[5/5] firmware: google memconsole: Add ARM/ARM64 support
diff mbox series

Message ID 1490303069-13230-6-git-send-email-thierry.escande@collabora.com
State New, archived
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Series
  • firmware: google memconsole
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Commit Message

Thierry Escande March 23, 2017, 9:04 p.m. UTC
This patch expands the Google firmware memory console driver to also
work on certain tree based platforms running coreboot, such as ARM/ARM64
Chromebooks. This patch now adds another path to find the coreboot table
through the device tree. In order to find that, a second level
bootloader must have installed the 'coreboot' compatible device tree
node that describes its base address and size.

This patch is a rework/split/merge of patches from the chromeos v4.4
kernel tree originally authored by:
 Wei-Ning Huang <wnhuang@chromium.org>
 Julius Werner <jwerner@chromium.org>
 Brian Norris <briannorris@chromium.org>

Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
---
 drivers/firmware/google/Kconfig             | 13 ++++-
 drivers/firmware/google/Makefile            |  1 +
 drivers/firmware/google/coreboot_table-of.c | 82 +++++++++++++++++++++++++++++
 3 files changed, 94 insertions(+), 2 deletions(-)
 create mode 100644 drivers/firmware/google/coreboot_table-of.c

Comments

Mark Rutland March 24, 2017, 12:28 p.m. UTC | #1
On Thu, Mar 23, 2017 at 10:04:29PM +0100, Thierry Escande wrote:
> This patch expands the Google firmware memory console driver to also
> work on certain tree based platforms running coreboot, such as ARM/ARM64
> Chromebooks. This patch now adds another path to find the coreboot table
> through the device tree. In order to find that, a second level
> bootloader must have installed the 'coreboot' compatible device tree
> node that describes its base address and size.

What exactly is the "memory console"? Is it a log that coreboot writes into?

[...]

> +static const struct of_device_id coreboot_of_match[] = {
> +	{ .compatible = "coreboot" },
> +	{},
> +};
> +
> +static struct platform_driver coreboot_table_of_driver = {
> +	.probe = coreboot_table_of_probe,
> +	.remove = coreboot_table_of_remove,
> +	.driver = {
> +		.name = "coreboot_table_of",
> +		.of_match_table = coreboot_of_match,
> +	},
> +};
> +
> +static int __init platform_coreboot_table_of_init(void)
> +{
> +	struct platform_device *pdev;
> +	struct device_node *of_node;
> +
> +	/* Limit device creation to the presence of /firmware/coreboot node */
> +	of_node = of_find_node_by_path("/firmware/coreboot");
> +	if (!of_node)
> +		return -ENODEV;
> +

I don't beleive that you need this module init function. Please use the
usual DT probing infrastrucutre instead, e.g. add:

MODULE_DEVICE_TABLE(of, coreboot_of_match);
module_platform_driver(coreboot_table_of_driver);

Thanks,
Mark.
Brian Norris March 24, 2017, 6 p.m. UTC | #2
On Fri, Mar 24, 2017 at 12:28:59PM +0000, Mark Rutland wrote:
> On Thu, Mar 23, 2017 at 10:04:29PM +0100, Thierry Escande wrote:
> > +static const struct of_device_id coreboot_of_match[] = {
> > +	{ .compatible = "coreboot" },
> > +	{},
> > +};
> > +
> > +static struct platform_driver coreboot_table_of_driver = {
> > +	.probe = coreboot_table_of_probe,
> > +	.remove = coreboot_table_of_remove,
> > +	.driver = {
> > +		.name = "coreboot_table_of",
> > +		.of_match_table = coreboot_of_match,
> > +	},
> > +};
> > +
> > +static int __init platform_coreboot_table_of_init(void)
> > +{
> > +	struct platform_device *pdev;
> > +	struct device_node *of_node;
> > +
> > +	/* Limit device creation to the presence of /firmware/coreboot node */
> > +	of_node = of_find_node_by_path("/firmware/coreboot");
> > +	if (!of_node)
> > +		return -ENODEV;
> > +
> 
> I don't beleive that you need this module init function. Please use the
> usual DT probing infrastrucutre instead, e.g. add:
> 
> MODULE_DEVICE_TABLE(of, coreboot_of_match);
> module_platform_driver(coreboot_table_of_driver);

That doesn't work. If this node is placed under /firmware, which isn't a
proper "bus", then we have to explicitly look for the sub-device.

