On Fri, Aug 23, 2024 at 04:34:54AM -0700, Saurabh Singh Sengar wrote:
> On Thu, Aug 22, 2024 at 08:53:09AM -0700, Shradha Gupta wrote:
> > Currently the values of WQs for RX and TX queues for MANA devices
> > are hardcoded to default sizes.
> > Allow configuring these values for MANA devices as ringparam
> > configuration(get/set) through ethtool_ops.
> > Pre-allocate buffers at the beginning of this operation, to
> > prevent complete network loss in low-memory conditions.
> >
> > Signed-off-by: Shradha Gupta <shradhagupta@xxxxxxxxxxxxxxxxxxx>
> > Reviewed-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> > ---
> > Changes in v4:
> > * Roundup the ring parameter value to a power of 2
> > * Skip the max value check for parameters
> > * Use extack to log errors
> > ---
> > Changes in v3:
> > * pre-allocate buffers before changing the queue sizes
> > * rebased to latest net-next
> > ---
> > Changes in v2:
> > * Removed unnecessary validations in mana_set_ringparam()
> > * Fixed codespell error
> > * Improved error message to indicate issue with the parameter
> > ---
> > drivers/net/ethernet/microsoft/mana/mana_en.c | 24 +++---
> > .../ethernet/microsoft/mana/mana_ethtool.c | 74 +++++++++++++++++++
> > include/net/mana/mana.h | 23 +++++-
> > 3 files changed, 108 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> > index d2f07e179e86..4e3ade5926bc 100644
> > --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> > +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> > @@ -511,7 +511,7 @@ static u16 mana_select_queue(struct net_device *ndev, struct sk_buff *skb,
> > }
> >
> > /* Release pre-allocated RX buffers */
> > -static void mana_pre_dealloc_rxbufs(struct mana_port_context *mpc)
> > +void mana_pre_dealloc_rxbufs(struct mana_port_context *mpc)
> > {
> > struct device *dev;
> > int i;
> > @@ -604,7 +604,7 @@ static void mana_get_rxbuf_cfg(int mtu, u32 *datasize, u32 *alloc_size,
> > *datasize = mtu + ETH_HLEN;
> > }
> >
> > -static int mana_pre_alloc_rxbufs(struct mana_port_context *mpc, int new_mtu)
> > +int mana_pre_alloc_rxbufs(struct mana_port_context *mpc, int new_mtu)
> > {
> > struct device *dev;
> > struct page *page;
> > @@ -618,7 +618,7 @@ static int mana_pre_alloc_rxbufs(struct mana_port_context *mpc, int new_mtu)
> >
> > dev = mpc->ac->gdma_dev->gdma_context->dev;
> >
> > - num_rxb = mpc->num_queues * RX_BUFFERS_PER_QUEUE;
> > + num_rxb = mpc->num_queues * mpc->rx_queue_size;
> >
> > WARN(mpc->rxbufs_pre, "mana rxbufs_pre exists\n");
> > mpc->rxbufs_pre = kmalloc_array(num_rxb, sizeof(void *), GFP_KERNEL);
> > @@ -1899,14 +1899,15 @@ static int mana_create_txq(struct mana_port_context *apc,
> > return -ENOMEM;
> >
> > /* The minimum size of the WQE is 32 bytes, hence
> > - * MAX_SEND_BUFFERS_PER_QUEUE represents the maximum number of WQEs
> > + * apc->tx_queue_size represents the maximum number of WQEs
> > * the SQ can store. This value is then used to size other queues
> > * to prevent overflow.
> > + * Also note that the txq_size is always going to be MANA_PAGE_ALIGNED,
> > + * as tx_queue_size is always a power of 2.
> > */
>
> MANA_PAGE_ALIGNED aligned means aligned by 0x1000. tx_queue_size being
> 'power of 2' * 32 is not a sufficient condition for it to be aligned to
> 0x1000. We possibly can explain more.
>
>
> > - txq_size = MAX_SEND_BUFFERS_PER_QUEUE * 32;
> > - BUILD_BUG_ON(!MANA_PAGE_ALIGNED(txq_size));
> > + txq_size = apc->tx_queue_size * 32;
> >
> > - cq_size = MAX_SEND_BUFFERS_PER_QUEUE * COMP_ENTRY_SIZE;
> > + cq_size = apc->tx_queue_size * COMP_ENTRY_SIZE;
> > cq_size = MANA_PAGE_ALIGN(cq_size);
>
> COMP_ENTRY_SIZE is 64, that means cq_size is double of txq_size.
> If we are certain that txq_size is always aligned to MANA_PAGE,
> that means cq_size is already aligned to MANA_PAGE as well.
>
> - Saurabh
Thanks Saurabh.
I'll incorporate these in the next version
