The user can specify a static enumeration profile via kernel command
line. A future commit will parse those options.
Signed-off-by: Jason Tang <jason.tang2@xxxxxxx>
---
drivers/pci/Makefile | 2 ++
drivers/pci/pci.c | 2 ++
drivers/pci/pci.h | 2 ++
drivers/pci/pci_static_enum.c | 54 +++++++++++++++++++++++++++++++++++++++++
4 files changed, 60 insertions(+)
create mode 100644 drivers/pci/pci_static_enum.c
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 73e4af4..3cacdfc 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -59,5 +59,7 @@ obj-$(CONFIG_OF) += of.o
ccflags-$(CONFIG_PCI_DEBUG) := -DDEBUG
+obj-$(CONFIG_PCI_STATIC_ENUMERATION) += pci_static_enum.o
+
# PCI host controller drivers
obj-y += host/
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 81f06e8..5d8c0e0 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4607,6 +4607,8 @@ static int __init pci_setup(char *str)
pcie_bus_config = PCIE_BUS_PEER2PEER;
} else if (!strncmp(str, "pcie_scan_all", 13)) {
pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
+ } else if (!strncmp(str, "enum=", 5)) {
+ pci_static_enum_set_opt(str + 5);
} else {
printk(KERN_ERR "PCI: Unknown option `%s'\n",
str);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 075bd9d..3282b51 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -322,6 +322,7 @@ static inline int pci_dev_specific_reset(struct pci_dev *dev, int probe)
#endif
#ifdef CONFIG_PCI_STATIC_ENUMERATION
+void pci_static_enum_set_opt(const char *str);
/**
* pci_bus_subordinate() - return the subordinate bus number assigned
* to @dev by the static enumeration profile, or 0 if not set
@@ -331,6 +332,7 @@ static inline unsigned char pci_bus_subordinate(struct pci_bus *bus)
return bus->subordinate;
}
#else
+static inline void pci_static_enum_set_opt(const char *str) { return; }
static inline unsigned char pci_bus_subordinate(struct pci_bus *bus)
{
return 0;
diff --git a/drivers/pci/pci_static_enum.c b/drivers/pci/pci_static_enum.c
new file mode 100644
index 0000000..a28bd33
--- /dev/null
+++ b/drivers/pci/pci_static_enum.c
@@ -0,0 +1,54 @@
+/*
+ * PCI static enumeration
+ *
+ * Copyright (C) 2015 Northrop Grumman Corporation. All rights reserved.
+ * Jason Tang <jason.tang2@xxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+
+#include <asm/setup.h>
+
+#define PREFIX "PCI ENUM: "
+
+static DEFINE_SPINLOCK(static_enum_lock);
+
+#define PCI_STATIC_ENUM_PARAM_SIZE COMMAND_LINE_SIZE
+static char pci_static_enum_param[PCI_STATIC_ENUM_PARAM_SIZE] = { 0 };
+
+/**
+ * pci_static_enum_set_opt() - set/append the PCI static enumeration
+ * options as given by kernel command line
+ * @str: static enumeration options
+ */
+void __init pci_static_enum_set_opt(const char *str)
+{
+ /*
+ So why store the options and parse later? The reason is
+ because the static enumerator is stateful, in that it keeps
+ track of which devices it has overridden. It cannot call
+ kmalloc() yet because memory allocation has not been set up
+ yet when this function is called. The next best thing is
+ store the options in a statically-allocated string, and then
+ parse it later, when kmalloc() is legal.
+ */
+ size_t cur, len;
+
+ spin_lock(&static_enum_lock);
+ cur = strlen(pci_static_enum_param);
+ len = strlen(str);
+ /* use ';' to separate each option */
+ if (cur > 0 && cur < PCI_STATIC_ENUM_PARAM_SIZE - 1)
+ pci_static_enum_param[cur++] = ';';
+ if (len > PCI_STATIC_ENUM_PARAM_SIZE - 1 - cur)
+ len = PCI_STATIC_ENUM_PARAM_SIZE - 1 - cur;
+ strncat(pci_static_enum_param + cur, str, len);
+ spin_unlock(&static_enum_lock);
+}
--
1.7.9.5
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