xen-pcifront: Xen PCI frontend driver.

This is a port of the 2.6.18 Xen PCI front driver with fixes
to make it build under 2.6.34 and later (for the full list of
changes: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git
historic/xen-pcifront-0.1). It also includes the fixes
to make it work properly.

[v2: Updated Kconfig, removed crud, added Reviewed-by]
[v3: Added 'static', fixed grant table leak, redid Kconfig]
[v4: Added one more 'static' and removed comments]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Jan Beulich <JBeulich@novell.com>

drivers/pci/Kconfig

@@ -40,6 +40,27 @@ config PCI_STUB
 
 	  When in doubt, say N.
 
+config XEN_PCIDEV_FRONTEND
+        tristate "Xen PCI Frontend"
+        depends on PCI && X86 && XEN
+        select HOTPLUG
+        select PCI_XEN
+        default y
+        help
+          The PCI device frontend driver allows the kernel to import arbitrary
+          PCI devices from a PCI backend to support PCI driver domains.
+
+config XEN_PCIDEV_FE_DEBUG
+        bool "Xen PCI Frontend debugging"
+        depends on XEN_PCIDEV_FRONTEND && PCI_DEBUG
+	help
+	  Say Y here if you want the Xen PCI frontend to produce a bunch of debug
+	  messages to the system log.  Select this if you are having a
+	  problem with Xen PCI frontend support and want to see more of what is
+	  going on.
+
+	  When in doubt, say N.
+
 config HT_IRQ
 	bool "Interrupts on hypertransport devices"
 	default y

drivers/pci/Makefile

@@ -65,6 +65,8 @@ obj-$(CONFIG_PCI_SYSCALL) += syscall.o
 
 obj-$(CONFIG_PCI_STUB) += pci-stub.o
 
+obj-$(CONFIG_XEN_PCIDEV_FRONTEND) += xen-pcifront.o
+
 ifeq ($(CONFIG_PCI_DEBUG),y)
 EXTRA_CFLAGS += -DDEBUG
 endif

include/xen/interface/io/pciif.h

+/*
+ * PCI Backend/Frontend Common Data Structures & Macros
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
+ */
+#ifndef __XEN_PCI_COMMON_H__
+#define __XEN_PCI_COMMON_H__
+
+/* Be sure to bump this number if you change this file */
+#define XEN_PCI_MAGIC "7"
+
+/* xen_pci_sharedinfo flags */
+#define	_XEN_PCIF_active		(0)
+#define	XEN_PCIF_active			(1<<_XEN_PCIF_active)
+#define	_XEN_PCIB_AERHANDLER		(1)
+#define	XEN_PCIB_AERHANDLER		(1<<_XEN_PCIB_AERHANDLER)
+#define	_XEN_PCIB_active		(2)
+#define	XEN_PCIB_active			(1<<_XEN_PCIB_active)
+
+/* xen_pci_op commands */
+#define	XEN_PCI_OP_conf_read		(0)
+#define	XEN_PCI_OP_conf_write		(1)
+#define	XEN_PCI_OP_enable_msi		(2)
+#define	XEN_PCI_OP_disable_msi		(3)
+#define	XEN_PCI_OP_enable_msix		(4)
+#define	XEN_PCI_OP_disable_msix		(5)
+#define	XEN_PCI_OP_aer_detected		(6)
+#define	XEN_PCI_OP_aer_resume		(7)
+#define	XEN_PCI_OP_aer_mmio		(8)
+#define	XEN_PCI_OP_aer_slotreset	(9)
+
+/* xen_pci_op error numbers */
+#define	XEN_PCI_ERR_success		(0)
+#define	XEN_PCI_ERR_dev_not_found	(-1)
+#define	XEN_PCI_ERR_invalid_offset	(-2)
+#define	XEN_PCI_ERR_access_denied	(-3)
+#define	XEN_PCI_ERR_not_implemented	(-4)
+/* XEN_PCI_ERR_op_failed - backend failed to complete the operation */
+#define XEN_PCI_ERR_op_failed		(-5)
+
+/*
+ * it should be PAGE_SIZE-sizeof(struct xen_pci_op))/sizeof(struct msix_entry))
+ * Should not exceed 128
+ */
+#define SH_INFO_MAX_VEC			128
+
+struct xen_msix_entry {
+	uint16_t vector;
+	uint16_t entry;
+};
+struct xen_pci_op {
+	/* IN: what action to perform: XEN_PCI_OP_* */
+	uint32_t cmd;
+
+	/* OUT: will contain an error number (if any) from errno.h */
+	int32_t err;
+
+	/* IN: which device to touch */
+	uint32_t domain; /* PCI Domain/Segment */
+	uint32_t bus;
+	uint32_t devfn;
+
+	/* IN: which configuration registers to touch */
+	int32_t offset;
+	int32_t size;
+
+	/* IN/OUT: Contains the result after a READ or the value to WRITE */
+	uint32_t value;
+	/* IN: Contains extra infor for this operation */
+	uint32_t info;
+	/*IN:  param for msi-x */
+	struct xen_msix_entry msix_entries[SH_INFO_MAX_VEC];
+};
+
+/*used for pcie aer handling*/
+struct xen_pcie_aer_op {
+	/* IN: what action to perform: XEN_PCI_OP_* */
+	uint32_t cmd;
+	/*IN/OUT: return aer_op result or carry error_detected state as input*/
+	int32_t err;
+
+	/* IN: which device to touch */
+	uint32_t domain; /* PCI Domain/Segment*/
+	uint32_t bus;
+	uint32_t devfn;
+};
+struct xen_pci_sharedinfo {
+	/* flags - XEN_PCIF_* */
+	uint32_t flags;
+	struct xen_pci_op op;
+	struct xen_pcie_aer_op aer_op;
+};
+
+#endif /* __XEN_PCI_COMMON_H__ */