Re: [PATCH 2/3] ntb_hw_switchtec: Added support of >=4G memory windows

From: Jon Mason
Date: Tue Nov 27 2018 - 11:06:32 EST


On Wed, Nov 21, 2018 at 9:19 PM Wesley Sheng <wesley.sheng@xxxxxxxxxxxxx> wrote:
>
> From: Paul Selles <paul.selles@xxxxxxxxxxxxx>
>
> Current Switchtec's BAR setup registers are limited to 32bits,
> corresponding to the maximum MW (memory window) size is <4G.
>
> Increase the MW sizes with the addition of the BAR Setup Extension
> Register for the upper 32bits of a 64bits MW size. This increases the MW
> range to between 4K and 2^63.
>
> Reported-by: Boris Glimcher <boris.glimcher@xxxxxxx>
> Signed-off-by: Paul Selles <paul.selles@xxxxxxxxxxxxx>
> Signed-off-by: Wesley Sheng <wesley.sheng@xxxxxxxxxxxxx>
> ---
> drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 9 +++++++--
> include/linux/switchtec.h | 6 +++++-
> 2 files changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
> index 9916bc5..32850fb 100644
> --- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
> +++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
> @@ -264,6 +264,7 @@ static void switchtec_ntb_mw_clr_direct(struct switchtec_ntb *sndev, int idx)
> ctl_val &= ~NTB_CTRL_BAR_DIR_WIN_EN;
> iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
> iowrite32(0, &ctl->bar_entry[bar].win_size);
> + iowrite32(0, &ctl->bar_ext_entry[bar].win_size);
> iowrite64(sndev->self_partition, &ctl->bar_entry[bar].xlate_addr);
> }
>
> @@ -286,7 +287,9 @@ static void switchtec_ntb_mw_set_direct(struct switchtec_ntb *sndev, int idx,
> ctl_val |= NTB_CTRL_BAR_DIR_WIN_EN;
>
> iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
> - iowrite32(xlate_pos | size, &ctl->bar_entry[bar].win_size);
> + iowrite32(xlate_pos | (size & 0xFFFFF000),
> + &ctl->bar_entry[bar].win_size);
> + iowrite32(size >> 32, &ctl->bar_ext_entry[bar].win_size);

Thanks for the patches. Overall the look good. Per the kbuild email,
size_t is 32bits on 32bit arch. So, this is going to have compile
warnings on those. Please address this and resubmit.

Also, patches 1 and 3 are bug fixes. Please do the following, reorder
the patches to make the bug fixes first and add a "Fixes" line to the
commit messages (see
https://www.kernel.org/doc/html/latest/process/submitting-patches.html#using-reported-by-tested-by-reviewed-by-suggested-by-and-fixes).
This will allow me to split up the series and get the bug fixes into
v4.20 (and the stable trees).

Thanks,
Jon

> iowrite64(sndev->self_partition | addr,
> &ctl->bar_entry[bar].xlate_addr);
> }
> @@ -1053,7 +1056,9 @@ static int crosslink_setup_mws(struct switchtec_ntb *sndev, int ntb_lut_idx,
> ctl_val |= NTB_CTRL_BAR_DIR_WIN_EN;
>
> iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
> - iowrite32(xlate_pos | size, &ctl->bar_entry[bar].win_size);
> + iowrite32(xlate_pos | (size & 0xFFFFF000),
> + &ctl->bar_entry[bar].win_size);
> + iowrite32(size >> 32, &ctl->bar_ext_entry[bar].win_size);
> iowrite64(sndev->peer_partition | addr,
> &ctl->bar_entry[bar].xlate_addr);
> }
> diff --git a/include/linux/switchtec.h b/include/linux/switchtec.h
> index eee0412..1e6e333 100644
> --- a/include/linux/switchtec.h
> +++ b/include/linux/switchtec.h
> @@ -248,7 +248,11 @@ struct ntb_ctrl_regs {
> u32 win_size;
> u64 xlate_addr;
> } bar_entry[6];
> - u32 reserved2[216];
> + struct {
> + u32 win_size;
> + u32 reserved[3];
> + } bar_ext_entry[6];
> + u32 reserved2[192];
> u32 req_id_table[256];
> u32 reserved3[512];
> u64 lut_entry[512];
> --
> 2.7.4
>