[PATCH v4 0/5] efi/firmware/platform-x86: Add EFI embedded fw support

[PATCH v4 0/5] efi/firmware/platform-x86: Add EFI embedded fw support

[Hans de Goede]

Hi All,

Here is v4 of my patch-set to add support for EFI embedded fw to the kernel.

Changes since v3:
-Drop note in docs about EFI_FIRMWARE_VOLUME_PROTOCOL, it is not part of
 UEFI proper, so the EFI maintainers don't want us referring people to it
-Use new EFI_BOOT_SERVICES flag
-Put the new fw_get_efi_embedded_fw() function in its own fallback_efi.c
 file which only gets built when EFI_EMBEDDED_FIRMWARE is selected
-Define an empty stub for fw_get_efi_embedded_fw() in fallback.h hwen
 EFI_EMBEDDED_FIRMWARE is not selected, to avoid the need for #ifdefs
 in firmware_loader/main.c
-Properly call security_kernel_post_read_file() on the firmware returned
 by efi_get_embedded_fw() to make sure that we are allowed to use it

So I think this patch-set is getting close to ready for merging, which
brings us to the question of how to merge this, I think that patches 1
and 2 should probably both be merged through the same tree. Then an
unmutable branch should be created on that tree, merged into the
platform/x86 tree and then the last 3 patches can be merged through
that tree.

For the record, here is the coverletter of v2 of this patchset:

The 3 most prominent changes in v2 are:

1) Add documentation describing the EFI embedded firmware mechanism to:
   Documentation/driver-api/firmware/request_firmware.rst

2) Instead of having a single dmi_system_id array with its driver_data
   members pointing to efi_embedded_fw_desc structs, have the drivers which
   need EFI embedded-fw support export a dmi_system_id array and register
   that with the EFI embedded-fw code

   This series also includes the first driver to use this, in the form of
   the touchscreen_dmi code (formerly silead_dmi) from drivers/platfrom/x86

3) As discussed during the review of v1 we want to make the firmware_loader
   code fallback to EFI embedded-fw optional.  Rather the adding yet another
   firmware_request_foo variant for this, with the risk of later also needing
   firmware_request_foo_nowait, etc. variants I've decided to make the code
   check if the device has a "efi-embedded-firmware" device-property bool set.

   This also seemed better because the same driver may want to use the
   fallback on some systems, but not on others since e.g. not all (x86)
   systems with a silead touchscreen have their touchscreen firmware embedded
   in their EFI.

   Note that (as discussed) when the EFI fallback path is requested, the
   usermodehelper fallback path is skipped.

Here is the full changelog of patch 2/5 which is where most of the changes are:

Changes in v2:
-Rebased on driver-core/driver-core-next
-Add documentation describing the EFI embedded firmware mechanism to:
 Documentation/driver-api/firmware/request_firmware.rst
-Add a new EFI_EMBEDDED_FIRMWARE Kconfig bool and only build the embedded
 fw support if this is set. This is an invisible option which should be
 selected by drivers which need this
-Remove the efi_embedded_fw_desc and dmi_system_id-s for known devices
 from the efi-embedded-fw code, instead drivers using this are expected to
 export a dmi_system_id array, with each entries' driver_data pointing to a
 efi_embedded_fw_desc struct and register this with the efi-embedded-fw code
-Use kmemdup to make a copy instead of efi_mem_reserve()-ing the firmware,
 this avoids us messing with the EFI memmap and avoids the need to make
 changes to efi_mem_desc_lookup()
-Make the firmware-loader code only fallback to efi_get_embedded_fw() if the
 passed in device has the "efi-embedded-firmware" device-property bool set
-Skip usermodehelper fallback when "efi-embedded-firmware" device-property
 is set

Patches 3-5 are new and implement using the EFI embedded-fw mechanism for
Silead gslXXXX and Chipone icn8505 touchscreens on x86 devices.

Regards,

Hans

[PATCH v4 1/5] efi: Export boot-services code and data as debugfs-blobs

[Hans de Goede]

Sometimes it is useful to be able to dump the efi boot-services code and
data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
but only if efi=debug is passed on the kernel-commandline as this requires
not freeing those memory-regions, which costs 20+ MB of RAM.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v4:
-Add new EFI_BOOT_SERVICES flag and use it to determine if the boot-services
 memory segments are available (and thus if it makes sense to register the
 debugfs bits for them)

Changes in v2:
-Do not call pr_err on debugfs call failures
---
 arch/x86/platform/efi/efi.c    |  1 +
 arch/x86/platform/efi/quirks.c |  4 +++
 drivers/firmware/efi/efi.c     | 53 ++++++++++++++++++++++++++++++++++
 include/linux/efi.h            |  1 +
 4 files changed, 59 insertions(+)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 9061babfbc83..568b7ee3d323 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -208,6 +208,7 @@ int __init efi_memblock_x86_reserve_range(void)
 	     efi.memmap.desc_version);
 
 	memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
+	set_bit(EFI_BOOT_SERVICES, &efi.flags);
 
 	return 0;
 }
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 36c1f8b9f7e0..16bdb9e3b343 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -376,6 +376,10 @@ void __init efi_free_boot_services(void)
 	int num_entries = 0;
 	void *new, *new_md;
 
+	/* Keep all regions for /sys/kernel/debug/efi */
+	if (efi_enabled(EFI_DBG))
+		return;
+
 	for_each_efi_memory_desc(md) {
 		unsigned long long start = md->phys_addr;
 		unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 232f4915223b..498a720a7684 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -18,6 +18,7 @@
 #include <linux/kobject.h>
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/efi.h>
 #include <linux/of.h>
@@ -325,6 +326,55 @@ static __init int efivar_ssdt_load(void)
 static inline int efivar_ssdt_load(void) { return 0; }
 #endif
 
+#ifdef CONFIG_DEBUG_FS
+
+#define EFI_DEBUGFS_MAX_BLOBS 32
+
+static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS];
+
+static void __init efi_debugfs_init(void)
+{
+	struct dentry *efi_debugfs;
+	efi_memory_desc_t *md;
+	char name[32];
+	int type_count[EFI_BOOT_SERVICES_DATA + 1] = {};
+	int i = 0;
+
+	efi_debugfs = debugfs_create_dir("efi", NULL);
+	if (IS_ERR_OR_NULL(efi_debugfs))
+		return;
+
+	for_each_efi_memory_desc(md) {
+		switch (md->type) {
+		case EFI_BOOT_SERVICES_CODE:
+			snprintf(name, sizeof(name), "boot_services_code%d",
+				 type_count[md->type]++);
+			break;
+		case EFI_BOOT_SERVICES_DATA:
+			snprintf(name, sizeof(name), "boot_services_data%d",
+				 type_count[md->type]++);
+			break;
+		default:
+			continue;
+		}
+
+		debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT;
+		debugfs_blob[i].data = memremap(md->phys_addr,
+						debugfs_blob[i].size,
+						MEMREMAP_WB);
+		if (!debugfs_blob[i].data)
+			continue;
+
+		debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]);
+		i++;
+		if (i == EFI_DEBUGFS_MAX_BLOBS)
+			break;
+	}
+}
+#else
+static inline void efi_debugfs_init(void) {}
+#endif
+
 /*
  * We register the efi subsystem with the firmware subsystem and the
  * efivars subsystem with the efi subsystem, if the system was booted with
@@ -369,6 +419,9 @@ static int __init efisubsys_init(void)
 		goto err_remove_group;
 	}
 
+	if (efi_enabled(EFI_DBG) && efi_enabled(EFI_BOOT_SERVICES))
+		efi_debugfs_init();
+
 	return 0;
 
 err_remove_group:
diff --git a/include/linux/efi.h b/include/linux/efi.h
index f1b7d68ac460..396bf18ace5c 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1144,6 +1144,7 @@ extern int __init efi_setup_pcdp_console(char *);
 #define EFI_DBG			8	/* Print additional debug info at runtime */
 #define EFI_NX_PE_DATA		9	/* Can runtime data regions be mapped non-executable? */
 #define EFI_MEM_ATTR		10	/* Did firmware publish an EFI_MEMORY_ATTRIBUTES table? */
+#define EFI_BOOT_SERVICES	11	/* Are EFI boot-services memory segments available? */
 
 #ifdef CONFIG_EFI
 /*
-- 
2.17.0

[PATCH v4 2/5] efi: Add embedded peripheral firmware support

[Hans de Goede]

Just like with PCI options ROMs, which we save in the setup_efi_pci*
functions from arch/x86/boot/compressed/eboot.c, the EFI code / ROM itself
sometimes may contain data which is useful/necessary for peripheral drivers
to have access to.

Specifically the EFI code may contain an embedded copy of firmware which
needs to be (re)loaded into the peripheral. Normally such firmware would be
part of linux-firmware, but in some cases this is not feasible, for 2
reasons:

1) The firmware is customized for a specific use-case of the chipset / use
with a specific hardware model, so we cannot have a single firmware file
for the chipset. E.g. touchscreen controller firmwares are compiled
specifically for the hardware model they are used with, as they are
calibrated for a specific model digitizer.

2) Despite repeated attempts we have failed to get permission to
redistribute the firmware. This is especially a problem with customized
firmwares, these get created by the chip vendor for a specific ODM and the
copyright may partially belong with the ODM, so the chip vendor cannot
give a blanket permission to distribute these.

This commit adds support for finding peripheral firmware embedded in the
EFI code and making this available to peripheral drivers through the
standard firmware loading mechanism.

Note we check the EFI_BOOT_SERVICES_CODE for embedded firmware near the end
of start_kernel(), just before calling rest_init(), this is on purpose
because the typical EFI_BOOT_SERVICES_CODE memory-segment is too large for
early_memremap(), so the check must be done after mm_init(). This relies
on EFI_BOOT_SERVICES_CODE not being free-ed until efi_free_boot_services()
is called, which means that this will only work on x86 for now.

Reported-by: Dave Olsthoorn <dave@bewaar.me>
Suggested-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v4:
-Drop note in docs about EFI_FIRMWARE_VOLUME_PROTOCOL, it is not part of
 UEFI proper, so the EFI maintainers don't want us referring people to it
-Use new EFI_BOOT_SERVICES flag
-Put the new fw_get_efi_embedded_fw() function in its own fallback_efi.c
 file which only gets built when EFI_EMBEDDED_FIRMWARE is selected
-Define an empty stub for fw_get_efi_embedded_fw() in fallback.h hwen
 EFI_EMBEDDED_FIRMWARE is not selected, to avoid the need for #ifdefs
 in firmware_loader/main.c
-Properly call security_kernel_post_read_file() on the firmware returned
 by efi_get_embedded_fw() to make sure that we are allowed to use it

Changes in v3:
-Fix the docs using "efi-embedded-fw" as property name instead of
 "efi-embedded-firmware"

Changes in v2:
-Rebased on driver-core/driver-core-next
-Add documentation describing the EFI embedded firmware mechanism to:
 Documentation/driver-api/firmware/request_firmware.rst
-Add a new EFI_EMBEDDED_FIRMWARE Kconfig bool and only build the embedded
 fw support if this is set. This is an invisible option which should be
 selected by drivers which need this
-Remove the efi_embedded_fw_desc and dmi_system_id-s for known devices
 from the efi-embedded-fw code, instead drivers using this are expected to
 export a dmi_system_id array, with each entries' driver_data pointing to a
 efi_embedded_fw_desc struct and register this with the efi-embedded-fw code
-Use kmemdup to make a copy instead of efi_mem_reserve()-ing the firmware,
 this avoids us messing with the EFI memmap and avoids the need to make
 changes to efi_mem_desc_lookup()
-Make the firmware-loader code only fallback to efi_get_embedded_fw() if the
 passed in device has the "efi-embedded-firmware" device-property bool set
-Skip usermodehelper fallback when "efi-embedded-firmware" device-property
 is set
---
 .../driver-api/firmware/request_firmware.rst  |  66 ++++++++
 drivers/base/firmware_loader/Makefile         |   1 +
 drivers/base/firmware_loader/fallback.h       |  12 ++
 drivers/base/firmware_loader/fallback_efi.c   |  51 ++++++
 drivers/base/firmware_loader/main.c           |   4 +
 drivers/firmware/efi/Kconfig                  |   3 +
 drivers/firmware/efi/Makefile                 |   1 +
 drivers/firmware/efi/embedded-firmware.c      | 152 ++++++++++++++++++
 include/linux/efi.h                           |   6 +
 include/linux/efi_embedded_fw.h               |  25 +++
 init/main.c                                   |   3 +
 11 files changed, 324 insertions(+)
 create mode 100644 drivers/base/firmware_loader/fallback_efi.c
 create mode 100644 drivers/firmware/efi/embedded-firmware.c
 create mode 100644 include/linux/efi_embedded_fw.h

