lib.pci: Support short/canonical ("01:00.0") PCI addresses

src/lib/hardware/README.md

@@ -23,6 +23,19 @@ An array of supported hardware devices. Must be populated by calling
 `pci.scan_devices`. Each entry is a table as returned by
 `pci.device_info`.
 
+— Function **pci.canonical** *pciaddress*
+
+Returns the canonical representation of a PCI address. The canonical
+representation is preferred internally in Snabb Switch and for
+presenting to users. It shortens addresses with leading zeros like
+this: `0000:01:00.0` becomes `01:00.0`.
+
+— Function **pci.qualified** *pciaddress*
+
+Returns the fully qualified representation of a PCI address. Fully
+qualified addresses have the form `0000:01:00.0` and so this function
+undoes any abbreviation in the canonical representation.
+
 — Function **pci.scan_devices**
 
 Scans for available PCI devices and populates the `pci.devices` table.

src/lib/hardware/README.md.src

@@ -23,6 +23,19 @@ An array of supported hardware devices. Must be populated by calling
 `pci.scan_devices`. Each entry is a table as returned by
 `pci.device_info`.
 
+— Function **pci.canonical** *pciaddress*
+
+Returns the canonical representation of a PCI address. The canonical
+representation is preferred internally in Snabb Switch and for
+presenting to users. It shortens addresses with leading zeros like
+this: `0000:01:00.0` becomes `01:00.0`.
+
+— Function **pci.qualified** *pciaddress*
+
+Returns the fully qualified representation of a PCI address. Fully
+qualified addresses have the form `0000:01:00.0` and so this function
+undoes any abbreviation in the canonical representation.
+
 — Function **pci.scan_devices**
 
 Scans for available PCI devices and populates the `pci.devices` table.

src/lib/hardware/pci.lua

@@ -34,7 +34,7 @@ end
 function device_info (pciaddress)
    local info = {}
    local p = path(pciaddress)
-   info.pciaddress = pciaddress
+   info.pciaddress = canonical(pciaddress)
    info.vendor = lib.firstline(p.."/vendor")
    info.device = lib.firstline(p.."/device")
    info.model = which_model(info.vendor, info.device)
@@ -50,7 +50,7 @@ function device_info (pciaddress)
 end
 
 --- Return the path to the sysfs directory for `pcidev`.
-function path(pcidev) return "/sys/bus/pci/devices/"..pcidev end
+function path(pcidev) return "/sys/bus/pci/devices/"..qualified(pcidev) end
 
 model = {
    ["82599_SFP"] = 'Intel 82599 SFP',
@@ -97,10 +97,10 @@ end
 --- The corresponding network interface (e.g. `eth0`) will disappear.
 function unbind_device_from_linux (pciaddress)
    root_check()
-    local p = path(pciaddress).."/driver/unbind"
-    if lib.can_write(p) then
-        lib.writefile(path(pciaddress).."/driver/unbind", pciaddress)
-    end
+   local p = path(pciaddress).."/driver/unbind"
+   if lib.can_write(p) then
+       lib.writefile(path(pciaddress).."/driver/unbind", qualified(pciaddress))
+   end
 end
 
 -- Memory map PCI device configuration space.
@@ -142,13 +142,31 @@ function root_check ()
    lib.root_check("error: must run as root to access PCI devices")
 end
 
+-- Return the canonical (abbreviated) representation of the PCI address.
+-- 
+-- example: canonical("0000:01:00.0") -> "01:00.0"
+function canonical (address)
+   return address:gsub("^0000:", "")
+end
+
+-- Return the fully-qualified representation of a PCI address.
+--
+-- example: qualified("01:00.0") -> "0000:01:00.0"
+function qualified (address)
+   return address:gsub("^%d%d:%d%d[.]%d+$", "0000:%1")
+end
+
 --- ### Selftest
 ---
 --- PCI selftest scans for available devices and performs our driver's
 --- self-test on each of them.
 
 function selftest ()
    print("selftest: pci")
+   assert(qualified("0000:01:00.0") == "0000:01:00.0", "qualified 1")
+   assert(qualified(     "01:00.0") == "0000:01:00.0", "qualified 2")
+   assert(canonical("0000:01:00.0") ==      "01:00.0", "canonical 1")
+   assert(canonical(     "01:00.0") ==      "01:00.0", "canonical 2")
    scan_devices()
    print_device_summary()
 end

src/program/packetblaster/packetblaster.lua

@@ -67,7 +67,7 @@ function is_device_suitable (pcidev, patterns)
       return true
    end
    for _, pattern in ipairs(patterns) do
-      if pcidev.pciaddress:gmatch(pattern)() then
+      if pci.qualified(pcidev.pciaddress):gmatch(pattern)() then
          return true
       end
    end