[PATCH v3 0/6] Krait L1/L2 EDAC driver

[PATCH v3 0/6] Krait L1/L2 EDAC driver

[Stephen Boyd]

This patchset adds support for the Krait L1/L2 cache error detection
hardware. The first patch fixes a generic framework bug. The next
two patches lay the groundwork for this driver to be added by 
exporting percpu irq functions as well as adding the Krait l2 indirection
register code. The next two patches add the driver and the binding and 
the final patch hooks it all up by adding the device tree node.

I'm not sure which tree this is supposed to go through. Ideally we could
send the first 3 plus the 5th one through an edac tree. The final dts changes
could go through arm-soc via davidb's tree and the Documentation patch could
go through the devicetree tree.

Changes since v2:
 * Picked up acks
 * s/an/a/ in DT binding

Changes since v1:
 * Moved binding into cpus node
 * Picked up acks on first two patches
 * Commented krait l2 accessor functions

Stephen Boyd (6):
  edac: Don't try to cancel workqueue when it's never setup
  genirq: export percpu irq functions for module usage
  ARM: Add Krait L2 accessor functions
  edac: Document Krait L1/L2 EDAC driver binding
  edac: Add support for Krait CPU cache error detection
  ARM: dts: msm: Add Krait CPU/L2 nodes

 Documentation/devicetree/bindings/arm/cpus.txt |  49 ++++
 arch/arm/boot/dts/qcom-msm8974.dtsi            |  37 +++
 arch/arm/common/Kconfig                        |   3 +
 arch/arm/common/Makefile                       |   1 +
 arch/arm/common/krait-l2-accessors.c           |  58 +++++
 arch/arm/include/asm/krait-l2-accessors.h      |  20 ++
 drivers/edac/Kconfig                           |   8 +
 drivers/edac/Makefile                          |   2 +
 drivers/edac/edac_device.c                     |   3 +
 drivers/edac/krait_edac.c                      | 346 +++++++++++++++++++++++++
 kernel/irq/manage.c                            |   2 +
 11 files changed, 529 insertions(+)
 create mode 100644 arch/arm/common/krait-l2-accessors.c
 create mode 100644 arch/arm/include/asm/krait-l2-accessors.h
 create mode 100644 drivers/edac/krait_edac.c

-- 
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[PATCH v3 1/6] edac: Don't try to cancel workqueue when it's never setup

[Stephen Boyd]

We only setup a workqueue for edac devices that use the polling
method. We still try to cancel the workqueue if an edac_device
uses the irq method though. This causes a warning from debug
objects when we remove an edac device:

WARNING: CPU: 0 PID: 56 at lib/debugobjects.c:260 debug_print_object+0x98/0xc0()
ODEBUG: assert_init not available (active state 0) object type: timer_list hint: stub_timer+0x0/0x28
Modules linked in: krait_edac(-)
CPU: 0 PID: 56 Comm: rmmod Not tainted 3.12.0-rc2-00035-g15292a0 #69
(unwind_backtrace+0x0/0x144)
(show_stack+0x20/0x24)
(dump_stack+0x74/0xb4)
(warn_slowpath_common+0x78/0x9c)
(warn_slowpath_fmt+0x40/0x48)
(debug_print_object+0x98/0xc0)
(debug_object_assert_init+0xdc/0xec)
(del_timer+0x24/0x7c)
(try_to_grab_pending+0xc0/0x1b0)
(cancel_delayed_work+0x2c/0xa0)
(edac_device_workq_teardown+0x1c/0x38)
(edac_device_del_device+0xb8/0xe4)
(krait_edac_remove+0x50/0x70 [krait_edac])
(platform_drv_remove+0x24/0x28)
(__device_release_driver+0x68/0xc0)
(driver_detach+0xc4/0xc8)
(bus_remove_driver+0xac/0x114)
(driver_unregister+0x38/0x58)
(platform_driver_unregister+0x1c/0x20)
(krait_edac_driver_exit+0x14/0x1c [krait_edac])
(SyS_delete_module+0x178/0x2b4)

Fix it by skipping the workqueue teardown for such devices.

Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
 drivers/edac/edac_device.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
index 211021d..203561b 100644
--- a/drivers/edac/edac_device.c
+++ b/drivers/edac/edac_device.c
@@ -437,6 +437,9 @@ void edac_device_workq_teardown(struct edac_device_ctl_info *edac_dev)
 {
 	int status;
 
+	if (!edac_dev->edac_check)
+		return;
+
 	status = cancel_delayed_work(&edac_dev->work);
 	if (status == 0) {
 		/* workq instance might be running, wait for it */
-- 
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hosted by The Linux Foundation

[PATCH v3 2/6] genirq: export percpu irq functions for module usage

[Stephen Boyd]

In the near future we're going to use these percpu irq functions
in the Krait CPU EDAC driver. Export them so that the EDAC driver
can be compiled as a module.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
 kernel/irq/manage.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 514bcfd..c6009d1 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1623,6 +1623,7 @@ void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
 	kfree(__free_percpu_irq(irq, dev_id));
 	chip_bus_sync_unlock(desc);
 }
+EXPORT_SYMBOL_GPL(free_percpu_irq);
 
 /**
  *	setup_percpu_irq - setup a per-cpu interrupt
@@ -1693,3 +1694,4 @@ int request_percpu_irq(unsigned int irq, irq_handler_t handler,
 
 	return retval;
 }
+EXPORT_SYMBOL_GPL(request_percpu_irq);
-- 
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hosted by The Linux Foundation

[PATCH v3 3/6] ARM: Add Krait L2 accessor functions

[Stephen Boyd]

Qualcomm's Krait CPUs have a handful of L2 cache controller
registers that live behind a cp15 based indirection register.
First you program the indirection register (l2cpselr) to point
the L2 'window' register (l2cpdr) at what you want to read/write.
Then you read/write the 'window' register to do what you want.
The l2cpselr register is not banked per-cpu so we must lock
around accesses to it to prevent other CPUs from re-pointing
l2cpdr underneath us.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
 arch/arm/common/Kconfig                   |  3 ++
 arch/arm/common/Makefile                  |  1 +
 arch/arm/common/krait-l2-accessors.c      | 58 +++++++++++++++++++++++++++++++
 arch/arm/include/asm/krait-l2-accessors.h | 20 +++++++++++
 4 files changed, 82 insertions(+)
 create mode 100644 arch/arm/common/krait-l2-accessors.c
 create mode 100644 arch/arm/include/asm/krait-l2-accessors.h

diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
index c3a4e9c..9da52dc 100644
--- a/arch/arm/common/Kconfig
+++ b/arch/arm/common/Kconfig
@@ -9,6 +9,9 @@ config DMABOUNCE
 	bool
 	select ZONE_DMA
 
