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* [PATCH 3/3] ARM: dts: socfpga: Enable QSPI on the Cyclone5 sockit
From: dinguyen at opensource.altera.com @ 2016-10-19 20:18 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476908324-12313-1-git-send-email-dinguyen@opensource.altera.com>

From: Dinh Nguyen <dinguyen@opensource.altera.com>

Enable the QSPI node and add the flash chip.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
---
 arch/arm/boot/dts/socfpga_cyclone5_sockit.dts |   33 +++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/arch/arm/boot/dts/socfpga_cyclone5_sockit.dts b/arch/arm/boot/dts/socfpga_cyclone5_sockit.dts
index 02e22f5..2f75e0f 100644
--- a/arch/arm/boot/dts/socfpga_cyclone5_sockit.dts
+++ b/arch/arm/boot/dts/socfpga_cyclone5_sockit.dts
@@ -175,6 +175,39 @@
 	status = "okay";
 };
 
+&qspi {
+	status = "okay";
+
+	flash: flash at 0 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "n25q256a";
+		reg = <0>;
+		spi-max-frequency = <100000000>;
+
+		m25p,fast-read;
+		cdns,page-size = <256>;
+		cdns,block-size = <16>;
+		cdns,read-delay = <4>;
+		cdns,tshsl-ns = <50>;
+		cdns,tsd2d-ns = <50>;
+		cdns,tchsh-ns = <4>;
+		cdns,tslch-ns = <4>;
+
+		partition at qspi-boot {
+			/* 8MB for raw data. */
+			label = "Flash 0 Raw Data";
+			reg = <0x0 0x800000>;
+		};
+
+		partition at qspi-rootfs {
+			/* 120MB for jffs2 data. */
+			label = "Flash 0 jffs2 Filesystem";
+			reg = <0x800000 0x7800000>;
+		};
+	};
+};
+
 &usb1 {
 	status = "okay";
 };
-- 
1.7.9.5

^ permalink raw reply related

* [PATCH 2/3] ARM: dts: socfpga: Enable QSPI in Arria10 devkit
From: dinguyen at opensource.altera.com @ 2016-10-19 20:18 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476908324-12313-1-git-send-email-dinguyen@opensource.altera.com>

From: Dinh Nguyen <dinguyen@opensource.altera.com>

Enable the QSPI node and add the flash chip.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
---
 arch/arm/boot/dts/Makefile                       |    1 +
 arch/arm/boot/dts/socfpga_arria10_socdk_qspi.dts |   49 ++++++++++++++++++++++
 2 files changed, 50 insertions(+)
 create mode 100644 arch/arm/boot/dts/socfpga_arria10_socdk_qspi.dts

diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
index 7c5f0c3..081fd94 100644
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -690,6 +690,7 @@ dtb-$(CONFIG_ARCH_SHMOBILE_MULTI) += \
 	sh73a0-kzm9g.dtb
 dtb-$(CONFIG_ARCH_SOCFPGA) += \
 	socfpga_arria5_socdk.dtb \
+	socfpga_arria10_socdk_qspi.dtb \
 	socfpga_arria10_socdk_sdmmc.dtb \
 	socfpga_cyclone5_mcvevk.dtb \
 	socfpga_cyclone5_socdk.dtb \
diff --git a/arch/arm/boot/dts/socfpga_arria10_socdk_qspi.dts b/arch/arm/boot/dts/socfpga_arria10_socdk_qspi.dts
new file mode 100644
index 0000000..beb2fc6
--- /dev/null
+++ b/arch/arm/boot/dts/socfpga_arria10_socdk_qspi.dts
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2016 Intel. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/dts-v1/;
+#include "socfpga_arria10_socdk.dtsi"
+
+&qspi {
+	status = "okay";
+
+	flash0: n25q00 at 0 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "n25q00aa";
+		reg = <0>;
+		spi-max-frequency = <100000000>;
+
+		m25p,fast-read;
+		cdns,page-size = <256>;
+		cdns,block-size = <16>;
+		cdns,read-delay = <4>;
+		cdns,tshsl-ns = <50>;
+		cdns,tsd2d-ns = <50>;
+		cdns,tchsh-ns = <4>;
+		cdns,tslch-ns = <4>;
+
+		partition at qspi-boot {
+			label = "Boot and fpga data";
+			reg = <0x0 0x2720000>;
+		};
+
+		partition at qspi-rootfs {
+			label = "Root Filesystem - JFFS2";
+			reg = <0x2720000 0x58E0000>;
+		};
+	};
+};
-- 
1.7.9.5

^ permalink raw reply related

* [PATCH 1/3] ARM: dts: socfpga: Add QSPI node for the Arria10
From: dinguyen at opensource.altera.com @ 2016-10-19 20:18 UTC (permalink / raw)
  To: linux-arm-kernel

From: Dinh Nguyen <dinguyen@opensource.altera.com>

Add the QSPI device node for Arria10 SOC.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
---
 arch/arm/boot/dts/socfpga_arria10.dtsi |   14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/arm/boot/dts/socfpga_arria10.dtsi b/arch/arm/boot/dts/socfpga_arria10.dtsi
index 1149216..551c636 100644
--- a/arch/arm/boot/dts/socfpga_arria10.dtsi
+++ b/arch/arm/boot/dts/socfpga_arria10.dtsi
@@ -675,6 +675,20 @@
 			};
 		};
 
+		qspi: spi at ff809000 {
+			compatible = "cdns,qspi-nor";
+			#address-cells = <1>;
+			#size-cells = <0>;
+			reg = <0xff809000 0x100>,
+			      <0xffa00000 0x100000>;
+			interrupts = <0 100 IRQ_TYPE_LEVEL_HIGH>;
+			cdns,fifo-depth = <128>;
+			cdns,fifo-width = <4>;
+			cdns,trigger-address = <0x00000000>;
+			clocks = <&qspi_clk>;
+			status = "disabled";
+		};
+
 		rst: rstmgr at ffd05000 {
 			#reset-cells = <1>;
 			compatible = "altr,rst-mgr";
-- 
1.7.9.5

^ permalink raw reply related

* [PATCH 1/2] efi: add support for seeding the RNG from a UEFI config table
From: Ard Biesheuvel @ 2016-10-19 20:18 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <CAGXu5jJ-KTVJLwAp6iZ-tp5AKnAzSHz80yZkg4dh3uYDz3MsJw@mail.gmail.com>

On 19 October 2016 at 21:14, Kees Cook <keescook@chromium.org> wrote:
> On Wed, Oct 19, 2016 at 4:22 AM, Matt Fleming <matt@codeblueprint.co.uk> wrote:
>> On Wed, 19 Oct, at 12:13:55PM, Ard Biesheuvel wrote:
>>> On 19 October 2016 at 12:09, Mark Rutland <mark.rutland@arm.com> wrote:
>>>
>>> > I think to some extent this mush be treated as an ABI, given cases like
>>> > kexec.
>>> >
>>>
>>> Perhaps, yes. That would also allow GRUB or other EFI aware
>>> bootloaders to generate the seed.
>>
>> If we're going to go down this route, we should try and get the GUID
>> into the UEFI spec.
>
> It seems like maybe under UEFI, both this table (which sounds like
> it'll not be rotated regularly)

What do you mean 'rotated'? It is generated at boot. My 2/2 patch
generates it from the stub using the EFI_RNG_PROTOCOL on ARM/arm64

> could be mixed with calls to
> EFI_PROTOCOL_RNG by the kernel? (Similar to how kaslr is seeded?)
>

That is kind of the point. KASLR is different because we need the
entropy before even jumping to C code, but for all other uses of early
entropy, this seemed like a useful approach

^ permalink raw reply

* [PATCH] clk: uniphier: fix memory overrun bug
From: Stephen Boyd @ 2016-10-19 20:14 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476877779-27854-1-git-send-email-yamada.masahiro@socionext.com>

On 10/19, Masahiro Yamada wrote:
> The first loop of this "for" statement writes memory beyond the
> allocated clk_hw_onecell_data.
> 
> It should be:
>     for (clk_num--; clk_num >= 0; clk_num--)
>             ...
> 
> Or more simply:
>     while (--clk_num >= 0)
>             ...
> 
> Fixes: 734d82f4a678 ("clk: uniphier: add core support code for UniPhier clock driver")
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---

Applied to clk-fixes

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

^ permalink raw reply

* [PATCH 1/2] efi: add support for seeding the RNG from a UEFI config table
From: Kees Cook @ 2016-10-19 20:14 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20161019112243.GD31476@codeblueprint.co.uk>

On Wed, Oct 19, 2016 at 4:22 AM, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> On Wed, 19 Oct, at 12:13:55PM, Ard Biesheuvel wrote:
>> On 19 October 2016 at 12:09, Mark Rutland <mark.rutland@arm.com> wrote:
>>
>> > I think to some extent this mush be treated as an ABI, given cases like
>> > kexec.
>> >
>>
>> Perhaps, yes. That would also allow GRUB or other EFI aware
>> bootloaders to generate the seed.
>
> If we're going to go down this route, we should try and get the GUID
> into the UEFI spec.

It seems like maybe under UEFI, both this table (which sounds like
it'll not be rotated regularly) could be mixed with calls to
EFI_PROTOCOL_RNG by the kernel? (Similar to how kaslr is seeded?)