diff --git a/Documentation/driver-api/firmware/request_firmware.rst b/Documentation/driver-api/firmware/request_firmware.rst
index c8bddbdcfd10..560dfed76e38 100644
--- a/Documentation/driver-api/firmware/request_firmware.rst
+++ b/Documentation/driver-api/firmware/request_firmware.rst
@@ -73,3 +73,69 @@ If something went wrong firmware_request() returns non-zero and fw_entry
 is set to NULL. Once your driver is done with processing the firmware it
 can call call firmware_release(fw_entry) to release the firmware image
 and any related resource.
+
+EFI embedded firmware support
+=============================
+
+On some devices the system's EFI code / ROM may contain an embedded copy
+of firmware for some of the system's integrated peripheral devices and
+the peripheral's Linux device-driver needs to access this firmware.
+
+A device driver which needs this can describe the firmware it needs
+using an efi_embedded_fw_desc struct:
+
+.. kernel-doc:: include/linux/efi_embedded_fw.h
+   :functions: efi_embedded_fw_desc
+
+The EFI embedded-fw code works by scanning all EFI_BOOT_SERVICES_CODE memory
+segments for an eight byte sequence matching prefix, if the prefix is found it
+then does a crc32 over length bytes and if that matches makes a copy of length
+bytes and adds that to its list with found firmwares.
+
+To avoid doing this somewhat expensive scan on all systems, dmi matching is
+used. Drivers are expected to export a dmi_system_id array, with each entries'
+driver_data pointing to an efi_embedded_fw_desc.
+
+To register this array with the efi-embedded-fw code, a driver needs to:
+
+1. Always be builtin to the kernel or store the dmi_system_id array in a
+   separate object file which always gets builtin.
+
+2. Add an extern declaration for the dmi_system_id array to
+   include/linux/efi_embedded_fw.h.
+
+3. Add the dmi_system_id array to the embedded_fw_table in
+   drivers/firmware/efi/embedded-firmware.c wrapped in a #ifdef testing that
+   the driver is being builtin.
+
+4. Add "select EFI_EMBEDDED_FIRMWARE if EFI_STUB" to its Kconfig entry.
+
+The request_firmware() function will always first try to load firmware with
+the specified name directly from the disk, so the EFI embedded-fw can always
+be overridden by placing a file under /lib/firmare.
+
+To make request_firmware() fallback to trying EFI embedded firmwares after this,
+the driver must set a boolean "efi-embedded-firmware" device-property on the
+device before passing it to request_firmware(). Note that this disables the
+usual usermodehelper fallback, so you may want to only set this on systems
+which match your dmi_system_id array.
+
+Once the device-property is set, the driver can use the regular
+request_firmware() function to get the firmware, using the name filled in
+in the efi_embedded_fw_desc.
+
+Note that:
+
+1. The code scanning for EFI embbedded-firmware runs near the end
+   of start_kernel(), just before calling rest_init(). For normal drivers and
+   subsystems using subsys_initcall() to register themselves this does not
+   matter. This means that code running earlier cannot use EFI
+   embbedded-firmware.
+
+2. ATM the EFI embedded-fw code assumes that firmwares always start at an offset
+   which is a multiple of 8 bytes, if this is not true for your case send in
+   a patch to fix this.
+
+3. ATM the EFI embedded-fw code only works on x86 because other archs free
+   EFI_BOOT_SERVICES_CODE before the EFI embedded-fw code gets a chance to
+   scan it.
diff --git a/drivers/base/firmware_loader/Makefile b/drivers/base/firmware_loader/Makefile
index a97eeb0be1d8..365a040995d3 100644
--- a/drivers/base/firmware_loader/Makefile
+++ b/drivers/base/firmware_loader/Makefile
@@ -5,3 +5,4 @@ obj-y			:= fallback_table.o
 obj-$(CONFIG_FW_LOADER)	+= firmware_class.o
 firmware_class-objs := main.o
 firmware_class-$(CONFIG_FW_LOADER_USER_HELPER) += fallback.o
+firmware_class-$(CONFIG_EFI_EMBEDDED_FIRMWARE) += fallback_efi.o
diff --git a/drivers/base/firmware_loader/fallback.h b/drivers/base/firmware_loader/fallback.h
index 8cfaa3299bb7..92f462415d25 100644
--- a/drivers/base/firmware_loader/fallback.h
+++ b/drivers/base/firmware_loader/fallback.h
@@ -66,4 +66,16 @@ static inline void unregister_sysfs_loader(void)
 }
 #endif /* CONFIG_FW_LOADER_USER_HELPER */
 
+#ifdef CONFIG_EFI_EMBEDDED_FIRMWARE
+int fw_get_efi_embedded_fw(struct device *dev, struct fw_priv *fw_priv,
+			   enum fw_opt *opt_flags, int ret);
+#else
+static inline int fw_get_efi_embedded_fw(struct device *dev,
+					 struct fw_priv *fw_priv,
+					 enum fw_opt *opt_flags, int ret)
+{
+	return ret;
+}
+#endif /* CONFIG_EFI_EMBEDDED_FIRMWARE */
+
 #endif /* __FIRMWARE_FALLBACK_H */
diff --git a/drivers/base/firmware_loader/fallback_efi.c b/drivers/base/firmware_loader/fallback_efi.c
new file mode 100644
index 000000000000..82ba82f48a79
--- /dev/null
+++ b/drivers/base/firmware_loader/fallback_efi.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/efi_embedded_fw.h>
+#include <linux/property.h>
+#include <linux/security.h>
+#include <linux/vmalloc.h>
+
+#include "fallback.h"
+#include "firmware.h"
+
+int fw_get_efi_embedded_fw(struct device *dev, struct fw_priv *fw_priv,
+			   enum fw_opt *opt_flags, int ret)
+{
+	enum kernel_read_file_id id = READING_FIRMWARE;
+	size_t size, max = INT_MAX;
+	int rc;
+
+	if (!dev)
+		return ret;
+
+	if (!device_property_read_bool(dev, "efi-embedded-firmware"))
+		return ret;
+
+	*opt_flags |= FW_OPT_NO_WARN | FW_OPT_NOCACHE | FW_OPT_NOFALLBACK;
+
+	/* Already populated data member means we're loading into a buffer */
+	if (fw_priv->data) {
+		id = READING_FIRMWARE_PREALLOC_BUFFER;
+		max = fw_priv->allocated_size;
+	}
+
+	rc = efi_get_embedded_fw(fw_priv->fw_name, &fw_priv->data, &size, max);
+	if (rc) {
+		dev_warn(dev, "Firmware %s not in EFI\n", fw_priv->fw_name);
+		return ret;
+	}
+
+	rc = security_kernel_post_read_file(NULL, fw_priv->data, size, id);
+	if (rc) {
+		if (id != READING_FIRMWARE_PREALLOC_BUFFER) {
+			vfree(fw_priv->data);
+			fw_priv->data = NULL;
+		}
+		return rc;
+	}
+
+	dev_dbg(dev, "using efi-embedded fw %s\n", fw_priv->fw_name);
+	fw_priv->size = size;
+	fw_state_done(fw_priv);
+	return 0;
+}
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index f009566acd35..adcc248f7b91 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -33,6 +33,8 @@
 #include <linux/syscore_ops.h>
 #include <linux/reboot.h>
 #include <linux/security.h>
+#include <linux/efi_embedded_fw.h>
+#include <linux/property.h>
 
 #include <generated/utsrelease.h>
 
@@ -576,6 +578,8 @@ _firmware_request(const struct firmware **firmware_p, const char *name,
 		goto out;
 
 	ret = fw_get_filesystem_firmware(device, fw->priv);
+	if (ret)
+		ret = fw_get_efi_embedded_fw(device, fw->priv, &opt_flags, ret);
 	if (ret) {
 		if (!(opt_flags & FW_OPT_NO_WARN))
 			dev_warn(device,
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 3098410abad8..faefeff7fb34 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -164,6 +164,9 @@ config RESET_ATTACK_MITIGATION
 	  have been evicted, since otherwise it will trigger even on clean
 	  reboots.
 
+config EFI_EMBEDDED_FIRMWARE
+	bool
+
 endmenu
 
 config UEFI_CPER
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index cb805374f4bc..dde12cea8aac 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_EFI_BOOTLOADER_CONTROL)	+= efibc.o
 obj-$(CONFIG_EFI_TEST)			+= test/
 obj-$(CONFIG_EFI_DEV_PATH_PARSER)	+= dev-path-parser.o
 obj-$(CONFIG_APPLE_PROPERTIES)		+= apple-properties.o
+obj-$(CONFIG_EFI_EMBEDDED_FIRMWARE)	+= embedded-firmware.o
 
 arm-obj-$(CONFIG_EFI)			:= arm-init.o arm-runtime.o
 obj-$(CONFIG_ARM)			+= $(arm-obj-y)
diff --git a/drivers/firmware/efi/embedded-firmware.c b/drivers/firmware/efi/embedded-firmware.c
new file mode 100644
index 000000000000..ef6282945307
--- /dev/null
+++ b/drivers/firmware/efi/embedded-firmware.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Support for extracting embedded firmware for peripherals from EFI code,
+ *
+ * Copyright (c) 2018 Hans de Goede <hdegoede@redhat.com>
+ */
+
+#include <linux/crc32.h>
+#include <linux/dmi.h>
+#include <linux/efi.h>
+#include <linux/efi_embedded_fw.h>
+#include <linux/io.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+
+struct embedded_fw {
+	struct list_head list;
+	const char *name;
+	void *data;
+	size_t length;
+};
+
+static LIST_HEAD(found_fw_list);
+
+static const struct dmi_system_id * const embedded_fw_table[] = {
+	NULL
+};
+
+/*
+ * Note the efi_check_for_embedded_firmwares() code currently makes the
+ * following 2 assumptions. This may needs to be revisited if embedded firmware
+ * is found where this is not true:
+ * 1) The firmware is only found in EFI_BOOT_SERVICES_CODE memory segments
+ * 2) The firmware always starts at an offset which is a multiple of 8 bytes
+ */
+static int __init efi_check_md_for_embedded_firmware(
+	efi_memory_desc_t *md, const struct efi_embedded_fw_desc *desc)
+{
+	struct embedded_fw *fw;
+	u64 i, size;
+	u32 crc;
+	u8 *mem;
+
+	size = md->num_pages << EFI_PAGE_SHIFT;
+	mem = memremap(md->phys_addr, size, MEMREMAP_WB);
+	if (!mem) {
+		pr_err("Error mapping EFI mem at %#llx\n", md->phys_addr);
+		return -ENOMEM;
+	}
+
+	size -= desc->length;
+	for (i = 0; i < size; i += 8) {
+		if (*((u64 *)(mem + i)) != *((u64 *)desc->prefix))
+			continue;
+
+		/* Seed with ~0, invert to match crc32 userspace utility */
+		crc = ~crc32(~0, mem + i, desc->length);
+		if (crc == desc->crc)
+			break;
+	}
+
+	memunmap(mem);
+
+	if (i >= size)
+		return -ENOENT;
+
+	pr_info("Found EFI embedded fw '%s' crc %08x\n", desc->name, desc->crc);
+
+	fw = kmalloc(sizeof(*fw), GFP_KERNEL);
+	if (!fw)
+		return -ENOMEM;
+
+	mem = memremap(md->phys_addr + i, desc->length, MEMREMAP_WB);
+	if (!mem) {
+		pr_err("Error mapping embedded firmware\n");
+		goto error_free_fw;
+	}
+	fw->data = kmemdup(mem, desc->length, GFP_KERNEL);
+	memunmap(mem);
+	if (!fw->data)
+		goto error_free_fw;
+
+	fw->name = desc->name;
+	fw->length = desc->length;
+	list_add(&fw->list, &found_fw_list);
+
+	return 0;
+
+error_free_fw:
+	kfree(fw);
+	return -ENOMEM;
+}
+
+void __init efi_check_for_embedded_firmwares(void)
+{
+	const struct efi_embedded_fw_desc *fw_desc;
+	const struct dmi_system_id *dmi_id;
+	efi_memory_desc_t *md;
+	int i, r;
+
+	if (!efi_enabled(EFI_BOOT_SERVICES))
+		return;
+
+	for (i = 0; embedded_fw_table[i]; i++) {
+		dmi_id = dmi_first_match(embedded_fw_table[i]);
+		if (!dmi_id)
+			continue;
+
+		fw_desc = dmi_id->driver_data;
+		for_each_efi_memory_desc(md) {
+			if (md->type != EFI_BOOT_SERVICES_CODE)
+				continue;
+
+			r = efi_check_md_for_embedded_firmware(md, fw_desc);
+			if (r == 0)
+				break;
+		}
+	}
+}
+
+int efi_get_embedded_fw(const char *name, void **data, size_t *size,
+			size_t msize)
+{
+	struct embedded_fw *iter, *fw = NULL;
+	void *buf = *data;
+
+	list_for_each_entry(iter, &found_fw_list, list) {
+		if (strcmp(name, iter->name) == 0) {
+			fw = iter;
+			break;
+		}
+	}
+
+	if (!fw)
+		return -ENOENT;
+
+	if (msize && msize < fw->length)
+		return -EFBIG;
+
+	if (!buf) {
+		buf = vmalloc(fw->length);
+		if (!buf)
+			return -ENOMEM;
+	}
+
+	memcpy(buf, fw->data, fw->length);
+	*size = fw->length;
+	*data = buf;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(efi_get_embedded_fw);
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 396bf18ace5c..fc1ea2cee210 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1575,6 +1575,12 @@ static inline void
 efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg) { }
 #endif
 