+config KRAIT_L2_ACCESSORS
+	bool
+
 config SHARP_LOCOMO
 	bool
 
diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index 8c60f47..606131a 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_ICST)		+= icst.o
 obj-$(CONFIG_SA1111)		+= sa1111.o
 obj-$(CONFIG_PCI_HOST_VIA82C505) += via82c505.o
 obj-$(CONFIG_DMABOUNCE)		+= dmabounce.o
+obj-$(CONFIG_KRAIT_L2_ACCESSORS) += krait-l2-accessors.o
 obj-$(CONFIG_SHARP_LOCOMO)	+= locomo.o
 obj-$(CONFIG_SHARP_PARAM)	+= sharpsl_param.o
 obj-$(CONFIG_SHARP_SCOOP)	+= scoop.o
diff --git a/arch/arm/common/krait-l2-accessors.c b/arch/arm/common/krait-l2-accessors.c
new file mode 100644
index 0000000..f17c361
--- /dev/null
+++ b/arch/arm/common/krait-l2-accessors.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/export.h>
+
+#include <asm/barrier.h>
+#include <asm/krait-l2-accessors.h>
+
+static DEFINE_RAW_SPINLOCK(krait_l2_lock);
+
+void set_l2_indirect_reg(u32 addr, u32 val)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&krait_l2_lock, flags);
+	/*
+	 * Select the L2 window by poking l2cpselr, then write to the window
+	 * via l2cpdr.
+	 */
+	asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
+	isb();
+	asm volatile ("mcr p15, 3, %0, c15, c0, 7 @ l2cpdr" : : "r" (val));
+	isb();
+
+	raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
+}
+EXPORT_SYMBOL(set_l2_indirect_reg);
+
+u32 get_l2_indirect_reg(u32 addr)
+{
+	u32 val;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&krait_l2_lock, flags);
+	/*
+	 * Select the L2 window by poking l2cpselr, then read from the window
+	 * via l2cpdr.
+	 */
+	asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
+	isb();
+	asm volatile ("mrc p15, 3, %0, c15, c0, 7 @ l2cpdr" : "=r" (val));
+
+	raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
+
+	return val;
+}
+EXPORT_SYMBOL(get_l2_indirect_reg);
diff --git a/arch/arm/include/asm/krait-l2-accessors.h b/arch/arm/include/asm/krait-l2-accessors.h
new file mode 100644
index 0000000..d5305c4
--- /dev/null
+++ b/arch/arm/include/asm/krait-l2-accessors.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __ASMARM_KRAIT_L2_ACCESSORS_H
+#define __ASMARM_KRAIT_L2_ACCESSORS_H
+
+extern void set_l2_indirect_reg(u32 addr, u32 val);
+extern u32 get_l2_indirect_reg(u32 addr);
+
+#endif
-- 
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hosted by The Linux Foundation

[PATCH v3 4/6] edac: Document Krait L1/L2 EDAC driver binding

[Stephen Boyd]

The Krait L1/L2 error reporting device is made up of two
interrupts, one per-CPU interrupt for the L1 caches and one
interrupt for the L2 cache.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Kumar Gala <galak@codeaurora.org>
Cc: <devicetree@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
 Documentation/devicetree/bindings/arm/cpus.txt | 49 ++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt
index f32494d..c30d547 100644
--- a/Documentation/devicetree/bindings/arm/cpus.txt
+++ b/Documentation/devicetree/bindings/arm/cpus.txt
@@ -44,6 +44,8 @@ For the ARM architecture every CPU node must contain the following properties:
 		"marvell,mohawk"
 		"marvell,xsc3"
 		"marvell,xscale"
+		"qcom,scorpion"
+		"qcom,krait"
 
 Example:
 
@@ -75,3 +77,50 @@ Example:
 			reg = <0x101>;
 		};
 	};
+
+If the compatible string contains "qcom,krait" there shall be an interrupts
+property containing the L1/CPU error interrupt number. There shall also be a
+l2-cache node containing the following properties:
+
+ - compatible: Shall contain at least "cache"
+ - cache-level: Must be 2
+ - interrupts: Shall contain the L2 error interrupt
+
+Example:
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		interrupts = <1 9 0xf04>;
+		compatible = "qcom,krait";
+
+		cpu at 0 {
+			device_type = "cpu";
+			reg = <0>;
+			next-level-cache = <&L2>;
+		};
+
+		cpu at 1 {
+			device_type = "cpu";
+			reg = <1>;
+			next-level-cache = <&L2>;
+		};
+
+		cpu at 2 {
+			device_type = "cpu";
+			reg = <2>;
+			next-level-cache = <&L2>;
+		};
+
+		cpu at 3 {
+			device_type = "cpu";
+			reg = <3>;
+			next-level-cache = <&L2>;
+		};
+
+		L2: l2-cache {
+			compatible = "cache";
+			cache-level = <2>;
+			interrupts = <0 2 0x4>;
+		};
+	};
-- 
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hosted by The Linux Foundation

[PATCH v3 5/6] edac: Add support for Krait CPU cache error detection

[Stephen Boyd]

Add support for the Krait CPU cache error detection. This is a
simplified version of the code originally written by Stepan
Moskovchenko[1] ported to the EDAC device framework.

