x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 513 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinctrl-falcon.c b/drivers/pinctrl/pinctrl-falcon.c
new file mode 100644
index 000000000..100eed175
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-falcon.c
@@ -0,0 +1,513 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/drivers/pinctrl/pinmux-falcon.c
+ *  based on linux/drivers/pinctrl/pinmux-pxa910.c
+ *
+ *  Copyright (C) 2012 Thomas Langer <thomas.langer@lantiq.com>
+ *  Copyright (C) 2012 John Crispin <john@phrozen.org>
+ */
+
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+
+#include "pinctrl-lantiq.h"
+
+#include <lantiq_soc.h>
+
+/* Multiplexer Control Register */
+#define LTQ_PADC_MUX(x)         (x * 0x4)
+/* Pull Up Enable Register */
+#define LTQ_PADC_PUEN		0x80
+/* Pull Down Enable Register */
+#define LTQ_PADC_PDEN		0x84
+/* Slew Rate Control Register */
+#define LTQ_PADC_SRC		0x88
+/* Drive Current Control Register */
+#define LTQ_PADC_DCC		0x8C
+/* Pad Control Availability Register */
+#define LTQ_PADC_AVAIL          0xF0
+
+#define pad_r32(p, reg)		ltq_r32(p + reg)
+#define pad_w32(p, val, reg)	ltq_w32(val, p + reg)
+#define pad_w32_mask(c, clear, set, reg) \
+		pad_w32(c, (pad_r32(c, reg) & ~(clear)) | (set), reg)
+
+#define pad_getbit(m, r, p)	(!!(ltq_r32(m + r) & (1 << p)))
+
+#define PORTS			5
+#define PINS			32
+#define PORT(x)                 (x / PINS)
+#define PORT_PIN(x)             (x % PINS)
+
+#define MFP_FALCON(a, f0, f1, f2, f3)		\
+{						\
+	.name = #a,				\
+	.pin = a,				\
+	.func = {				\
+		FALCON_MUX_##f0,		\
+		FALCON_MUX_##f1,		\
+		FALCON_MUX_##f2,		\
+		FALCON_MUX_##f3,		\
+	},					\
+}
+
+#define GRP_MUX(a, m, p)	\
+{				\
+	.name = a,		\
+	.mux = FALCON_MUX_##m,	\
+	.pins = p,		\
+	.npins = ARRAY_SIZE(p),	\
+}
+
+enum falcon_mux {
+	FALCON_MUX_GPIO = 0,
+	FALCON_MUX_RST,
+	FALCON_MUX_NTR,
+	FALCON_MUX_PPS,
+	FALCON_MUX_MDIO,
+	FALCON_MUX_LED,
+	FALCON_MUX_SPI,
+	FALCON_MUX_ASC,
+	FALCON_MUX_I2C,
+	FALCON_MUX_HOSTIF,
+	FALCON_MUX_SLIC,
+	FALCON_MUX_JTAG,
+	FALCON_MUX_PCM,
+	FALCON_MUX_MII,
+	FALCON_MUX_PHY,
+	FALCON_MUX_NONE = 0xffff,
+};
+
+static struct pinctrl_pin_desc falcon_pads[PORTS * PINS];
+static int pad_count[PORTS];
+
+static void lantiq_load_pin_desc(struct pinctrl_pin_desc *d, int bank, int len)
+{
+	int base = bank * PINS;
+	int i;
+
+	for (i = 0; i < len; i++) {
+		d[i].number = base + i;
+		d[i].name = kasprintf(GFP_KERNEL, "io%d", base + i);
+	}
+	pad_count[bank] = len;
+}
+
+static struct ltq_mfp_pin falcon_mfp[] = {
+	/*	pin		f0	f1	f2	f3 */
+	MFP_FALCON(GPIO0,	RST,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO1,	GPIO,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO2,	GPIO,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO3,	GPIO,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO4,	NTR,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO5,	NTR,	GPIO,   PPS,    NONE),