-Kees

-- 
Kees Cook
Nexus Security

^ permalink raw reply

* [PATCH v2 3/3] mtd: s3c2410: parse the device configuration from OF node
From: Boris Brezillon @ 2016-10-19 20:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476906725-22613-4-git-send-email-sergio.prado@e-labworks.com>

On Wed, 19 Oct 2016 17:52:05 -0200
Sergio Prado <sergio.prado@e-labworks.com> wrote:

> Allows configuring Samsung's s3c2410 memory controller using a
> devicetree.
> 
> Signed-off-by: Sergio Prado <sergio.prado@e-labworks.com>
> ---
>  drivers/mtd/nand/s3c2410.c                     | 155 ++++++++++++++++++++++---
>  include/linux/platform_data/mtd-nand-s3c2410.h |   1 +
>  2 files changed, 140 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
> index 371db0d48135..52f768f01b0d 100644
> --- a/drivers/mtd/nand/s3c2410.c
> +++ b/drivers/mtd/nand/s3c2410.c
> @@ -39,6 +39,8 @@
>  #include <linux/slab.h>
>  #include <linux/clk.h>
>  #include <linux/cpufreq.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
>  
>  #include <linux/mtd/mtd.h>
>  #include <linux/mtd/nand.h>
> @@ -185,6 +187,22 @@ struct s3c2410_nand_info {
>  #endif
>  };
>  
> +struct s3c24XX_nand_devtype_data {
> +	enum s3c_cpu_type type;
> +};
> +
> +static const struct s3c24XX_nand_devtype_data s3c2410_nand_devtype_data = {
> +	.type = TYPE_S3C2410,
> +};
> +
> +static const struct s3c24XX_nand_devtype_data s3c2412_nand_devtype_data = {
> +	.type = TYPE_S3C2412,
> +};
> +
> +static const struct s3c24XX_nand_devtype_data s3c2440_nand_devtype_data = {
> +	.type = TYPE_S3C2440,
> +};
> +
>  /* conversion functions */
>  
>  static struct s3c2410_nand_mtd *s3c2410_nand_mtd_toours(struct mtd_info *mtd)
> @@ -794,6 +812,34 @@ static int s3c2410_nand_add_partition(struct s3c2410_nand_info *info,
>  	return -ENODEV;
>  }
>  
> +static int s3c2410_nand_setup_data_interface(struct mtd_info *mtd,
> +					     const struct nand_data_interface *conf,
> +					     bool check_only)
> +{
> +	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
> +	struct s3c2410_platform_nand *pdata = info->platform;
> +	struct device_node *np = info->device->of_node;
> +	const struct nand_sdr_timings *timings;
> +	int tacls;
> +
> +	/* auto-detect timings when booting with a device tree */
> +	if (np) {

That's not really dependent on the use of DT, but I understand why you
want to keep it unchanged for users who did not switch to DT.

Instead of testing the np value here, I'd recommend that you
conditionally assign chip->setup_data_interface to
s3c2410_nand_setup_data_interface in s3c2410_nand_init_chip().

Can you also explain in more details in the comment why you don't want
to do it for non-DT configs (keep behavior unchanged for legacy boards)?

> +		timings = nand_get_sdr_timings(conf);
> +		if (IS_ERR(timings))
> +			return -ENOTSUPP;
> +
> +		tacls = timings->tCLS_min - timings->tWP_min;
> +		if (tacls < 0)
> +			tacls = 0;
> +
> +		pdata->tacls  = DIV_ROUND_UP(tacls, 1000);
> +		pdata->twrph0 = DIV_ROUND_UP(timings->tWP_min, 1000);
> +		pdata->twrph1 = DIV_ROUND_UP(timings->tCLH_min, 1000);
> +	}
> +
> +	return 0;
> +}

^ permalink raw reply

* [PATCH v2 1/4] cpufreq: pxa: use generic platdev driver for device-tree
From: Robert Jarzmik @ 2016-10-19 20:06 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20161019135208.GG11471@vireshk-i7>

Viresh Kumar <viresh.kumar@linaro.org> writes:

>> >> +	{ .compatible = "marvell,pxa250", },
>> >> +	{ .compatible = "marvell,pxa270", },
>> >>  
>> >>  	{ .compatible = "samsung,exynos3250", },
>> >>  	{ .compatible = "samsung,exynos4210", },
>> >
>> > Isn't there a race between cpufreq-dt and the platform driver to
>> > register first ?
>> Ah, could you be more specific about the race you're talking of ?
>> 
>> My understanding was that cpufreq-dt-platdev does create the device, and
>> cpufreq-dt is a driver for it, so there is no race but a direct relationship
>> AFAIU.
>
> I mean that both the driver may try to register to the cpufreq core if
> they are both compiled in a single image.
Euh I still don't follow you. The only driver that can register to the cpufreq
core is cpufreq-dt.

Now the only case I see is that there are 2 cpufreq-dt platform_device created
from cpufreq-dt-platdev. Given that there is only 1 call to
platform_device_register_data() in it, I don't see how it is possible.

Now if you are worried that 2 cpufreq-dt devices are created, ie. 1 for pxa25x
and one for pxa27x:
 - this looks impossible given the cpufreq_dt_platdev_init() code
 - no device-tree will ever be compatible with both of them, even if a single
   kernel binary will be compatible with both of them

Tell me if this is the information you're looking for.

Cheers.

-- 
Robert

^ permalink raw reply

* [PATCH v2 3/3] mtd: s3c2410: parse the device configuration from OF node
From: Sergio Prado @ 2016-10-19 19:52 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476906725-22613-1-git-send-email-sergio.prado@e-labworks.com>

Allows configuring Samsung's s3c2410 memory controller using a
devicetree.

Signed-off-by: Sergio Prado <sergio.prado@e-labworks.com>
---
 drivers/mtd/nand/s3c2410.c                     | 155 ++++++++++++++++++++++---
 include/linux/platform_data/mtd-nand-s3c2410.h |   1 +
 2 files changed, 140 insertions(+), 16 deletions(-)

diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index 371db0d48135..52f768f01b0d 100644
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -39,6 +39,8 @@
 #include <linux/slab.h>
 #include <linux/clk.h>
 #include <linux/cpufreq.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/nand.h>
@@ -185,6 +187,22 @@ struct s3c2410_nand_info {
 #endif
 };
 
+struct s3c24XX_nand_devtype_data {
+	enum s3c_cpu_type type;
+};
+
+static const struct s3c24XX_nand_devtype_data s3c2410_nand_devtype_data = {
+	.type = TYPE_S3C2410,
+};
+
+static const struct s3c24XX_nand_devtype_data s3c2412_nand_devtype_data = {
+	.type = TYPE_S3C2412,
+};
+
+static const struct s3c24XX_nand_devtype_data s3c2440_nand_devtype_data = {
+	.type = TYPE_S3C2440,
+};
+
 /* conversion functions */
 
 static struct s3c2410_nand_mtd *s3c2410_nand_mtd_toours(struct mtd_info *mtd)
@@ -794,6 +812,34 @@ static int s3c2410_nand_add_partition(struct s3c2410_nand_info *info,
 	return -ENODEV;
 }
 
+static int s3c2410_nand_setup_data_interface(struct mtd_info *mtd,
+					     const struct nand_data_interface *conf,
+					     bool check_only)
+{
+	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
+	struct s3c2410_platform_nand *pdata = info->platform;
+	struct device_node *np = info->device->of_node;
+	const struct nand_sdr_timings *timings;
+	int tacls;
+
+	/* auto-detect timings when booting with a device tree */
+	if (np) {
+		timings = nand_get_sdr_timings(conf);
+		if (IS_ERR(timings))
+			return -ENOTSUPP;
+
+		tacls = timings->tCLS_min - timings->tWP_min;
+		if (tacls < 0)
+			tacls = 0;
+
+		pdata->tacls  = DIV_ROUND_UP(tacls, 1000);
+		pdata->twrph0 = DIV_ROUND_UP(timings->tWP_min, 1000);
+		pdata->twrph1 = DIV_ROUND_UP(timings->tCLH_min, 1000);
+	}
+
+	return 0;
+}
+
 /**
  * s3c2410_nand_init_chip - initialise a single instance of an chip
  * @info: The base NAND controller the chip is on.
@@ -811,9 +857,12 @@ static void s3c2410_nand_init_chip(struct s3c2410_nand_info *info,
 	struct nand_chip *chip = &nmtd->chip;
 	void __iomem *regs = info->regs;
 
+	nand_set_flash_node(chip, set->of_node);
+
 	chip->write_buf    = s3c2410_nand_write_buf;
 	chip->read_buf     = s3c2410_nand_read_buf;
 	chip->select_chip  = s3c2410_nand_select_chip;
+	chip->setup_data_interface = s3c2410_nand_setup_data_interface;
 	chip->chip_delay   = 50;
 	nand_set_controller_data(chip, nmtd);
 	chip->options	   = set->options;
@@ -859,12 +908,9 @@ static void s3c2410_nand_init_chip(struct s3c2410_nand_info *info,
 	chip->ecc.mode = info->platform->ecc_mode;
 
 	/* If you use u-boot BBT creation code, specifying this flag will
-	 * let the kernel fish out the BBT from the NAND, and also skip the
-	 * full NAND scan that can take 1/2s or so. Little things... */
-	if (set->flash_bbt) {
+	 * let the kernel fish out the BBT from the NAND */
+	if (set->flash_bbt)
 		chip->bbt_options |= NAND_BBT_USE_FLASH;
-		chip->options |= NAND_SKIP_BBTSCAN;
-	}
 }
 
 /**
@@ -943,6 +989,77 @@ static int s3c2410_nand_update_chip(struct s3c2410_nand_info *info,
 		return -EINVAL;
 	}
 
+	if (chip->bbt_options & NAND_BBT_USE_FLASH)
+		chip->options |= NAND_SKIP_BBTSCAN;
+
+	return 0;
+}
+
+static const struct of_device_id s3c24xx_nand_dt_ids[] = {
+	{
+		.compatible = "samsung,s3c2410-nand",
+		.data = &s3c2410_nand_devtype_data,
+	}, {
+		.compatible = "samsung,s3c2412-nand", /* also compatible with s3c6400 */
+		.data = &s3c2412_nand_devtype_data,
+	}, {
+		.compatible = "samsung,s3c2440-nand",
+		.data = &s3c2440_nand_devtype_data,
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, s3c24xx_nand_dt_ids);
+
+static int s3c24xx_nand_probe_dt(struct platform_device *pdev)
+{
+	const struct s3c24XX_nand_devtype_data *devtype_data;
+	struct s3c2410_platform_nand *pdata;
+	struct s3c2410_nand_info *info = platform_get_drvdata(pdev);
+	struct device_node *np = pdev->dev.of_node, *child;
+	struct s3c2410_nand_set *sets;
+
+	devtype_data = of_device_get_match_data(&pdev->dev);
+	if (!devtype_data)
+		return -ENODEV;
+
+	info->cpu_type = devtype_data->type;
+
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	pdev->dev.platform_data = pdata;
+
+	pdata->nr_sets = of_get_child_count(np);
+	if (!pdata->nr_sets)
+		return 0;
+
+	sets = devm_kzalloc(&pdev->dev, sizeof(*sets) * pdata->nr_sets, GFP_KERNEL);
+	if (!sets)
+		return -ENOMEM;
+
+	pdata->sets = sets;
+
+	for_each_available_child_of_node(np, child) {
+
+		sets->name = (char *)child->name;
+		sets->of_node = child;
+		sets->nr_chips = 1;
+
+		of_node_get(child);
+
+		sets++;
+	}
+
+	return 0;
+}
+
+static int s3c24xx_nand_probe_pdata(struct platform_device *pdev)
+{
+	struct s3c2410_nand_info *info = platform_get_drvdata(pdev);
+
+	info->cpu_type = platform_get_device_id(pdev)->driver_data;
+
 	return 0;
 }
 