[1] https://www.codeaurora.org/cgit/quic/la/kernel/msm/tree/arch/arm/mach-msm/cache_erp.c?h=msm-3.4

Cc: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
 drivers/edac/Kconfig      |   8 ++
 drivers/edac/Makefile     |   2 +
 drivers/edac/krait_edac.c | 346 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 356 insertions(+)
 create mode 100644 drivers/edac/krait_edac.c

diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index 878f090..68f612d 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -368,4 +368,12 @@ config EDAC_OCTEON_PCI
 	  Support for error detection and correction on the
 	  Cavium Octeon family of SOCs.
 
+config EDAC_KRAIT_CACHE
+	tristate "Krait L1/L2 Cache"
+	depends on EDAC_MM_EDAC && ARCH_MSM
+	select KRAIT_L2_ACCESSORS
+	help
+	  Support for error detection and correction on the
+	  Krait L1/L2 cache controller.
+
 endif # EDAC
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index 4154ed6..b6ea505 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -64,3 +64,5 @@ obj-$(CONFIG_EDAC_OCTEON_PC)		+= octeon_edac-pc.o
 obj-$(CONFIG_EDAC_OCTEON_L2C)		+= octeon_edac-l2c.o
 obj-$(CONFIG_EDAC_OCTEON_LMC)		+= octeon_edac-lmc.o
 obj-$(CONFIG_EDAC_OCTEON_PCI)		+= octeon_edac-pci.o
+
+obj-$(CONFIG_EDAC_KRAIT_CACHE)		+= krait_edac.o
diff --git a/drivers/edac/krait_edac.c b/drivers/edac/krait_edac.c
new file mode 100644
index 0000000..b1d9f52
--- /dev/null
+++ b/drivers/edac/krait_edac.c
@@ -0,0 +1,346 @@
+/* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/cpu.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+
+#include <asm/krait-l2-accessors.h>
+
+#include "edac_core.h"
+
+#define CESR_DCTPE		BIT(0)
+#define CESR_DCDPE		BIT(1)
+#define CESR_ICTPE		BIT(2)
+#define CESR_ICDPE		BIT(3)
+#define CESR_DCTE		(BIT(4) | BIT(5))
+#define CESR_ICTE		(BIT(6) | BIT(7))
+#define CESR_TLBMH		BIT(16)
+#define CESR_I_MASK		0x000000cc
+/* Print a message for everything but TLB MH events */
+#define CESR_PRINT_MASK		0x000000ff
+
+#define L2ESR			0x204
+#define L2ESR_MPDCD		BIT(0)
+#define L2ESR_MPSLV		BIT(1)
+#define L2ESR_TSESB		BIT(2)
+#define L2ESR_TSEDB		BIT(3)
+#define L2ESR_DSESB		BIT(4)
+#define L2ESR_DSEDB		BIT(5)
+#define L2ESR_MSE		BIT(6)
+#define L2ESR_MPLDREXNOK	BIT(8)
+#define L2ESR_CPU_MASK		0xf
+#define L2ESR_CPU_SHIFT		16
+#define L2ESR_SP		BIT(20)
+
+#define L2ESYNR0		0x208
+#define L2ESYNR1		0x209
+#define L2EAR0			0x20c
+#define L2EAR1			0x20d
+
+struct krait_edac {
+	int l1_irq;
+	struct edac_device_ctl_info * __percpu *edev;
+	struct notifier_block notifier;
+};
+
+struct krait_edac_error {
+	const char * const msg;
+	void (*func)(struct edac_device_ctl_info *edac_dev,
+			int inst_nr, int block_nr, const char *msg);
+};
+
+static unsigned int read_cesr(void)
+{
+	unsigned int cesr;
+
+	asm volatile ("mrc p15, 7, %0, c15, c0, 1 @ cesr" : "=r" (cesr));
+	return cesr;
+}
+
+static void write_cesr(unsigned int cesr)
+{
+	asm volatile ("mcr p15, 7, %0, c15, c0, 1 @ cesr" : : "r" (cesr));
+}
+
+static unsigned int read_cesynr(void)
+{
+	unsigned int cesynr;
+
+	asm volatile ("mrc p15, 7, %0, c15, c0, 3 @ cesynr" : "=r" (cesynr));
+	return cesynr;
+}
+
+static irqreturn_t krait_l1_irq(int irq, void *dev_id)
+{
+	struct edac_device_ctl_info *edac = dev_id;
+	unsigned int cesr = read_cesr();
+	unsigned int i_cesynr, d_cesynr;
+	unsigned int cpu = smp_processor_id();
