[PATCH v1 03/10] xue: add support for selecting specific xhci

[Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>]

Handle parameters similar to dbgp=ehci.

Implement this by not resettting xhc_cf8 again in xue_init_xhc(), but
using a value found there if non-zero. Additionally, add xue->xhc_num to
select n-th controller.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
---
 docs/misc/xen-command-line.pandoc |  5 +++-
 xen/drivers/char/xue.c            | 56 ++++++++++++++++++++++++--------
 2 files changed, 47 insertions(+), 14 deletions(-)

diff --git a/docs/misc/xen-command-line.pandoc 
b/docs/misc/xen-command-line.pandoc
index 881fe409ac76..37a564c2386f 100644
--- a/docs/misc/xen-command-line.pandoc
+++ b/docs/misc/xen-command-line.pandoc
@@ -721,10 +721,15 @@ Available alternatives, with their meaning, are:
 
 ### dbgp
 > `= ehci[ <integer> | @pci<bus>:<slot>.<func> ]`
+> `= xue[ <integer> | @pci<bus>:<slot>.<func> ]`
 
 Specify the USB controller to use, either by instance number (when going
 over the PCI busses sequentially) or by PCI device (must be on segment 0).
 
+Use `ehci` for EHCI debug port, use `xue` for XHCI debug capability.
+Xue driver will wait indefinitely for the debug host to connect - make sure the
+cable is connected.
+
 ### debug_stack_lines
 > `= <integer>`
 
diff --git a/xen/drivers/char/xue.c b/xen/drivers/char/xue.c
index a9ba25d9d07e..b253426a95f8 100644
--- a/xen/drivers/char/xue.c
+++ b/xen/drivers/char/xue.c
@@ -204,6 +204,7 @@ struct xue {
     void *xhc_mmio;
 
     int open;
+    int xhc_num; /* look for n-th xhc */
 };
 
 static void xue_sys_pause(void)
@@ -252,24 +253,34 @@ static int xue_init_xhc(struct xue *xue)
     uint64_t bar1;
     uint64_t devfn;
 
-    /*
-     * Search PCI bus 0 for the xHC. All the host controllers supported so far
-     * are part of the chipset and are on bus 0.
-     */
-    for ( devfn = 0; devfn < 256; devfn++ ) {
-        uint32_t dev = (devfn & 0xF8) >> 3;
-        uint32_t fun = devfn & 0x07;
-        pci_sbdf_t sbdf = PCI_SBDF(0, dev, fun);
-        uint32_t hdr = pci_conf_read8(sbdf, PCI_HEADER_TYPE);
-
-        if ( hdr == 0 || hdr == 0x80 )
+    if ( xue->sbdf.sbdf == 0 )
+    {
+        /*
+         * Search PCI bus 0 for the xHC. All the host controllers supported so 
far
+         * are part of the chipset and are on bus 0.
+         */
+        for ( devfn = 0; devfn < 256; devfn++ )
         {
-            if ( (pci_conf_read32(sbdf, PCI_CLASS_REVISION) >> 8) == 
XUE_XHC_CLASSC )
+            uint32_t dev = (devfn & 0xF8) >> 3;
+            uint32_t fun = devfn & 0x07;
+            pci_sbdf_t sbdf = PCI_SBDF(0, dev, fun);
+            uint32_t hdr = pci_conf_read8(sbdf, PCI_HEADER_TYPE);
+
+            if ( hdr == 0 || hdr == 0x80 )
             {
-                xue->sbdf = sbdf;
-                break;
+                if ( (pci_conf_read32(sbdf, PCI_CLASS_REVISION) >> 8) == 
XUE_XHC_CLASSC )
+                {
+                    if ( xue->xhc_num-- )
+                        continue;
+                    xue->sbdf = sbdf;
+                    break;
+                }
             }
         }
+    } else {
+        /* Verify if selected device is really xHC */
+        if ( (pci_conf_read32(xue->sbdf, PCI_CLASS_REVISION) >> 8) != 
XUE_XHC_CLASSC )
+            xue->sbdf.sbdf = 0;
     }
 
     if ( !xue->sbdf.sbdf )
@@ -999,12 +1010,29 @@ void __init xue_uart_init(void)
 {
     struct xue_uart *uart = &xue_uart;
     struct xue *xue = &uart->xue;
+    const char *e;
 
     if ( strncmp(opt_dbgp, "xue", 3) )
         return;
 
     memset(xue, 0, sizeof(*xue));
 
+    if ( isdigit(opt_dbgp[3]) || !opt_dbgp[3] )
+    {
+        if ( opt_dbgp[3] )
+            xue->xhc_num = simple_strtoul(opt_dbgp + 3, &e, 10);
+    }
+    else if ( strncmp(opt_dbgp + 3, "@pci", 4) == 0 )
+    {
+        unsigned int bus, slot, func;
+
+        e = parse_pci(opt_dbgp + 7, NULL, &bus, &slot, &func);
+        if ( !e || *e )
+            return;
+
+        xue->sbdf = PCI_SBDF(0, bus, slot, func);
+    }
+
     xue->dbc_ctx = &ctx;
     xue->dbc_erst = &erst;
     xue->dbc_ering.trb = evt_trb;
-- 
git-series 0.9.1