@@ -955,8 +1072,7 @@ static int s3c2410_nand_update_chip(struct s3c2410_nand_info *info,
 */
 static int s3c24xx_nand_probe(struct platform_device *pdev)
 {
-	struct s3c2410_platform_nand *plat = to_nand_plat(pdev);
-	enum s3c_cpu_type cpu_type;
+	struct s3c2410_platform_nand *plat;
 	struct s3c2410_nand_info *info;
 	struct s3c2410_nand_mtd *nmtd;
 	struct s3c2410_nand_set *sets;
@@ -966,8 +1082,6 @@ static int s3c24xx_nand_probe(struct platform_device *pdev)
 	int nr_sets;
 	int setno;
 
-	cpu_type = platform_get_device_id(pdev)->driver_data;
-
 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
 	if (info == NULL) {
 		err = -ENOMEM;
@@ -989,6 +1103,16 @@ static int s3c24xx_nand_probe(struct platform_device *pdev)
 
 	s3c2410_nand_clk_set_state(info, CLOCK_ENABLE);
 
+	if (pdev->dev.of_node)
+		err = s3c24xx_nand_probe_dt(pdev);
+	else
+		err = s3c24xx_nand_probe_pdata(pdev);
+
+	if (err)
+		goto exit_error;
+
+	plat = to_nand_plat(pdev);
+
 	/* allocate and map the resource */
 
 	/* currently we assume we have the one resource */
@@ -997,7 +1121,6 @@ static int s3c24xx_nand_probe(struct platform_device *pdev)
 
 	info->device	= &pdev->dev;
 	info->platform	= plat;
-	info->cpu_type	= cpu_type;
 
 	info->regs = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(info->regs)) {
@@ -1007,12 +1130,6 @@ static int s3c24xx_nand_probe(struct platform_device *pdev)
 
 	dev_dbg(&pdev->dev, "mapped registers at %p\n", info->regs);
 
-	/* initialise the hardware */
-
-	err = s3c2410_nand_inithw(info);
-	if (err != 0)
-		goto exit_error;
-
 	sets = (plat != NULL) ? plat->sets : NULL;
 	nr_sets = (plat != NULL) ? plat->nr_sets : 1;
 
@@ -1056,6 +1173,11 @@ static int s3c24xx_nand_probe(struct platform_device *pdev)
 			sets++;
 	}
 
+	/* initialise the hardware */
+	err = s3c2410_nand_inithw(info);
+	if (err != 0)
+		goto exit_error;
+
 	err = s3c2410_nand_cpufreq_register(info);
 	if (err < 0) {
 		dev_err(&pdev->dev, "failed to init cpufreq support\n");
@@ -1156,6 +1278,7 @@ static int s3c24xx_nand_resume(struct platform_device *dev)
 	.id_table	= s3c24xx_driver_ids,
 	.driver		= {
 		.name	= "s3c24xx-nand",
+		.of_match_table = s3c24xx_nand_dt_ids,
 	},
 };
 
diff --git a/include/linux/platform_data/mtd-nand-s3c2410.h b/include/linux/platform_data/mtd-nand-s3c2410.h
index 729af13d1773..f01659026b26 100644
--- a/include/linux/platform_data/mtd-nand-s3c2410.h
+++ b/include/linux/platform_data/mtd-nand-s3c2410.h
@@ -40,6 +40,7 @@ struct s3c2410_nand_set {
 	char			*name;
 	int			*nr_map;
 	struct mtd_partition	*partitions;
+	struct device_node	*of_node;
 };
 
 struct s3c2410_platform_nand {
-- 
1.9.1

^ permalink raw reply related

* [PATCH v2 2/3] dt-bindings: mtd: add DT binding for s3c2410 flash controller
From: Sergio Prado @ 2016-10-19 19:52 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476906725-22613-1-git-send-email-sergio.prado@e-labworks.com>

Adds the device tree bindings description for Samsung S3C2410 and
compatible NAND flash controller.

Signed-off-by: Sergio Prado <sergio.prado@e-labworks.com>
---
 .../devicetree/bindings/mtd/samsung-s3c2410.txt    | 56 ++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/samsung-s3c2410.txt

diff --git a/Documentation/devicetree/bindings/mtd/samsung-s3c2410.txt b/Documentation/devicetree/bindings/mtd/samsung-s3c2410.txt
new file mode 100644
index 000000000000..0040eb8895e0
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/samsung-s3c2410.txt
@@ -0,0 +1,56 @@
+* Samsung S3C2410 and compatible NAND flash controller
+
+Required properties:
+- compatible : The possible values are:
+	"samsung,s3c2410-nand"
+	"samsung,s3c2412-nand"
+	"samsung,s3c2440-nand"
+- reg : register's location and length.
+- #address-cells, #size-cells : see nand.txt
+- clocks : phandle to the nand controller clock
+- clock-names : must contain "nand"
+
+Optional child nodes:
+Child nodes representing the available nand chips.
+
+Optional child properties:
+- nand-ecc-mode : see nand.txt
+- nand-on-flash-bbt : see nand.txt
+
+Each child device node may optionally contain a 'partitions' sub-node,
+which further contains sub-nodes describing the flash partition mapping.
+See partition.txt for more detail.
+
+Example:
+
+nand-controller at 4e000000 {
+	compatible = "samsung,s3c2440-nand";
+	reg = <0x4e000000 0x40>;
+
+	#address-cells = <1>;
+        #size-cells = <0>;
+
+	clocks = <&clocks HCLK_NAND>;
+	clock-names = "nand";
+
+	nand {
+		nand-ecc-mode = "soft";
+		nand-on-flash-bbt;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition at 0 {
+				label = "u-boot";
+				reg = <0 0x040000>;
+			};
+
+			partition at 40000 {
+				label = "kernel";
+				reg = <0x040000 0x500000>;
+			};
+		};
+	};
+};
-- 
1.9.1

^ permalink raw reply related

* [PATCH v2 1/3] mtd: s3c2410: make ecc mode configurable via platform data
From: Sergio Prado @ 2016-10-19 19:52 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476906725-22613-1-git-send-email-sergio.prado@e-labworks.com>

Removing CONFIG_MTD_NAND_S3C2410_HWECC option and adding a ecc_mode
field in the drivers's platform data structure so it can be selectable
via platform data.

Also setting this field to NAND_ECC_SOFT in all boards using this
driver since none of them had CONFIG_MTD_NAND_S3C2410_HWECC enabled.

Signed-off-by: Sergio Prado <sergio.prado@e-labworks.com>
---
 arch/arm/mach-s3c24xx/common-smdk.c            |   1 +
 arch/arm/mach-s3c24xx/mach-anubis.c            |   1 +
 arch/arm/mach-s3c24xx/mach-at2440evb.c         |   1 +
 arch/arm/mach-s3c24xx/mach-bast.c              |   1 +
 arch/arm/mach-s3c24xx/mach-gta02.c             |   1 +
 arch/arm/mach-s3c24xx/mach-jive.c              |   1 +
 arch/arm/mach-s3c24xx/mach-mini2440.c          |   1 +
 arch/arm/mach-s3c24xx/mach-osiris.c            |   1 +
 arch/arm/mach-s3c24xx/mach-qt2410.c            |   1 +
 arch/arm/mach-s3c24xx/mach-rx1950.c            |   1 +
 arch/arm/mach-s3c24xx/mach-rx3715.c            |   1 +
 arch/arm/mach-s3c24xx/mach-vstms.c             |   1 +
 arch/arm/mach-s3c64xx/mach-hmt.c               |   1 +
 arch/arm/mach-s3c64xx/mach-mini6410.c          |   1 +
 arch/arm/mach-s3c64xx/mach-real6410.c          |   1 +
 drivers/mtd/nand/Kconfig                       |   9 --
 drivers/mtd/nand/s3c2410.c                     | 119 +++++++++++++------------
 include/linux/platform_data/mtd-nand-s3c2410.h |   6 +-
 18 files changed, 79 insertions(+), 70 deletions(-)