+#ifdef CONFIG_EFI_EMBEDDED_FIRMWARE
+void efi_check_for_embedded_firmwares(void);
+#else
+static inline void efi_check_for_embedded_firmwares(void) { }
+#endif
+
 void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table);
 
 /*
diff --git a/include/linux/efi_embedded_fw.h b/include/linux/efi_embedded_fw.h
new file mode 100644
index 000000000000..0f7d4df3f57a
--- /dev/null
+++ b/include/linux/efi_embedded_fw.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_EFI_EMBEDDED_FW_H
+#define _LINUX_EFI_EMBEDDED_FW_H
+
+#include <linux/mod_devicetable.h>
+
+/**
+ * struct efi_embedded_fw_desc - This struct is used by the EFI embedded-fw
+ *                               code to search for embedded firmwares.
+ *
+ * @name:   Name to register the firmware with if found
+ * @prefix: First 8 bytes of the firmware
+ * @length: Length of the firmware in bytes including prefix
+ * @crc:    Inverted little endian Ethernet style CRC32, with 0xffffffff seed
+ */
+struct efi_embedded_fw_desc {
+	const char *name;
+	u8 prefix[8];
+	u32 length;
+	u32 crc;
+};
+
+int efi_get_embedded_fw(const char *name, void **dat, size_t *sz, size_t msize);
+
+#endif
diff --git a/init/main.c b/init/main.c
index b795aa341a3a..be48ff4a1f60 100644
--- a/init/main.c
+++ b/init/main.c
@@ -729,6 +729,9 @@ asmlinkage __visible void __init start_kernel(void)
 	arch_post_acpi_subsys_init();
 	sfi_init_late();
 
+	if (efi_enabled(EFI_BOOT_SERVICES))
+		efi_check_for_embedded_firmwares();
+
 	if (efi_enabled(EFI_RUNTIME_SERVICES)) {
 		efi_free_boot_services();
 	}
-- 
2.17.0

[PATCH v4 3/5] platform/x86: Rename silead_dmi to touchscreen_dmi

[Hans de Goede]

Not only silead touchscreens need some extra info not available in the
ACPI tables to work properly. X86 devices with a Chipone ICN8505 chip also
need some DMI based extra configuration.

There is no reason to have separate dmi config code per touchscreen
controller vendor. This commit renames silead_dmi to a more generic
touchscreen_dmi name (and Kconfig option) in preparation of adding
info for tablets with an ICN8505 based touchscreen.

Note there are no functional changes all code changes are limited to
removing references to silead where these are no longer applicable.

Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 MAINTAINERS                                   |  2 +-
 drivers/platform/x86/Kconfig                  | 16 ++---
 drivers/platform/x86/Makefile                 |  2 +-
 .../x86/{silead_dmi.c => touchscreen_dmi.c}   | 66 +++++++++----------
 4 files changed, 43 insertions(+), 43 deletions(-)
 rename drivers/platform/x86/{silead_dmi.c => touchscreen_dmi.c} (87%)

diff --git a/MAINTAINERS b/MAINTAINERS
index bee29977a3bd..5a215bcd6660 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12795,7 +12795,7 @@ L:	linux-input@vger.kernel.org
 L:	platform-driver-x86@vger.kernel.org
 S:	Maintained
 F:	drivers/input/touchscreen/silead.c
-F:	drivers/platform/x86/silead_dmi.c
+F:	drivers/platform/x86/touchscreen_dmi.c
 
 SILICON MOTION SM712 FRAME BUFFER DRIVER
 M:	Sudip Mukherjee <sudipm.mukherjee@gmail.com>
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 39d06dd1f63a..7ff206e5edfe 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -1196,16 +1196,16 @@ config INTEL_TURBO_MAX_3
 	  This driver is only required when the system is not using Hardware
 	  P-States (HWP). In HWP mode, priority can be read from ACPI tables.
 
-config SILEAD_DMI
-	bool "Tablets with Silead touchscreens"
+config TOUCHSCREEN_DMI
+	bool "DMI based touchscreen configuration info"
 	depends on ACPI && DMI && I2C=y && TOUCHSCREEN_SILEAD
 	---help---
-	  Certain ACPI based tablets with Silead touchscreens do not have
-	  enough data in ACPI tables for the touchscreen driver to handle
-	  the touchscreen properly, as OEMs expected the data to be baked
-	  into the tablet model specific version of the driver shipped
-	  with the OS-image for the device. This option supplies the missing
-	  information. Enable this for x86 tablets with Silead touchscreens.
+	  Certain ACPI based tablets with e.g. Silead or Chipone touchscreens
+	  do not have enough data in ACPI tables for the touchscreen driver to
+	  handle the touchscreen properly, as OEMs expect the data to be baked
+	  into the tablet model specific version of the driver shipped with the
+	  the OS-image for the device. This option supplies the missing info.
+	  Enable this for x86 tablets with Silead or Chipone touchscreens.
 
 config INTEL_CHTDC_TI_PWRBTN
 	tristate "Intel Cherry Trail Dollar Cove TI power button driver"
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 2ba6cb795338..8d9477114fb5 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -78,7 +78,7 @@ obj-$(CONFIG_INTEL_SMARTCONNECT)	+= intel-smartconnect.o
 obj-$(CONFIG_PVPANIC)           += pvpanic.o
 obj-$(CONFIG_ALIENWARE_WMI)	+= alienware-wmi.o
 obj-$(CONFIG_INTEL_PMC_IPC)	+= intel_pmc_ipc.o
-obj-$(CONFIG_SILEAD_DMI)	+= silead_dmi.o
+obj-$(CONFIG_TOUCHSCREEN_DMI)	+= touchscreen_dmi.o
 obj-$(CONFIG_SURFACE_PRO3_BUTTON)	+= surfacepro3_button.o
 obj-$(CONFIG_SURFACE_3_BUTTON)	+= surface3_button.o
 obj-$(CONFIG_INTEL_PUNIT_IPC)  += intel_punit_ipc.o
diff --git a/drivers/platform/x86/silead_dmi.c b/drivers/platform/x86/touchscreen_dmi.c
similarity index 87%
rename from drivers/platform/x86/silead_dmi.c
rename to drivers/platform/x86/touchscreen_dmi.c
index 452aacabaa8e..87fc839b28f7 100644
--- a/drivers/platform/x86/silead_dmi.c
+++ b/drivers/platform/x86/touchscreen_dmi.c
@@ -1,5 +1,5 @@
 /*
- * Silead touchscreen driver DMI based configuration code
+ * Touchscreen driver DMI based configuration code
  *
  * Copyright (c) 2017 Red Hat Inc.
  *
@@ -20,7 +20,7 @@
 #include <linux/property.h>
 #include <linux/string.h>
 
-struct silead_ts_dmi_data {
+struct ts_dmi_data {
 	const char *acpi_name;
 	const struct property_entry *properties;
 };
@@ -34,7 +34,7 @@ static const struct property_entry cube_iwork8_air_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data cube_iwork8_air_data = {
+static const struct ts_dmi_data cube_iwork8_air_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= cube_iwork8_air_props,
 };
@@ -48,7 +48,7 @@ static const struct property_entry jumper_ezpad_mini3_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data jumper_ezpad_mini3_data = {
+static const struct ts_dmi_data jumper_ezpad_mini3_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= jumper_ezpad_mini3_props,
 };
@@ -62,7 +62,7 @@ static const struct property_entry dexp_ursus_7w_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data dexp_ursus_7w_data = {
+static const struct ts_dmi_data dexp_ursus_7w_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= dexp_ursus_7w_props,
 };
@@ -77,7 +77,7 @@ static const struct property_entry surftab_twin_10_1_st10432_8_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data surftab_twin_10_1_st10432_8_data = {
+static const struct ts_dmi_data surftab_twin_10_1_st10432_8_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= surftab_twin_10_1_st10432_8_props,
 };
@@ -92,7 +92,7 @@ static const struct property_entry surftab_wintron70_st70416_6_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data surftab_wintron70_st70416_6_data = {
+static const struct ts_dmi_data surftab_wintron70_st70416_6_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= surftab_wintron70_st70416_6_props,
 };
@@ -107,7 +107,7 @@ static const struct property_entry gp_electronic_t701_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data gp_electronic_t701_data = {
+static const struct ts_dmi_data gp_electronic_t701_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= gp_electronic_t701_props,
 };
@@ -122,7 +122,7 @@ static const struct property_entry pipo_w2s_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data pipo_w2s_data = {
+static const struct ts_dmi_data pipo_w2s_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= pipo_w2s_props,
 };
@@ -137,7 +137,7 @@ static const struct property_entry pov_mobii_wintab_p800w_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data pov_mobii_wintab_p800w_data = {
+static const struct ts_dmi_data pov_mobii_wintab_p800w_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= pov_mobii_wintab_p800w_props,
 };
@@ -151,7 +151,7 @@ static const struct property_entry itworks_tw891_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data itworks_tw891_data = {
+static const struct ts_dmi_data itworks_tw891_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= itworks_tw891_props,
 };
@@ -165,7 +165,7 @@ static const struct property_entry chuwi_hi8_pro_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data chuwi_hi8_pro_data = {
+static const struct ts_dmi_data chuwi_hi8_pro_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= chuwi_hi8_pro_props,
 };
@@ -181,7 +181,7 @@ static const struct property_entry digma_citi_e200_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data digma_citi_e200_data = {
+static const struct ts_dmi_data digma_citi_e200_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= digma_citi_e200_props,
 };
@@ -198,7 +198,7 @@ static const struct property_entry onda_obook_20_plus_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data onda_obook_20_plus_data = {
+static const struct ts_dmi_data onda_obook_20_plus_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= onda_obook_20_plus_props,
 };
@@ -212,7 +212,7 @@ static const struct property_entry chuwi_hi8_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data chuwi_hi8_data = {
+static const struct ts_dmi_data chuwi_hi8_data = {
 	.acpi_name      = "MSSL0001:00",
 	.properties     = chuwi_hi8_props,
 };
@@ -227,7 +227,7 @@ static const struct property_entry chuwi_vi8_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data chuwi_vi8_data = {
+static const struct ts_dmi_data chuwi_vi8_data = {
 	.acpi_name      = "MSSL1680:00",
 	.properties     = chuwi_vi8_props,
 };
@@ -242,7 +242,7 @@ static const struct property_entry trekstor_primebook_c13_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data trekstor_primebook_c13_data = {
+static const struct ts_dmi_data trekstor_primebook_c13_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= trekstor_primebook_c13_props,
 };
@@ -258,7 +258,7 @@ static const struct property_entry teclast_x98plus2_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data teclast_x98plus2_data = {
+static const struct ts_dmi_data teclast_x98plus2_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= teclast_x98plus2_props,
 };
@@ -272,12 +272,12 @@ static const struct property_entry teclast_x3_plus_props[] = {
 	{ }
 };
 
-static const struct silead_ts_dmi_data teclast_x3_plus_data = {
+static const struct ts_dmi_data teclast_x3_plus_data = {
 	.acpi_name	= "MSSL1680:00",
 	.properties	= teclast_x3_plus_props,
 };
 
-static const struct dmi_system_id silead_ts_dmi_table[] = {
+static const struct dmi_system_id touchscreen_dmi_table[] = {
 	{
 		/* CUBE iwork8 Air */
 		.driver_data = (void *)&cube_iwork8_air_data,
@@ -466,22 +466,22 @@ static const struct dmi_system_id silead_ts_dmi_table[] = {
 	{ },
 };
 
-static const struct silead_ts_dmi_data *silead_ts_data;
+static const struct ts_dmi_data *ts_data;
 
-static void silead_ts_dmi_add_props(struct i2c_client *client)
+static void ts_dmi_add_props(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	int error;
 
 	if (has_acpi_companion(dev) &&
-	    !strncmp(silead_ts_data->acpi_name, client->name, I2C_NAME_SIZE)) {
-		error = device_add_properties(dev, silead_ts_data->properties);
+	    !strncmp(ts_data->acpi_name, client->name, I2C_NAME_SIZE)) {
+		error = device_add_properties(dev, ts_data->properties);
 		if (error)
 			dev_err(dev, "failed to add properties: %d\n", error);
 	}
 }
 
