On Fri, Jun 06, 2014 at 12:54:17PM +0200, Michal Privoznik wrote:
These functions will handle PCIe devices and their link capabilities
to query some info about it.
Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
---
src/libvirt_private.syms | 3 ++
src/util/virpci.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++-
src/util/virpci.h | 8 +++++
3 files changed, 91 insertions(+), 1 deletion(-)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index d73a9f5..f72a3ad 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1690,6 +1690,8 @@ virPCIDeviceFree;
virPCIDeviceGetDriverPathAndName;
virPCIDeviceGetIOMMUGroupDev;
virPCIDeviceGetIOMMUGroupList;
+virPCIDeviceGetLinkCap;
+virPCIDeviceGetLinkSta;
virPCIDeviceGetManaged;
virPCIDeviceGetName;
virPCIDeviceGetRemoveSlot;
@@ -1698,6 +1700,7 @@ virPCIDeviceGetStubDriver;
virPCIDeviceGetUnbindFromStub;
virPCIDeviceGetUsedBy;
virPCIDeviceIsAssignable;
+virPCIDeviceIsPCIExpress;
virPCIDeviceListAdd;
virPCIDeviceListAddCopy;
virPCIDeviceListCount;
diff --git a/src/util/virpci.c b/src/util/virpci.c
index e0f2344..8ad28b8 100644
--- a/src/util/virpci.c
+++ b/src/util/virpci.c
@@ -130,7 +130,13 @@ struct _virPCIDeviceList {
/* PCIe20 7.8.3 Device Capabilities Register (Offset 04h) */
#define PCI_EXP_DEVCAP 0x4 /* Device capabilities */
-#define PCI_EXP_DEVCAP_FLR (1<<28) /* Function Level Reset */
+#define PCI_EXP_LNKCAP 0xc /* Link Capabilities */
+#define PCI_EXP_LNKSTA 0x12 /* Link Status */
+#define PCI_EXP_DEVCAP_FLR (1<<28) /* Function Level Reset */
+#define PCI_EXP_LNKCAP_SPEED 0x0000f /* Maximum Link Speed */
+#define PCI_EXP_LNKCAP_WIDTH 0x003f0 /* Maximum Link Width */
+#define PCI_EXP_LNKSTA_SPEED 0x000f /* Negotiated Link Speed */
+#define PCI_EXP_LNKSTA_WIDTH 0x03f0 /* Negotiated Link Width */
These two sets are essentially the same, just keep it as e.g. PCI_EXP_LINK_(SPEED|WIDTH) with 0x(f|3f) respectively. And keep the order of the names alphabetical.
/* Header type 1 BR12 3.2 PCI-to-PCI Bridge Configuration Space Header Format */
#define PCI_PRIMARY_BUS 0x18 /* BR12 3.2.5.2 Primary bus number */
@@ -2750,3 +2756,76 @@ virPCIGetVirtualFunctionInfo(const char *vf_sysfs_device_path ATTRIBUTE_UNUSED,
return -1;
}
#endif /* __linux__ */
+
+int
+virPCIDeviceIsPCIExpress(virPCIDevicePtr dev)
+{
+ int fd;
+ int ret = -1;
+
+ if ((fd = virPCIDeviceConfigOpen(dev, true)) < 0)
+ return ret;
+
+ if (virPCIDeviceInit(dev, fd) < 0)
+ goto cleanup;
+
+ ret = dev->pcie_cap_pos != 0;
+
+ cleanup:
+ virPCIDeviceConfigClose(dev, fd);
+ return ret;
+}
+
+int
+virPCIDeviceGetLinkCap(virPCIDevicePtr dev,
+ int *port,
+ unsigned int *speed,
+ unsigned int *width)
+{
+ uint32_t t;
+ int fd;
+ int ret = -1;
+
+ if ((fd = virPCIDeviceConfigOpen(dev, true) < 0))
+ return ret;
+
+ if (virPCIDeviceInit(dev, fd) < 0)
+ goto cleanup;
+
+ t = virPCIDeviceRead32(dev, fd, dev->pcie_cap_pos + PCI_EXP_LNKCAP);
+
+ *port = t >> 0x18;
Took me second to figure out you just want the highest byte. s/0x18/24/ would make that much more clear, at least for me.
+ *speed = t & PCI_EXP_LNKCAP_SPEED; + *width = (t & PCI_EXP_LNKCAP_WIDTH) >> 4;
And if I wanted to be *really* digging deep into this and nitpicking a lot, I'd say you can do: port = Read8 speed = Read16 & SPEED width = Read8
+ ret = 0;
+
+ cleanup:
+ virPCIDeviceConfigClose(dev, fd);
+ return ret;
+}
+
+int
+virPCIDeviceGetLinkSta(virPCIDevicePtr dev,
+ unsigned int *speed,
+ unsigned int *width)
+{
+ uint32_t t;
+ int fd;
+ int ret = -1;
+
+ if ((fd = virPCIDeviceConfigOpen(dev, true) < 0))
+ return ret;
+
+ if (virPCIDeviceInit(dev, fd) < 0)
+ goto cleanup;
+
+ t = virPCIDeviceRead32(dev, fd, dev->pcie_cap_pos + PCI_EXP_LNKSTA);
+
+ *speed = t & PCI_EXP_LNKSTA_SPEED;
+ *width = (t & PCI_EXP_LNKSTA_WIDTH) >> 4;
+ ret = 0;
+
+ cleanup:
+ virPCIDeviceConfigClose(dev, fd);
+ return ret;
+}
Both these functions do the same thing with 2 micro differences, either merge it to one, so you avoid double open, init, etc. Or create one that at least takes a parameter saying whether the caller wants CAPability or STAtus data. Other than that it looks good. Martin
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