Due to this, the MODULE_DEVICE_TABLE() also isn't useful, because the
/firmware/coreboot/ device won't be generated automatically, and so no
matching uevent will occur.

Brian
Julius Werner March 24, 2017, 7:50 p.m. UTC | #3
> What exactly is the "memory console"? Is it a log that coreboot writes into?

Yes. It contains log messages, like coreboot's equivalent of dmesg.
kbuild test robot March 26, 2017, 1:41 a.m. UTC | #4
Hi Thierry,

[auto build test ERROR on linus/master]
[also build test ERROR on v4.11-rc3]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Thierry-Escande/firmware-google-memconsole/20170326-080828
config: ia64-allmodconfig (attached as .config)
compiler: ia64-linux-gcc (GCC) 6.2.0
reproduce:
        wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=ia64 

All errors (new ones prefixed by >>):

   drivers/firmware/google/gsmi.c: In function 'gsmi_exec.constprop':
>> drivers/firmware/google/gsmi.c:198:3: error: inconsistent operand constraints in an 'asm'
      asm volatile (
      ^~~
   drivers/firmware/google/gsmi.c:213:3: error: inconsistent operand constraints in an 'asm'
      asm volatile (
      ^~~
   drivers/firmware/google/gsmi.c:229:3: error: inconsistent operand constraints in an 'asm'
      asm volatile (
      ^~~

vim +/asm +198 drivers/firmware/google/gsmi.c

74c5b31c Mike Waychison 2011-04-29  182  	/*
74c5b31c Mike Waychison 2011-04-29  183  	 * AH  : Subfunction number
74c5b31c Mike Waychison 2011-04-29  184  	 * AL  : Function number
74c5b31c Mike Waychison 2011-04-29  185  	 * EBX : Parameter block address
74c5b31c Mike Waychison 2011-04-29  186  	 * DX  : SMI command port
74c5b31c Mike Waychison 2011-04-29  187  	 *
74c5b31c Mike Waychison 2011-04-29  188  	 * Three protocols here. See also the comment in gsmi_init().
74c5b31c Mike Waychison 2011-04-29  189  	 */
74c5b31c Mike Waychison 2011-04-29  190  	if (gsmi_dev.handshake_type == GSMI_HANDSHAKE_CF) {
74c5b31c Mike Waychison 2011-04-29  191  		/*
74c5b31c Mike Waychison 2011-04-29  192  		 * If handshake_type == HANDSHAKE_CF then set CF on the
74c5b31c Mike Waychison 2011-04-29  193  		 * way in and wait for the handler to clear it; this avoids
74c5b31c Mike Waychison 2011-04-29  194  		 * corrupting register state on those chipsets which have
74c5b31c Mike Waychison 2011-04-29  195  		 * a delay between writing the SMI trigger register and
74c5b31c Mike Waychison 2011-04-29  196  		 * entering SMM.
74c5b31c Mike Waychison 2011-04-29  197  		 */
74c5b31c Mike Waychison 2011-04-29 @198  		asm volatile (
74c5b31c Mike Waychison 2011-04-29  199  			"stc\n"
74c5b31c Mike Waychison 2011-04-29  200  			"outb %%al, %%dx\n"
74c5b31c Mike Waychison 2011-04-29  201  		"1:      jc 1b\n"
74c5b31c Mike Waychison 2011-04-29  202  			: "=a" (result)
74c5b31c Mike Waychison 2011-04-29  203  			: "0" (cmd),
74c5b31c Mike Waychison 2011-04-29  204  			  "d" (gsmi_dev.smi_cmd),
74c5b31c Mike Waychison 2011-04-29  205  			  "b" (gsmi_dev.param_buf->address)
74c5b31c Mike Waychison 2011-04-29  206  			: "memory", "cc"

