> >  	u32 head = eq->head % (eq->queue_size / GDMA_EQE_SIZE);
> >  	struct gdma_context *gc = eq->gdma_dev->gdma_context;
> >  	struct gdma_eqe *eq_eqe_ptr = eq->queue_mem_ptr;
> > +	struct mana_serv_work *mns_wk;
> >  	union gdma_eqe_info eqe_info;
> >  	enum gdma_eqe_type type;
> >  	struct gdma_event event;
> > @@ -400,6 +441,26 @@ static void mana_gd_process_eqe(struct gdma_queue
> *eq)
> >  		eq->eq.callback(eq->eq.context, eq, &event);
> >  		break;
> >
> > +	case GDMA_EQE_HWC_FPGA_RECONFIG:
> > +	case GDMA_EQE_HWC_SOCMANA_CRASH:
> 
> may be we also add a log(dev_dbg) to indicate if the servicing is for
> FPGA reconfig or socmana crash.

Thanks, I will add this.

- Haiyang