diff --git a/arch/arm/mach-s3c24xx/common-smdk.c b/arch/arm/mach-s3c24xx/common-smdk.c
index e9fbcc91c5c0..9e0bc46e90ec 100644
--- a/arch/arm/mach-s3c24xx/common-smdk.c
+++ b/arch/arm/mach-s3c24xx/common-smdk.c
@@ -171,6 +171,7 @@
 	.twrph1		= 20,
 	.nr_sets	= ARRAY_SIZE(smdk_nand_sets),
 	.sets		= smdk_nand_sets,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 /* devices we initialise */
diff --git a/arch/arm/mach-s3c24xx/mach-anubis.c b/arch/arm/mach-s3c24xx/mach-anubis.c
index d03df0df01fa..029ef1b58925 100644
--- a/arch/arm/mach-s3c24xx/mach-anubis.c
+++ b/arch/arm/mach-s3c24xx/mach-anubis.c
@@ -223,6 +223,7 @@ static void anubis_nand_select(struct s3c2410_nand_set *set, int slot)
 	.nr_sets	= ARRAY_SIZE(anubis_nand_sets),
 	.sets		= anubis_nand_sets,
 	.select_chip	= anubis_nand_select,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 /* IDE channels */
diff --git a/arch/arm/mach-s3c24xx/mach-at2440evb.c b/arch/arm/mach-s3c24xx/mach-at2440evb.c
index 9ae170fef2a7..7b28eb623fc1 100644
--- a/arch/arm/mach-s3c24xx/mach-at2440evb.c
+++ b/arch/arm/mach-s3c24xx/mach-at2440evb.c
@@ -114,6 +114,7 @@
 	.twrph1		= 40,
 	.nr_sets	= ARRAY_SIZE(at2440evb_nand_sets),
 	.sets		= at2440evb_nand_sets,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 /* DM9000AEP 10/100 ethernet controller */
diff --git a/arch/arm/mach-s3c24xx/mach-bast.c b/arch/arm/mach-s3c24xx/mach-bast.c
index ed07cf392d4b..5185036765db 100644
--- a/arch/arm/mach-s3c24xx/mach-bast.c
+++ b/arch/arm/mach-s3c24xx/mach-bast.c
@@ -299,6 +299,7 @@ static void bast_nand_select(struct s3c2410_nand_set *set, int slot)
 	.nr_sets	= ARRAY_SIZE(bast_nand_sets),
 	.sets		= bast_nand_sets,
 	.select_chip	= bast_nand_select,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 /* DM9000 */
diff --git a/arch/arm/mach-s3c24xx/mach-gta02.c b/arch/arm/mach-s3c24xx/mach-gta02.c
index 27ae6877550f..b0ed401da3a3 100644
--- a/arch/arm/mach-s3c24xx/mach-gta02.c
+++ b/arch/arm/mach-s3c24xx/mach-gta02.c
@@ -443,6 +443,7 @@ static void gta02_udc_vbus_draw(unsigned int ma)
 	.twrph1		= 15,
 	.nr_sets	= ARRAY_SIZE(gta02_nand_sets),
 	.sets		= gta02_nand_sets,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 
diff --git a/arch/arm/mach-s3c24xx/mach-jive.c b/arch/arm/mach-s3c24xx/mach-jive.c
index 7d99fe8f6157..895aca225952 100644
--- a/arch/arm/mach-s3c24xx/mach-jive.c
+++ b/arch/arm/mach-s3c24xx/mach-jive.c
@@ -232,6 +232,7 @@
 	.twrph1		= 40,
 	.sets		= jive_nand_sets,
 	.nr_sets	= ARRAY_SIZE(jive_nand_sets),
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 static int __init jive_mtdset(char *options)
diff --git a/arch/arm/mach-s3c24xx/mach-mini2440.c b/arch/arm/mach-s3c24xx/mach-mini2440.c
index ec60bd4a1646..71af8d2fd320 100644
--- a/arch/arm/mach-s3c24xx/mach-mini2440.c
+++ b/arch/arm/mach-s3c24xx/mach-mini2440.c
@@ -287,6 +287,7 @@
 	.nr_sets	= ARRAY_SIZE(mini2440_nand_sets),
 	.sets		= mini2440_nand_sets,
 	.ignore_unset_ecc = 1,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 /* DM9000AEP 10/100 ethernet controller */
diff --git a/arch/arm/mach-s3c24xx/mach-osiris.c b/arch/arm/mach-s3c24xx/mach-osiris.c
index 2f6fdc326835..70b0eb7d3134 100644
--- a/arch/arm/mach-s3c24xx/mach-osiris.c
+++ b/arch/arm/mach-s3c24xx/mach-osiris.c
@@ -238,6 +238,7 @@ static void osiris_nand_select(struct s3c2410_nand_set *set, int slot)
 	.nr_sets	= ARRAY_SIZE(osiris_nand_sets),
 	.sets		= osiris_nand_sets,
 	.select_chip	= osiris_nand_select,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 /* PCMCIA control and configuration */
diff --git a/arch/arm/mach-s3c24xx/mach-qt2410.c b/arch/arm/mach-s3c24xx/mach-qt2410.c
index 984516e8307a..868c82087403 100644
--- a/arch/arm/mach-s3c24xx/mach-qt2410.c
+++ b/arch/arm/mach-s3c24xx/mach-qt2410.c
@@ -284,6 +284,7 @@
 	.twrph1		= 20,
 	.nr_sets	= ARRAY_SIZE(qt2410_nand_sets),
 	.sets		= qt2410_nand_sets,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 /* UDC */
diff --git a/arch/arm/mach-s3c24xx/mach-rx1950.c b/arch/arm/mach-s3c24xx/mach-rx1950.c
index 25a139bb9826..e86ad6a68a0b 100644
--- a/arch/arm/mach-s3c24xx/mach-rx1950.c
+++ b/arch/arm/mach-s3c24xx/mach-rx1950.c
@@ -611,6 +611,7 @@ static void rx1950_set_mmc_power(unsigned char power_mode, unsigned short vdd)
 	.twrph1 = 15,
 	.nr_sets = ARRAY_SIZE(rx1950_nand_sets),
 	.sets = rx1950_nand_sets,
+	.ecc_mode = NAND_ECC_SOFT,
 };
 
 static struct s3c2410_udc_mach_info rx1950_udc_cfg __initdata = {
diff --git a/arch/arm/mach-s3c24xx/mach-rx3715.c b/arch/arm/mach-s3c24xx/mach-rx3715.c
index cf55196f89ca..a39fb9780dd3 100644
--- a/arch/arm/mach-s3c24xx/mach-rx3715.c
+++ b/arch/arm/mach-s3c24xx/mach-rx3715.c
@@ -164,6 +164,7 @@
 	.twrph1		= 15,
 	.nr_sets	= ARRAY_SIZE(rx3715_nand_sets),
 	.sets		= rx3715_nand_sets,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 static struct platform_device *rx3715_devices[] __initdata = {
diff --git a/arch/arm/mach-s3c24xx/mach-vstms.c b/arch/arm/mach-s3c24xx/mach-vstms.c
index b4460d5f7011..f5e6322145fa 100644
--- a/arch/arm/mach-s3c24xx/mach-vstms.c
+++ b/arch/arm/mach-s3c24xx/mach-vstms.c
@@ -117,6 +117,7 @@
 	.twrph1		= 20,
 	.nr_sets	= ARRAY_SIZE(vstms_nand_sets),
 	.sets		= vstms_nand_sets,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 static struct platform_device *vstms_devices[] __initdata = {
diff --git a/arch/arm/mach-s3c64xx/mach-hmt.c b/arch/arm/mach-s3c64xx/mach-hmt.c
index bc7dc1fcbf7d..59b5531f1987 100644
--- a/arch/arm/mach-s3c64xx/mach-hmt.c
+++ b/arch/arm/mach-s3c64xx/mach-hmt.c
@@ -204,6 +204,7 @@ static void hmt_bl_exit(struct device *dev)
 	.twrph1		= 40,
 	.nr_sets	= ARRAY_SIZE(hmt_nand_sets),
 	.sets		= hmt_nand_sets,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 static struct gpio_led hmt_leds[] = {
diff --git a/arch/arm/mach-s3c64xx/mach-mini6410.c b/arch/arm/mach-s3c64xx/mach-mini6410.c
index ae999fb3fe6d..a3e3e25728b4 100644
--- a/arch/arm/mach-s3c64xx/mach-mini6410.c
+++ b/arch/arm/mach-s3c64xx/mach-mini6410.c
@@ -142,6 +142,7 @@
 	.twrph1		= 40,
 	.nr_sets	= ARRAY_SIZE(mini6410_nand_sets),
 	.sets		= mini6410_nand_sets,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 static struct s3c_fb_pd_win mini6410_lcd_type0_fb_win = {
diff --git a/arch/arm/mach-s3c64xx/mach-real6410.c b/arch/arm/mach-s3c64xx/mach-real6410.c
index 4e240ffa7ac7..d6b3ffd7704b 100644
--- a/arch/arm/mach-s3c64xx/mach-real6410.c
+++ b/arch/arm/mach-s3c64xx/mach-real6410.c
@@ -194,6 +194,7 @@
 	.twrph1		= 40,
 	.nr_sets	= ARRAY_SIZE(real6410_nand_sets),
 	.sets		= real6410_nand_sets,
+	.ecc_mode       = NAND_ECC_SOFT,
 };
 
 static struct platform_device *real6410_devices[] __initdata = {
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 7b7a887b4709..9748f3580d4b 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -179,15 +179,6 @@ config MTD_NAND_S3C2410_DEBUG
 	help
 	  Enable debugging of the S3C NAND driver
 
-config MTD_NAND_S3C2410_HWECC
-	bool "Samsung S3C NAND Hardware ECC"
-	depends on MTD_NAND_S3C2410
-	help
-	  Enable the use of the controller's internal ECC generator when
-	  using NAND. Early versions of the chips have had problems with
-	  incorrect ECC generation, and if using these, the default of
-	  software ECC is preferable.
-
 config MTD_NAND_NDFC
 	tristate "NDFC NanD Flash Controller"
 	depends on 4xx
diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index d459c19d78de..371db0d48135 100644
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -497,7 +497,6 @@ static int s3c2412_nand_devready(struct mtd_info *mtd)
 
 /* ECC handling functions */
 
-#ifdef CONFIG_MTD_NAND_S3C2410_HWECC
 static int s3c2410_nand_correct_data(struct mtd_info *mtd, u_char *dat,
 				     u_char *read_ecc, u_char *calc_ecc)
 {
@@ -649,7 +648,6 @@ static int s3c2440_nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
 
 	return 0;
 }
-#endif
 
 /* over-ride the standard functions for a little more speed. We can
  * use read/write block to move the data buffers to/from the controller
@@ -858,50 +856,7 @@ static void s3c2410_nand_init_chip(struct s3c2410_nand_info *info,
 	nmtd->info	   = info;
 	nmtd->set	   = set;
 
-#ifdef CONFIG_MTD_NAND_S3C2410_HWECC
-	chip->ecc.calculate = s3c2410_nand_calculate_ecc;
-	chip->ecc.correct   = s3c2410_nand_correct_data;
-	chip->ecc.mode	    = NAND_ECC_HW;
-	chip->ecc.strength  = 1;
-
-	switch (info->cpu_type) {
-	case TYPE_S3C2410:
-		chip->ecc.hwctl	    = s3c2410_nand_enable_hwecc;
-		chip->ecc.calculate = s3c2410_nand_calculate_ecc;
-		break;
-
-	case TYPE_S3C2412:
-		chip->ecc.hwctl     = s3c2412_nand_enable_hwecc;
-		chip->ecc.calculate = s3c2412_nand_calculate_ecc;
-		break;
-
-	case TYPE_S3C2440:
-		chip->ecc.hwctl     = s3c2440_nand_enable_hwecc;
-		chip->ecc.calculate = s3c2440_nand_calculate_ecc;
-		break;
-	}
-#else
-	chip->ecc.mode	    = NAND_ECC_SOFT;
-	chip->ecc.algo	= NAND_ECC_HAMMING;
-#endif
-
-	if (set->disable_ecc)
-		chip->ecc.mode	= NAND_ECC_NONE;
-
-	switch (chip->ecc.mode) {
-	case NAND_ECC_NONE:
-		dev_info(info->device, "NAND ECC disabled\n");
-		break;
-	case NAND_ECC_SOFT:
-		dev_info(info->device, "NAND soft ECC\n");
-		break;
-	case NAND_ECC_HW:
-		dev_info(info->device, "NAND hardware ECC\n");
-		break;
-	default:
-		dev_info(info->device, "NAND ECC UNKNOWN\n");
-		break;
-	}
+	chip->ecc.mode = info->platform->ecc_mode;
 
 	/* If you use u-boot BBT creation code, specifying this flag will
 	 * let the kernel fish out the BBT from the NAND, and also skip the
@@ -923,28 +878,72 @@ static void s3c2410_nand_init_chip(struct s3c2410_nand_info *info,
  *
  * The internal state is currently limited to the ECC state information.
 */
-static void s3c2410_nand_update_chip(struct s3c2410_nand_info *info,
+static int s3c2410_nand_update_chip(struct s3c2410_nand_info *info,
 				     struct s3c2410_nand_mtd *nmtd)
 {
 	struct nand_chip *chip = &nmtd->chip;
 