:::::: The code at line 198 was first introduced by commit
:::::: 74c5b31c6618f01079212332b2e5f6c42f2d6307 driver: Google EFI SMI

:::::: TO: Mike Waychison <mikew@google.com>
:::::: CC: Greg Kroah-Hartman <gregkh@suse.de>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Brian Norris March 27, 2017, 4:56 p.m. UTC | #5
Hi Thierry,

In case this wasn't obvious from the build report:

On Thu, Mar 23, 2017 at 10:04:29PM +0100, Thierry Escande wrote:
> --- a/drivers/firmware/google/Kconfig
> +++ b/drivers/firmware/google/Kconfig
> @@ -1,6 +1,5 @@
>  menuconfig GOOGLE_FIRMWARE
>  	bool "Google Firmware Drivers"
> -	depends on X86

The build bots complained: you're relaxing the compile-time restriction
here, so you should probably move it to the GOOGLE_SMI symbol, since
that file uses X86 assembly.

>  	default n
>  	help
>  	  These firmware drivers are used by Google's servers.  They are
> @@ -21,7 +20,7 @@ config GOOGLE_SMI
>  
>  config GOOGLE_COREBOOT_TABLE
>  	tristate
> -	depends on GOOGLE_COREBOOT_TABLE_ACPI
> +	depends on GOOGLE_COREBOOT_TABLE_ACPI || GOOGLE_COREBOOT_TABLE_OF
>  
>  config GOOGLE_COREBOOT_TABLE_ACPI
>  	tristate "Coreboot Table Access - ACPI"
> @@ -33,6 +32,16 @@ config GOOGLE_COREBOOT_TABLE_ACPI
>  	  pointer is accessed through the ACPI "GOOGCB00" object.
>  	  If unsure say N.
>  
> +config GOOGLE_COREBOOT_TABLE_OF
> +	tristate "Coreboot Table Access - Device Tree"
> +	depends on OF
> +	select GOOGLE_COREBOOT_TABLE
> +	help
> +	  This option enable the coreboot_table module, which provide other
> +	  firmware modules to access coreboot table. The coreboot table pointer
> +	  is accessed through the device tree node /firmware/coreboot.
> +	  If unsure say N.
> +
>  config GOOGLE_MEMCONSOLE
>  	tristate
>  	depends on GOOGLE_MEMCONSOLE_X86_LEGACY || GOOGLE_MEMCONSOLE_COREBOOT

Brian

Patch
diff mbox series

diff --git a/drivers/firmware/google/Kconfig b/drivers/firmware/google/Kconfig
index 840bd62..baabd70 100644
--- a/drivers/firmware/google/Kconfig
+++ b/drivers/firmware/google/Kconfig
@@ -1,6 +1,5 @@ 
 menuconfig GOOGLE_FIRMWARE
 	bool "Google Firmware Drivers"
-	depends on X86
 	default n
 	help
 	  These firmware drivers are used by Google's servers.  They are
@@ -21,7 +20,7 @@  config GOOGLE_SMI
 
 config GOOGLE_COREBOOT_TABLE
 	tristate
-	depends on GOOGLE_COREBOOT_TABLE_ACPI
+	depends on GOOGLE_COREBOOT_TABLE_ACPI || GOOGLE_COREBOOT_TABLE_OF
 
 config GOOGLE_COREBOOT_TABLE_ACPI
 	tristate "Coreboot Table Access - ACPI"
@@ -33,6 +32,16 @@  config GOOGLE_COREBOOT_TABLE_ACPI
 	  pointer is accessed through the ACPI "GOOGCB00" object.
 	  If unsure say N.
 
