On Thu, Mar 26, 2020 at 3:08 PM Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
> From: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
>
> This commit introduced two layers to drive IFC VF:
>
> (1) ifcvf_base layer, which handles IFC VF NIC hardware operations and
> configurations.
>
> (2) ifcvf_main layer, which complies to VDPA bus framework,
> implemented device operations for VDPA bus, handles device probe,
> bus attaching, vring operations, etc.
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
> Signed-off-by: Bie Tiwei <tiwei.bie@xxxxxxxxx>
> Signed-off-by: Wang Xiao <xiao.w.wang@xxxxxxxxx>
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> +
> +#define IFCVF_QUEUE_ALIGNMENT PAGE_SIZE
> +#define IFCVF_QUEUE_MAX 32768
> +static u16 ifcvf_vdpa_get_vq_align(struct vdpa_device *vdpa_dev)
> +{
> + return IFCVF_QUEUE_ALIGNMENT;
> +}
This fails to build on arm64 with 64kb page size (found in linux-next):
/drivers/vdpa/ifcvf/ifcvf_main.c: In function 'ifcvf_vdpa_get_vq_align':
arch/arm64/include/asm/page-def.h:17:20: error: conversion from 'long
unsigned int' to 'u16' {aka 'short unsigned int'} changes value from
'65536' to '0' [-Werror=overflow]
17 | #define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT)
| ^
drivers/vdpa/ifcvf/ifcvf_base.h:37:31: note: in expansion of macro 'PAGE_SIZE'
37 | #define IFCVF_QUEUE_ALIGNMENT PAGE_SIZE
| ^~~~~~~~~
drivers/vdpa/ifcvf/ifcvf_main.c:231:9: note: in expansion of macro
'IFCVF_QUEUE_ALIGNMENT'
231 | return IFCVF_QUEUE_ALIGNMENT;
| ^~~~~~~~~~~~~~~~~~~~~
It's probably good enough to just not allow the driver to be built in that
configuration as it's fairly rare but unfortunately there is no simple Kconfig
symbol for it.
In a similar driver, we did
config VMXNET3
tristate "VMware VMXNET3 ethernet driver"
depends on PCI && INET
depends on !(PAGE_SIZE_64KB || ARM64_64K_PAGES || \
IA64_PAGE_SIZE_64KB || MICROBLAZE_64K_PAGES || \
PARISC_PAGE_SIZE_64KB || PPC_64K_PAGES)
I think we should probably make PAGE_SIZE_64KB a global symbol
in arch/Kconfig and have it selected by the other symbols so drivers
like yours can add a dependency for it.
Arnd