+	int print_regs = cesr & CESR_PRINT_MASK;
+	int i;
+	static const struct krait_edac_error errors[] = {
+		{ "D-cache tag parity error", edac_device_handle_ue },
+		{ "D-cache data parity error", edac_device_handle_ue },
+		{ "I-cache tag parity error", edac_device_handle_ce },
+		{ "I-cache data parity error", edac_device_handle_ce },
+		{ "D-cache tag timing error", edac_device_handle_ue },
+		{ "D-cache data timing error", edac_device_handle_ue },
+		{ "I-cache tag timing error", edac_device_handle_ce },
+		{ "I-cache data timing error", edac_device_handle_ce }
+	};
+
+	if (print_regs) {
+		pr_alert("L1 / TLB Error detected on CPU %d!\n", cpu);
+		pr_alert("CESR      = 0x%08x\n", cesr);
+		pr_alert("MIDR      = 0x%08x\n", read_cpuid_id());
+	}
+
+	for (i = 0; i < ARRAY_SIZE(errors); i++)
+		if (BIT(i) & cesr)
+			errors[i].func(edac, cpu, 0, errors[i].msg);
+
+	if (cesr & CESR_TLBMH) {
+		asm ("mcr p15, 0, r0, c8, c7, 0");
+		edac_device_handle_ce(edac, cpu, 0, "TLB Multi-Hit error");
+	}
+
+	if (cesr & (CESR_ICTPE | CESR_ICDPE | CESR_ICTE)) {
+		i_cesynr = read_cesynr();
+		pr_alert("I-side CESYNR = 0x%08x\n", i_cesynr);
+		write_cesr(CESR_I_MASK);
+
+		/*
+		 * Clear the I-side bits from the captured CESR value so that we
+		 * don't accidentally clear any new I-side errors when we do
+		 * the CESR write-clear operation.
+		 */
+		cesr &= ~CESR_I_MASK;
+	}
+
+	if (cesr & (CESR_DCTPE | CESR_DCDPE | CESR_DCTE)) {
+		d_cesynr = read_cesynr();
+		pr_alert("D-side CESYNR = 0x%08x\n", d_cesynr);
+	}
+
+	/* Clear the interrupt bits we processed */
+	write_cesr(cesr);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t krait_l2_irq(int irq, void *dev_id)
+{
+	struct edac_device_ctl_info *edac = dev_id;
+	unsigned int l2esr;
+	unsigned int l2esynr0;
+	unsigned int l2esynr1;
+	unsigned int l2ear0;
+	unsigned int l2ear1;
+	unsigned long cpu;
+	int i;
+	static const struct krait_edac_error errors[] = {
+		{ "master port decode error", edac_device_handle_ce },
+		{ "master port slave error", edac_device_handle_ce },
+		{ "tag soft error, single-bit", edac_device_handle_ce },
+		{ "tag soft error, double-bit", edac_device_handle_ue },
+		{ "data soft error, single-bit", edac_device_handle_ce },
+		{ "data soft error, double-bit", edac_device_handle_ue },
+		{ "modified soft error", edac_device_handle_ce },
+		{ "slave port exclusive monitor not available",
+			edac_device_handle_ue},
+		{ "master port LDREX received Normal OK response",
+			edac_device_handle_ce },
+	};
+
+	l2esr = get_l2_indirect_reg(L2ESR);
+	pr_alert("Error detected!\n");
+	pr_alert("L2ESR    = 0x%08x\n", l2esr);
+
+	if (l2esr & (L2ESR_TSESB | L2ESR_TSEDB | L2ESR_MSE | L2ESR_SP)) {
+		l2esynr0 = get_l2_indirect_reg(L2ESYNR0);
+		l2esynr1 = get_l2_indirect_reg(L2ESYNR1);
+		l2ear0 = get_l2_indirect_reg(L2EAR0);
+		l2ear1 = get_l2_indirect_reg(L2EAR1);
+
+		pr_alert("L2ESYNR0 = 0x%08x\n", l2esynr0);
+		pr_alert("L2ESYNR1 = 0x%08x\n", l2esynr1);
+		pr_alert("L2EAR0   = 0x%08x\n", l2ear0);
+		pr_alert("L2EAR1   = 0x%08x\n", l2ear1);
+	}
+
+	cpu = (l2esr >> L2ESR_CPU_SHIFT) & L2ESR_CPU_MASK;
+	cpu = __ffs(cpu);
+	if (cpu)
+		cpu--;
+	for (i = 0; i < ARRAY_SIZE(errors); i++)
+		if (BIT(i) & l2esr)
+			errors[i].func(edac, cpu, 1, errors[i].msg);
+
+	set_l2_indirect_reg(L2ESR, l2esr);
+
+	return IRQ_HANDLED;
+}
+