+config GOOGLE_COREBOOT_TABLE_OF
+	tristate "Coreboot Table Access - Device Tree"
+	depends on OF
+	select GOOGLE_COREBOOT_TABLE
+	help
+	  This option enable the coreboot_table module, which provide other
+	  firmware modules to access coreboot table. The coreboot table pointer
+	  is accessed through the device tree node /firmware/coreboot.
+	  If unsure say N.
+
 config GOOGLE_MEMCONSOLE
 	tristate
 	depends on GOOGLE_MEMCONSOLE_X86_LEGACY || GOOGLE_MEMCONSOLE_COREBOOT
diff --git a/drivers/firmware/google/Makefile b/drivers/firmware/google/Makefile
index 662a83e..bb952c6 100644
--- a/drivers/firmware/google/Makefile
+++ b/drivers/firmware/google/Makefile
@@ -2,6 +2,7 @@ 
 obj-$(CONFIG_GOOGLE_SMI)		+= gsmi.o
 obj-$(CONFIG_GOOGLE_COREBOOT_TABLE)        += coreboot_table.o
 obj-$(CONFIG_GOOGLE_COREBOOT_TABLE_ACPI)   += coreboot_table-acpi.o
+obj-$(CONFIG_GOOGLE_COREBOOT_TABLE_OF)     += coreboot_table-of.o
 obj-$(CONFIG_GOOGLE_MEMCONSOLE)            += memconsole.o
 obj-$(CONFIG_GOOGLE_MEMCONSOLE_COREBOOT)   += memconsole-coreboot.o
 obj-$(CONFIG_GOOGLE_MEMCONSOLE_X86_LEGACY) += memconsole-x86-legacy.o
diff --git a/drivers/firmware/google/coreboot_table-of.c b/drivers/firmware/google/coreboot_table-of.c
new file mode 100644
index 0000000..727acdc
--- /dev/null
+++ b/drivers/firmware/google/coreboot_table-of.c
@@ -0,0 +1,82 @@ 
+/*
+ * coreboot_table-of.c
+ *
+ * Coreboot table access through open firmware.
+ *
+ * Copyright 2017 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License v2.0 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/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include "coreboot_table.h"
+
+static int coreboot_table_of_probe(struct platform_device *pdev)
+{
+	struct device_node *fw_dn = pdev->dev.of_node;
+	void __iomem *ptr;
+
+	ptr = of_iomap(fw_dn, 0);
+	of_node_put(fw_dn);
+	if (!ptr)
+		return -ENOMEM;
+
+	return coreboot_table_init(ptr);
+}
+
+static int coreboot_table_of_remove(struct platform_device *pdev)
+{
+	return coreboot_table_exit();
+}
+
+static const struct of_device_id coreboot_of_match[] = {
+	{ .compatible = "coreboot" },
+	{},
+};
+
+static struct platform_driver coreboot_table_of_driver = {
+	.probe = coreboot_table_of_probe,
+	.remove = coreboot_table_of_remove,
+	.driver = {
+		.name = "coreboot_table_of",
+		.of_match_table = coreboot_of_match,
+	},
+};
+
+static int __init platform_coreboot_table_of_init(void)
+{
+	struct platform_device *pdev;
+	struct device_node *of_node;
+
+	/* Limit device creation to the presence of /firmware/coreboot node */
+	of_node = of_find_node_by_path("/firmware/coreboot");
+	if (!of_node)
+		return -ENODEV;
+
+	if (!of_match_node(coreboot_of_match, of_node))
+		return -ENODEV;
+
+	pdev = of_platform_device_create(of_node, "coreboot_table_of", NULL);
+	if (!pdev)
+		return -ENODEV;
+
+	return platform_driver_register(&coreboot_table_of_driver);
+}
+
+module_init(platform_coreboot_table_of_init);
+
+MODULE_AUTHOR("Google, Inc.");
+MODULE_LICENSE("GPL");