-	dev_dbg(info->device, "chip %p => page shift %d\n",
-		chip, chip->page_shift);
+	switch (chip->ecc.mode) {
 
-	if (chip->ecc.mode != NAND_ECC_HW)
-		return;
+	case NAND_ECC_NONE:
+		dev_info(info->device, "ECC disabled\n");
+		break;
+
+	case NAND_ECC_SOFT:
+		/*
+		 * This driver expects Hamming based ECC when ecc_mode is set
+		 * to NAND_ECC_SOFT. Force ecc.algo to NAND_ECC_HAMMING to
+		 * avoid adding an extra ecc_algo field to s3c2410_platform_nand.
+		 */
+		chip->ecc.algo = NAND_ECC_HAMMING;
+		dev_info(info->device, "soft ECC\n");
+		break;
+
+	case NAND_ECC_HW:
+		chip->ecc.calculate = s3c2410_nand_calculate_ecc;
+		chip->ecc.correct   = s3c2410_nand_correct_data;
+		chip->ecc.strength  = 1;
+
+		switch (info->cpu_type) {
+		case TYPE_S3C2410:
+			chip->ecc.hwctl	    = s3c2410_nand_enable_hwecc;
+			chip->ecc.calculate = s3c2410_nand_calculate_ecc;
+			break;
+
+		case TYPE_S3C2412:
+			chip->ecc.hwctl     = s3c2412_nand_enable_hwecc;
+			chip->ecc.calculate = s3c2412_nand_calculate_ecc;
+			break;
+
+		case TYPE_S3C2440:
+			chip->ecc.hwctl     = s3c2440_nand_enable_hwecc;
+			chip->ecc.calculate = s3c2440_nand_calculate_ecc;
+			break;
+		}
+
+		dev_dbg(info->device, "chip %p => page shift %d\n",
+			chip, chip->page_shift);
 
 		/* change the behaviour depending on whether we are using
 		 * the large or small page nand device */
+		if (chip->page_shift > 10) {
+			chip->ecc.size	    = 256;
+			chip->ecc.bytes	    = 3;
+		} else {
+			chip->ecc.size	    = 512;
+			chip->ecc.bytes	    = 3;
+			mtd_set_ooblayout(nand_to_mtd(chip), &s3c2410_ooblayout_ops);
+		}
 
-	if (chip->page_shift > 10) {
-		chip->ecc.size	    = 256;
-		chip->ecc.bytes	    = 3;
-	} else {
-		chip->ecc.size	    = 512;
-		chip->ecc.bytes	    = 3;
-		mtd_set_ooblayout(nand_to_mtd(chip), &s3c2410_ooblayout_ops);
+		dev_info(info->device, "hardware ECC\n");
+		break;
+
+	default:
+		dev_err(info->device, "invalid ECC mode!\n");
+		return -EINVAL;
 	}
+
+	return 0;
 }
 
 /* s3c24xx_nand_probe
@@ -1046,7 +1045,9 @@ static int s3c24xx_nand_probe(struct platform_device *pdev)
 						 NULL);
 
 		if (nmtd->scan_res == 0) {
-			s3c2410_nand_update_chip(info, nmtd);
+			err = s3c2410_nand_update_chip(info, nmtd);
+			if (err < 0)
+				goto exit_error;
 			nand_scan_tail(mtd);
 			s3c2410_nand_add_partition(info, nmtd, sets);
 		}
diff --git a/include/linux/platform_data/mtd-nand-s3c2410.h b/include/linux/platform_data/mtd-nand-s3c2410.h
index c55e42ee57fa..729af13d1773 100644
--- a/include/linux/platform_data/mtd-nand-s3c2410.h
+++ b/include/linux/platform_data/mtd-nand-s3c2410.h
@@ -12,9 +12,10 @@
 #ifndef __MTD_NAND_S3C2410_H
 #define __MTD_NAND_S3C2410_H
 
+#include <linux/mtd/nand.h>
+
 /**
  * struct s3c2410_nand_set - define a set of one or more nand chips
- * @disable_ecc:	Entirely disable ECC - Dangerous
  * @flash_bbt: 		Openmoko u-boot can create a Bad Block Table
  *			Setting this flag will allow the kernel to
  *			look for it at boot time and also skip the NAND
@@ -31,7 +32,6 @@
  * a warning at boot time.
  */
 struct s3c2410_nand_set {
-	unsigned int		disable_ecc:1;
 	unsigned int		flash_bbt:1;
 
 	unsigned int		options;
@@ -51,6 +51,8 @@ struct s3c2410_platform_nand {
 
 	unsigned int	ignore_unset_ecc:1;
 
+	nand_ecc_modes_t	ecc_mode;
+
 	int			nr_sets;
 	struct s3c2410_nand_set *sets;
 
-- 
1.9.1

^ permalink raw reply related

* [PATCH v2 0/3] mtd: s3c2410: add device tree support
From: Sergio Prado @ 2016-10-19 19:52 UTC (permalink / raw)
  To: linux-arm-kernel

This series adds support for configuring Samsung's s3c2410 and
compatible flash memory controller via devicetree.

Tested on FriendlyARM mini2440, based on s3c2440 SoC.

Patch 3 depends on patch 1.

Changes since v1:
- automate timing selection when booting with a device tree
- make s3c24XX_nand_devtype_data structs "static const"
- removing samsung,s3c6400-nand compatible since it is equivalent to
  samsung,s3c2412-nand

Changes since initial version:
- patch converted to a patch series
- read timings from nand_sdr_timings when booting with a device tree
- naming improvements in the device tree binding
  (s/nand/nand-controller/, s/_/-, s/children/child)
- dropped property samsung,ignore_unset_ecc
- remove @0 from nand device node
- checking pdev->dev.of_node instead of using ifdef CONFIG_OF_MTD
- preventing from parsing device tree properties twice
- increment the nand controller child node refcount, since we
  maintain a reference to it and its name field
- using of_device_get_match_data() instead of of_match_device()
  to make the code simpler
- remove CONFIG_MTD_NAND_S3C2410_HWECC compile option so we can
  select ECC mode using nand-ecc-mode property in the device tree

Sergio Prado (3):
  mtd: s3c2410: make ecc mode configurable via platform data
  dt-bindings: mtd: add DT binding for s3c2410 flash controller
  mtd: s3c2410: parse the device configuration from OF node

 .../devicetree/bindings/mtd/samsung-s3c2410.txt    |  56 +++++
 arch/arm/mach-s3c24xx/common-smdk.c                |   1 +
 arch/arm/mach-s3c24xx/mach-anubis.c                |   1 +
 arch/arm/mach-s3c24xx/mach-at2440evb.c             |   1 +
 arch/arm/mach-s3c24xx/mach-bast.c                  |   1 +
 arch/arm/mach-s3c24xx/mach-gta02.c                 |   1 +
 arch/arm/mach-s3c24xx/mach-jive.c                  |   1 +
 arch/arm/mach-s3c24xx/mach-mini2440.c              |   1 +
 arch/arm/mach-s3c24xx/mach-osiris.c                |   1 +
 arch/arm/mach-s3c24xx/mach-qt2410.c                |   1 +
 arch/arm/mach-s3c24xx/mach-rx1950.c                |   1 +
 arch/arm/mach-s3c24xx/mach-rx3715.c                |   1 +
 arch/arm/mach-s3c24xx/mach-vstms.c                 |   1 +
 arch/arm/mach-s3c64xx/mach-hmt.c                   |   1 +
 arch/arm/mach-s3c64xx/mach-mini6410.c              |   1 +
 arch/arm/mach-s3c64xx/mach-real6410.c              |   1 +
 drivers/mtd/nand/Kconfig                           |   9 -
 drivers/mtd/nand/s3c2410.c                         | 274 +++++++++++++++------
 include/linux/platform_data/mtd-nand-s3c2410.h     |   7 +-
 19 files changed, 275 insertions(+), 86 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mtd/samsung-s3c2410.txt

-- 
1.9.1

^ permalink raw reply

* [PATCH] hwrng: meson: Remove unneeded platform MODULE_ALIAS
From: Javier Martinez Canillas @ 2016-10-19 19:50 UTC (permalink / raw)
  To: linux-arm-kernel

The Amlogic Meson is a DT-only platform, which means the devices are
registered via OF and not using the legacy platform devices support.

So there's no need to have a MODULE_ALIAS("platform:meson-rng") since
the reported uevent MODALIAS to user-space will always be the OF one.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
---

 drivers/char/hw_random/meson-rng.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c
index 51864a509be7..119d698439ae 100644
--- a/drivers/char/hw_random/meson-rng.c
+++ b/drivers/char/hw_random/meson-rng.c
@@ -122,7 +122,6 @@ static struct platform_driver meson_rng_driver = {
 
 module_platform_driver(meson_rng_driver);
 
-MODULE_ALIAS("platform:meson-rng");
 MODULE_DESCRIPTION("Meson H/W Random Number Generator driver");
 MODULE_AUTHOR("Lawrence Mok <lawrence.mok@amlogic.com>");
 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
-- 
2.7.4

^ permalink raw reply related

* [PATCH] pwm: meson: Remove unneeded platform MODULE_ALIAS
From: Javier Martinez Canillas @ 2016-10-19 19:49 UTC (permalink / raw)
  To: linux-arm-kernel

The Amlogic Meson is a DT-only platform, which means the devices are
registered via OF and not using the legacy platform devices support.

So there's no need to have a MODULE_ALIAS("platform:meson-pwm") since
the reported uevent MODALIAS to user-space will always be the OF one.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
---

 drivers/pwm/pwm-meson.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
index 381871b2bb46..5678092cad4b 100644
--- a/drivers/pwm/pwm-meson.c
+++ b/drivers/pwm/pwm-meson.c
@@ -523,7 +523,6 @@ static struct platform_driver meson_pwm_driver = {
 };
 module_platform_driver(meson_pwm_driver);
 
-MODULE_ALIAS("platform:meson-pwm");
 MODULE_DESCRIPTION("Amlogic Meson PWM Generator driver");
 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
 MODULE_LICENSE("Dual BSD/GPL");
-- 
2.7.4

^ permalink raw reply related

* [PATCH] watchdog: meson: Remove unneeded platform MODULE_ALIAS
From: Javier Martinez Canillas @ 2016-10-19 19:49 UTC (permalink / raw)
  To: linux-arm-kernel

The Amlogic Meson is a DT-only platform, which means the devices are
registered via OF and not using the legacy platform devices support.

