[PULL 4/7] hw/usb/hcd-ohci: Add big endian and consistency check support

[Helge Deller <deller@kernel.org>]

From: Abizer Lokhandwala <abizerlokhandwalastd10@gmail.com>

The OHCI controller allows running in big endian mode. If this mode is enabled, swap the
buffer contents before accessing them since we by default run OHCI in little endian mode.

Additionally add the architected consistency check which halts OHCI on errors.

Signed-off-by: Abizer Lokhandwala <abizerlokhandwalastd10@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
---
 hw/usb/hcd-ohci.c | 35 +++++++++++++++++++++++++++++++++++
 hw/usb/hcd-ohci.h |  5 +++++
 2 files changed, 40 insertions(+)

diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c
index 23990115ab..5e5fe41f47 100644
--- a/hw/usb/hcd-ohci.c
+++ b/hw/usb/hcd-ohci.c
@@ -74,6 +74,7 @@ struct ohci_hcca {
 /* Flags in the head field of an Endpoint Descriptor. */
 #define OHCI_ED_H         1
 #define OHCI_ED_C         2
+#define OHCI_ED_HEAD_RSVD   (1 << 2 | 1 << 3)
 
 /* Bitfields for the first word of a Transfer Descriptor. */
 #define OHCI_TD_R         (1 << 18)
@@ -371,6 +372,8 @@ void ohci_hard_reset(OHCIState *ohci)
     ohci_soft_reset(ohci);
     ohci->ctl = 0;
     ohci_roothub_reset(ohci);
+    ohci->big_endian = false;
+    ohci->consistency_check = false;
 }
 
 /* Get an array of dwords from main memory */
@@ -867,6 +870,18 @@ static void ohci_td_pkt(const char *msg, const uint8_t *buf, size_t len)
     }
 }
 
+static void ohci_bswap_buf(uint8_t *buf, size_t len)
+{
+    uint32_t w;
+    while (len >= sizeof(w)) {
+        memcpy(&w, buf, sizeof(w));
+        w = bswap32(w);
+        memcpy(buf, &w, sizeof(w));
+        buf += sizeof(w);
+        len -= sizeof(w);
+    }
+}
+
 /*
  * Service a transport descriptor.
  * Returns nonzero to terminate processing of this endpoint.
@@ -975,6 +990,9 @@ static int ohci_service_td(OHCIState *ohci, struct ohci_ed *ed)
                                  DMA_DIRECTION_TO_DEVICE)) {
                     ohci_die(ohci);
                 }
+                if (ohci->big_endian) {
+                    ohci_bswap_buf(ohci->usb_buf, pktlen);
+                }
             }
         }
     }
@@ -1024,6 +1042,9 @@ static int ohci_service_td(OHCIState *ohci, struct ohci_ed *ed)
 
     if (ret >= 0) {
         if (dir == OHCI_TD_DIR_IN) {
+            if (ohci->big_endian) {
+                ohci_bswap_buf(ohci->usb_buf, ret);
+            }
             if (ohci_copy_td(ohci, &td, ohci->usb_buf, ret,
                              DMA_DIRECTION_FROM_DEVICE)) {
                 ohci_die(ohci);
@@ -1108,6 +1129,13 @@ static int ohci_service_td(OHCIState *ohci, struct ohci_ed *ed)
         ohci->done_count = i;
     }
 exit_no_retire:
+    if (ohci->media_error) {
+        int cc = OHCI_BM(td.flags, TD_CC);
+        /* only these 2 errors will ever actually be possible in qemu */
+        if (cc == OHCI_CC_DEVICENOTRESPONDING || cc == OHCI_CC_UNDEXPETEDPID) {
+            ohci->media_error(ohci);
+        }
+    }
     if (ohci_put_td(ohci, addr, &td)) {
         ohci_die(ohci);
         return 1;
@@ -1136,6 +1164,13 @@ static int ohci_service_ed_list(OHCIState *ohci, uint32_t head)
             ohci_die(ohci);
             return 0;
         }
+        if (ohci->consistency_check && (ed.head & OHCI_ED_HEAD_RSVD)) {
+            if (ohci->descriptor_error) {
+                ohci->descriptor_error(ohci);
+            }
+            ohci_die(ohci);
+            return 0;
+        }
 
         next_ed = ed.next & OHCI_DPTR_MASK;
 
diff --git a/hw/usb/hcd-ohci.h b/hw/usb/hcd-ohci.h
index 243cd1f46a..d079f8d24e 100644
--- a/hw/usb/hcd-ohci.h
+++ b/hw/usb/hcd-ohci.h
@@ -93,6 +93,11 @@ struct OHCIState {
     bool async_complete;
 
     void (*ohci_die)(OHCIState *ohci);
+    void (*media_error)(OHCIState *ohci);
+    void (*descriptor_error)(OHCIState *ohci);
+
+    bool big_endian;
+    bool consistency_check;
 };
 
 #define TYPE_SYSBUS_OHCI "sysbus-ohci"
-- 
2.54.0