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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/firmware/google/cbmem.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'drivers/firmware/google/cbmem.c')
-rw-r--r--drivers/firmware/google/cbmem.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/drivers/firmware/google/cbmem.c b/drivers/firmware/google/cbmem.c
new file mode 100644
index 000000000..4d20477ed
--- /dev/null
+++ b/drivers/firmware/google/cbmem.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * cbmem.c
+ *
+ * Driver for exporting cbmem entries in sysfs.
+ *
+ * Copyright 2022 Google LLC
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/device-id/coreboot.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+
+#include "coreboot_table.h"
+
+struct cbmem_entry {
+ char *mem_file_buf;
+ u32 size;
+};
+
+static struct cbmem_entry *to_cbmem_entry(struct kobject *kobj)
+{
+ return dev_get_drvdata(kobj_to_dev(kobj));
+}
+
+static ssize_t mem_read(struct file *filp, struct kobject *kobj,
+ const struct bin_attribute *bin_attr, char *buf, loff_t pos,
+ size_t count)
+{
+ struct cbmem_entry *entry = to_cbmem_entry(kobj);
+
+ return memory_read_from_buffer(buf, count, &pos, entry->mem_file_buf,
+ entry->size);
+}
+
+static ssize_t mem_write(struct file *filp, struct kobject *kobj,
+ const struct bin_attribute *bin_attr, char *buf, loff_t pos,
+ size_t count)
+{
+ struct cbmem_entry *entry = to_cbmem_entry(kobj);
+
+ if (pos < 0 || pos >= entry->size)
+ return -EINVAL;
+ if (count > entry->size - pos)
+ count = entry->size - pos;
+
+ memcpy(entry->mem_file_buf + pos, buf, count);
+ return count;
+}
+static const BIN_ATTR_ADMIN_RW(mem, 0);
+
+static ssize_t address_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct coreboot_device *cbdev = dev_to_coreboot_device(dev);
+
+ return sysfs_emit(buf, "0x%llx\n", cbdev->cbmem_entry.address);
+}
+static DEVICE_ATTR_RO(address);
+
+static ssize_t size_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct coreboot_device *cbdev = dev_to_coreboot_device(dev);
+
+ return sysfs_emit(buf, "0x%x\n", cbdev->cbmem_entry.entry_size);
+}
+static DEVICE_ATTR_RO(size);
+
+static struct attribute *attrs[] = {
+ &dev_attr_address.attr,
+ &dev_attr_size.attr,
+ NULL,
+};
+
+static const struct bin_attribute *const bin_attrs[] = {
+ &bin_attr_mem,
+ NULL,
+};
+
+static const struct attribute_group cbmem_entry_group = {
+ .attrs = attrs,
+ .bin_attrs = bin_attrs,
+};
+
+static const struct attribute_group *dev_groups[] = {
+ &cbmem_entry_group,
+ NULL,
+};
+
+static int cbmem_entry_probe(struct coreboot_device *dev)
+{
+ struct cbmem_entry *entry;
+
+ entry = devm_kzalloc(&dev->dev, sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return -ENOMEM;
+
+ dev_set_drvdata(&dev->dev, entry);
+ entry->mem_file_buf = devm_memremap(&dev->dev, dev->cbmem_entry.address,
+ dev->cbmem_entry.entry_size,
+ MEMREMAP_WB);
+ if (IS_ERR(entry->mem_file_buf))
+ return PTR_ERR(entry->mem_file_buf);
+
+ entry->size = dev->cbmem_entry.entry_size;
+
+ return 0;
+}
+
+static const struct coreboot_device_id cbmem_ids[] = {
+ { .tag = LB_TAG_CBMEM_ENTRY },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(coreboot, cbmem_ids);
+
+static struct coreboot_driver cbmem_entry_driver = {
+ .probe = cbmem_entry_probe,
+ .drv = {
+ .name = "cbmem",
+ .dev_groups = dev_groups,
+ },
+ .id_table = cbmem_ids,
+};
+module_coreboot_driver(cbmem_entry_driver);
+
+MODULE_AUTHOR("Jack Rosenthal <jrosenth@chromium.org>");
+MODULE_DESCRIPTION("Driver for exporting CBMEM entries in sysfs");
+MODULE_LICENSE("GPL");