[osv-dev] [PATCH v2 1/3] pci: add batch capability discovery

[Fotis Xenakis]

Signed-off-by: Fotis Xenakis <fo...@windowslive.com>
---
 drivers/pci-function.cc | 39 +++++++++++++++++++++++++++++++++------
 drivers/pci-function.hh |  1 +
 2 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/drivers/pci-function.cc b/drivers/pci-function.cc
index 369f22e9..2cc8b837 100644
--- a/drivers/pci-function.cc
+++ b/drivers/pci-function.cc
@@ -807,36 +807,63 @@ namespace pci {
         write_pci_config(_bus, _device, _func, offset, val);
     }
 
+    // Returns the offset of the first capability with id matching @cap_id, or
+    // 0xFF if none found.
     u8 function::find_capability(u8 cap_id)
     {
-        return this->find_capability(cap_id, [](function *fun, u8 off) { 
return true; } );
+        return find_capability(cap_id, [](function *fun, u8 off) { return 
true; } );
     }
 
+    // Returns the offset of the first capability with id matching @cap_id and
+    // satisfying @predicate (if specified). If none found, returns 0xFF.
     u8 function::find_capability(u8 cap_id, std::function<bool (function*, 
u8)> predicate)
+    {
+        u8 bad_offset = 0xFF;
+        std::vector<u8> cap_offs;
+
+        if (!find_capabilities(cap_offs, cap_id)) {
+            return bad_offset;
+        }
+
+        if (!predicate) {
+            predicate = [](function *fun, u8 off) { return true; };
+        }
+        for (auto off: cap_offs) {
+            if (predicate(this, off)) {
+                return off;
+            }
+        }
+        return bad_offset;
+    }
+
+    // Append to @cap_offs the offsets of all capabilities with id matching
+    // @cap_id. Returns whether any such capabilities were found.
+    bool function::find_capabilities(std::vector<u8>& cap_offs, u8 cap_id)
     {
         u8 capabilities_base = pci_readb(PCI_CAPABILITIES_PTR);
         u8 off = capabilities_base;
-        u8 bad_offset = 0xFF;
         u8 max_capabilities = 0xF0;
         u8 ctr = 0;
+        bool found = false;
 
         while (off != 0) {
             // Read capability
             u8 capability = pci_readb(off + PCI_CAP_OFF_ID);
-            if (capability == cap_id && predicate(this, off)) {
-                return off;
+            if (capability == cap_id) {
+                cap_offs.push_back(off);
+                found = true;
             }
 
             ctr++;
             if (ctr > max_capabilities) {
-                return bad_offset;
+                return found;
             }
 
             // Next
             off = pci_readb(off + PCI_CAP_OFF_NEXT);
         }
 
-        return bad_offset;
+        return found;
     }
 
     bar * function::get_bar(int idx)
diff --git a/drivers/pci-function.hh b/drivers/pci-function.hh
index 59d57a1e..a8904cb0 100644
--- a/drivers/pci-function.hh
+++ b/drivers/pci-function.hh
@@ -342,6 +342,7 @@ namespace pci {
         // Capability parsing
         u8 find_capability(u8 cap_id);
         u8 find_capability(u8 cap_id, std::function<bool (function*, u8)> 
predicate);
+        bool find_capabilities(std::vector<u8>& caps, u8 cap_id);
 
         bar * get_bar(int idx);
         void add_bar(int idx, bar* bar);
-- 
2.25.1

-- 
You received this message because you are subscribed to the Google Groups "OSv 
Development" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to osv-dev+unsubscr...@googlegroups.com.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/osv-dev/VI1PR03MB43832582C29166DC3D5C7093A6F80%40VI1PR03MB4383.eurprd03.prod.outlook.com.