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Message-ID: <5265C0CD.5030705@linux.intel.com>
Date: Mon, 21 Oct 2013 17:03:25 -0700
From: Bin Gao <bin.gao@...ux.intel.com>
To: Arnd Bergmann <arnd@...db.de>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
linux-kernel@...r.kernel.org
Subject: [PATCH 2/4] drivers/misc: add rawio pci driver
With pci rawio driver, you can read/write any pci config space register
by debug fs interface. This driver is based on the rawio framework.
Signed-off-by: Bin Gao <bin.gao@...el.com>
---
drivers/misc/rawio/Kconfig | 15 +++
drivers/misc/rawio/Makefile | 1 +
drivers/misc/rawio/rawio_pci.c | 235
+++++++++++++++++++++++++++++++++++++++++
3 files changed, 251 insertions(+)
create mode 100644 drivers/misc/rawio/rawio_pci.c
diff --git a/drivers/misc/rawio/Kconfig b/drivers/misc/rawio/Kconfig
index fd4272e..47be40a 100644
--- a/drivers/misc/rawio/Kconfig
+++ b/drivers/misc/rawio/Kconfig
@@ -19,3 +19,18 @@ menuconfig RAWIO
be called rawio.
If you are not sure, say N here.
+
+if RAWIO
+
+config RAWIO_PCI
+ tristate "rawio PCI driver"
+ depends on RAWIO && PCI
+ default no
+ help
+ This option enables the rawio PCI driver.
+ With this driver, you can read or write any PCI device's
+ configuration space via debugfs.
+ To compile this driver as a module, choose M: the module will
+ be called rawio_pci.
+
+endif # RAWIO
diff --git a/drivers/misc/rawio/Makefile b/drivers/misc/rawio/Makefile
index c21453c..0933ca6 100644
--- a/drivers/misc/rawio/Makefile
+++ b/drivers/misc/rawio/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_RAWIO) += rawio.o
+obj-$(CONFIG_RAWIO_PCI) += rawio_pci.o
diff --git a/drivers/misc/rawio/rawio_pci.c b/drivers/misc/rawio/rawio_pci.c
new file mode 100644
index 0000000..052ad1b
--- /dev/null
+++ b/drivers/misc/rawio/rawio_pci.c
@@ -0,0 +1,235 @@
+/*
+ * rawio_pci.c - a driver to read/write pci configuration space
registers based
+ * on the rawio framework.
+ *
+ * 1: byte, 2: word, 4: dword
+ *
+ * read pci config space registers
+ * echo "r[1|2|4] pci <domain> <bus> <dev> <func> <reg> [<len>]" >
+ * /sys/kernel/debug/rawio_cmd
+ * cat /sys/kernel/debug/rawio_output
+ * e.g. echo "r1 pci 0 0 3 0 8 12" > /sys/kernel/debug/rawio_cmd
+ * cat /sys/kernel/debug/rawio_output
+ *
+ * write a pci config space register:
+ * echo "w[1|2|4] pci <domain> <bus> <dev> <func> <reg> <val>" >
+ * /sys/kernel/debug/rawio_output
+ * cat /sys/kernel/debug/rawio_output
+ * e.g. echo "w pci 0 0 0x11 2 0x10 0xffffffff" >
/sys/kernel/debug/rawio_cmd
+ * cat /sys/kernel/debug/rawio_output
+ *
+ *
+ * Copyright (c) 2013 Bin Gao <bin.gao@...el.com>
+ *
+ * This file is released under the GPLv2
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/pm_runtime.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/rawio.h>
+
+static int pci_prepare(int pci_domain, unsigned int pci_bus,
+ u8 pci_dev, u8 pci_func, enum width width,
+ u16 pci_reg, u16 len, struct pci_dev **ppdev)
+{
+ struct pci_dev *pdev;
+ int ret;
+
+ if (((width == WIDTH_2) && (pci_reg & 0x1)) ||
+ ((width == WIDTH_4) && (pci_reg & 0x3))) {
+ rawio_err("register address requires 2 bytes aligned for 16 bit
access, and 4 bytes aligned for 32 bit access\n");
+ return -EINVAL;
+ }
+
+ pdev = pci_get_domain_bus_and_slot(pci_domain, pci_bus,
+ PCI_DEVFN(pci_dev, pci_func));
+ if (!pdev) {
+ rawio_err("pci device %04x:%02x:%02x.%01x doesn't exist\n",
+ pci_domain, pci_bus, pci_dev, pci_func);
+ return -ENODEV;
+ }
+
+ if (((pci_reg >= 0x100) && !pci_is_pcie(pdev)) ||
+ (pci_reg >= 0x1000)) {
+ rawio_err("register address is out of range\n");
+ return -EINVAL;
+ }
+
+ if ((((pci_reg + len * width) >= 0x100) && !pci_is_pcie(pdev)) ||
+ ((pci_reg + len * width) >= 0x1000)) {
