[v2,12/35] xen/console: move vpl011-related code to vpl011 emulator

Commit Message

Denis Mukhin via B4 Relay Dec. 6, 2024, 4:41 a.m. UTC

From: Denis Mukhin <[e-mail]>

Xen console driver has vpl011-related logic which shall belong vpl011 emulator
code. Move vpl011-related to vpl011.c.

Signed-off-by: Denis Mukhin <[e-mail]>
---
 xen/arch/arm/include/asm/vpl011.h |  2 +-
 xen/arch/arm/vpl011.c             | 15 +++++++++++----
 xen/drivers/char/console.c        |  4 +---
 3 files changed, 13 insertions(+), 8 deletions(-)

Comments

Jan Beulich Dec. 10, 2024, 1:33 p.m. UTC | #1

On 06.12.2024 05:41, Denis Mukhin via B4 Relay wrote:
> --- a/xen/arch/arm/include/asm/vpl011.h
> +++ b/xen/arch/arm/include/asm/vpl011.h
> @@ -69,7 +69,7 @@ struct vpl011_init_info {
>  int domain_vpl011_init(struct domain *d,
>                         struct vpl011_init_info *info);
>  void domain_vpl011_deinit(struct domain *d);
> -void vpl011_rx_char_xen(struct domain *d, char c);
> +int vpl011_rx_char_xen(struct domain *d, char c);

If you make the function return an error indicator, ...

> --- a/xen/drivers/char/console.c
> +++ b/xen/drivers/char/console.c
> @@ -559,9 +559,7 @@ static void __serial_rx(char c)
>           * domain, without a full PV ring to Dom0 (in that case input
>           * comes from the PV ring), then send the character to it.
>           */
> -        if ( d != NULL &&
> -             !d->arch.vpl011.backend_in_domain &&
> -             d->arch.vpl011.backend.xen != NULL )
> +        if ( d != NULL )
>              vpl011_rx_char_xen(d, c);
>          else
>              printk("Cannot send chars to Dom%d: no UART available\n",
> 

... how come that return value then isn't used anywhere?

Jan

Patch

diff --git a/xen/arch/arm/include/asm/vpl011.h b/xen/arch/arm/include/asm/vpl011.h
index c09abcd7a9b3356d0809743517934adae00087f5..cc838682815c0d049ba33d3bf9966a64b2e527dd 100644
--- a/xen/arch/arm/include/asm/vpl011.h
+++ b/xen/arch/arm/include/asm/vpl011.h
@@ -69,7 +69,7 @@  struct vpl011_init_info {
 int domain_vpl011_init(struct domain *d,
                        struct vpl011_init_info *info);
 void domain_vpl011_deinit(struct domain *d);
-void vpl011_rx_char_xen(struct domain *d, char c);
+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)
diff --git a/xen/arch/arm/vpl011.c b/xen/arch/arm/vpl011.c
index 8ade6f2588b8bbcc58fb0f9edc324502a1992ce7..fe36fe2bd1529a4114884580ded6d6fa55a22f0e 100644
--- a/xen/arch/arm/vpl011.c
+++ b/xen/arch/arm/vpl011.c
@@ -567,16 +567,21 @@  static void vpl011_data_avail(struct domain *d,
 
 /*
  * vpl011_rx_char_xen adds a char to a domain's vpl011 receive buffer.
- * It is only used when the vpl011 backend is in Xen.
  */
-void vpl011_rx_char_xen(struct domain *d, char c)
+int vpl011_rx_char_xen(struct domain *d, char c)
 {
     unsigned long flags;
     struct vpl011 *vpl011 = &d->arch.vpl011;
     struct vpl011_xen_backend *intf = vpl011->backend.xen;
     XENCONS_RING_IDX in_cons, in_prod, in_fifo_level;
 
-    ASSERT(!vpl011->backend_in_domain);
+    /* Forward input iff the vpl011 backend is in Xen. */
+    if ( vpl011->backend_in_domain )
+        return -ENODEV;
+
+    if ( intf == NULL )
+        return -ENODEV;
+
     VPL011_LOCK(d, flags);
 
     in_cons = intf->in_cons;
@@ -584,7 +589,7 @@  void vpl011_rx_char_xen(struct domain *d, char c)
     if ( xencons_queued(in_prod, in_cons, sizeof(intf->in)) == sizeof(intf->in) )
     {
         VPL011_UNLOCK(d, flags);
-        return;
+        return -ENOSPC;
     }
 
     intf->in[xencons_mask(in_prod, sizeof(intf->in))] = c;
@@ -596,6 +601,8 @@  void vpl011_rx_char_xen(struct domain *d, char c)
 
     vpl011_data_avail(d, in_fifo_level, sizeof(intf->in), 0, SBSA_UART_FIFO_SIZE);
     VPL011_UNLOCK(d, flags);
+
+    return 0;
 }
 
 static void vpl011_notification(struct vcpu *v, unsigned int port)
diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index bb56953bab681a13da8d41431aba4632f1919df9..0af4b551801356f242f1770b3826608136d65653 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -559,9 +559,7 @@  static void __serial_rx(char c)
          * domain, without a full PV ring to Dom0 (in that case input
          * comes from the PV ring), then send the character to it.
          */
-        if ( d != NULL &&
-             !d->arch.vpl011.backend_in_domain &&
-             d->arch.vpl011.backend.xen != NULL )
+        if ( d != NULL )
             vpl011_rx_char_xen(d, c);
         else
             printk("Cannot send chars to Dom%d: no UART available\n",