-static int silead_ts_dmi_notifier_call(struct notifier_block *nb,
+static int ts_dmi_notifier_call(struct notifier_block *nb,
 				       unsigned long action, void *data)
 {
 	struct device *dev = data;
@@ -491,7 +491,7 @@ static int silead_ts_dmi_notifier_call(struct notifier_block *nb,
 	case BUS_NOTIFY_ADD_DEVICE:
 		client = i2c_verify_client(dev);
 		if (client)
-			silead_ts_dmi_add_props(client);
+			ts_dmi_add_props(client);
 		break;
 
 	default:
@@ -501,22 +501,22 @@ static int silead_ts_dmi_notifier_call(struct notifier_block *nb,
 	return 0;
 }
 
-static struct notifier_block silead_ts_dmi_notifier = {
-	.notifier_call = silead_ts_dmi_notifier_call,
+static struct notifier_block ts_dmi_notifier = {
+	.notifier_call = ts_dmi_notifier_call,
 };
 
-static int __init silead_ts_dmi_init(void)
+static int __init ts_dmi_init(void)
 {
 	const struct dmi_system_id *dmi_id;
 	int error;
 
-	dmi_id = dmi_first_match(silead_ts_dmi_table);
+	dmi_id = dmi_first_match(touchscreen_dmi_table);
 	if (!dmi_id)
 		return 0; /* Not an error */
 
-	silead_ts_data = dmi_id->driver_data;
+	ts_data = dmi_id->driver_data;
 
-	error = bus_register_notifier(&i2c_bus_type, &silead_ts_dmi_notifier);
+	error = bus_register_notifier(&i2c_bus_type, &ts_dmi_notifier);
 	if (error)
 		pr_err("%s: failed to register i2c bus notifier: %d\n",
 			__func__, error);
@@ -529,4 +529,4 @@ static int __init silead_ts_dmi_init(void)
  * itself is ready (which happens at postcore initcall level), but before
  * ACPI starts enumerating devices (at subsys initcall level).
  */
-arch_initcall(silead_ts_dmi_init);
+arch_initcall(ts_dmi_init);
-- 
2.17.0

[PATCH v4 4/5] platform/x86: touchscreen_dmi: Add EFI embedded firmware info support

[Hans de Goede]

Sofar we have been unable to get permission from the vendors to put the
firmware for touchscreens listed in touchscreen_dmi in linux-firmware.

Some of the tablets with such a touchscreen have a touchscreen driver, and
thus a copy of the firmware, as part of their EFI code.

This commit adds the necessary info for the new EFI embedded-firmware code
to extract these firmwares, making the touchscreen work OOTB without the
user needing to manually add the firmware.

Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/firmware/efi/embedded-firmware.c |  3 +++
 drivers/platform/x86/Kconfig             |  1 +
 drivers/platform/x86/touchscreen_dmi.c   | 26 +++++++++++++++++++++++-
 include/linux/efi_embedded_fw.h          |  2 ++
 4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/embedded-firmware.c b/drivers/firmware/efi/embedded-firmware.c
index ef6282945307..bbc6d218a82d 100644
--- a/drivers/firmware/efi/embedded-firmware.c
+++ b/drivers/firmware/efi/embedded-firmware.c
@@ -23,6 +23,9 @@ struct embedded_fw {
 static LIST_HEAD(found_fw_list);
 
 static const struct dmi_system_id * const embedded_fw_table[] = {
+#ifdef CONFIG_TOUCHSCREEN_DMI
+	touchscreen_dmi_table,
+#endif
 	NULL
 };
 
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 7ff206e5edfe..cc4d95459190 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -1199,6 +1199,7 @@ config INTEL_TURBO_MAX_3
 config TOUCHSCREEN_DMI
 	bool "DMI based touchscreen configuration info"
 	depends on ACPI && DMI && I2C=y && TOUCHSCREEN_SILEAD
+	select EFI_EMBEDDED_FIRMWARE if EFI
 	---help---
 	  Certain ACPI based tablets with e.g. Silead or Chipone touchscreens
 	  do not have enough data in ACPI tables for the touchscreen driver to
diff --git a/drivers/platform/x86/touchscreen_dmi.c b/drivers/platform/x86/touchscreen_dmi.c
index 87fc839b28f7..6488cd50ba79 100644
--- a/drivers/platform/x86/touchscreen_dmi.c
+++ b/drivers/platform/x86/touchscreen_dmi.c
@@ -15,12 +15,15 @@
 #include <linux/acpi.h>
 #include <linux/device.h>
 #include <linux/dmi.h>
+#include <linux/efi_embedded_fw.h>
 #include <linux/i2c.h>
 #include <linux/notifier.h>
 #include <linux/property.h>
 #include <linux/string.h>
 
 struct ts_dmi_data {
+	/* The EFI embedded-fw code expects this to be the first member! */
+	struct efi_embedded_fw_desc embedded_fw;
 	const char *acpi_name;
 	const struct property_entry *properties;
 };
@@ -31,10 +34,17 @@ static const struct property_entry cube_iwork8_air_props[] = {
 	PROPERTY_ENTRY_BOOL("touchscreen-swapped-x-y"),
 	PROPERTY_ENTRY_STRING("firmware-name", "gsl3670-cube-iwork8-air.fw"),
 	PROPERTY_ENTRY_U32("silead,max-fingers", 10),
+	PROPERTY_ENTRY_BOOL("efi-embedded-firmware"),
 	{ }
 };
 
 static const struct ts_dmi_data cube_iwork8_air_data = {
+	.embedded_fw = {
+		.name	= "silead/gsl3670-cube-iwork8-air.fw",
+		.prefix = { 0xf0, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00 },
+		.length	= 38808,
+		.crc	= 0xfecde51f,
+	},
 	.acpi_name	= "MSSL1680:00",
 	.properties	= cube_iwork8_air_props,
 };
@@ -119,10 +129,17 @@ static const struct property_entry pipo_w2s_props[] = {
 	PROPERTY_ENTRY_BOOL("touchscreen-swapped-x-y"),
 	PROPERTY_ENTRY_STRING("firmware-name",
 			      "gsl1680-pipo-w2s.fw"),
+	PROPERTY_ENTRY_BOOL("efi-embedded-firmware"),
 	{ }
 };
 
 static const struct ts_dmi_data pipo_w2s_data = {
+	.embedded_fw = {
+		.name	= "silead/gsl1680-pipo-w2s.fw",
+		.prefix = { 0xf0, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00 },
+		.length	= 39072,
+		.crc	= 0x28d5dc6c,
+	},
 	.acpi_name	= "MSSL1680:00",
 	.properties	= pipo_w2s_props,
 };
@@ -162,10 +179,17 @@ static const struct property_entry chuwi_hi8_pro_props[] = {
 	PROPERTY_ENTRY_BOOL("touchscreen-swapped-x-y"),
 	PROPERTY_ENTRY_STRING("firmware-name", "gsl3680-chuwi-hi8-pro.fw"),
 	PROPERTY_ENTRY_BOOL("silead,home-button"),
+	PROPERTY_ENTRY_BOOL("efi-embedded-firmware"),
 	{ }
 };
 
 static const struct ts_dmi_data chuwi_hi8_pro_data = {
+	.embedded_fw = {
+		.name	= "silead/gsl3680-chuwi-hi8-pro.fw",
+		.prefix = { 0xf0, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00 },
+		.length	= 39864,
+		.crc	= 0xfe2bedba,
+	},
 	.acpi_name	= "MSSL1680:00",
 	.properties	= chuwi_hi8_pro_props,
 };
@@ -277,7 +301,7 @@ static const struct ts_dmi_data teclast_x3_plus_data = {
 	.properties	= teclast_x3_plus_props,
 };
 
-static const struct dmi_system_id touchscreen_dmi_table[] = {
+const struct dmi_system_id touchscreen_dmi_table[] = {
 	{
 		/* CUBE iwork8 Air */
 		.driver_data = (void *)&cube_iwork8_air_data,
diff --git a/include/linux/efi_embedded_fw.h b/include/linux/efi_embedded_fw.h
index 0f7d4df3f57a..4c8cfe38ec02 100644
--- a/include/linux/efi_embedded_fw.h
+++ b/include/linux/efi_embedded_fw.h
@@ -20,6 +20,8 @@ struct efi_embedded_fw_desc {
 	u32 crc;
 };
 
+extern const struct dmi_system_id touchscreen_dmi_table[];
+
 int efi_get_embedded_fw(const char *name, void **dat, size_t *sz, size_t msize);
 
 #endif
-- 
2.17.0

[PATCH v4 5/5] platform/x86: touchscreen_dmi: Add info for the Chuwi Vi8 Plus tablet

[Hans de Goede]

Add touchscreen info for the Chuwi Vi8 Plus tablet. This tablet uses a
Chipone ICN8505 touchscreen controller, with the firmware used by the
touchscreen embedded in the EFI firmware.

Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/platform/x86/touchscreen_dmi.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/platform/x86/touchscreen_dmi.c b/drivers/platform/x86/touchscreen_dmi.c
index 6488cd50ba79..5fdb6fe878f4 100644
--- a/drivers/platform/x86/touchscreen_dmi.c
+++ b/drivers/platform/x86/touchscreen_dmi.c
@@ -301,6 +301,22 @@ static const struct ts_dmi_data teclast_x3_plus_data = {
 	.properties	= teclast_x3_plus_props,
 };
 
+static const struct property_entry efi_embedded_fw_props[] = {
+	PROPERTY_ENTRY_BOOL("efi-embedded-firmware"),
+	{ }
+};
+
+static const struct ts_dmi_data chuwi_vi8_plus_data = {
+	.embedded_fw = {
+		.name	= "chipone/icn8505-HAMP0002.fw",
+		.prefix = { 0xb0, 0x07, 0x00, 0x00, 0xe4, 0x07, 0x00, 0x00 },
+		.length	= 35012,
+		.crc	= 0x74dfd3fc,
+	},
+	.acpi_name	= "CHPN0001:00",
+	.properties	= efi_embedded_fw_props,
+};
+
 const struct dmi_system_id touchscreen_dmi_table[] = {
 	{
 		/* CUBE iwork8 Air */
@@ -487,6 +503,15 @@ const struct dmi_system_id touchscreen_dmi_table[] = {
 			DMI_MATCH(DMI_PRODUCT_NAME, "Y8W81"),
 		},
 	},
+	{
+		/* Chuwi Vi8 Plus (CWI506) */
+		.driver_data = (void *)&chuwi_vi8_plus_data,
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Hampoo"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "D2D3_Vi8A1"),
+			DMI_MATCH(DMI_BOARD_NAME, "Cherry Trail CR"),
+		},
+	},
 	{ },
 };
 
-- 
2.17.0

Re: [PATCH v4 1/5] efi: Export boot-services code and data as debugfs-blobs

[Ard Biesheuvel]

On 26 April 2018 at 14:06, Hans de Goede <hdegoede@redhat.com> wrote:
> Sometimes it is useful to be able to dump the efi boot-services code and
> data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
> but only if efi=debug is passed on the kernel-commandline as this requires
> not freeing those memory-regions, which costs 20+ MB of RAM.
>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Changes in v4:
> -Add new EFI_BOOT_SERVICES flag and use it to determine if the boot-services
>  memory segments are available (and thus if it makes sense to register the
>  debugfs bits for them)
>
> Changes in v2:
> -Do not call pr_err on debugfs call failures
> ---
>  arch/x86/platform/efi/efi.c    |  1 +
>  arch/x86/platform/efi/quirks.c |  4 +++
>  drivers/firmware/efi/efi.c     | 53 ++++++++++++++++++++++++++++++++++
>  include/linux/efi.h            |  1 +
>  4 files changed, 59 insertions(+)
>
> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> index 9061babfbc83..568b7ee3d323 100644
> --- a/arch/x86/platform/efi/efi.c
> +++ b/arch/x86/platform/efi/efi.c
> @@ -208,6 +208,7 @@ int __init efi_memblock_x86_reserve_range(void)
>              efi.memmap.desc_version);
>
>         memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
> +       set_bit(EFI_BOOT_SERVICES, &efi.flags);
>

I think it would be better if the flag conveys whether boot services
regions are being preserved, because they will always exist when
EFI_BOOT is set.
The name should then reflect that as well, e.g., EFI_PRESERVE_BS_REGIONS.

>         return 0;
>  }
> diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
> index 36c1f8b9f7e0..16bdb9e3b343 100644
> --- a/arch/x86/platform/efi/quirks.c
> +++ b/arch/x86/platform/efi/quirks.c
> @@ -376,6 +376,10 @@ void __init efi_free_boot_services(void)
>         int num_entries = 0;
>         void *new, *new_md;
>
> +       /* Keep all regions for /sys/kernel/debug/efi */
> +       if (efi_enabled(EFI_DBG))
> +               return;
> +

Why is this only necessary when EFI_DBG is enabled? How are you
ensuring that the firmware is still in memory when the subsequent
patches start relying on that?