+static void enable_l1_irq(void *info)
+{
+	const struct krait_edac *k = info;
+
+	enable_percpu_irq(k->l1_irq, IRQ_TYPE_LEVEL_HIGH);
+}
+
+static void disable_l1_irq(void *info)
+{
+	const struct krait_edac *k = info;
+
+	disable_percpu_irq(k->l1_irq);
+}
+
+static int
+krait_edac_notify(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+	struct krait_edac *p = container_of(nfb, struct krait_edac, notifier);
+
+	switch (action & ~CPU_TASKS_FROZEN) {
+	case CPU_STARTING:
+		enable_l1_irq(p);
+		break;
+
+	case CPU_DYING:
+		disable_l1_irq(p);
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static int krait_edac_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct edac_device_ctl_info *edev;
+	struct krait_edac *p;
+	int l1_irq, l2_irq;
+	int ret, cpu;
+	struct device_node *node;
+
+	node = of_get_cpu_node(0, NULL);
+	if (!node)
+		return -ENODEV;
+
+	node = of_parse_phandle(node, "next-level-cache", 0);
+	if (!node)
+		return -ENODEV;
+
+	l2_irq = irq_of_parse_and_map(node, 0);
+	of_node_put(node);
+	if (l2_irq < 0)
+		return l2_irq;
+
+	l1_irq = platform_get_irq(pdev, 0);
+	if (l1_irq < 0)
+		return l1_irq;
+
+	p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, p);
+	p->l1_irq = l1_irq;
+
+	p->edev = alloc_percpu(struct edac_device_ctl_info *);
+	if (!p->edev)
+		return -ENOMEM;
+
+	edev = edac_device_alloc_ctl_info(0, "cpu", num_possible_cpus(),
+						 "L", 2, 1, NULL, 0,
+						 edac_device_alloc_index());
+	if (!edev) {
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+
+	edev->dev = dev;
+	edev->mod_name = dev_name(dev);
+	edev->dev_name = dev_name(dev);
+	edev->ctl_name = "cache";
+
+	for_each_possible_cpu(cpu)
+		*per_cpu_ptr(p->edev, cpu) = edev;
+
+	ret = edac_device_add_device(edev);
+	if (ret)
+		goto err_add;
+
+	ret = request_percpu_irq(l1_irq, krait_l1_irq, "L1 err",
+				p->edev);
+	if (ret)
+		goto err_l1_irq;
+
+	ret = devm_request_irq(dev, l2_irq, krait_l2_irq, 0, "L2 err",
+				edev);
+	if (ret)
+		goto err_l2_irq;
+
+	p->notifier.notifier_call = krait_edac_notify;
+	register_hotcpu_notifier(&p->notifier);
+	on_each_cpu(enable_l1_irq, p, true);
+
+	return 0;
+err_l2_irq:
+	free_percpu_irq(p->l1_irq, p->edev);
+err_l1_irq:
+	edac_device_del_device(dev);
+err_add:
+	edac_device_free_ctl_info(edev);
+err_alloc:
+	free_percpu(p->edev);
+	return ret;
+}
+
+static int krait_edac_remove(struct platform_device *pdev)
+{
+	struct krait_edac *p = platform_get_drvdata(pdev);
+
+	unregister_hotcpu_notifier(&p->notifier);
+	on_each_cpu(disable_l1_irq, p, true);
+	free_percpu_irq(p->l1_irq, p->edev);
+	edac_device_del_device(&pdev->dev);
+	edac_device_free_ctl_info(*__this_cpu_ptr(p->edev));
+	free_percpu(p->edev);
+
+	return 0;
+}
+
+static const struct of_device_id krait_edac_match_table[] = {
+	{ .compatible = "qcom,krait" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, krait_edac_match_table);
+
+static struct platform_driver krait_edac_driver = {
+	.probe = krait_edac_probe,
+	.remove = krait_edac_remove,
+	.driver = {
+		.name = "krait_edac",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(krait_edac_match_table),
+	},
+};
+module_platform_driver(krait_edac_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Krait CPU cache error reporting driver");
+MODULE_ALIAS("platform:krait_edac");
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