+	MFP_FALCON(GPIO6,	RST,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO7,	MDIO,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO8,	MDIO,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO9,	LED,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO10,	LED,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO11,	LED,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO12,	LED,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO13,	LED,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO14,	LED,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO32,	ASC,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO33,	ASC,	GPIO,   NONE,   NONE),
+	MFP_FALCON(GPIO34,	SPI,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO35,	SPI,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO36,	SPI,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO37,	SPI,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO38,	SPI,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO39,	I2C,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO40,	I2C,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO41,	HOSTIF,	GPIO,	HOSTIF,	JTAG),
+	MFP_FALCON(GPIO42,	HOSTIF,	GPIO,	HOSTIF,	NONE),
+	MFP_FALCON(GPIO43,	SLIC,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO44,	SLIC,	GPIO,	PCM,	ASC),
+	MFP_FALCON(GPIO45,	SLIC,	GPIO,	PCM,	ASC),
+	MFP_FALCON(GPIO64,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO65,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO66,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO67,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO68,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO69,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO70,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO71,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO72,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO73,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO74,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO75,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO76,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO77,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO78,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO79,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO80,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO81,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO82,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO83,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO84,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO85,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO86,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO87,	MII,	GPIO,	NONE,	NONE),
+	MFP_FALCON(GPIO88,	PHY,	GPIO,	NONE,	NONE),
+};
+
+static const unsigned pins_por[] = {GPIO0};
+static const unsigned pins_ntr[] = {GPIO4};
+static const unsigned pins_ntr8k[] = {GPIO5};
+static const unsigned pins_pps[] = {GPIO5};
+static const unsigned pins_hrst[] = {GPIO6};
+static const unsigned pins_mdio[] = {GPIO7, GPIO8};
+static const unsigned pins_bled[] = {GPIO9, GPIO10, GPIO11,
+					GPIO12, GPIO13, GPIO14};
+static const unsigned pins_asc0[] = {GPIO32, GPIO33};
+static const unsigned pins_spi[] = {GPIO34, GPIO35, GPIO36};
+static const unsigned pins_spi_cs0[] = {GPIO37};
+static const unsigned pins_spi_cs1[] = {GPIO38};
+static const unsigned pins_i2c[] = {GPIO39, GPIO40};
+static const unsigned pins_jtag[] = {GPIO41};