So there's no need to have a MODULE_ALIAS("platform:meson-gxbb-wdt")
since the reported uevent MODALIAS to user-space will be the OF one.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
---

 drivers/watchdog/meson_gxbb_wdt.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
index 44d180a2c5e5..45d47664a00a 100644
--- a/drivers/watchdog/meson_gxbb_wdt.c
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -264,7 +264,6 @@ static struct platform_driver meson_gxbb_wdt_driver = {
 
 module_platform_driver(meson_gxbb_wdt_driver);
 
-MODULE_ALIAS("platform:meson-gxbb-wdt");
 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
 MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver");
 MODULE_LICENSE("Dual BSD/GPL");
-- 
2.7.4

^ permalink raw reply related

* [PATCH 10/10] arm64: split thread_info from task stack
From: Mark Rutland @ 2016-10-19 19:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476904234-9511-1-git-send-email-mark.rutland@arm.com>

This patch moves arm64's struct thread_info from the task stack into
task_struct. This protects thread_info from corruption in the case of
stack overflows, and makes its address harder to determine if stack
addresses are leaked, making a number of attacks more difficult. Precise
detection and handling of overflow is left for subsequent patches.

Largely, this involves changing code to store the task_struct in sp_el0,
and acquire the thread_info from the task struct (which is the opposite
way around to the current code). Both secondary entry and idle are
updated to stash the sp and task pointer separately.

Userspace clobbers sp_el0, and we can no longer restore this from the
stack. Instead, the current task is cached in a per-cpu variable that we
can safely access from early assembly as interrupts are disabled (and we
are thus not preemptible).

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/Kconfig                   |  1 +
 arch/arm64/include/asm/Kbuild        |  1 -
 arch/arm64/include/asm/current.h     | 22 ++++++++++++++++++++++
 arch/arm64/include/asm/smp.h         |  1 +
 arch/arm64/include/asm/thread_info.h | 24 ------------------------
 arch/arm64/kernel/asm-offsets.c      |  1 +
 arch/arm64/kernel/entry.S            |  4 ++--
 arch/arm64/kernel/head.S             | 11 ++++++-----
 arch/arm64/kernel/process.c          | 13 +++++++++++++
 arch/arm64/kernel/smp.c              |  2 ++
 10 files changed, 48 insertions(+), 32 deletions(-)
 create mode 100644 arch/arm64/include/asm/current.h

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 30398db..1874b61 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -109,6 +109,7 @@ config ARM64
 	select POWER_SUPPLY
 	select SPARSE_IRQ
 	select SYSCTL_EXCEPTION_TRACE
+	select THREAD_INFO_IN_TASK
 	help
 	  ARM 64-bit (AArch64) Linux support.
 
diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild
index 44e1d7f1..28196b1 100644
--- a/arch/arm64/include/asm/Kbuild
+++ b/arch/arm64/include/asm/Kbuild
@@ -1,7 +1,6 @@
 generic-y += bugs.h
 generic-y += clkdev.h
 generic-y += cputime.h
-generic-y += current.h
 generic-y += delay.h
 generic-y += div64.h
 generic-y += dma.h
diff --git a/arch/arm64/include/asm/current.h b/arch/arm64/include/asm/current.h
new file mode 100644
index 0000000..f2bcbe2
--- /dev/null
+++ b/arch/arm64/include/asm/current.h
@@ -0,0 +1,22 @@
+#ifndef __ASM_CURRENT_H
+#define __ASM_CURRENT_H
+
+#include <linux/compiler.h>
+
+#include <asm/sysreg.h>
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+
+static __always_inline struct task_struct *get_current(void)
+{
+	return (struct task_struct *)read_sysreg(sp_el0);
+}
+
+#define current get_current()
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_CURRENT_H */
+
diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h
index f77ac0d..4400719 100644
--- a/arch/arm64/include/asm/smp.h
+++ b/arch/arm64/include/asm/smp.h
@@ -77,6 +77,7 @@
  */
 struct secondary_data {
 	void *stack;
+	struct task_struct *task;
 	long status;
 };
 
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 3a4f85d..7a4e0e4 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -47,41 +47,17 @@
 struct thread_info {
 	unsigned long		flags;		/* low level flags */
 	mm_segment_t		addr_limit;	/* address limit */
-	struct task_struct	*task;		/* main task structure */
 	int			preempt_count;	/* 0 => preemptable, <0 => bug */
-	int			cpu;		/* cpu */
 };
 
 #define INIT_THREAD_INFO(tsk)						\
 {									\
-	.task		= &tsk,						\
-	.flags		= 0,						\
 	.preempt_count	= INIT_PREEMPT_COUNT,				\
 	.addr_limit	= KERNEL_DS,					\
 }
 
 #define init_stack		(init_thread_union.stack)
 
-/*
- * how to get the thread information struct from C
- */
-static inline struct thread_info *current_thread_info(void) __attribute_const__;
-
-/*
- * struct thread_info can be accessed directly via sp_el0.
- *
- * We don't use read_sysreg() as we want the compiler to cache the value where
- * possible.
- */
-static inline struct thread_info *current_thread_info(void)
-{
-	unsigned long sp_el0;
-
-	asm ("mrs %0, sp_el0" : "=r" (sp_el0));
-
-	return (struct thread_info *)sp_el0;
-}
-
 #define thread_saved_pc(tsk)	\
 	((unsigned long)(tsk->thread.cpu_context.pc))
 #define thread_saved_sp(tsk)	\
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index d30b232..9c2c770 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -121,6 +121,7 @@ int main(void)
   DEFINE(TZ_DSTTIME,		offsetof(struct timezone, tz_dsttime));
   BLANK();
   DEFINE(CPU_BOOT_STACK,	offsetof(struct secondary_data, stack));
+  DEFINE(CPU_BOOT_TASK,		offsetof(struct secondary_data, task));
   BLANK();
 #ifdef CONFIG_KVM_ARM_HOST
   DEFINE(VCPU_CONTEXT,		offsetof(struct kvm_vcpu, arch.ctxt));
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 2d4c83b..e781391 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -123,6 +123,7 @@
 	 * Set sp_el0 to current thread_info.
 	 */
 	.if	\el == 0
+	ldr_this_cpu	tsk, __entry_task, x21
 	msr	sp_el0, tsk
 	.endif
 
@@ -674,8 +675,7 @@ ENTRY(cpu_switch_to)
 	ldp	x29, x9, [x8], #16
 	ldr	lr, [x8]
 	mov	sp, x9
-	and	x9, x9, #~(THREAD_SIZE - 1)
-	msr	sp_el0, x9
+	msr	sp_el0, x1
 	ret
 ENDPROC(cpu_switch_to)
 
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 427f6d3..12cf383 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -428,7 +428,8 @@ ENDPROC(__create_page_tables)
 __primary_switched:
 	adrp	x4, init_thread_union
 	add	sp, x4, #THREAD_SIZE
-	msr	sp_el0, x4			// Save thread_info
+	adr_l	x5, init_task
+	msr	sp_el0, x5			// Save thread_info
 
 	adr_l	x8, vectors			// load VBAR_EL1 with virtual
 	msr	vbar_el1, x8			// vector table address
@@ -698,10 +699,10 @@ __secondary_switched:
 	isb
 
 	adr_l	x0, secondary_data
-	ldr	x0, [x0, #CPU_BOOT_STACK]	// get secondary_data.stack
-	mov	sp, x0
-	and	x0, x0, #~(THREAD_SIZE - 1)
-	msr	sp_el0, x0			// save thread_info
+	ldr	x1, [x0, #CPU_BOOT_STACK]	// get secondary_data.stack
+	mov	sp, x1
+	ldr	x2, [x0, #CPU_BOOT_TASK]
+	msr	sp_el0, x2
 	mov	x29, #0
 	b	secondary_start_kernel
 ENDPROC(__secondary_switched)
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 2f39036..ddce61b 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -45,6 +45,7 @@
 #include <linux/personality.h>
 #include <linux/notifier.h>
 #include <trace/events/power.h>
+#include <linux/percpu.h>
 
 #include <asm/alternative.h>
 #include <asm/compat.h>
@@ -312,6 +313,17 @@ static void uao_thread_switch(struct task_struct *next)
 }
 
 /*
+ * We store our current task in sp_el0, which is clobbered by userspace. Keep a
+ * shadow copy so that we can restore this upon entry from userspace.
+ */
+DEFINE_PER_CPU(struct task_struct *, __entry_task) = &init_task;
+
+static void entry_task_switch(struct task_struct *next)
+{
+	__this_cpu_write(__entry_task, next);
+}
+
+/*
  * Thread switching.
  */
 struct task_struct *__switch_to(struct task_struct *prev,
@@ -323,6 +335,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
 	tls_thread_switch(next);
 	hw_breakpoint_thread_switch(next);
 	contextidr_thread_switch(next);
+	entry_task_switch(next);
 	uao_thread_switch(next);
 
 	/*
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 2679722..cde25f4 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -149,6 +149,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
 	 * We need to tell the secondary core where to find its stack and the
 	 * page tables.
 	 */
+	secondary_data.task = idle;
 	secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
 	update_cpu_boot_status(CPU_MMU_OFF);
 	__flush_dcache_area(&secondary_data, sizeof(secondary_data));
@@ -173,6 +174,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
 		pr_err("CPU%u: failed to boot: %d\n", cpu, ret);
 	}
 
+	secondary_data.task = NULL;
 	secondary_data.stack = NULL;
 	status = READ_ONCE(secondary_data.status);
 	if (ret && status) {
-- 
1.9.1

^ permalink raw reply related

* [PATCH 09/10] arm64: assembler: introduce ldr_this_cpu
From: Mark Rutland @ 2016-10-19 19:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476904234-9511-1-git-send-email-mark.rutland@arm.com>

Shortly we will want to load a percpu variable in the return from
userspace path. We can save an instruction by folding the addition of
the percpu offset into the load instruction, and this patch adds a new
helper to do so.

