[PATCH 20/36] xen/console: introduce consoled_is_enabled()

[Denis Mukhin via B4 Relay <devnull+dmukhin.ford.com@xxxxxxxxxx>]

From: Denis Mukhin <dmukhin@xxxxxxxx>

There are few places which check pv_shim console under CONFIG_PV_SHIM in xen
console driver. Instead of #ifdef-ing, use new consoled_is_enabled() to
customize the logic.

Header file now can be included w/o CONFIG_X86.

Signature of consoled_guest_{rx,tx} has changed to account for follow-on
console switch logic cleanup.

Signed-off-by: Denis Mukhin <dmukhin@xxxxxxxx>
---
 xen/drivers/char/console.c  | 10 +++-------
 xen/drivers/char/consoled.c | 18 ++++++++++++++----
 xen/include/xen/consoled.h  | 35 +++++++++++++++++++++++++++++++++--
 3 files changed, 50 insertions(+), 13 deletions(-)

diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index 
f034ce5aab3f3bf59b0df9fa583ee9ce32dbf665..60c055396b697869b04b9132b0dcfa832fabe932
 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -33,9 +33,9 @@
 #include <xen/pv_console.h>
 #include <asm/setup.h>
 #include <xen/sections.h>
+#include <xen/consoled.h>
 
 #ifdef CONFIG_X86
-#include <xen/consoled.h>
 #include <asm/guest.h>
 #endif
 #ifdef CONFIG_SBSA_VUART_CONSOLE
@@ -505,11 +505,9 @@ static void console_find_owner(void)
             break;
         }
 
-#ifdef CONFIG_PV_SHIM
-        if ( next_rx == 1 )
+        if ( consoled_is_enabled() && next_rx == 1 )
             domid = get_initial_domain_id();
         else
-#endif
             domid = next_rx - 1;
         d = rcu_lock_domain_by_id(domid);
         if ( d )
@@ -573,10 +571,8 @@ static void __serial_rx(char c)
 #endif
     }
 
-#ifdef CONFIG_X86
-    if ( pv_shim && pv_console )
+    if ( consoled_is_enabled() )
         consoled_guest_tx(c);
-#endif
 }
 
 static void cf_check serial_rx(char c)
diff --git a/xen/drivers/char/consoled.c b/xen/drivers/char/consoled.c
index 
b415b632cecc0a80e161b701d7b70ba4f3cc5fb8..d6624e7697f56e1a1959b0efa5dca104f34af002
 100644
--- a/xen/drivers/char/consoled.c
+++ b/xen/drivers/char/consoled.c
@@ -43,13 +43,13 @@ struct xencons_interface *consoled_get_ring_addr(void)
 static char buf[BUF_SZ + 1];
 
 /* Receives characters from a domain's PV console */
-void consoled_guest_rx(void)
+int consoled_guest_rx(void)
 {
     size_t idx = 0;
     XENCONS_RING_IDX cons, prod;
 
     if ( !cons_ring )
-        return;
+        return 0;
 
     spin_lock(&rx_lock);
 
@@ -91,15 +91,17 @@ void consoled_guest_rx(void)
 
  out:
     spin_unlock(&rx_lock);
+
+    return 0;
 }
 
 /* Sends a character into a domain's PV console */
-void consoled_guest_tx(char c)
+int consoled_guest_tx(char c)
 {
     XENCONS_RING_IDX cons, prod;
 
     if ( !cons_ring )
-        return;
+        return 0;
 
     cons = ACCESS_ONCE(cons_ring->in_cons);
     prod = cons_ring->in_prod;
@@ -118,6 +120,7 @@ void consoled_guest_tx(char c)
 
     cons_ring->in[MASK_XENCONS_IDX(prod++, cons_ring->in)] = c;
 
+
     /* Write to the ring before updating the pointer */
     smp_wmb();
     ACCESS_ONCE(cons_ring->in_prod) = prod;
@@ -125,6 +128,13 @@ void consoled_guest_tx(char c)
  notify:
     /* Always notify the guest: prevents receive path from getting stuck. */
     pv_shim_inject_evtchn(pv_console_evtchn());
+
+    return 0;
+}
+
+bool consoled_is_enabled(void)
+{
+    return pv_shim && pv_console;
 }
 
 /*
diff --git a/xen/include/xen/consoled.h b/xen/include/xen/consoled.h
index 
bd7ab6329ee8a7c466484021247241ded8ed03c7..b88e3025fde84a52d7027b785b0a51ada8493832
 100644
--- a/xen/include/xen/consoled.h
+++ b/xen/include/xen/consoled.h
@@ -3,10 +3,41 @@
 
 #include <public/io/console.h>
 
+#if defined(CONFIG_PV_SHIM)
+
 void consoled_set_ring_addr(struct xencons_interface *ring);
 struct xencons_interface *consoled_get_ring_addr(void);
-void consoled_guest_rx(void);
-void consoled_guest_tx(char c);
+int consoled_guest_rx(void);
+int consoled_guest_tx(char c);
+bool consoled_is_enabled(void);
+
+#else
+
+void consoled_set_ring_addr(struct xencons_interface *ring)
+{
+}
+
+struct xencons_interface *consoled_get_ring_addr(void)
+{
+    return NULL;
+}
+
+int consoled_guest_rx(void)
+{
+    return 0;
+}
+
+int consoled_guest_tx(char c)
+{
+    return 0;
+}
+
+bool consoled_is_enabled(void)
+{
+    return false;
+}
+
+#endif /* #if defined(CONFIG_PV_SHIM) */
 
 #endif /* __XEN_CONSOLED_H__ */
 /*

-- 
2.34.1