+static const unsigned pins_slic[] = {GPIO43, GPIO44, GPIO45};
+static const unsigned pins_pcm[] = {GPIO44, GPIO45};
+static const unsigned pins_asc1[] = {GPIO44, GPIO45};
+
+static struct ltq_pin_group falcon_grps[] = {
+	GRP_MUX("por", RST, pins_por),
+	GRP_MUX("ntr", NTR, pins_ntr),
+	GRP_MUX("ntr8k", NTR, pins_ntr8k),
+	GRP_MUX("pps", PPS, pins_pps),
+	GRP_MUX("hrst", RST, pins_hrst),
+	GRP_MUX("mdio", MDIO, pins_mdio),
+	GRP_MUX("bootled", LED, pins_bled),
+	GRP_MUX("asc0", ASC, pins_asc0),
+	GRP_MUX("spi", SPI, pins_spi),
+	GRP_MUX("spi cs0", SPI, pins_spi_cs0),
+	GRP_MUX("spi cs1", SPI, pins_spi_cs1),
+	GRP_MUX("i2c", I2C, pins_i2c),
+	GRP_MUX("jtag", JTAG, pins_jtag),
+	GRP_MUX("slic", SLIC, pins_slic),
+	GRP_MUX("pcm", PCM, pins_pcm),
+	GRP_MUX("asc1", ASC, pins_asc1),
+};
+
+static const char * const ltq_rst_grps[] = {"por", "hrst"};
+static const char * const ltq_ntr_grps[] = {"ntr", "ntr8k", "pps"};
+static const char * const ltq_mdio_grps[] = {"mdio"};
+static const char * const ltq_bled_grps[] = {"bootled"};
+static const char * const ltq_asc_grps[] = {"asc0", "asc1"};
+static const char * const ltq_spi_grps[] = {"spi", "spi cs0", "spi cs1"};
+static const char * const ltq_i2c_grps[] = {"i2c"};
+static const char * const ltq_jtag_grps[] = {"jtag"};
+static const char * const ltq_slic_grps[] = {"slic"};
+static const char * const ltq_pcm_grps[] = {"pcm"};
+
+static struct ltq_pmx_func falcon_funcs[] = {
+	{"rst",		ARRAY_AND_SIZE(ltq_rst_grps)},
+	{"ntr",		ARRAY_AND_SIZE(ltq_ntr_grps)},
+	{"mdio",	ARRAY_AND_SIZE(ltq_mdio_grps)},
+	{"led",		ARRAY_AND_SIZE(ltq_bled_grps)},
+	{"asc",		ARRAY_AND_SIZE(ltq_asc_grps)},
+	{"spi",		ARRAY_AND_SIZE(ltq_spi_grps)},
+	{"i2c",		ARRAY_AND_SIZE(ltq_i2c_grps)},
+	{"jtag",	ARRAY_AND_SIZE(ltq_jtag_grps)},
+	{"slic",	ARRAY_AND_SIZE(ltq_slic_grps)},
+	{"pcm",		ARRAY_AND_SIZE(ltq_pcm_grps)},
+};
+
+
+
+
+/* ---------  pinconf related code --------- */
+static int falcon_pinconf_group_get(struct pinctrl_dev *pctrldev,
+				unsigned group, unsigned long *config)
+{
+	return -ENOTSUPP;
+}
+
+static int falcon_pinconf_group_set(struct pinctrl_dev *pctrldev,
+				unsigned group, unsigned long *configs,
+				unsigned num_configs)
+{
+	return -ENOTSUPP;
+}
+
+static int falcon_pinconf_get(struct pinctrl_dev *pctrldev,
+				unsigned pin, unsigned long *config)
+{
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
+	enum ltq_pinconf_param param = LTQ_PINCONF_UNPACK_PARAM(*config);
+	void __iomem *mem = info->membase[PORT(pin)];
+
+	switch (param) {
+	case LTQ_PINCONF_PARAM_DRIVE_CURRENT:
+		*config = LTQ_PINCONF_PACK(param,
+			!!pad_getbit(mem, LTQ_PADC_DCC, PORT_PIN(pin)));
+		break;
+
+	case LTQ_PINCONF_PARAM_SLEW_RATE:
+		*config = LTQ_PINCONF_PACK(param,
+			!!pad_getbit(mem, LTQ_PADC_SRC, PORT_PIN(pin)));
+		break;
+
+	case LTQ_PINCONF_PARAM_PULL:
+		if (pad_getbit(mem, LTQ_PADC_PDEN, PORT_PIN(pin)))
+			*config = LTQ_PINCONF_PACK(param, 1);
+		else if (pad_getbit(mem, LTQ_PADC_PUEN, PORT_PIN(pin)))
+			*config = LTQ_PINCONF_PACK(param, 2);
+		else
+			*config = LTQ_PINCONF_PACK(param, 0);
+
+		break;
+
+	default:
+		return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+static int falcon_pinconf_set(struct pinctrl_dev *pctrldev,
