Re: [PATCH v1 03/16] arm/vpl011: use vuart_ prefix in vpl011 public calls

[dmkhn@xxxxxxxxx]

On Tue, Jun 24, 2025 at 12:11:10PM +0200, Orzel, Michal wrote:
> 
> 
> On 24/06/2025 05:55, dmkhn@xxxxxxxxx wrote:
> > From: Denis Mukhin <dmukhin@xxxxxxxx>
> >
> > Use generic names prefixed with 'vuart_' in public PL011 emulator data
> > structures and functions.
> >
> > No functional change intended.
> >
> > Signed-off-by: Denis Mukhin <dmukhin@xxxxxxxx>
> > ---
> >  xen/arch/arm/dom0less-build.c     |  4 ++--
> >  xen/arch/arm/domain.c             |  3 ++-
> >  xen/arch/arm/domctl.c             | 14 +++++++------
> >  xen/arch/arm/include/asm/vpl011.h | 20 ------------------
> >  xen/arch/arm/vpl011.c             | 24 +++++++++++-----------
> >  xen/drivers/char/console.c        |  6 ++----
> >  xen/include/xen/vuart.h           | 34 ++++++++++++++++++++++++++++++-
> >  7 files changed, 59 insertions(+), 46 deletions(-)
> >
> > diff --git a/xen/arch/arm/dom0less-build.c b/xen/arch/arm/dom0less-build.c
> > index 7c1b59750fb5..11b8498d3b22 100644
> > --- a/xen/arch/arm/dom0less-build.c
> > +++ b/xen/arch/arm/dom0less-build.c
> > @@ -216,7 +216,7 @@ int __init init_vuart(struct domain *d, struct 
> > kernel_info *kinfo,
> As can be seen here ...
> 
> >       */
> >      if ( kinfo->arch.vpl011 )
> >      {
> > -        rc = domain_vpl011_init(d, NULL);
> > +        rc = vuart_init(d, NULL);
> we end up with init_vuart() and vuart_init(). That's quite confusing. Maybe
> domain_vuart_init() or alike?

That's right!
But domain_vuart_init() is used by MMIO-based variant :)
I will write an extra patch and put it to the end of the series to update the
name here.

> 
> >          if ( rc < 0 )
> >              return rc;
> >      }
> > @@ -247,7 +247,7 @@ void __init arch_create_domUs(struct dt_device_node 
> > *node,
> >           * d->arch.vpl011.irq. So the logic to find the vIRQ has to
> >           * be hardcoded.
> >           * The logic here shall be consistent with the one in
> > -         * domain_vpl011_init().
> > +         * vuart_init().
> >           */
> >          if ( flags & CDF_directmap )
> >          {
> > diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
> > index be58a23dd725..68297e619bad 100644
> > --- a/xen/arch/arm/domain.c
> > +++ b/xen/arch/arm/domain.c
> > @@ -11,6 +11,7 @@
> >  #include <xen/sched.h>
> >  #include <xen/softirq.h>
> >  #include <xen/wait.h>
> > +#include <xen/vuart.h>
> >
> >  #include <asm/arm64/sve.h>
> >  #include <asm/cpuerrata.h>
> > @@ -1072,7 +1073,7 @@ int domain_relinquish_resources(struct domain *d)
> >           * Release the resources allocated for vpl011 which were
> >           * allocated via a DOMCTL call XEN_DOMCTL_vuart_op.
> >           */
> > -        domain_vpl011_deinit(d);
> > +        vuart_exit(d);
> IMO, deinit is more meaningful here.

Yeah, it's just MMIO UART uses init/free, here it is init/deinit.

So I just picked init/exit similar to module_{init,exit} in Linux driver model
and applied to all existing vUARTs.