>         for_each_efi_memory_desc(md) {
>                 unsigned long long start = md->phys_addr;
>                 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 232f4915223b..498a720a7684 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -18,6 +18,7 @@
>  #include <linux/kobject.h>
>  #include <linux/module.h>
>  #include <linux/init.h>
> +#include <linux/debugfs.h>
>  #include <linux/device.h>
>  #include <linux/efi.h>
>  #include <linux/of.h>
> @@ -325,6 +326,55 @@ static __init int efivar_ssdt_load(void)
>  static inline int efivar_ssdt_load(void) { return 0; }
>  #endif
>
> +#ifdef CONFIG_DEBUG_FS
> +
> +#define EFI_DEBUGFS_MAX_BLOBS 32
> +
> +static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS];
> +
> +static void __init efi_debugfs_init(void)
> +{
> +       struct dentry *efi_debugfs;
> +       efi_memory_desc_t *md;
> +       char name[32];
> +       int type_count[EFI_BOOT_SERVICES_DATA + 1] = {};
> +       int i = 0;
> +
> +       efi_debugfs = debugfs_create_dir("efi", NULL);
> +       if (IS_ERR_OR_NULL(efi_debugfs))
> +               return;
> +
> +       for_each_efi_memory_desc(md) {
> +               switch (md->type) {
> +               case EFI_BOOT_SERVICES_CODE:
> +                       snprintf(name, sizeof(name), "boot_services_code%d",
> +                                type_count[md->type]++);
> +                       break;
> +               case EFI_BOOT_SERVICES_DATA:
> +                       snprintf(name, sizeof(name), "boot_services_data%d",
> +                                type_count[md->type]++);
> +                       break;
> +               default:
> +                       continue;
> +               }
> +
> +               debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT;
> +               debugfs_blob[i].data = memremap(md->phys_addr,
> +                                               debugfs_blob[i].size,
> +                                               MEMREMAP_WB);
> +               if (!debugfs_blob[i].data)
> +                       continue;
> +
> +               debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]);
> +               i++;
> +               if (i == EFI_DEBUGFS_MAX_BLOBS)
> +                       break;
> +       }
> +}
> +#else
> +static inline void efi_debugfs_init(void) {}
> +#endif
> +
>  /*
>   * We register the efi subsystem with the firmware subsystem and the
>   * efivars subsystem with the efi subsystem, if the system was booted with
> @@ -369,6 +419,9 @@ static int __init efisubsys_init(void)
>                 goto err_remove_group;
>         }
>
> +       if (efi_enabled(EFI_DBG) && efi_enabled(EFI_BOOT_SERVICES))
> +               efi_debugfs_init();
> +
>         return 0;
>
>  err_remove_group:
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index f1b7d68ac460..396bf18ace5c 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -1144,6 +1144,7 @@ extern int __init efi_setup_pcdp_console(char *);
>  #define EFI_DBG                        8       /* Print additional debug info at runtime */
>  #define EFI_NX_PE_DATA         9       /* Can runtime data regions be mapped non-executable? */
>  #define EFI_MEM_ATTR           10      /* Did firmware publish an EFI_MEMORY_ATTRIBUTES table? */
> +#define EFI_BOOT_SERVICES      11      /* Are EFI boot-services memory segments available? */
>
>  #ifdef CONFIG_EFI
>  /*
> --
> 2.17.0
>

Re: [PATCH v4 1/5] efi: Export boot-services code and data as debugfs-blobs

[Ard Biesheuvel]

On 26 April 2018 at 14:06, Hans de Goede <hdegoede@redhat.com> wrote:
> Sometimes it is useful to be able to dump the efi boot-services code and
> data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
> but only if efi=debug is passed on the kernel-commandline as this requires
> not freeing those memory-regions, which costs 20+ MB of RAM.
>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Changes in v4:
> -Add new EFI_BOOT_SERVICES flag and use it to determine if the boot-services
>  memory segments are available (and thus if it makes sense to register the
>  debugfs bits for them)
>
> Changes in v2:
> -Do not call pr_err on debugfs call failures
> ---
>  arch/x86/platform/efi/efi.c    |  1 +
>  arch/x86/platform/efi/quirks.c |  4 +++
>  drivers/firmware/efi/efi.c     | 53 ++++++++++++++++++++++++++++++++++
>  include/linux/efi.h            |  1 +
>  4 files changed, 59 insertions(+)
>
> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> index 9061babfbc83..568b7ee3d323 100644
> --- a/arch/x86/platform/efi/efi.c
> +++ b/arch/x86/platform/efi/efi.c
> @@ -208,6 +208,7 @@ int __init efi_memblock_x86_reserve_range(void)
>              efi.memmap.desc_version);
>
>         memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
> +       set_bit(EFI_BOOT_SERVICES, &efi.flags);
>

I think it would be better if the flag conveys whether boot services
regions are being preserved, because they will always exist when
EFI_BOOT is set.
The name should then reflect that as well, e.g., EFI_PRESERVE_BS_REGIONS.

>         return 0;
>  }
> diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
> index 36c1f8b9f7e0..16bdb9e3b343 100644
> --- a/arch/x86/platform/efi/quirks.c
> +++ b/arch/x86/platform/efi/quirks.c
> @@ -376,6 +376,10 @@ void __init efi_free_boot_services(void)
>         int num_entries = 0;
>         void *new, *new_md;
>
> +       /* Keep all regions for /sys/kernel/debug/efi */
> +       if (efi_enabled(EFI_DBG))
> +               return;
> +

Why is this only necessary when EFI_DBG is enabled? How are you
ensuring that the firmware is still in memory when the subsequent
patches start relying on that?


>         for_each_efi_memory_desc(md) {
>                 unsigned long long start = md->phys_addr;
>                 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 232f4915223b..498a720a7684 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -18,6 +18,7 @@
>  #include <linux/kobject.h>
>  #include <linux/module.h>
>  #include <linux/init.h>
> +#include <linux/debugfs.h>
>  #include <linux/device.h>
>  #include <linux/efi.h>
>  #include <linux/of.h>
> @@ -325,6 +326,55 @@ static __init int efivar_ssdt_load(void)
>  static inline int efivar_ssdt_load(void) { return 0; }
>  #endif
>
> +#ifdef CONFIG_DEBUG_FS
> +
> +#define EFI_DEBUGFS_MAX_BLOBS 32
> +
> +static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS];
> +
> +static void __init efi_debugfs_init(void)
> +{
> +       struct dentry *efi_debugfs;
> +       efi_memory_desc_t *md;
> +       char name[32];
> +       int type_count[EFI_BOOT_SERVICES_DATA + 1] = {};
> +       int i = 0;
> +
> +       efi_debugfs = debugfs_create_dir("efi", NULL);
> +       if (IS_ERR_OR_NULL(efi_debugfs))
> +               return;
> +
> +       for_each_efi_memory_desc(md) {
> +               switch (md->type) {
> +               case EFI_BOOT_SERVICES_CODE:
> +                       snprintf(name, sizeof(name), "boot_services_code%d",
> +                                type_count[md->type]++);
> +                       break;
> +               case EFI_BOOT_SERVICES_DATA:
> +                       snprintf(name, sizeof(name), "boot_services_data%d",
> +                                type_count[md->type]++);
> +                       break;
> +               default:
> +                       continue;
> +               }
> +
> +               debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT;
> +               debugfs_blob[i].data = memremap(md->phys_addr,
> +                                               debugfs_blob[i].size,
> +                                               MEMREMAP_WB);
> +               if (!debugfs_blob[i].data)
> +                       continue;
> +
> +               debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]);
> +               i++;
> +               if (i == EFI_DEBUGFS_MAX_BLOBS)
> +                       break;
> +       }
> +}
> +#else
> +static inline void efi_debugfs_init(void) {}
> +#endif
> +
>  /*
>   * We register the efi subsystem with the firmware subsystem and the
>   * efivars subsystem with the efi subsystem, if the system was booted with
> @@ -369,6 +419,9 @@ static int __init efisubsys_init(void)
>                 goto err_remove_group;
>         }
>
> +       if (efi_enabled(EFI_DBG) && efi_enabled(EFI_BOOT_SERVICES))
> +               efi_debugfs_init();
> +
>         return 0;
>
>  err_remove_group:
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index f1b7d68ac460..396bf18ace5c 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -1144,6 +1144,7 @@ extern int __init efi_setup_pcdp_console(char *);
>  #define EFI_DBG                        8       /* Print additional debug info at runtime */
>  #define EFI_NX_PE_DATA         9       /* Can runtime data regions be mapped non-executable? */
>  #define EFI_MEM_ATTR           10      /* Did firmware publish an EFI_MEMORY_ATTRIBUTES table? */
> +#define EFI_BOOT_SERVICES      11      /* Are EFI boot-services memory segments available? */
>
>  #ifdef CONFIG_EFI
>  /*
> --
> 2.17.0
>

Re: [PATCH v4 0/5] efi/firmware/platform-x86: Add EFI embedded fw support

[Ard Biesheuvel]

On 26 April 2018 at 14:06, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi All,
>
> Here is v4 of my patch-set to add support for EFI embedded fw to the kernel.
>
> Changes since v3:
> -Drop note in docs about EFI_FIRMWARE_VOLUME_PROTOCOL, it is not part of
>  UEFI proper, so the EFI maintainers don't want us referring people to it
> -Use new EFI_BOOT_SERVICES flag
> -Put the new fw_get_efi_embedded_fw() function in its own fallback_efi.c
>  file which only gets built when EFI_EMBEDDED_FIRMWARE is selected
> -Define an empty stub for fw_get_efi_embedded_fw() in fallback.h hwen
>  EFI_EMBEDDED_FIRMWARE is not selected, to avoid the need for #ifdefs
>  in firmware_loader/main.c
> -Properly call security_kernel_post_read_file() on the firmware returned
>  by efi_get_embedded_fw() to make sure that we are allowed to use it
>
> So I think this patch-set is getting close to ready for merging, which
> brings us to the question of how to merge this, I think that patches 1
> and 2 should probably both be merged through the same tree. Then an
> unmutable branch should be created on that tree, merged into the
> platform/x86 tree and then the last 3 patches can be merged through
> that tree.
>

I am perfectly happy to either ack the patches that fall under my
responsibility so they can be taken via another tree, or take the
whole thing via the EFI tree, whichever works for other maintainers.

> For the record, here is the coverletter of v2 of this patchset:
>
> The 3 most prominent changes in v2 are:
>
> 1) Add documentation describing the EFI embedded firmware mechanism to:
>    Documentation/driver-api/firmware/request_firmware.rst
>
> 2) Instead of having a single dmi_system_id array with its driver_data
>    members pointing to efi_embedded_fw_desc structs, have the drivers which
>    need EFI embedded-fw support export a dmi_system_id array and register
>    that with the EFI embedded-fw code
>
>    This series also includes the first driver to use this, in the form of
>    the touchscreen_dmi code (formerly silead_dmi) from drivers/platfrom/x86
>
> 3) As discussed during the review of v1 we want to make the firmware_loader
>    code fallback to EFI embedded-fw optional.  Rather the adding yet another
>    firmware_request_foo variant for this, with the risk of later also needing
>    firmware_request_foo_nowait, etc. variants I've decided to make the code
>    check if the device has a "efi-embedded-firmware" device-property bool set.
>
>    This also seemed better because the same driver may want to use the
>    fallback on some systems, but not on others since e.g. not all (x86)
>    systems with a silead touchscreen have their touchscreen firmware embedded
>    in their EFI.
>
>    Note that (as discussed) when the EFI fallback path is requested, the
>    usermodehelper fallback path is skipped.
>
> Here is the full changelog of patch 2/5 which is where most of the changes are:
>
> Changes in v2:
> -Rebased on driver-core/driver-core-next
> -Add documentation describing the EFI embedded firmware mechanism to:
>  Documentation/driver-api/firmware/request_firmware.rst
> -Add a new EFI_EMBEDDED_FIRMWARE Kconfig bool and only build the embedded
>  fw support if this is set. This is an invisible option which should be
>  selected by drivers which need this
> -Remove the efi_embedded_fw_desc and dmi_system_id-s for known devices
>  from the efi-embedded-fw code, instead drivers using this are expected to
>  export a dmi_system_id array, with each entries' driver_data pointing to a
>  efi_embedded_fw_desc struct and register this with the efi-embedded-fw code
> -Use kmemdup to make a copy instead of efi_mem_reserve()-ing the firmware,
>  this avoids us messing with the EFI memmap and avoids the need to make
>  changes to efi_mem_desc_lookup()
> -Make the firmware-loader code only fallback to efi_get_embedded_fw() if the
>  passed in device has the "efi-embedded-firmware" device-property bool set
> -Skip usermodehelper fallback when "efi-embedded-firmware" device-property
>  is set
>
> Patches 3-5 are new and implement using the EFI embedded-fw mechanism for
> Silead gslXXXX and Chipone icn8505 touchscreens on x86 devices.
>
> Regards,
>
> Hans
>

Re: [PATCH v4 0/5] efi/firmware/platform-x86: Add EFI embedded fw support

[Ard Biesheuvel]

On 26 April 2018 at 14:06, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi All,
>
> Here is v4 of my patch-set to add support for EFI embedded fw to the kernel.
>
> Changes since v3:
> -Drop note in docs about EFI_FIRMWARE_VOLUME_PROTOCOL, it is not part of
>  UEFI proper, so the EFI maintainers don't want us referring people to it
> -Use new EFI_BOOT_SERVICES flag
> -Put the new fw_get_efi_embedded_fw() function in its own fallback_efi.c
>  file which only gets built when EFI_EMBEDDED_FIRMWARE is selected
> -Define an empty stub for fw_get_efi_embedded_fw() in fallback.h hwen
>  EFI_EMBEDDED_FIRMWARE is not selected, to avoid the need for #ifdefs
>  in firmware_loader/main.c
> -Properly call security_kernel_post_read_file() on the firmware returned
>  by efi_get_embedded_fw() to make sure that we are allowed to use it
>
> So I think this patch-set is getting close to ready for merging, which
> brings us to the question of how to merge this, I think that patches 1
> and 2 should probably both be merged through the same tree. Then an
> unmutable branch should be created on that tree, merged into the
> platform/x86 tree and then the last 3 patches can be merged through
> that tree.
>

I am perfectly happy to either ack the patches that fall under my
responsibility so they can be taken via another tree, or take the
whole thing via the EFI tree, whichever works for other maintainers.