+			unsigned pin, unsigned long *configs,
+			unsigned num_configs)
+{
+	enum ltq_pinconf_param param;
+	int arg;
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
+	void __iomem *mem = info->membase[PORT(pin)];
+	u32 reg;
+	int i;
+
+	for (i = 0; i < num_configs; i++) {
+		param = LTQ_PINCONF_UNPACK_PARAM(configs[i]);
+		arg = LTQ_PINCONF_UNPACK_ARG(configs[i]);
+
+		switch (param) {
+		case LTQ_PINCONF_PARAM_DRIVE_CURRENT:
+			reg = LTQ_PADC_DCC;
+			break;
+
+		case LTQ_PINCONF_PARAM_SLEW_RATE:
+			reg = LTQ_PADC_SRC;
+			break;
+
+		case LTQ_PINCONF_PARAM_PULL:
+			if (arg == 1)
+				reg = LTQ_PADC_PDEN;
+			else
+				reg = LTQ_PADC_PUEN;
+			break;
+
+		default:
+			pr_err("%s: Invalid config param %04x\n",
+			pinctrl_dev_get_name(pctrldev), param);
+			return -ENOTSUPP;
+		}
+
+		pad_w32(mem, BIT(PORT_PIN(pin)), reg);
+		if (!(pad_r32(mem, reg) & BIT(PORT_PIN(pin))))
+			return -ENOTSUPP;
+	} /* for each config */
+
+	return 0;
+}
+
+static void falcon_pinconf_dbg_show(struct pinctrl_dev *pctrldev,
+			struct seq_file *s, unsigned offset)
+{
+	unsigned long config;
+	struct pin_desc *desc;
+
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
+	int port = PORT(offset);
+
+	seq_printf(s, " (port %d) mux %d -- ", port,
+		pad_r32(info->membase[port], LTQ_PADC_MUX(PORT_PIN(offset))));
+
+	config = LTQ_PINCONF_PACK(LTQ_PINCONF_PARAM_PULL, 0);
+	if (!falcon_pinconf_get(pctrldev, offset, &config))
+		seq_printf(s, "pull %d ",
+			(int)LTQ_PINCONF_UNPACK_ARG(config));
+
+	config = LTQ_PINCONF_PACK(LTQ_PINCONF_PARAM_DRIVE_CURRENT, 0);
+	if (!falcon_pinconf_get(pctrldev, offset, &config))
+		seq_printf(s, "drive-current %d ",
+			(int)LTQ_PINCONF_UNPACK_ARG(config));
+
+	config = LTQ_PINCONF_PACK(LTQ_PINCONF_PARAM_SLEW_RATE, 0);
+	if (!falcon_pinconf_get(pctrldev, offset, &config))
+		seq_printf(s, "slew-rate %d ",
+			(int)LTQ_PINCONF_UNPACK_ARG(config));
+
+	desc = pin_desc_get(pctrldev, offset);
+	if (desc) {
+		if (desc->gpio_owner)
+			seq_printf(s, " owner: %s", desc->gpio_owner);
+	} else {
+		seq_printf(s, " not registered");
+	}
+}
+
+static void falcon_pinconf_group_dbg_show(struct pinctrl_dev *pctrldev,
+			struct seq_file *s, unsigned selector)
+{
+}
+
+static const struct pinconf_ops falcon_pinconf_ops = {
+	.pin_config_get			= falcon_pinconf_get,
+	.pin_config_set			= falcon_pinconf_set,
+	.pin_config_group_get		= falcon_pinconf_group_get,
+	.pin_config_group_set		= falcon_pinconf_group_set,
+	.pin_config_dbg_show		= falcon_pinconf_dbg_show,
+	.pin_config_group_dbg_show	= falcon_pinconf_group_dbg_show,
+};
+
+static struct pinctrl_desc falcon_pctrl_desc = {
+	.owner		= THIS_MODULE,
+	.pins		= falcon_pads,
+	.confops	= &falcon_pinconf_ops,
+};
+
+static inline int falcon_mux_apply(struct pinctrl_dev *pctrldev,
+			int mfp, int mux)
+{
+	struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
+	int port = PORT(info->mfp[mfp].pin);
+
+	if ((port >= PORTS) || (!info->membase[port]))
+		return -ENODEV;
+
+	pad_w32(info->membase[port], mux,
+		LTQ_PADC_MUX(PORT_PIN(info->mfp[mfp].pin)));
+	return 0;
+}
+
+static const struct ltq_cfg_param falcon_cfg_params[] = {
+	{"lantiq,pull",			LTQ_PINCONF_PARAM_PULL},