At the same time, we clean up this_cpu_ptr for consistency. As with
{adr,ldr,str}_l, we change the template to take the destination register
first, and name this dst. Secondly, we rename the macro to adr_this_cpu,
following the scheme of adr_l, and matching the newly added
ldr_this_cpu.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/assembler.h | 19 +++++++++++++++----
 arch/arm64/kernel/entry.S          |  2 +-
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 28bfe61..128a9ca 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -202,14 +202,25 @@
 	.endm
 
 	/*
+	 * @dst: Result of per_cpu(sym, smp_processor_id())
 	 * @sym: The name of the per-cpu variable
-	 * @reg: Result of per_cpu(sym, smp_processor_id())
 	 * @tmp: scratch register
 	 */
-	.macro this_cpu_ptr, sym, reg, tmp
-	adr_l	\reg, \sym
+	.macro adr_this_cpu, dst, sym, tmp
+	adr_l	\dst, \sym
 	mrs	\tmp, tpidr_el1
-	add	\reg, \reg, \tmp
+	add	\dst, \dst, \tmp
+	.endm
+
+	/*
+	 * @dst: Result of READ_ONCE(per_cpu(sym, smp_processor_id()))
+	 * @sym: The name of the per-cpu variable
+	 * @tmp: scratch register
+	 */
+	.macro ldr_this_cpu dst, sym, tmp
+	adr_l	\dst, \sym
+	mrs	\tmp, tpidr_el1
+	ldr	\dst, [\dst, \tmp]
 	.endm
 
 /*
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 223d54a..2d4c83b 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -200,7 +200,7 @@ alternative_else_nop_endif
 	cmp	x25, tsk
 	b.ne	9998f
 
-	this_cpu_ptr irq_stack, x25, x26
+	adr_this_cpu x25, irq_stack, x26
 	mov	x26, #IRQ_STACK_START_SP
 	add	x26, x25, x26
 
-- 
1.9.1

^ permalink raw reply related

* [PATCH 08/10] arm64: make cpu number a percpu variable
From: Mark Rutland @ 2016-10-19 19:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476904234-9511-1-git-send-email-mark.rutland@arm.com>

In the absence of CONFIG_THREAD_INFO_IN_TASK, core code maintains
thread_info::cpu, and low-level architecture code can access this to
build raw_smp_processor_id(). With CONFIG_THREAD_INFO_IN_TASK, core code
maintains task_struct::cpu, which for reasons of hte header soup is not
accessible to low-level arch code.

Instead, we can maintain a percpu variable containing the cpu number.
Non-preemptible code will receive the current CPU's number, while
preemptible code may race (as was previosuly the case), and see a stale
value. Thus, there shouldn't be a change in observable behaviour.

For both the old and new implementation of raw_smp_processor_id(), we
read a syreg into a GPR, add an offset, and load the result. As the
offset is now large, it probably won't be folded into the load, but
otherwise the assembly shouldn't change much.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/smp.h | 6 +++++-
 arch/arm64/kernel/smp.c      | 5 +++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h
index 0226447..f77ac0d 100644
--- a/arch/arm64/include/asm/smp.h
+++ b/arch/arm64/include/asm/smp.h
@@ -29,11 +29,15 @@
 
 #ifndef __ASSEMBLY__
 
+#include <asm/percpu.h>
+
 #include <linux/threads.h>
 #include <linux/cpumask.h>
 #include <linux/thread_info.h>
 
-#define raw_smp_processor_id() (current_thread_info()->cpu)
+DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number);
+
+#define raw_smp_processor_id() (*this_cpu_ptr(&cpu_number))
 
 struct seq_file;
 
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 7af46bf..2679722 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -58,6 +58,9 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/ipi.h>
 
+DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number);
+EXPORT_PER_CPU_SYMBOL(cpu_number);
+
 /*
  * as from 2.5, kernels no longer have an init_tasks structure
  * so we need some other way of telling a new secondary core
@@ -718,6 +721,8 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 	 */
 	for_each_possible_cpu(cpu) {
 
+		per_cpu(cpu_number, cpu) = cpu;
+
 		if (cpu == smp_processor_id())
 			continue;
 
-- 
1.9.1

^ permalink raw reply related

* [PATCH 07/10] arm64: smp: prepare for smp_processor_id() rework
From: Mark Rutland @ 2016-10-19 19:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476904234-9511-1-git-send-email-mark.rutland@arm.com>

Subsequent patches will make smp_processor_id() use a percpu variable.
This will make smp_processor_id() dependent on the percpu offset, and
thus we cannot use smp_processor_id() to figure out what to initialise
the offset to.

Prepare for this by initialising the percpu offset based on
current::cpu, which will work regardless of how smp_processor_id() is
implemented. Also, make this relationship obvious by placing this code
together at the start of secondary_start_kernel().

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/kernel/smp.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index d3f151c..7af46bf 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -208,7 +208,10 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
 asmlinkage void secondary_start_kernel(void)
 {
 	struct mm_struct *mm = &init_mm;
-	unsigned int cpu = smp_processor_id();
+	unsigned int cpu;
+
+	cpu = task_cpu(current);
+	set_my_cpu_offset(per_cpu_offset(cpu));
 
 	/*
 	 * All kernel threads share the same mm context; grab a
@@ -217,8 +220,6 @@ asmlinkage void secondary_start_kernel(void)
 	atomic_inc(&mm->mm_count);
 	current->active_mm = mm;
 
-	set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
-
 	/*
 	 * TTBR0 is only used for the identity mapping at this stage. Make it
 	 * point to zero page to avoid speculatively fetching new entries.
-- 
1.9.1

^ permalink raw reply related

* [PATCH 06/10] arm64: move sp_el0 and tpidr_el1 into cpu_suspend_ctx
From: Mark Rutland @ 2016-10-19 19:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476904234-9511-1-git-send-email-mark.rutland@arm.com>

When returning from idle, we rely on the fact that thread_info lives at
the end of the kernel stack, and restore this by masking the saved stack
pointer. Subsequent patches will sever the relationship between the
stack and thread_info, and to cater for this we must save/restore sp_el0
explicitly, storing it in cpu_suspend_ctx.

As cpu_suspend_ctx must be doubleword aligned, this leaves us with an
extra slot in cpu_suspend_ctx. We can use this to save/restore tpidr_el1
in the same way, which simplifies the code, avoiding pointer chasing on
the restore path (as we no longer need to load thread_info::cpu followed
by the relevant slot in __per_cpu_offset based on this).

This patch stashes both registers in cpu_suspend_ctx.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/suspend.h | 2 +-
 arch/arm64/kernel/sleep.S        | 3 ---
 arch/arm64/kernel/suspend.c      | 6 ------
 arch/arm64/mm/proc.S             | 6 ++++++
 4 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/suspend.h b/arch/arm64/include/asm/suspend.h
index b8a313f..de5600f 100644
--- a/arch/arm64/include/asm/suspend.h
+++ b/arch/arm64/include/asm/suspend.h
@@ -1,7 +1,7 @@
 #ifndef __ASM_SUSPEND_H
 #define __ASM_SUSPEND_H
 
-#define NR_CTX_REGS 10
+#define NR_CTX_REGS 12
 #define NR_CALLEE_SAVED_REGS 12
 
 /*
diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index b8799e7..5062fd9 100644
--- a/arch/arm64/kernel/sleep.S
+++ b/arch/arm64/kernel/sleep.S
@@ -125,9 +125,6 @@ ENTRY(_cpu_resume)
 	/* load sp from context */
 	ldr	x2, [x0, #CPU_CTX_SP]
 	mov	sp, x2
-	/* save thread_info */
-	and	x2, x2, #~(THREAD_SIZE - 1)
-	msr	sp_el0, x2
 	/*
 	 * cpu_do_resume expects x0 to contain context address pointer
 	 */
diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c
index ad73414..7db5620 100644
--- a/arch/arm64/kernel/suspend.c
+++ b/arch/arm64/kernel/suspend.c
@@ -44,12 +44,6 @@ void notrace __cpu_suspend_exit(void)
 	cpu_uninstall_idmap();
 
 	/*
-	 * Restore per-cpu offset before any kernel
-	 * subsystem relying on it has a chance to run.
-	 */
-	set_my_cpu_offset(per_cpu_offset(cpu));
-
-	/*
 	 * Restore HW breakpoint registers to sane values
 	 * before debug exceptions are possibly reenabled
 	 * through local_dbg_restore.
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 352c73b..6a853a8 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -70,11 +70,14 @@ ENTRY(cpu_do_suspend)
 	mrs	x8, mdscr_el1
 	mrs	x9, oslsr_el1
 	mrs	x10, sctlr_el1
+	mrs	x11, tpidr_el1
+	mrs	x12, sp_el0
 	stp	x2, x3, [x0]
 	stp	x4, xzr, [x0, #16]
 	stp	x5, x6, [x0, #32]
 	stp	x7, x8, [x0, #48]
 	stp	x9, x10, [x0, #64]
+	stp	x11, x12, [x0, #80]
 	ret
 ENDPROC(cpu_do_suspend)
 
@@ -90,6 +93,7 @@ ENTRY(cpu_do_resume)
 	ldp	x6, x8, [x0, #32]
 	ldp	x9, x10, [x0, #48]
 	ldp	x11, x12, [x0, #64]
+	ldp	x13, x14, [x0, #80]
 	msr	tpidr_el0, x2
 	msr	tpidrro_el0, x3
 	msr	contextidr_el1, x4
@@ -112,6 +116,8 @@ ENTRY(cpu_do_resume)
 	msr	mdscr_el1, x10
 
 	msr	sctlr_el1, x12
+	msr	tpidr_el1, x13
+	msr	sp_el0, x14
 	/*
 	 * Restore oslsr_el1 by writing oslar_el1
 	 */
-- 
1.9.1

^ permalink raw reply related

* [PATCH 05/10] arm64: prep stack walkers for THREAD_INFO_IN_TASK
From: Mark Rutland @ 2016-10-19 19:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476904234-9511-1-git-send-email-mark.rutland@arm.com>

When CONFIG_THREAD_INFO_IN_TASK is selected, task stacks may be freed
before a task is destroyed. To account for this, the stacks are
refcounted, and when manipulating the stack of another task, it is
necessary to get/put the stack to ensure it isn't freed and/or re-used
while we do so.

