Subject: Re: [net PATCH v4 09/10] octeontx2-af: Skip PFs if not enabled

From: Simon Horman <[email-masked]>
Date: Wed, 26 Apr 2023 12:00:49 +0200

On Wed, Apr 26, 2023 at 01:13:44PM +0530, Sai Krishna wrote:
> From: Ratheesh Kannoth <[email-masked]>
> 
> Fiwmware enables set of PFs and allocate mbox resources based on the
> number of enabled PFs. Current driver tries to initialize the mbox
> resources even for disabled PFs, which may waste the resources.
> This patch fixes the issue by skipping the mbox initialization of
> disabled PFs.

FWIIW, this feels more like an enhancement than a fix to me.

> Fixes: 9bdc47a6e328 ("octeontx2-af: Mbox communication support btw AF and it's VFs")
> Signed-off-by: Ratheesh Kannoth <[email-masked]>
> Signed-off-by: Sunil Kovvuri Goutham <[email-masked]>
> Signed-off-by: Sai Krishna <[email-masked]>
> ---
>  .../net/ethernet/marvell/octeontx2/af/mbox.c  |  5 ++-
>  .../net/ethernet/marvell/octeontx2/af/mbox.h  |  3 +-
>  .../net/ethernet/marvell/octeontx2/af/rvu.c   | 44 ++++++++++++++++---
>  3 files changed, 44 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/octeontx2/af/mbox.c b/drivers/net/ethernet/marvell/octeontx2/af/mbox.c
> index 2898931d5260..9690ac01f02c 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/af/mbox.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/af/mbox.c
> @@ -157,7 +157,7 @@ EXPORT_SYMBOL(otx2_mbox_init);
>   */
>  int otx2_mbox_regions_init(struct otx2_mbox *mbox, void **hwbase,
>  			   struct pci_dev *pdev, void *reg_base,
> -			   int direction, int ndevs)
> +			   int direction, int ndevs, unsigned long *pf_bmap)
>  {
>  	struct otx2_mbox_dev *mdev;
>  	int devid, err;
> @@ -169,6 +169,9 @@ int otx2_mbox_regions_init(struct otx2_mbox *mbox, void **hwbase,
>  	mbox->hwbase = hwbase[0];
>  
>  	for (devid = 0; devid < ndevs; devid++) {
> +		if (!test_bit(devid, pf_bmap))
> +			continue;
> +
>  		mdev = &mbox->dev[devid];
>  		mdev->mbase = hwbase[devid];
>  		mdev->hwbase = hwbase[devid];
> diff --git a/drivers/net/ethernet/marvell/octeontx2/af/mbox.h b/drivers/net/ethernet/marvell/octeontx2/af/mbox.h
> index 0ce533848536..26636a4d7dcc 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/af/mbox.h
> +++ b/drivers/net/ethernet/marvell/octeontx2/af/mbox.h
> @@ -96,9 +96,10 @@ void otx2_mbox_destroy(struct otx2_mbox *mbox);
>  int otx2_mbox_init(struct otx2_mbox *mbox, void __force *hwbase,
>  		   struct pci_dev *pdev, void __force *reg_base,
>  		   int direction, int ndevs);
> +
>  int otx2_mbox_regions_init(struct otx2_mbox *mbox, void __force **hwbase,
>  			   struct pci_dev *pdev, void __force *reg_base,
> -			   int direction, int ndevs);
> +			   int direction, int ndevs, unsigned long *bmap);
>  void otx2_mbox_msg_send(struct otx2_mbox *mbox, int devid);
>  int otx2_mbox_wait_for_rsp(struct otx2_mbox *mbox, int devid);
>  int otx2_mbox_busy_poll_for_rsp(struct otx2_mbox *mbox, int devid);
> diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu.c
> index 8683ce57ed3f..242089b6f199 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/af/rvu.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu.c
> @@ -2282,7 +2282,7 @@ static inline void rvu_afvf_mbox_up_handler(struct work_struct *work)
>  }
>  
>  static int rvu_get_mbox_regions(struct rvu *rvu, void **mbox_addr,
> -				int num, int type)
> +				int num, int type, unsigned long *pf_bmap)
>  {
>  	struct rvu_hwinfo *hw = rvu->hw;
>  	int region;
> @@ -2294,6 +2294,9 @@ static int rvu_get_mbox_regions(struct rvu *rvu, void **mbox_addr,
>  	 */
>  	if (type == TYPE_AFVF) {
>  		for (region = 0; region < num; region++) {
> +			if (!test_bit(region, pf_bmap))
> +				continue;
> +
>  			if (hw->cap.per_pf_mbox_regs) {
>  				bar4 = rvu_read64(rvu, BLKADDR_RVUM,
>  						  RVU_AF_PFX_BAR4_ADDR(0)) +
> @@ -2315,6 +2318,9 @@ static int rvu_get_mbox_regions(struct rvu *rvu, void **mbox_addr,
>  	 * RVU_AF_PF_BAR4_ADDR register.
>  	 */
>  	for (region = 0; region < num; region++) {
> +		if (!test_bit(region, pf_bmap))
> +			continue;
> +
>  		if (hw->cap.per_pf_mbox_regs) {
>  			bar4 = rvu_read64(rvu, BLKADDR_RVUM,
>  					  RVU_AF_PFX_BAR4_ADDR(region));
> @@ -2343,12 +2349,33 @@ static int rvu_mbox_init(struct rvu *rvu, struct mbox_wq_info *mw,
>  	int err = -EINVAL, i, dir, dir_up;
>  	void __iomem *reg_base;
>  	struct rvu_work *mwork;
> +	unsigned long *pf_bmap;
>  	void **mbox_regions;
>  	const char *name;
> +	u64 cfg;
> +
> +	pf_bmap = bitmap_zalloc(num, GFP_KERNEL);
> +	if (!pf_bmap)
> +		return -ENOMEM;
> +
> +	/* RVU VFs */
> +	if (type == TYPE_AFVF)
> +		bitmap_set(pf_bmap, 0, num);
> +
> +	if (type == TYPE_AFPF) {
> +		/* Mark enabled PFs in bitmap */
> +		for (i = 0; i < num; i++) {
> +			cfg = rvu_read64(rvu, BLKADDR_RVUM, RVU_PRIV_PFX_CFG(i));
> +			if (cfg & BIT_ULL(20))
> +				set_bit(i, pf_bmap);
> +		}
> +	}
>  
>  	mbox_regions = kcalloc(num, sizeof(void *), GFP_KERNEL);
> -	if (!mbox_regions)
> +	if (!mbox_regions) {
> +		bitmap_free(pf_bmap);
>  		return -ENOMEM;