+	{"lantiq,drive-current",	LTQ_PINCONF_PARAM_DRIVE_CURRENT},
+	{"lantiq,slew-rate",		LTQ_PINCONF_PARAM_SLEW_RATE},
+};
+
+static struct ltq_pinmux_info falcon_info = {
+	.desc		= &falcon_pctrl_desc,
+	.apply_mux	= falcon_mux_apply,
+	.params		= falcon_cfg_params,
+	.num_params	= ARRAY_SIZE(falcon_cfg_params),
+};
+
+
+
+
+/* --------- register the pinctrl layer --------- */
+
+int pinctrl_falcon_get_range_size(int id)
+{
+	u32 avail;
+
+	if ((id >= PORTS) || (!falcon_info.membase[id]))
+		return -EINVAL;
+
+	avail = pad_r32(falcon_info.membase[id], LTQ_PADC_AVAIL);
+
+	return fls(avail);
+}
+
+void pinctrl_falcon_add_gpio_range(struct pinctrl_gpio_range *range)
+{
+	pinctrl_add_gpio_range(falcon_info.pctrl, range);
+}
+
+static int pinctrl_falcon_probe(struct platform_device *pdev)
+{
+	struct device_node *np;
+	int pad_count = 0;
+	int ret = 0;
+
+	/* load and remap the pad resources of the different banks */
+	for_each_compatible_node(np, NULL, "lantiq,pad-falcon") {
+		const __be32 *bank = of_get_property(np, "lantiq,bank", NULL);
+		struct resource res;
+		struct platform_device *ppdev;
+		u32 avail;
+		int pins;
+
+		if (!of_device_is_available(np))
+			continue;
+
+		if (!bank || *bank >= PORTS)
+			continue;
+		if (of_address_to_resource(np, 0, &res))
+			continue;
+
+		ppdev = of_find_device_by_node(np);
+		if (!ppdev) {
+			dev_err(&pdev->dev, "failed to find pad pdev\n");
+			continue;
+		}
+
+		falcon_info.clk[*bank] = clk_get(&ppdev->dev, NULL);
+		put_device(&ppdev->dev);
+		if (IS_ERR(falcon_info.clk[*bank])) {
+			dev_err(&ppdev->dev, "failed to get clock\n");
+			of_node_put(np);
+			return PTR_ERR(falcon_info.clk[*bank]);
+		}
+		falcon_info.membase[*bank] = devm_ioremap_resource(&pdev->dev,
+								   &res);
+		if (IS_ERR(falcon_info.membase[*bank])) {
+			of_node_put(np);
+			return PTR_ERR(falcon_info.membase[*bank]);
+		}
+
+		avail = pad_r32(falcon_info.membase[*bank],
+					LTQ_PADC_AVAIL);
+		pins = fls(avail);
+		lantiq_load_pin_desc(&falcon_pads[pad_count], *bank, pins);
+		pad_count += pins;
+		clk_enable(falcon_info.clk[*bank]);
+		dev_dbg(&pdev->dev, "found %s with %d pads\n",
+				res.name, pins);
+	}
+	dev_dbg(&pdev->dev, "found a total of %d pads\n", pad_count);
+	falcon_pctrl_desc.name	= dev_name(&pdev->dev);
+	falcon_pctrl_desc.npins	= pad_count;
+
+	falcon_info.mfp		= falcon_mfp;
+	falcon_info.num_mfp	= ARRAY_SIZE(falcon_mfp);
+	falcon_info.grps	= falcon_grps;
+	falcon_info.num_grps	= ARRAY_SIZE(falcon_grps);
+	falcon_info.funcs	= falcon_funcs;
+	falcon_info.num_funcs	= ARRAY_SIZE(falcon_funcs);
+
+	ret = ltq_pinctrl_register(pdev, &falcon_info);
+	if (!ret)
+		dev_info(&pdev->dev, "Init done\n");
+	return ret;
+}
+
+static const struct of_device_id falcon_match[] = {
+	{ .compatible = "lantiq,pinctrl-falcon" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, falcon_match);
+
+static struct platform_driver pinctrl_falcon_driver = {
+	.probe = pinctrl_falcon_probe,
+	.driver = {
+		.name = "pinctrl-falcon",
+		.of_match_table = falcon_match,
+	},
+};
+
+static int __init pinctrl_falcon_init(void)
+{
+	return platform_driver_register(&pinctrl_falcon_driver);
+}
+
+core_initcall_sync(pinctrl_falcon_init);