> For the record, here is the coverletter of v2 of this patchset:
>
> The 3 most prominent changes in v2 are:
>
> 1) Add documentation describing the EFI embedded firmware mechanism to:
>    Documentation/driver-api/firmware/request_firmware.rst
>
> 2) Instead of having a single dmi_system_id array with its driver_data
>    members pointing to efi_embedded_fw_desc structs, have the drivers which
>    need EFI embedded-fw support export a dmi_system_id array and register
>    that with the EFI embedded-fw code
>
>    This series also includes the first driver to use this, in the form of
>    the touchscreen_dmi code (formerly silead_dmi) from drivers/platfrom/x86
>
> 3) As discussed during the review of v1 we want to make the firmware_loader
>    code fallback to EFI embedded-fw optional.  Rather the adding yet another
>    firmware_request_foo variant for this, with the risk of later also needing
>    firmware_request_foo_nowait, etc. variants I've decided to make the code
>    check if the device has a "efi-embedded-firmware" device-property bool set.
>
>    This also seemed better because the same driver may want to use the
>    fallback on some systems, but not on others since e.g. not all (x86)
>    systems with a silead touchscreen have their touchscreen firmware embedded
>    in their EFI.
>
>    Note that (as discussed) when the EFI fallback path is requested, the
>    usermodehelper fallback path is skipped.
>
> Here is the full changelog of patch 2/5 which is where most of the changes are:
>
> Changes in v2:
> -Rebased on driver-core/driver-core-next
> -Add documentation describing the EFI embedded firmware mechanism to:
>  Documentation/driver-api/firmware/request_firmware.rst
> -Add a new EFI_EMBEDDED_FIRMWARE Kconfig bool and only build the embedded
>  fw support if this is set. This is an invisible option which should be
>  selected by drivers which need this
> -Remove the efi_embedded_fw_desc and dmi_system_id-s for known devices
>  from the efi-embedded-fw code, instead drivers using this are expected to
>  export a dmi_system_id array, with each entries' driver_data pointing to a
>  efi_embedded_fw_desc struct and register this with the efi-embedded-fw code
> -Use kmemdup to make a copy instead of efi_mem_reserve()-ing the firmware,
>  this avoids us messing with the EFI memmap and avoids the need to make
>  changes to efi_mem_desc_lookup()
> -Make the firmware-loader code only fallback to efi_get_embedded_fw() if the
>  passed in device has the "efi-embedded-firmware" device-property bool set
> -Skip usermodehelper fallback when "efi-embedded-firmware" device-property
>  is set
>
> Patches 3-5 are new and implement using the EFI embedded-fw mechanism for
> Silead gslXXXX and Chipone icn8505 touchscreens on x86 devices.
>
> Regards,
>
> Hans
>

Re: [PATCH v4 1/5] efi: Export boot-services code and data as debugfs-blobs

[Hans de Goede]

Hi,

On 26-04-18 18:51, Ard Biesheuvel wrote:
> On 26 April 2018 at 14:06, Hans de Goede <hdegoede@redhat.com> wrote:
>> Sometimes it is useful to be able to dump the efi boot-services code and
>> data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
>> but only if efi=debug is passed on the kernel-commandline as this requires
>> not freeing those memory-regions, which costs 20+ MB of RAM.
>>
>> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>> Changes in v4:
>> -Add new EFI_BOOT_SERVICES flag and use it to determine if the boot-services
>>   memory segments are available (and thus if it makes sense to register the
>>   debugfs bits for them)
>>
>> Changes in v2:
>> -Do not call pr_err on debugfs call failures
>> ---
>>   arch/x86/platform/efi/efi.c    |  1 +
>>   arch/x86/platform/efi/quirks.c |  4 +++
>>   drivers/firmware/efi/efi.c     | 53 ++++++++++++++++++++++++++++++++++
>>   include/linux/efi.h            |  1 +
>>   4 files changed, 59 insertions(+)
>>
>> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
>> index 9061babfbc83..568b7ee3d323 100644
>> --- a/arch/x86/platform/efi/efi.c
>> +++ b/arch/x86/platform/efi/efi.c
>> @@ -208,6 +208,7 @@ int __init efi_memblock_x86_reserve_range(void)
>>               efi.memmap.desc_version);
>>
>>          memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
>> +       set_bit(EFI_BOOT_SERVICES, &efi.flags);
>>
> 
> I think it would be better if the flag conveys whether boot services
> regions are being preserved, because they will always exist when
> EFI_BOOT is set.
> The name should then reflect that as well, e.g., EFI_PRESERVE_BS_REGIONS.

Ok, I will rename the flag to EFI_PRESERVE_BS_REGIONS for v5
(I'm going to wait a bit with sending out v5 to give others a change
  to comment on v4).

>>          return 0;
>>   }
>> diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
>> index 36c1f8b9f7e0..16bdb9e3b343 100644
>> --- a/arch/x86/platform/efi/quirks.c
>> +++ b/arch/x86/platform/efi/quirks.c
>> @@ -376,6 +376,10 @@ void __init efi_free_boot_services(void)
>>          int num_entries = 0;
>>          void *new, *new_md;
>>
>> +       /* Keep all regions for /sys/kernel/debug/efi */
>> +       if (efi_enabled(EFI_DBG))
>> +               return;
>> +
> 
> Why is this only necessary when EFI_DBG is enabled? How are you
> ensuring that the firmware is still in memory when the subsequent
> patches start relying on that?

The 2nd patch in this series makes init/main.c call
efi_check_for_embedded_firmwares() before efi_free_boot_services(),
efi_check_for_embedded_firmwares() then walks the dmi_system_id-s
"registered" (its a static list) by drivers and if their is a dmi_match
searches for the firmware described by the dmi_system_id.driver_data
ptr. If a firmware gets found it gets memdup-ed, so that we do not
have to keep all of the boot-services code around.

Regards,

Hans

Re: [PATCH v4 1/5] efi: Export boot-services code and data as debugfs-blobs

[Hans de Goede]

Hi,

On 26-04-18 18:51, Ard Biesheuvel wrote:
> On 26 April 2018 at 14:06, Hans de Goede <hdegoede@redhat.com> wrote:
>> Sometimes it is useful to be able to dump the efi boot-services code and
>> data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
>> but only if efi=debug is passed on the kernel-commandline as this requires
>> not freeing those memory-regions, which costs 20+ MB of RAM.
>>
>> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>> Changes in v4:
>> -Add new EFI_BOOT_SERVICES flag and use it to determine if the boot-services
>>   memory segments are available (and thus if it makes sense to register the
>>   debugfs bits for them)
>>
>> Changes in v2:
>> -Do not call pr_err on debugfs call failures
>> ---
>>   arch/x86/platform/efi/efi.c    |  1 +
>>   arch/x86/platform/efi/quirks.c |  4 +++
>>   drivers/firmware/efi/efi.c     | 53 ++++++++++++++++++++++++++++++++++
>>   include/linux/efi.h            |  1 +
>>   4 files changed, 59 insertions(+)
>>
>> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
>> index 9061babfbc83..568b7ee3d323 100644
>> --- a/arch/x86/platform/efi/efi.c
>> +++ b/arch/x86/platform/efi/efi.c
>> @@ -208,6 +208,7 @@ int __init efi_memblock_x86_reserve_range(void)
>>               efi.memmap.desc_version);
>>
>>          memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
>> +       set_bit(EFI_BOOT_SERVICES, &efi.flags);
>>
> 
> I think it would be better if the flag conveys whether boot services
> regions are being preserved, because they will always exist when
> EFI_BOOT is set.
> The name should then reflect that as well, e.g., EFI_PRESERVE_BS_REGIONS.

Ok, I will rename the flag to EFI_PRESERVE_BS_REGIONS for v5
(I'm going to wait a bit with sending out v5 to give others a change
  to comment on v4).

>>          return 0;
>>   }
>> diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
>> index 36c1f8b9f7e0..16bdb9e3b343 100644
>> --- a/arch/x86/platform/efi/quirks.c
>> +++ b/arch/x86/platform/efi/quirks.c
>> @@ -376,6 +376,10 @@ void __init efi_free_boot_services(void)
>>          int num_entries = 0;
>>          void *new, *new_md;
>>
>> +       /* Keep all regions for /sys/kernel/debug/efi */
>> +       if (efi_enabled(EFI_DBG))
>> +               return;
>> +
> 
> Why is this only necessary when EFI_DBG is enabled? How are you
> ensuring that the firmware is still in memory when the subsequent
> patches start relying on that?

The 2nd patch in this series makes init/main.c call
efi_check_for_embedded_firmwares() before efi_free_boot_services(),
efi_check_for_embedded_firmwares() then walks the dmi_system_id-s
"registered" (its a static list) by drivers and if their is a dmi_match
searches for the firmware described by the dmi_system_id.driver_data
ptr. If a firmware gets found it gets memdup-ed, so that we do not
have to keep all of the boot-services code around.

Regards,

Hans

Re: [PATCH v4 1/5] efi: Export boot-services code and data as debugfs-blobs

[Ard Biesheuvel]

On 26 April 2018 at 23:02, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi,
>
>
> On 26-04-18 18:51, Ard Biesheuvel wrote:
>>
>> On 26 April 2018 at 14:06, Hans de Goede <hdegoede@redhat.com> wrote:
>>>
>>> Sometimes it is useful to be able to dump the efi boot-services code and
>>> data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
>>> but only if efi=debug is passed on the kernel-commandline as this
>>> requires
>>> not freeing those memory-regions, which costs 20+ MB of RAM.
>>>
>>> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>> ---
>>> Changes in v4:
>>> -Add new EFI_BOOT_SERVICES flag and use it to determine if the
>>> boot-services
>>>   memory segments are available (and thus if it makes sense to register
>>> the
>>>   debugfs bits for them)
>>>
>>> Changes in v2:
>>> -Do not call pr_err on debugfs call failures
>>> ---
>>>   arch/x86/platform/efi/efi.c    |  1 +
>>>   arch/x86/platform/efi/quirks.c |  4 +++
>>>   drivers/firmware/efi/efi.c     | 53 ++++++++++++++++++++++++++++++++++
>>>   include/linux/efi.h            |  1 +
>>>   4 files changed, 59 insertions(+)
>>>
>>> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
>>> index 9061babfbc83..568b7ee3d323 100644
>>> --- a/arch/x86/platform/efi/efi.c
>>> +++ b/arch/x86/platform/efi/efi.c
>>> @@ -208,6 +208,7 @@ int __init efi_memblock_x86_reserve_range(void)
>>>               efi.memmap.desc_version);
>>>
>>>          memblock_reserve(pmap, efi.memmap.nr_map *
>>> efi.memmap.desc_size);
>>> +       set_bit(EFI_BOOT_SERVICES, &efi.flags);
>>>
>>
>> I think it would be better if the flag conveys whether boot services
>> regions are being preserved, because they will always exist when
>> EFI_BOOT is set.
>> The name should then reflect that as well, e.g., EFI_PRESERVE_BS_REGIONS.
>
>
> Ok, I will rename the flag to EFI_PRESERVE_BS_REGIONS for v5
> (I'm going to wait a bit with sending out v5 to give others a change
>  to comment on v4).
>
>>>          return 0;
>>>   }
>>> diff --git a/arch/x86/platform/efi/quirks.c
>>> b/arch/x86/platform/efi/quirks.c
>>> index 36c1f8b9f7e0..16bdb9e3b343 100644
>>> --- a/arch/x86/platform/efi/quirks.c
>>> +++ b/arch/x86/platform/efi/quirks.c
>>> @@ -376,6 +376,10 @@ void __init efi_free_boot_services(void)
>>>          int num_entries = 0;
>>>          void *new, *new_md;
>>>
>>> +       /* Keep all regions for /sys/kernel/debug/efi */
>>> +       if (efi_enabled(EFI_DBG))
>>> +               return;
>>> +
>>
>>
>> Why is this only necessary when EFI_DBG is enabled? How are you
>> ensuring that the firmware is still in memory when the subsequent
>> patches start relying on that?
>
>
> The 2nd patch in this series makes init/main.c call
> efi_check_for_embedded_firmwares() before efi_free_boot_services(),
> efi_check_for_embedded_firmwares() then walks the dmi_system_id-s
> "registered" (its a static list) by drivers and if their is a dmi_match
> searches for the firmware described by the dmi_system_id.driver_data
> ptr. If a firmware gets found it gets memdup-ed, so that we do not
> have to keep all of the boot-services code around.
>

Right, thanks for clearing that up.