Maybe it is more idiomatic to use

	goto free_bitmap;

> +	}
>  
>  	switch (type) {
>  	case TYPE_AFPF:
> @@ -2356,7 +2383,7 @@ static int rvu_mbox_init(struct rvu *rvu, struct mbox_wq_info *mw,
>  		dir = MBOX_DIR_AFPF;
>  		dir_up = MBOX_DIR_AFPF_UP;
>  		reg_base = rvu->afreg_base;
> -		err = rvu_get_mbox_regions(rvu, mbox_regions, num, TYPE_AFPF);
> +		err = rvu_get_mbox_regions(rvu, mbox_regions, num, TYPE_AFPF, pf_bmap);
>  		if (err)
>  			goto free_regions;
>  		break;
> @@ -2365,7 +2392,7 @@ static int rvu_mbox_init(struct rvu *rvu, struct mbox_wq_info *mw,
>  		dir = MBOX_DIR_PFVF;
>  		dir_up = MBOX_DIR_PFVF_UP;
>  		reg_base = rvu->pfreg_base;
> -		err = rvu_get_mbox_regions(rvu, mbox_regions, num, TYPE_AFVF);
> +		err = rvu_get_mbox_regions(rvu, mbox_regions, num, TYPE_AFVF, pf_bmap);
>  		if (err)
>  			goto free_regions;
>  		break;
> @@ -2396,16 +2423,19 @@ static int rvu_mbox_init(struct rvu *rvu, struct mbox_wq_info *mw,
>  	}
>  
>  	err = otx2_mbox_regions_init(&mw->mbox, mbox_regions, rvu->pdev,
> -				     reg_base, dir, num);
> +				     reg_base, dir, num, pf_bmap);
>  	if (err)
>  		goto exit;
>  
>  	err = otx2_mbox_regions_init(&mw->mbox_up, mbox_regions, rvu->pdev,
> -				     reg_base, dir_up, num);
> +				     reg_base, dir_up, num, pf_bmap);
>  	if (err)
>  		goto exit;
>  
>  	for (i = 0; i < num; i++) {
> +		if (!test_bit(i, pf_bmap))
> +			continue;
> +
>  		mwork = &mw->mbox_wrk[i];
>  		mwork->rvu = rvu;
>  		INIT_WORK(&mwork->work, mbox_handler);
> @@ -2415,6 +2445,7 @@ static int rvu_mbox_init(struct rvu *rvu, struct mbox_wq_info *mw,
>  		INIT_WORK(&mwork->work, mbox_up_handler);
>  	}
>  	kfree(mbox_regions);
> +	bitmap_free(pf_bmap);
>  	return 0;

Also, this could avoid duplication using:

	goto free_regions;

>  exit:
> @@ -2424,6 +2455,7 @@ static int rvu_mbox_init(struct rvu *rvu, struct mbox_wq_info *mw,
>  		iounmap((void __iomem *)mbox_regions[num]);
>  free_regions:
>  	kfree(mbox_regions);

free_bitmap:

> +	bitmap_free(pf_bmap);
>  	return err;
>  }
> -- 
> 2.25.1