+ rawio_err("register address is out of range\n");
+ return -EINVAL;
+ }
+
+ ret = pm_runtime_get_sync(&pdev->dev);
+ if ((ret >= 0) || (ret == -EACCES))
+ goto out;
+
+ rawio_err("can't put pci device %04x:%02x:%02x.%01xinto running state,
pm_runtime_get_sync() returned %d\n",
+ pci_domain, pci_bus, pci_dev, pci_func, ret);
+ return -EBUSY;
+
+out:
+ *ppdev = pdev;
+ return 0;
+}
+
+static void pci_finish(struct pci_dev *pdev)
+{
+ pm_runtime_put_sync(&pdev->dev);
+}
+
+static int rawio_pci_read(struct rawio_driver *driver, int width,
+ u64 *input, u8 *postfix, int input_num,
+ void **output, int *output_num)
+{
+ int i, ret, pci_domain;
+ struct pci_dev *pdev;
+ unsigned int pci_bus;
+ u8 pci_dev, pci_func;
+ u16 pci_reg, len;
+ void *buf;
+
+ pci_domain = (int)input[0];
+ pci_bus = (unsigned int)input[1];
+ pci_dev = (u8)input[2];
+ pci_func = (u8)input[3];
+ pci_reg = (u16)input[4];
+ len = 1;
+ if (input_num == 6)
+ len = (u16)input[5];
+
+ ret = pci_prepare(pci_domain, pci_bus, pci_dev, pci_func,
+ width, pci_reg, len, &pdev);
+ if (ret)
+ return ret;
+
+ buf = kzalloc(width * len, GFP_KERNEL);
+ if (buf == NULL) {
+ rawio_err("can't alloc memory\n");
+ pci_finish(pdev);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < len; i++) {
+ switch (width) {
+ case WIDTH_1:
+ pci_read_config_byte(pdev, pci_reg + i, (u8 *)buf + i);
+ break;
+ case WIDTH_2:
+ pci_read_config_word(pdev, pci_reg + i * 2,
+ (u16 *)buf + i);
+ break;
+ case WIDTH_4:
+ pci_read_config_dword(pdev, pci_reg + i * 4,
+ (u32 *)buf + i);
+ break;
+ default:
+ break;
+ }
+ }
+
+ pci_finish(pdev);
+ *output = buf;
+ *output_num = len;
+ return 0;
+}
+
+static int rawio_pci_write(struct rawio_driver *driver, int width,
+ u64 *input, u8 *postfix, int input_num)
+{
+ int ret, pci_domain;
+ struct pci_dev *pdev;
+ unsigned int pci_bus;
+ u8 pci_dev, pci_func;
+ u16 pci_reg;
+ u32 value;
+
+ pci_domain = (int)input[0];
+ pci_bus = (unsigned int)input[1];
+ pci_dev = (u8)input[2];
+ pci_func = (u8)input[3];
+ pci_reg = (u16)input[4];
+ value = (u32) input[5];
+
+ ret = pci_prepare(pci_domain, pci_bus, pci_dev, pci_func,
+ width, pci_reg, 1, &pdev);
+ if (ret)
+ return ret;
+
+ switch (width) {
+ case WIDTH_1:
+ pci_write_config_byte(pdev, pci_reg, (u8) value);
+ break;
+ case WIDTH_2:
+ pci_write_config_word(pdev, pci_reg, (u16) value);
+ break;
+ case WIDTH_4:
+ pci_write_config_dword(pdev, pci_reg, value);
+ break;
+ default:
+ break;
+ }
+
+ pci_finish(pdev);
+ return 0;
+}
+
+static struct rawio_ops rawio_pci_ops = {
+ rawio_pci_read,
+ NULL,
+ rawio_pci_write,
+};
+
+static struct rawio_driver rawio_pci = {
+ {NULL, NULL},
+ "pci",
+
+ /* read */
+ 6, /* max args */
+ {TYPE_S32, TYPE_U32, TYPE_U8, TYPE_U8, TYPE_U16, TYPE_S16}, /* types */
+ 5, /* min args */
+
+ { 0, }, /* postfix */
+
+ /* write */
+ 6, /* max args */
+ {TYPE_S32, TYPE_U32, TYPE_U8, TYPE_U8, TYPE_U16, TYPE_U32}, /* types */
+ 6, /* min args */
+ { 0, },
+
+ 4, /* index of address arg */
+
+ WIDTH_1 | WIDTH_2 | WIDTH_4, /* supported width */
+ WIDTH_4, /* default width */
+ "r[1|2|4] pci <domain> <bus> <dev> <func> <reg> [<len>]\n"
+ "w[1|2|4] pci <domain> <bus> <dev> <func> <reg> <val>\n",
+ &rawio_pci_ops,
+ NULL
+};
+
+static int __init rawio_pci_init(void)
+{
+ if (rawio_register_driver(&rawio_pci))
+ return -ENODEV;
+
+ return 0;
+}
+module_init(rawio_pci_init);
+
+static void __exit rawio_pci_exit(void)
+{
+ rawio_unregister_driver(&rawio_pci);
+}
+module_exit(rawio_pci_exit);
+
+MODULE_DESCRIPTION("Rawio PCI driver");
+MODULE_VERSION("1.0");
+MODULE_AUTHOR("Bin Gao <bin.gao@...el.com>");
+MODULE_LICENSE("GPL v2");
--
1.8.1.2
--
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