So that means that preserving the boot regions is really only
necessary if you want to inspect them via debugfs, and the firmware
loader does not rely on that. I missed that part.

That means the only reason we have the new flag is to ensure that the
shared debugfs code only exposes the boot services regions if they
were preserved to begin with by the arch code, right?

If so, after the flag rename:

Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

(for the series)

Re: [PATCH v4 1/5] efi: Export boot-services code and data as debugfs-blobs

[Ard Biesheuvel]

On 26 April 2018 at 23:02, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi,
>
>
> On 26-04-18 18:51, Ard Biesheuvel wrote:
>>
>> On 26 April 2018 at 14:06, Hans de Goede <hdegoede@redhat.com> wrote:
>>>
>>> Sometimes it is useful to be able to dump the efi boot-services code and
>>> data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
>>> but only if efi=debug is passed on the kernel-commandline as this
>>> requires
>>> not freeing those memory-regions, which costs 20+ MB of RAM.
>>>
>>> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>> ---
>>> Changes in v4:
>>> -Add new EFI_BOOT_SERVICES flag and use it to determine if the
>>> boot-services
>>>   memory segments are available (and thus if it makes sense to register
>>> the
>>>   debugfs bits for them)
>>>
>>> Changes in v2:
>>> -Do not call pr_err on debugfs call failures
>>> ---
>>>   arch/x86/platform/efi/efi.c    |  1 +
>>>   arch/x86/platform/efi/quirks.c |  4 +++
>>>   drivers/firmware/efi/efi.c     | 53 ++++++++++++++++++++++++++++++++++
>>>   include/linux/efi.h            |  1 +
>>>   4 files changed, 59 insertions(+)
>>>
>>> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
>>> index 9061babfbc83..568b7ee3d323 100644
>>> --- a/arch/x86/platform/efi/efi.c
>>> +++ b/arch/x86/platform/efi/efi.c
>>> @@ -208,6 +208,7 @@ int __init efi_memblock_x86_reserve_range(void)
>>>               efi.memmap.desc_version);
>>>
>>>          memblock_reserve(pmap, efi.memmap.nr_map *
>>> efi.memmap.desc_size);
>>> +       set_bit(EFI_BOOT_SERVICES, &efi.flags);
>>>
>>
>> I think it would be better if the flag conveys whether boot services
>> regions are being preserved, because they will always exist when
>> EFI_BOOT is set.
>> The name should then reflect that as well, e.g., EFI_PRESERVE_BS_REGIONS.
>
>
> Ok, I will rename the flag to EFI_PRESERVE_BS_REGIONS for v5
> (I'm going to wait a bit with sending out v5 to give others a change
>  to comment on v4).
>
>>>          return 0;
>>>   }
>>> diff --git a/arch/x86/platform/efi/quirks.c
>>> b/arch/x86/platform/efi/quirks.c
>>> index 36c1f8b9f7e0..16bdb9e3b343 100644
>>> --- a/arch/x86/platform/efi/quirks.c
>>> +++ b/arch/x86/platform/efi/quirks.c
>>> @@ -376,6 +376,10 @@ void __init efi_free_boot_services(void)
>>>          int num_entries = 0;
>>>          void *new, *new_md;
>>>
>>> +       /* Keep all regions for /sys/kernel/debug/efi */
>>> +       if (efi_enabled(EFI_DBG))
>>> +               return;
>>> +
>>
>>
>> Why is this only necessary when EFI_DBG is enabled? How are you
>> ensuring that the firmware is still in memory when the subsequent
>> patches start relying on that?
>
>
> The 2nd patch in this series makes init/main.c call
> efi_check_for_embedded_firmwares() before efi_free_boot_services(),
> efi_check_for_embedded_firmwares() then walks the dmi_system_id-s
> "registered" (its a static list) by drivers and if their is a dmi_match
> searches for the firmware described by the dmi_system_id.driver_data
> ptr. If a firmware gets found it gets memdup-ed, so that we do not
> have to keep all of the boot-services code around.
>

Right, thanks for clearing that up.

So that means that preserving the boot regions is really only
necessary if you want to inspect them via debugfs, and the firmware
loader does not rely on that. I missed that part.

That means the only reason we have the new flag is to ensure that the
shared debugfs code only exposes the boot services regions if they
were preserved to begin with by the arch code, right?

If so, after the flag rename:

Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

(for the series)

Re: [PATCH v4 1/5] efi: Export boot-services code and data as debugfs-blobs

[Hans de Goede]

Hi,

On 26-04-18 23:35, Ard Biesheuvel wrote:
> On 26 April 2018 at 23:02, Hans de Goede <hdegoede@redhat.com> wrote:
>> Hi,
>>
>>
>> On 26-04-18 18:51, Ard Biesheuvel wrote:
>>>
>>> On 26 April 2018 at 14:06, Hans de Goede <hdegoede@redhat.com> wrote:
>>>>
>>>> Sometimes it is useful to be able to dump the efi boot-services code and
>>>> data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
>>>> but only if efi=debug is passed on the kernel-commandline as this
>>>> requires
>>>> not freeing those memory-regions, which costs 20+ MB of RAM.
>>>>
>>>> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>> ---
>>>> Changes in v4:
>>>> -Add new EFI_BOOT_SERVICES flag and use it to determine if the
>>>> boot-services
>>>>    memory segments are available (and thus if it makes sense to register
>>>> the
>>>>    debugfs bits for them)
>>>>
>>>> Changes in v2:
>>>> -Do not call pr_err on debugfs call failures
>>>> ---
>>>>    arch/x86/platform/efi/efi.c    |  1 +
>>>>    arch/x86/platform/efi/quirks.c |  4 +++
>>>>    drivers/firmware/efi/efi.c     | 53 ++++++++++++++++++++++++++++++++++
>>>>    include/linux/efi.h            |  1 +
>>>>    4 files changed, 59 insertions(+)
>>>>
>>>> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
>>>> index 9061babfbc83..568b7ee3d323 100644
>>>> --- a/arch/x86/platform/efi/efi.c
>>>> +++ b/arch/x86/platform/efi/efi.c
>>>> @@ -208,6 +208,7 @@ int __init efi_memblock_x86_reserve_range(void)
>>>>                efi.memmap.desc_version);
>>>>
>>>>           memblock_reserve(pmap, efi.memmap.nr_map *
>>>> efi.memmap.desc_size);
>>>> +       set_bit(EFI_BOOT_SERVICES, &efi.flags);
>>>>
>>>
>>> I think it would be better if the flag conveys whether boot services
>>> regions are being preserved, because they will always exist when
>>> EFI_BOOT is set.
>>> The name should then reflect that as well, e.g., EFI_PRESERVE_BS_REGIONS.
>>
>>
>> Ok, I will rename the flag to EFI_PRESERVE_BS_REGIONS for v5
>> (I'm going to wait a bit with sending out v5 to give others a change
>>   to comment on v4).
>>
>>>>           return 0;
>>>>    }
>>>> diff --git a/arch/x86/platform/efi/quirks.c
>>>> b/arch/x86/platform/efi/quirks.c
>>>> index 36c1f8b9f7e0..16bdb9e3b343 100644
>>>> --- a/arch/x86/platform/efi/quirks.c
>>>> +++ b/arch/x86/platform/efi/quirks.c
>>>> @@ -376,6 +376,10 @@ void __init efi_free_boot_services(void)
>>>>           int num_entries = 0;
>>>>           void *new, *new_md;
>>>>
>>>> +       /* Keep all regions for /sys/kernel/debug/efi */
>>>> +       if (efi_enabled(EFI_DBG))
>>>> +               return;
>>>> +
>>>
>>>
>>> Why is this only necessary when EFI_DBG is enabled? How are you
>>> ensuring that the firmware is still in memory when the subsequent
>>> patches start relying on that?
>>
>>
>> The 2nd patch in this series makes init/main.c call
>> efi_check_for_embedded_firmwares() before efi_free_boot_services(),
>> efi_check_for_embedded_firmwares() then walks the dmi_system_id-s
>> "registered" (its a static list) by drivers and if their is a dmi_match
>> searches for the firmware described by the dmi_system_id.driver_data
>> ptr. If a firmware gets found it gets memdup-ed, so that we do not
>> have to keep all of the boot-services code around.
>>
> 
> Right, thanks for clearing that up.
> 
> So that means that preserving the boot regions is really only
> necessary if you want to inspect them via debugfs, and the firmware
> loader does not rely on that. I missed that part.
> 
> That means the only reason we have the new flag is to ensure that the
> shared debugfs code only exposes the boot services regions if they
> were preserved to begin with by the arch code, right?

Mostly right, since we have the flag now anyways I'm also using
it as a condition to call efi_check_for_embedded_firmwares(),
efi_check_for_embedded_firmwares() needs to happen after mm_init() (*)
and on non x86 the boot-services code/data is long gone then so
there is nothing for efi_check_for_embedded_firmwares() to look at.

> If so, after the flag rename:
> 
> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

I assume that the "mostly right" is good enough and I'm going to
add your Acked-by for the next version. Let me know if you've
any objections against that.

Regards,

Hans


*) efi_check_for_embedded_firmwares() mremap()s the boot-services
memory segments to scan then and they are too big for early_mremap()

Re: [PATCH v4 1/5] efi: Export boot-services code and data as debugfs-blobs

[Hans de Goede]

Hi,

On 26-04-18 23:35, Ard Biesheuvel wrote:
> On 26 April 2018 at 23:02, Hans de Goede <hdegoede@redhat.com> wrote:
>> Hi,
>>
>>
>> On 26-04-18 18:51, Ard Biesheuvel wrote:
>>>
>>> On 26 April 2018 at 14:06, Hans de Goede <hdegoede@redhat.com> wrote:
>>>>
>>>> Sometimes it is useful to be able to dump the efi boot-services code and
>>>> data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
>>>> but only if efi=debug is passed on the kernel-commandline as this
>>>> requires
>>>> not freeing those memory-regions, which costs 20+ MB of RAM.
>>>>
>>>> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>> ---
>>>> Changes in v4:
>>>> -Add new EFI_BOOT_SERVICES flag and use it to determine if the
>>>> boot-services
>>>>    memory segments are available (and thus if it makes sense to register
>>>> the
>>>>    debugfs bits for them)
>>>>
>>>> Changes in v2:
>>>> -Do not call pr_err on debugfs call failures
>>>> ---
>>>>    arch/x86/platform/efi/efi.c    |  1 +
>>>>    arch/x86/platform/efi/quirks.c |  4 +++
>>>>    drivers/firmware/efi/efi.c     | 53 ++++++++++++++++++++++++++++++++++
>>>>    include/linux/efi.h            |  1 +
>>>>    4 files changed, 59 insertions(+)
>>>>
>>>> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
>>>> index 9061babfbc83..568b7ee3d323 100644
>>>> --- a/arch/x86/platform/efi/efi.c
>>>> +++ b/arch/x86/platform/efi/efi.c
>>>> @@ -208,6 +208,7 @@ int __init efi_memblock_x86_reserve_range(void)
>>>>                efi.memmap.desc_version);
>>>>
>>>>           memblock_reserve(pmap, efi.memmap.nr_map *
>>>> efi.memmap.desc_size);
>>>> +       set_bit(EFI_BOOT_SERVICES, &efi.flags);
>>>>
>>>
>>> I think it would be better if the flag conveys whether boot services
>>> regions are being preserved, because they will always exist when
>>> EFI_BOOT is set.
>>> The name should then reflect that as well, e.g., EFI_PRESERVE_BS_REGIONS.
>>
>>
>> Ok, I will rename the flag to EFI_PRESERVE_BS_REGIONS for v5
>> (I'm going to wait a bit with sending out v5 to give others a change
>>   to comment on v4).
>>
>>>>           return 0;
>>>>    }
>>>> diff --git a/arch/x86/platform/efi/quirks.c
>>>> b/arch/x86/platform/efi/quirks.c
>>>> index 36c1f8b9f7e0..16bdb9e3b343 100644
>>>> --- a/arch/x86/platform/efi/quirks.c
>>>> +++ b/arch/x86/platform/efi/quirks.c
>>>> @@ -376,6 +376,10 @@ void __init efi_free_boot_services(void)
>>>>           int num_entries = 0;
>>>>           void *new, *new_md;
>>>>
>>>> +       /* Keep all regions for /sys/kernel/debug/efi */
>>>> +       if (efi_enabled(EFI_DBG))
>>>> +               return;
>>>> +
>>>
>>>
>>> Why is this only necessary when EFI_DBG is enabled? How are you
>>> ensuring that the firmware is still in memory when the subsequent
>>> patches start relying on that?
>>
>>
>> The 2nd patch in this series makes init/main.c call
>> efi_check_for_embedded_firmwares() before efi_free_boot_services(),
>> efi_check_for_embedded_firmwares() then walks the dmi_system_id-s
>> "registered" (its a static list) by drivers and if their is a dmi_match
>> searches for the firmware described by the dmi_system_id.driver_data
>> ptr. If a firmware gets found it gets memdup-ed, so that we do not
>> have to keep all of the boot-services code around.
>>
> 
> Right, thanks for clearing that up.
> 
> So that means that preserving the boot regions is really only
> necessary if you want to inspect them via debugfs, and the firmware
> loader does not rely on that. I missed that part.
> 
> That means the only reason we have the new flag is to ensure that the
> shared debugfs code only exposes the boot services regions if they
> were preserved to begin with by the arch code, right?