[PATCH v3 6/6] ARM: dts: msm: Add Krait CPU/L2 nodes

[Stephen Boyd]

This allows us to probe the krait-edac driver.

Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
 arch/arm/boot/dts/qcom-msm8974.dtsi | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/arch/arm/boot/dts/qcom-msm8974.dtsi b/arch/arm/boot/dts/qcom-msm8974.dtsi
index 152879d..bfe8b9c 100644
--- a/arch/arm/boot/dts/qcom-msm8974.dtsi
+++ b/arch/arm/boot/dts/qcom-msm8974.dtsi
@@ -9,6 +9,43 @@
 	compatible = "qcom,msm8974";
 	interrupt-parent = <&intc>;
 
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		interrupts = <1 9 0xf04>;
+		compatible = "qcom,krait";
+
+		cpu at 0 {
+			device_type = "cpu";
+			reg = <0>;
+			next-level-cache = <&L2>;
+		};
+
+		cpu at 1 {
+			device_type = "cpu";
+			reg = <1>;
+			next-level-cache = <&L2>;
+		};
+
+		cpu at 2 {
+			device_type = "cpu";
+			reg = <2>;
+			next-level-cache = <&L2>;
+		};
+
+		cpu at 3 {
+			device_type = "cpu";
+			reg = <3>;
+			next-level-cache = <&L2>;
+		};
+
+		L2: l2-cache {
+			compatible = "cache";
+			cache-level = <2>;
+			interrupts = <0 2 0x4>;
+		};
+	};
+
 	soc: soc {
 		#address-cells = <1>;
 		#size-cells = <1>;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation