* Re: [PATCH] staging: sm750fb: constify g_fbmode array
From: dipesh chaudhary @ 2026-03-09 10:06 UTC (permalink / raw)
To: gregkh
Cc: sudipm.mukherjee, teddy.wang, linux-fbdev, linux-staging,
linux-kernel
Hi Greg,
On Mon, Mar 09, 2026 at 09:49:57AM +0000, dipesh chaudhary wrote:
> --- a/Makefile
> +++ b/Makefile
> @@ -1,8 +1,8 @@
> # SPDX-License-Identifier: GPL-2.0
> -VERSION = 6
> -PATCHLEVEL = 19
> +VERSION = 7
> +PATCHLEVEL = 0
> SUBLEVEL = 0
> -EXTRAVERSION =
> +EXTRAVERSION = -rc1
> Why have you changed the Makefile?
I sincerely apologize for that. This is my very first kernel patch, and I was experimenting with the Makefile earlier on my local machine. I accidentally staged and included it in my commit alongside the driver fix without realizing it.
> And did you test-build your change?
To be completely honest, no. I only ran `checkpatch.pl` to verify the warning was resolved.
I will clean up my Git tree, figure out how to test-build the specific sm750 module locally, and then submit a clean v2 patch. Thank you for your patience with a beginner.
Best regards,
Dipesh Chaudhary
^ permalink raw reply
* Re: [PATCH] staging: sm750fb: constify g_fbmode array
From: Greg KH @ 2026-03-09 9:56 UTC (permalink / raw)
To: dipesh chaudhary
Cc: sudipm.mukherjee, teddy.wang, linux-fbdev, linux-staging,
linux-kernel
In-Reply-To: <9e566c42-8ec3-4d06-91be-0489de4e91c0@smtp-relay.sendinblue.com>
On Mon, Mar 09, 2026 at 09:49:57AM +0000, dipesh chaudhary wrote:
>
> Fix checkpatch warning for static const char array. Make the array of pointers read-only to improve memory safety.
>
> Signed-off-by: dipesh chaudhary <me@dipeshchaudhary.in>
> ---
> Makefile | 6 +++---
> drivers/staging/sm750fb/sm750.c | 2 +-
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index df471d4212cc..e944c6e71e81 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1,8 +1,8 @@
> # SPDX-License-Identifier: GPL-2.0
> -VERSION = 6
> -PATCHLEVEL = 19
> +VERSION = 7
> +PATCHLEVEL = 0
> SUBLEVEL = 0
> -EXTRAVERSION =
> +EXTRAVERSION = -rc1
> NAME = Baby Opossum Posse
>
> # *DOCUMENTATION*
Why have you changed the Makefile?
And did you test-build your change?
thanks,
greg k-h
^ permalink raw reply
* [PATCH] staging: sm750fb: constify g_fbmode array
From: dipesh chaudhary @ 2026-03-09 9:49 UTC (permalink / raw)
To: sudipm.mukherjee, teddy.wang, gregkh
Cc: linux-fbdev, linux-staging, linux-kernel, dipesh chaudhary
Fix checkpatch warning for static const char array. Make the array of pointers read-only to improve memory safety.
Signed-off-by: dipesh chaudhary <me@dipeshchaudhary.in>
---
Makefile | 6 +++---
drivers/staging/sm750fb/sm750.c | 2 +-
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/Makefile b/Makefile
index df471d4212cc..e944c6e71e81 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,8 @@
# SPDX-License-Identifier: GPL-2.0
-VERSION = 6
-PATCHLEVEL = 19
+VERSION = 7
+PATCHLEVEL = 0
SUBLEVEL = 0
-EXTRAVERSION =
+EXTRAVERSION = -rc1
NAME = Baby Opossum Posse
# *DOCUMENTATION*
diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c
index dec1f6b88a7d..08d4979c6755 100644
--- a/drivers/staging/sm750fb/sm750.c
+++ b/drivers/staging/sm750fb/sm750.c
@@ -33,7 +33,7 @@
static int g_hwcursor = 1;
static int g_noaccel;
static int g_nomtrr;
-static const char *g_fbmode[] = {NULL, NULL};
+static const char * const g_fbmode[] = {NULL, NULL};
static const char *g_def_fbmode = "1024x768-32@60";
static char *g_settings;
static int g_dualview;
--
2.47.3
^ permalink raw reply related
* [PATCH] staging: sm750fb: fix static const char * warning
From: sluisr @ 2026-03-09 0:28 UTC (permalink / raw)
To: sudipm.mukherjee, teddy.wang
Cc: gregkh, linux-fbdev, linux-staging, linux-kernel, sluisr
This patch fixes a checkpatch.pl warning:
WARNING: static const char * array should probably be static const char * const
by adding the missing const keyword to the g_fbmode array declaration.