This patch reworks the arm64 stack walking code to account for this.
When CONFIG_THREAD_INFO_IN_TASK is not selected these perform no
refcounting, and this should only be a structural change that does not
affect behaviour.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/kernel/process.c    | 20 ++++++++++++++------
 arch/arm64/kernel/stacktrace.c |  5 +++++
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 27b2f13..2f39036 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -340,27 +340,35 @@ struct task_struct *__switch_to(struct task_struct *prev,
 unsigned long get_wchan(struct task_struct *p)
 {
 	struct stackframe frame;
-	unsigned long stack_page;
+	unsigned long stack_page, ret = 0;
 	int count = 0;
 	if (!p || p == current || p->state == TASK_RUNNING)
 		return 0;
 
+	stack_page = (unsigned long)try_get_task_stack(p);
+	if (!stack_page)
+		return 0;
+
 	frame.fp = thread_saved_fp(p);
 	frame.sp = thread_saved_sp(p);
 	frame.pc = thread_saved_pc(p);
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	frame.graph = p->curr_ret_stack;
 #endif
-	stack_page = (unsigned long)task_stack_page(p);
 	do {
 		if (frame.sp < stack_page ||
 		    frame.sp >= stack_page + THREAD_SIZE ||
 		    unwind_frame(p, &frame))
-			return 0;
-		if (!in_sched_functions(frame.pc))
-			return frame.pc;
+			goto out;
+		if (!in_sched_functions(frame.pc)) {
+			ret = frame.pc;
+			goto out;
+		}
 	} while (count ++ < 16);
-	return 0;
+
+out:
+	put_task_stack(p);
+	return ret;
 }
 
 unsigned long arch_align_stack(unsigned long sp)
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 5b80068..c77e5b6 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -182,6 +182,9 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 	struct stack_trace_data data;
 	struct stackframe frame;
 
+	if (!try_get_task_stack(tsk))
+		return;
+
 	data.trace = trace;
 	data.skip = trace->skip;
 
@@ -203,6 +206,8 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 	walk_stackframe(tsk, &frame, save_trace, &data);
 	if (trace->nr_entries < trace->max_entries)
 		trace->entries[trace->nr_entries++] = ULONG_MAX;
+
+	put_task_stack(tsk);
 }
 
 void save_stack_trace(struct stack_trace *trace)
-- 
1.9.1

^ permalink raw reply related

* [PATCH 04/10] arm64: traps: simplify die() and __die()
From: Mark Rutland @ 2016-10-19 19:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476904234-9511-1-git-send-email-mark.rutland@arm.com>

In arm64's die and __die routines we pass around a thread_info, and
subsequently use this to determine the relevant task_struct, and the end
of the thread's stack. Subsequent patches will decouple thread_info from
the stack, and this approach will no longer work.

To figure out the end of the stack, we can use the new generic
end_of_stack() helper. As we only call __die() from die(), and die()
always deals with the current task, we can remove the parameter and have
both acquire current directly, which also makes it clear that __die
can't be called for arbitrary tasks.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/kernel/traps.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 32d4bdb..1cfbe10 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -228,10 +228,9 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
 #endif
 #define S_SMP " SMP"
 
-static int __die(const char *str, int err, struct thread_info *thread,
-		 struct pt_regs *regs)
+static int __die(const char *str, int err, struct pt_regs *regs)
 {
-	struct task_struct *tsk = thread->task;
+	struct task_struct *tsk = current;
 	static int die_counter;
 	int ret;
 
@@ -246,7 +245,8 @@ static int __die(const char *str, int err, struct thread_info *thread,
 	print_modules();
 	__show_regs(regs);
 	pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
-		 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);
+		 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk),
+		 end_of_stack(tsk));
 
 	if (!user_mode(regs)) {
 		dump_mem(KERN_EMERG, "Stack: ", regs->sp,
@@ -265,7 +265,6 @@ static int __die(const char *str, int err, struct thread_info *thread,
  */
 void die(const char *str, struct pt_regs *regs, int err)
 {
-	struct thread_info *thread = current_thread_info();
 	int ret;
 
 	oops_enter();
@@ -273,9 +272,9 @@ void die(const char *str, struct pt_regs *regs, int err)
 	raw_spin_lock_irq(&die_lock);
 	console_verbose();
 	bust_spinlocks(1);
-	ret = __die(str, err, thread, regs);
+	ret = __die(str, err, regs);
 
-	if (regs && kexec_should_crash(thread->task))
+	if (regs && kexec_should_crash(current))
 		crash_kexec(regs);
 
 	bust_spinlocks(0);
-- 
1.9.1

^ permalink raw reply related

* [PATCH 03/10] arm64: factor out current_stack_pointer
From: Mark Rutland @ 2016-10-19 19:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476904234-9511-1-git-send-email-mark.rutland@arm.com>

We define current_stack_pointer in <asm/thread_info.h>, though other
files and header relying upon it do not have this necessary include, and
are thus fragile to changes in the header soup.

Subsequent patches will affect the header soup such that directly
including <asm/thread_info.h> may result in a circular header include in
some of these cases, so we can't simply include <asm/thread_info.h>.

Instead, factor current_thread_info into its own header, and have all
existing users include this explicitly.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/percpu.h        | 2 ++
 arch/arm64/include/asm/perf_event.h    | 2 ++
 arch/arm64/include/asm/stack_pointer.h | 9 +++++++++
 arch/arm64/include/asm/thread_info.h   | 6 +-----
 arch/arm64/kernel/return_address.c     | 1 +
 arch/arm64/kernel/stacktrace.c         | 1 +
 arch/arm64/kernel/traps.c              | 1 +
 7 files changed, 17 insertions(+), 5 deletions(-)
 create mode 100644 arch/arm64/include/asm/stack_pointer.h

diff --git a/arch/arm64/include/asm/percpu.h b/arch/arm64/include/asm/percpu.h
index 2fee2f5..2127a41 100644
--- a/arch/arm64/include/asm/percpu.h
+++ b/arch/arm64/include/asm/percpu.h
@@ -16,6 +16,8 @@
 #ifndef __ASM_PERCPU_H
 #define __ASM_PERCPU_H
 
+#include <asm/stack_pointer.h>
+
 static inline void set_my_cpu_offset(unsigned long off)
 {
 	asm volatile("msr tpidr_el1, %0" :: "r" (off) : "memory");
diff --git a/arch/arm64/include/asm/perf_event.h b/arch/arm64/include/asm/perf_event.h
index 2065f46..9eee2be 100644
--- a/arch/arm64/include/asm/perf_event.h
+++ b/arch/arm64/include/asm/perf_event.h
@@ -17,6 +17,8 @@
 #ifndef __ASM_PERF_EVENT_H
 #define __ASM_PERF_EVENT_H
 
+#include <asm/stack_pointer.h>
+
 #define	ARMV8_PMU_MAX_COUNTERS	32
 #define	ARMV8_PMU_COUNTER_MASK	(ARMV8_PMU_MAX_COUNTERS - 1)
 
diff --git a/arch/arm64/include/asm/stack_pointer.h b/arch/arm64/include/asm/stack_pointer.h
new file mode 100644
index 0000000..ffcdf74
--- /dev/null
+++ b/arch/arm64/include/asm/stack_pointer.h
@@ -0,0 +1,9 @@
+#ifndef __ASM_STACK_POINTER_H
+#define __ASM_STACK_POINTER_H
+
+/*
+ * how to get the current stack pointer from C
+ */
+register unsigned long current_stack_pointer asm ("sp");
+
+#endif /* __ASM_STACK_POINTER_H */
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 76a9559..3a4f85d 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -36,6 +36,7 @@
 
 struct task_struct;
 
+#include <asm/stack_pointer.h>
 #include <asm/types.h>
 
 typedef unsigned long mm_segment_t;
@@ -62,11 +63,6 @@ struct thread_info {
 #define init_stack		(init_thread_union.stack)
 
 /*
- * how to get the current stack pointer from C
- */
-register unsigned long current_stack_pointer asm ("sp");
-
-/*
  * how to get the thread information struct from C
  */
 static inline struct thread_info *current_thread_info(void) __attribute_const__;
diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c
index 1718706..12a87f2 100644
--- a/arch/arm64/kernel/return_address.c
+++ b/arch/arm64/kernel/return_address.c
@@ -12,6 +12,7 @@
 #include <linux/export.h>
 #include <linux/ftrace.h>
 
+#include <asm/stack_pointer.h>
 #include <asm/stacktrace.h>
 
 struct return_address_data {
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index c2efddf..5b80068 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -22,6 +22,7 @@
 #include <linux/stacktrace.h>
 
 #include <asm/irq.h>
+#include <asm/stack_pointer.h>
 #include <asm/stacktrace.h>
 
 /*
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 5ff020f..32d4bdb 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -38,6 +38,7 @@
 #include <asm/esr.h>
 #include <asm/insn.h>
 #include <asm/traps.h>
+#include <asm/stack_pointer.h>
 #include <asm/stacktrace.h>
 #include <asm/exception.h>
 #include <asm/system_misc.h>
-- 
1.9.1

^ permalink raw reply related

* [PATCH 02/10] arm64: asm-offsets: remove unused definitions
From: Mark Rutland @ 2016-10-19 19:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476904234-9511-1-git-send-email-mark.rutland@arm.com>

Subsequent patches will move the thread_info::{task,cpu} fields, and the
current TI_{TASK,CPU} offset definitions are not used anywhere.

This patch removes the redundant definitions.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/kernel/asm-offsets.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index 4a2f0f0..d30b232 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -39,8 +39,6 @@ int main(void)
   DEFINE(TI_FLAGS,		offsetof(struct thread_info, flags));
   DEFINE(TI_PREEMPT,		offsetof(struct thread_info, preempt_count));
   DEFINE(TI_ADDR_LIMIT,		offsetof(struct thread_info, addr_limit));
-  DEFINE(TI_TASK,		offsetof(struct thread_info, task));
-  DEFINE(TI_CPU,		offsetof(struct thread_info, cpu));
   BLANK();
   DEFINE(THREAD_CPU_CONTEXT,	offsetof(struct task_struct, thread.cpu_context));
   BLANK();
-- 
1.9.1

^ permalink raw reply related

* [PATCH 01/10] arm64: thread_info remove stale items
From: Mark Rutland @ 2016-10-19 19:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476904234-9511-1-git-send-email-mark.rutland@arm.com>

We have a comment claiming __switch_to() cares about where cpu_context
is located relative to cpu_domain in thread_info. However arm64 has
never had a thread_info::cpu_domain field, and neither __switch_to nor
cpu_switch_to care where the cpu_context field is relative to others.

Additionally, the init_thread_info alias is never used anywhere in the
kernel, and will shortly become problematic when thread_info is moved
into task_struct.

This patch removes both.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/thread_info.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index e9ea5a6..76a9559 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -42,7 +42,6 @@
 
 /*
  * low level task data that entry.S needs immediate access to.
- * __switch_to() assumes cpu_context follows immediately after cpu_domain.
  */
 struct thread_info {
 	unsigned long		flags;		/* low level flags */
@@ -60,7 +59,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,					\
 }
 
-#define init_thread_info	(init_thread_union.thread_info)
 #define init_stack		(init_thread_union.stack)
 
 /*
-- 
1.9.1

^ permalink raw reply related


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