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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/block/rnull
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/block/rnull')
-rw-r--r--drivers/block/rnull/Kconfig13
-rw-r--r--drivers/block/rnull/Makefile3
-rw-r--r--drivers/block/rnull/configfs.rs261
-rw-r--r--drivers/block/rnull/rnull.rs100
4 files changed, 377 insertions, 0 deletions
diff --git a/drivers/block/rnull/Kconfig b/drivers/block/rnull/Kconfig
new file mode 100644
index 000000000..7bc5b376c
--- /dev/null
+++ b/drivers/block/rnull/Kconfig
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Rust null block device driver configuration
+
+config BLK_DEV_RUST_NULL
+ tristate "Rust null block driver (Experimental)"
+ depends on RUST && CONFIGFS_FS
+ help
+ This is the Rust implementation of the null block driver. Like
+ the C version, the driver allows the user to create virutal block
+ devices that can be configured via various configuration options.
+
+ If unsure, say N.
diff --git a/drivers/block/rnull/Makefile b/drivers/block/rnull/Makefile
new file mode 100644
index 000000000..11cfa5e61
--- /dev/null
+++ b/drivers/block/rnull/Makefile
@@ -0,0 +1,3 @@
+
+obj-$(CONFIG_BLK_DEV_RUST_NULL) += rnull_mod.o
+rnull_mod-y := rnull.o
diff --git a/drivers/block/rnull/configfs.rs b/drivers/block/rnull/configfs.rs
new file mode 100644
index 000000000..32c10c3f4
--- /dev/null
+++ b/drivers/block/rnull/configfs.rs
@@ -0,0 +1,261 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use super::NullBlkDevice;
+use kernel::{
+ block::mq::gen_disk::{GenDisk, GenDiskBuilder},
+ configfs::{self, AttributeOperations},
+ configfs_attrs,
+ fmt::{self, Write as _},
+ new_mutex,
+ page::PAGE_SIZE,
+ prelude::*,
+ str::{kstrtobool_bytes, CString},
+ sync::Mutex,
+};
+
+pub(crate) fn subsystem() -> impl PinInit<kernel::configfs::Subsystem<Config>, Error> {
+ let item_type = configfs_attrs! {
+ container: configfs::Subsystem<Config>,
+ data: Config,
+ child: DeviceConfig,
+ attributes: [
+ features: 0,
+ ],
+ };
+
+ kernel::configfs::Subsystem::new(c"rnull", item_type, try_pin_init!(Config {}))
+}
+
+#[pin_data]
+pub(crate) struct Config {}
+
+#[vtable]
+impl AttributeOperations<0> for Config {
+ type Data = Config;
+
+ fn show(_this: &Config, page: &mut [u8; PAGE_SIZE]) -> Result<usize> {
+ let mut writer = kernel::str::Formatter::new(page);
+ writer.write_str("blocksize,size,rotational,irqmode\n")?;
+ Ok(writer.bytes_written())
+ }
+}
+
+#[vtable]
+impl configfs::GroupOperations for Config {
+ type Child = DeviceConfig;
+
+ fn make_group(
+ &self,
+ name: &CStr,
+ ) -> Result<impl PinInit<configfs::Group<DeviceConfig>, Error>> {
+ let item_type = configfs_attrs! {
+ container: configfs::Group<DeviceConfig>,
+ data: DeviceConfig,
+ attributes: [
+ // Named for compatibility with C null_blk
+ power: 0,
+ blocksize: 1,
+ rotational: 2,
+ size: 3,
+ irqmode: 4,
+ ],
+ };
+
+ Ok(configfs::Group::new(
+ name.try_into()?,
+ item_type,
+ // TODO: cannot coerce new_mutex!() to impl PinInit<_, Error>, so put mutex inside
+ try_pin_init!( DeviceConfig {
+ data <- new_mutex!(DeviceConfigInner {
+ powered: false,
+ block_size: 4096,
+ rotational: false,
+ disk: None,
+ capacity_mib: 4096,
+ irq_mode: IRQMode::None,
+ name: name.try_into()?,
+ }),
+ }),
+ ))
+ }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub(crate) enum IRQMode {
+ None,
+ Soft,
+}
+
+impl TryFrom<u8> for IRQMode {
+ type Error = kernel::error::Error;
+
+ fn try_from(value: u8) -> Result<Self> {
+ match value {
+ 0 => Ok(Self::None),
+ 1 => Ok(Self::Soft),
+ _ => Err(EINVAL),
+ }
+ }
+}
+
+impl fmt::Display for IRQMode {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ match self {
+ Self::None => f.write_str("0")?,
+ Self::Soft => f.write_str("1")?,
+ }
+ Ok(())
+ }
+}
+
+#[pin_data]
+pub(crate) struct DeviceConfig {