Mostly right, since we have the flag now anyways I'm also using
it as a condition to call efi_check_for_embedded_firmwares(),
efi_check_for_embedded_firmwares() needs to happen after mm_init() (*)
and on non x86 the boot-services code/data is long gone then so
there is nothing for efi_check_for_embedded_firmwares() to look at.

> If so, after the flag rename:
> 
> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

I assume that the "mostly right" is good enough and I'm going to
add your Acked-by for the next version. Let me know if you've
any objections against that.

Regards,

Hans


*) efi_check_for_embedded_firmwares() mremap()s the boot-services
memory segments to scan then and they are too big for early_mremap()

Re: [PATCH v4 1/5] efi: Export boot-services code and data as debugfs-blobs

[Ard Biesheuvel]

On 27 April 2018 at 10:13, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi,
>
>
> On 26-04-18 23:35, Ard Biesheuvel wrote:
>>
>> On 26 April 2018 at 23:02, Hans de Goede <hdegoede@redhat.com> wrote:
>>>
>>> Hi,
>>>
>>>
>>> On 26-04-18 18:51, Ard Biesheuvel wrote:
>>>>
>>>>
>>>> On 26 April 2018 at 14:06, Hans de Goede <hdegoede@redhat.com> wrote:
>>>>>
>>>>>
>>>>> Sometimes it is useful to be able to dump the efi boot-services code
>>>>> and
>>>>> data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
>>>>> but only if efi=debug is passed on the kernel-commandline as this
>>>>> requires
>>>>> not freeing those memory-regions, which costs 20+ MB of RAM.
>>>>>
>>>>> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>>> ---
>>>>> Changes in v4:
>>>>> -Add new EFI_BOOT_SERVICES flag and use it to determine if the
>>>>> boot-services
>>>>>    memory segments are available (and thus if it makes sense to
>>>>> register
>>>>> the
>>>>>    debugfs bits for them)
>>>>>
>>>>> Changes in v2:
>>>>> -Do not call pr_err on debugfs call failures
>>>>> ---
>>>>>    arch/x86/platform/efi/efi.c    |  1 +
>>>>>    arch/x86/platform/efi/quirks.c |  4 +++
>>>>>    drivers/firmware/efi/efi.c     | 53
>>>>> ++++++++++++++++++++++++++++++++++
>>>>>    include/linux/efi.h            |  1 +
>>>>>    4 files changed, 59 insertions(+)
>>>>>
>>>>> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
>>>>> index 9061babfbc83..568b7ee3d323 100644
>>>>> --- a/arch/x86/platform/efi/efi.c
>>>>> +++ b/arch/x86/platform/efi/efi.c
>>>>> @@ -208,6 +208,7 @@ int __init efi_memblock_x86_reserve_range(void)
>>>>>                efi.memmap.desc_version);
>>>>>
>>>>>           memblock_reserve(pmap, efi.memmap.nr_map *
>>>>> efi.memmap.desc_size);
>>>>> +       set_bit(EFI_BOOT_SERVICES, &efi.flags);
>>>>>
>>>>
>>>> I think it would be better if the flag conveys whether boot services
>>>> regions are being preserved, because they will always exist when
>>>> EFI_BOOT is set.
>>>> The name should then reflect that as well, e.g.,
>>>> EFI_PRESERVE_BS_REGIONS.
>>>
>>>
>>>
>>> Ok, I will rename the flag to EFI_PRESERVE_BS_REGIONS for v5
>>> (I'm going to wait a bit with sending out v5 to give others a change
>>>   to comment on v4).
>>>
>>>>>           return 0;
>>>>>    }
>>>>> diff --git a/arch/x86/platform/efi/quirks.c
>>>>> b/arch/x86/platform/efi/quirks.c
>>>>> index 36c1f8b9f7e0..16bdb9e3b343 100644
>>>>> --- a/arch/x86/platform/efi/quirks.c
>>>>> +++ b/arch/x86/platform/efi/quirks.c
>>>>> @@ -376,6 +376,10 @@ void __init efi_free_boot_services(void)
>>>>>           int num_entries = 0;
>>>>>           void *new, *new_md;
>>>>>
>>>>> +       /* Keep all regions for /sys/kernel/debug/efi */
>>>>> +       if (efi_enabled(EFI_DBG))
>>>>> +               return;
>>>>> +
>>>>
>>>>
>>>>
>>>> Why is this only necessary when EFI_DBG is enabled? How are you
>>>> ensuring that the firmware is still in memory when the subsequent
>>>> patches start relying on that?
>>>
>>>
>>>
>>> The 2nd patch in this series makes init/main.c call
>>> efi_check_for_embedded_firmwares() before efi_free_boot_services(),
>>> efi_check_for_embedded_firmwares() then walks the dmi_system_id-s
>>> "registered" (its a static list) by drivers and if their is a dmi_match
>>> searches for the firmware described by the dmi_system_id.driver_data
>>> ptr. If a firmware gets found it gets memdup-ed, so that we do not
>>> have to keep all of the boot-services code around.
>>>
>>
>> Right, thanks for clearing that up.
>>
>> So that means that preserving the boot regions is really only
>> necessary if you want to inspect them via debugfs, and the firmware
>> loader does not rely on that. I missed that part.
>>
>> That means the only reason we have the new flag is to ensure that the
>> shared debugfs code only exposes the boot services regions if they
>> were preserved to begin with by the arch code, right?
>
>
> Mostly right, since we have the flag now anyways I'm also using
> it as a condition to call efi_check_for_embedded_firmwares(),
> efi_check_for_embedded_firmwares() needs to happen after mm_init() (*)
> and on non x86 the boot-services code/data is long gone then so
> there is nothing for efi_check_for_embedded_firmwares() to look at.
>

Ah, of course, yes that was the whole point.

>> If so, after the flag rename:
>>
>> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>
>
> I assume that the "mostly right" is good enough and I'm going to
> add your Acked-by for the next version. Let me know if you've
> any objections against that.
>

Yes that's fine.

Re: [PATCH v4 1/5] efi: Export boot-services code and data as debugfs-blobs

[Ard Biesheuvel]

On 27 April 2018 at 10:13, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi,
>
>
> On 26-04-18 23:35, Ard Biesheuvel wrote:
>>
>> On 26 April 2018 at 23:02, Hans de Goede <hdegoede@redhat.com> wrote:
>>>
>>> Hi,
>>>
>>>
>>> On 26-04-18 18:51, Ard Biesheuvel wrote:
>>>>
>>>>
>>>> On 26 April 2018 at 14:06, Hans de Goede <hdegoede@redhat.com> wrote:
>>>>>
>>>>>
>>>>> Sometimes it is useful to be able to dump the efi boot-services code
>>>>> and
>>>>> data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
>>>>> but only if efi=debug is passed on the kernel-commandline as this
>>>>> requires
>>>>> not freeing those memory-regions, which costs 20+ MB of RAM.
>>>>>
>>>>> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>>> ---
>>>>> Changes in v4:
>>>>> -Add new EFI_BOOT_SERVICES flag and use it to determine if the
>>>>> boot-services
>>>>>    memory segments are available (and thus if it makes sense to
>>>>> register
>>>>> the
>>>>>    debugfs bits for them)
>>>>>
>>>>> Changes in v2:
>>>>> -Do not call pr_err on debugfs call failures
>>>>> ---
>>>>>    arch/x86/platform/efi/efi.c    |  1 +
>>>>>    arch/x86/platform/efi/quirks.c |  4 +++
>>>>>    drivers/firmware/efi/efi.c     | 53
>>>>> ++++++++++++++++++++++++++++++++++
>>>>>    include/linux/efi.h            |  1 +
>>>>>    4 files changed, 59 insertions(+)
>>>>>
>>>>> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
>>>>> index 9061babfbc83..568b7ee3d323 100644
>>>>> --- a/arch/x86/platform/efi/efi.c
>>>>> +++ b/arch/x86/platform/efi/efi.c
>>>>> @@ -208,6 +208,7 @@ int __init efi_memblock_x86_reserve_range(void)
>>>>>                efi.memmap.desc_version);
>>>>>
>>>>>           memblock_reserve(pmap, efi.memmap.nr_map *
>>>>> efi.memmap.desc_size);
>>>>> +       set_bit(EFI_BOOT_SERVICES, &efi.flags);
>>>>>
>>>>
>>>> I think it would be better if the flag conveys whether boot services
>>>> regions are being preserved, because they will always exist when
>>>> EFI_BOOT is set.
>>>> The name should then reflect that as well, e.g.,
>>>> EFI_PRESERVE_BS_REGIONS.
>>>
>>>
>>>
>>> Ok, I will rename the flag to EFI_PRESERVE_BS_REGIONS for v5
>>> (I'm going to wait a bit with sending out v5 to give others a change
>>>   to comment on v4).
>>>
>>>>>           return 0;
>>>>>    }
>>>>> diff --git a/arch/x86/platform/efi/quirks.c
>>>>> b/arch/x86/platform/efi/quirks.c
>>>>> index 36c1f8b9f7e0..16bdb9e3b343 100644
>>>>> --- a/arch/x86/platform/efi/quirks.c
>>>>> +++ b/arch/x86/platform/efi/quirks.c
>>>>> @@ -376,6 +376,10 @@ void __init efi_free_boot_services(void)
>>>>>           int num_entries = 0;
>>>>>           void *new, *new_md;
>>>>>
>>>>> +       /* Keep all regions for /sys/kernel/debug/efi */
>>>>> +       if (efi_enabled(EFI_DBG))
>>>>> +               return;
>>>>> +
>>>>
>>>>
>>>>
>>>> Why is this only necessary when EFI_DBG is enabled? How are you
>>>> ensuring that the firmware is still in memory when the subsequent
>>>> patches start relying on that?
>>>
>>>
>>>
>>> The 2nd patch in this series makes init/main.c call
>>> efi_check_for_embedded_firmwares() before efi_free_boot_services(),
>>> efi_check_for_embedded_firmwares() then walks the dmi_system_id-s
>>> "registered" (its a static list) by drivers and if their is a dmi_match
>>> searches for the firmware described by the dmi_system_id.driver_data
>>> ptr. If a firmware gets found it gets memdup-ed, so that we do not
>>> have to keep all of the boot-services code around.
>>>
>>
>> Right, thanks for clearing that up.
>>
>> So that means that preserving the boot regions is really only
>> necessary if you want to inspect them via debugfs, and the firmware
>> loader does not rely on that. I missed that part.
>>
>> That means the only reason we have the new flag is to ensure that the
>> shared debugfs code only exposes the boot services regions if they
>> were preserved to begin with by the arch code, right?
>
>
> Mostly right, since we have the flag now anyways I'm also using
> it as a condition to call efi_check_for_embedded_firmwares(),
> efi_check_for_embedded_firmwares() needs to happen after mm_init() (*)
> and on non x86 the boot-services code/data is long gone then so
> there is nothing for efi_check_for_embedded_firmwares() to look at.
>

Ah, of course, yes that was the whole point.

>> If so, after the flag rename:
>>
>> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>
>
> I assume that the "mostly right" is good enough and I'm going to
> add your Acked-by for the next version. Let me know if you've
> any objections against that.
>

Yes that's fine.