Can update all vUARTs to deinit()

> 
> >
> >  #ifdef CONFIG_IOREQ_SERVER
> >          ioreq_server_destroy_all(d);
> > diff --git a/xen/arch/arm/domctl.c b/xen/arch/arm/domctl.c
> > index ad914c915f81..dde25ceff6d0 100644
> > --- a/xen/arch/arm/domctl.c
> > +++ b/xen/arch/arm/domctl.c
> > @@ -14,6 +14,7 @@
> >  #include <xen/mm.h>
> >  #include <xen/sched.h>
> >  #include <xen/types.h>
> > +#include <xen/vuart.h>
> >  #include <xsm/xsm.h>
> >  #include <public/domctl.h>
> >
> > @@ -30,10 +31,11 @@ static int handle_vuart_init(struct domain *d,
> >                               struct xen_domctl_vuart_op *vuart_op)
> >  {
> >      int rc;
> > -    struct vpl011_init_info info;
> > -
> > -    info.console_domid = vuart_op->console_domid;
> > -    info.gfn = _gfn(vuart_op->gfn);
> > +    struct vuart_params params = {
> > +        .console_domid = vuart_op->console_domid,
> > +        .gfn = _gfn(vuart_op->gfn),
> > +        .evtchn = 0,
> > +    };
> >
> >      if ( d->creation_finished )
> >          return -EPERM;
> > @@ -41,10 +43,10 @@ static int handle_vuart_init(struct domain *d,
> >      if ( vuart_op->type != XEN_DOMCTL_VUART_TYPE_VPL011 )
> >          return -EOPNOTSUPP;
> >
> > -    rc = domain_vpl011_init(d, &info);
> > +    rc = vuart_init(d, &params);
> >
> >      if ( !rc )
> > -        vuart_op->evtchn = info.evtchn;
> > +        vuart_op->evtchn = params.evtchn;
> >
> >      return rc;
> >  }
> > diff --git a/xen/arch/arm/include/asm/vpl011.h 
> > b/xen/arch/arm/include/asm/vpl011.h
> > index be64883b8628..5c308cc8c148 100644
> > --- a/xen/arch/arm/include/asm/vpl011.h
> > +++ b/xen/arch/arm/include/asm/vpl011.h
> > @@ -59,26 +59,6 @@ struct vpl011 {
> >      evtchn_port_t evtchn;
> >  };
> >
> > -struct vpl011_init_info {
> > -    domid_t console_domid;
> > -    gfn_t gfn;
> > -    evtchn_port_t evtchn;
> > -};
> > -
> > -#ifdef CONFIG_HAS_VUART_PL011
> > -int domain_vpl011_init(struct domain *d,
> > -                       struct vpl011_init_info *info);
> > -void domain_vpl011_deinit(struct domain *d);
> > -int vpl011_rx_char_xen(struct domain *d, char c);
> > -#else
> > -static inline int domain_vpl011_init(struct domain *d,
> > -                                     struct vpl011_init_info *info)
> > -{
> > -    return -ENOSYS;
> > -}
> > -
> > -static inline void domain_vpl011_deinit(struct domain *d) { }
> > -#endif
> >  #endif  /* _VPL011_H_ */
> >
> >  /*
> > diff --git a/xen/arch/arm/vpl011.c b/xen/arch/arm/vpl011.c
> > index cafc532cf028..2cf88a70ecdb 100644
> > --- a/xen/arch/arm/vpl011.c
> > +++ b/xen/arch/arm/vpl011.c
> > @@ -134,7 +134,7 @@ static void vpl011_write_data_xen(struct domain *d, 
> > uint8_t data)
> >
> >  /*
> >   * vpl011_read_data_xen reads data when the backend is xen. Characters
> > - * are added to the vpl011 receive buffer by vpl011_rx_char_xen.
> > + * are added to the vpl011 receive buffer by vuart_putchar.
> >   */
> >  static uint8_t vpl011_read_data_xen(struct domain *d)
> >  {
> > @@ -571,9 +571,9 @@ static void vpl011_data_avail(struct domain *d,
> >  }
> >
> >  /*
> > - * vpl011_rx_char_xen adds a char to a domain's vpl011 receive buffer.
> > + * vuart_putchar adds a char to a domain's vpl011 receive buffer.
> >   */
> > -int vpl011_rx_char_xen(struct domain *d, char c)
> > +int vuart_putchar(struct domain *d, char c)
> How can putchar refer to RX? By definition putchar() is used to print data to
> STDOUT. Here we receive a character and put it in the RX FIFO.

That's confusing, I agree; I think this is a leftover from the earlier vUART
series.

Will update, thanks!

> 
> ~Michal
> 
>