+ #[pin]
+ data: Mutex<DeviceConfigInner>,
+}
+
+#[pin_data]
+struct DeviceConfigInner {
+ powered: bool,
+ name: CString,
+ block_size: u32,
+ rotational: bool,
+ capacity_mib: u64,
+ irq_mode: IRQMode,
+ disk: Option<GenDisk<NullBlkDevice>>,
+}
+
+#[vtable]
+impl configfs::AttributeOperations<0> for DeviceConfig {
+ type Data = DeviceConfig;
+
+ fn show(this: &DeviceConfig, page: &mut [u8; PAGE_SIZE]) -> Result<usize> {
+ let mut writer = kernel::str::Formatter::new(page);
+
+ if this.data.lock().powered {
+ writer.write_str("1\n")?;
+ } else {
+ writer.write_str("0\n")?;
+ }
+
+ Ok(writer.bytes_written())
+ }
+
+ fn store(this: &DeviceConfig, page: &[u8]) -> Result {
+ let power_op = kstrtobool_bytes(page)?;
+ let mut guard = this.data.lock();
+
+ if !guard.powered && power_op {
+ guard.disk = Some(NullBlkDevice::new(
+ &guard.name,
+ guard.block_size,
+ guard.rotational,
+ guard.capacity_mib,
+ guard.irq_mode,
+ )?);
+ guard.powered = true;
+ } else if guard.powered && !power_op {
+ drop(guard.disk.take());
+ guard.powered = false;
+ }
+
+ Ok(())
+ }
+}
+
+#[vtable]
+impl configfs::AttributeOperations<1> for DeviceConfig {
+ type Data = DeviceConfig;
+
+ fn show(this: &DeviceConfig, page: &mut [u8; PAGE_SIZE]) -> Result<usize> {
+ let mut writer = kernel::str::Formatter::new(page);
+ writer.write_fmt(fmt!("{}\n", this.data.lock().block_size))?;
+ Ok(writer.bytes_written())
+ }
+
+ fn store(this: &DeviceConfig, page: &[u8]) -> Result {
+ if this.data.lock().powered {
+ return Err(EBUSY);
+ }
+
+ let text = core::str::from_utf8(page)?.trim();
+ let value = text.parse::<u32>().map_err(|_| EINVAL)?;
+
+ GenDiskBuilder::validate_block_size(value)?;
+ this.data.lock().block_size = value;
+ Ok(())
+ }
+}
+
+#[vtable]
+impl configfs::AttributeOperations<2> for DeviceConfig {
+ type Data = DeviceConfig;
+
+ fn show(this: &DeviceConfig, page: &mut [u8; PAGE_SIZE]) -> Result<usize> {
+ let mut writer = kernel::str::Formatter::new(page);
+
+ if this.data.lock().rotational {
+ writer.write_str("1\n")?;
+ } else {
+ writer.write_str("0\n")?;
+ }
+
+ Ok(writer.bytes_written())
+ }
+
+ fn store(this: &DeviceConfig, page: &[u8]) -> Result {
+ if this.data.lock().powered {
+ return Err(EBUSY);
+ }
+
+ this.data.lock().rotational = kstrtobool_bytes(page)?;
+
+ Ok(())
+ }
+}
+
+#[vtable]
+impl configfs::AttributeOperations<3> for DeviceConfig {
+ type Data = DeviceConfig;
+
+ fn show(this: &DeviceConfig, page: &mut [u8; PAGE_SIZE]) -> Result<usize> {
+ let mut writer = kernel::str::Formatter::new(page);
+ writer.write_fmt(fmt!("{}\n", this.data.lock().capacity_mib))?;
+ Ok(writer.bytes_written())
+ }
+
+ fn store(this: &DeviceConfig, page: &[u8]) -> Result {
+ if this.data.lock().powered {
+ return Err(EBUSY);
+ }
+
+ let text = core::str::from_utf8(page)?.trim();
+ let value = text.parse::<u64>().map_err(|_| EINVAL)?;
+
+ this.data.lock().capacity_mib = value;
+ Ok(())
+ }
+}
+
+#[vtable]
+impl configfs::AttributeOperations<4> for DeviceConfig {
+ type Data = DeviceConfig;
+
+ fn show(this: &DeviceConfig, page: &mut [u8; PAGE_SIZE]) -> Result<usize> {
+ let mut writer = kernel::str::Formatter::new(page);
+ writer.write_fmt(fmt!("{}\n", this.data.lock().irq_mode))?;
+ Ok(writer.bytes_written())
+ }
+
+ fn store(this: &DeviceConfig, page: &[u8]) -> Result {
+ if this.data.lock().powered {
+ return Err(EBUSY);
+ }
+
+ let text = core::str::from_utf8(page)?.trim();
+ let value = text.parse::<u8>().map_err(|_| EINVAL)?;
+
+ this.data.lock().irq_mode = IRQMode::try_from(value)?;
+ Ok(())
+ }
+}
diff --git a/drivers/block/rnull/rnull.rs b/drivers/block/rnull/rnull.rs
new file mode 100644
index 000000000..0ca8715fe
--- /dev/null
+++ b/drivers/block/rnull/rnull.rs
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! This is a Rust implementation of the C null block driver.
+
+mod configfs;
+
+use configfs::IRQMode;
+use kernel::{
+ block::{
+ self,
+ mq::{
+ self,
+ gen_disk::{self, GenDisk},
+ Operations, TagSet,
+ },
+ },
+ prelude::*,
+ sync::{aref::ARef, Arc},
+};
+
+module! {
+ type: NullBlkModule,
+ name: "rnull_mod",
+ authors: ["Andreas Hindborg"],
+ description: "Rust implementation of the C null block driver",
+ license: "GPL v2",
+}
+
+#[pin_data]
+struct NullBlkModule {
+ #[pin]
+ configfs_subsystem: kernel::configfs::Subsystem<configfs::Config>,
+}
+
+impl kernel::InPlaceModule for NullBlkModule {
+ fn init(_module: &'static ThisModule) -> impl PinInit<Self, Error> {
+ pr_info!("Rust null_blk loaded\n");
+
+ try_pin_init!(Self {
+ configfs_subsystem <- configfs::subsystem(),
+ })
+ }
+}
+
+struct NullBlkDevice;
+
+impl NullBlkDevice {
+ fn new(
+ name: &CStr,
+ block_size: u32,
+ rotational: bool,
+ capacity_mib: u64,
+ irq_mode: IRQMode,
+ ) -> Result<GenDisk<Self>> {
+ let tagset = Arc::pin_init(TagSet::new(1, 256, 1), GFP_KERNEL)?;
+
+ let queue_data = Box::new(QueueData { irq_mode }, GFP_KERNEL)?;
+
+ gen_disk::GenDiskBuilder::new()
+ .capacity_sectors(capacity_mib << (20 - block::SECTOR_SHIFT))
+ .logical_block_size(block_size)?
+ .physical_block_size(block_size)?
+ .rotational(rotational)
+ .build(fmt!("{}", name.to_str()?), tagset, queue_data)
+ }
+}
+
+struct QueueData {
+ irq_mode: IRQMode,
+}
+
+#[vtable]
+impl Operations for NullBlkDevice {
+ type QueueData = KBox<QueueData>;
+
+ #[inline(always)]
+ fn queue_rq(queue_data: &QueueData, rq: ARef<mq::Request<Self>>, _is_last: bool) -> Result {
+ match queue_data.irq_mode {
+ IRQMode::None => mq::Request::end_ok(rq)
+ .map_err(|_e| kernel::error::code::EIO)
+ // We take no refcounts on the request, so we expect to be able to
+ // end the request. The request reference must be unique at this
+ // point, and so `end_ok` cannot fail.
+ .expect("Fatal error - expected to be able to end request"),
+ IRQMode::Soft => mq::Request::complete(rq),
+ }
+ Ok(())
+ }
+
+ fn commit_rqs(_queue_data: &QueueData) {}
+
+ fn complete(rq: ARef<mq::Request<Self>>) {
+ mq::Request::end_ok(rq)
+ .map_err(|_e| kernel::error::code::EIO)
+ // We take no refcounts on the request, so we expect to be able to
+ // end the request. The request reference must be unique at this
+ // point, and so `end_ok` cannot fail.
+ .expect("Fatal error - expected to be able to end request");
+ }
+}