Signed-off-by: sluisr <contact@sluisr.com>
---
drivers/staging/sm750fb/sm750.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c
index dec1f6b88..08d4979c6 100644
--- a/drivers/staging/sm750fb/sm750.c
+++ b/drivers/staging/sm750fb/sm750.c
@@ -33,7 +33,7 @@
static int g_hwcursor = 1;
static int g_noaccel;
static int g_nomtrr;
-static const char *g_fbmode[] = {NULL, NULL};
+static const char * const g_fbmode[] = {NULL, NULL};
static const char *g_def_fbmode = "1024x768-32@60";
static char *g_settings;
static int g_dualview;
--
2.53.0
^ permalink raw reply related
* [PATCH v12 1/1] rust: gpu: Add GPU buddy allocator bindings
From: Joel Fernandes @ 2026-03-08 18:04 UTC (permalink / raw)
To: linux-kernel
Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Dave Airlie, Daniel Almeida, Koen Koning,
dri-devel, nouveau, rust-for-linux, Nikola Djukic,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Jonathan Corbet, Alex Deucher,
Christian König, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi,
Tvrtko Ursulin, Huang Rui, Matthew Auld, Matthew Brost,
Lucas De Marchi, Thomas Hellström, Helge Deller, Alex Gaynor,
Boqun Feng, John Hubbard, Alistair Popple, Timur Tabi, Edwin Peer,
Alexandre Courbot, Andrea Righi, Andy Ritger, Zhi Wang,
Balbir Singh, Philipp Stanner, Elle Rhumsaa, alexeyi,
Eliot Courtney, joel, linux-doc, amd-gfx, intel-gfx, intel-xe,
linux-fbdev, Joel Fernandes
In-Reply-To: <20260308180407.3988286-1-joelagnelf@nvidia.com>
Add safe Rust abstractions over the Linux kernel's GPU buddy
allocator for physical memory management. The GPU buddy allocator
implements a binary buddy system useful for GPU physical memory
allocation. nova-core will use it for physical memory allocation.
Christian Koenig mentioned he'd like to step down from reviewer role for
GPU buddy so updated accordingly. Arun/Matthew agree on the modified entry.
Cc: Nikola Djukic <ndjukic@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
---
MAINTAINERS | 6 +-
rust/bindings/bindings_helper.h | 11 +
rust/helpers/gpu.c | 23 ++
rust/helpers/helpers.c | 1 +
rust/kernel/gpu/buddy.rs | 611 ++++++++++++++++++++++++++++++++
rust/kernel/gpu/mod.rs | 5 +
rust/kernel/lib.rs | 2 +
7 files changed, 658 insertions(+), 1 deletion(-)
create mode 100644 rust/helpers/gpu.c
create mode 100644 rust/kernel/gpu/buddy.rs
create mode 100644 rust/kernel/gpu/mod.rs
diff --git a/MAINTAINERS b/MAINTAINERS
index 4c66f8261ff2..b2600dd05fc2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8513,7 +8513,9 @@ T: git https://gitlab.freedesktop.org/drm/rust/kernel.git
F: drivers/gpu/drm/nova/
F: drivers/gpu/drm/tyr/
F: drivers/gpu/nova-core/
+F: rust/helpers/gpu.c
F: rust/kernel/drm/
+F: rust/kernel/gpu/
DRM DRIVERS FOR ALLWINNER A10
M: Chen-Yu Tsai <wens@kernel.org>
@@ -8926,7 +8928,7 @@ F: include/drm/ttm/
GPU BUDDY ALLOCATOR
M: Matthew Auld <matthew.auld@intel.com>
M: Arun Pravin <arunpravin.paneerselvam@amd.com>
-R: Christian Koenig <christian.koenig@amd.com>
+R: Joel Fernandes <joelagnelf@nvidia.com>
L: dri-devel@lists.freedesktop.org
S: Maintained
T: git https://gitlab.freedesktop.org/drm/misc/kernel.git
@@ -8935,6 +8937,8 @@ F: drivers/gpu/buddy.c
F: drivers/gpu/tests/gpu_buddy_test.c
F: include/linux/gpu_buddy.h
F: include/drm/drm_buddy.h
+F: rust/helpers/gpu.c
+F: rust/kernel/gpu/
DRM AUTOMATED TESTING
M: Helen Koike <helen.fornazier@gmail.com>
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 083cc44aa952..dbb765a9fdbd 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -29,6 +29,7 @@
#include <linux/hrtimer_types.h>
#include <linux/acpi.h>
+#include <linux/gpu_buddy.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
@@ -146,6 +147,16 @@ const vm_flags_t RUST_CONST_HELPER_VM_MIXEDMAP = VM_MIXEDMAP;
const vm_flags_t RUST_CONST_HELPER_VM_HUGEPAGE = VM_HUGEPAGE;
const vm_flags_t RUST_CONST_HELPER_VM_NOHUGEPAGE = VM_NOHUGEPAGE;
+#if IS_ENABLED(CONFIG_GPU_BUDDY)
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_RANGE_ALLOCATION = GPU_BUDDY_RANGE_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_TOPDOWN_ALLOCATION = GPU_BUDDY_TOPDOWN_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_CONTIGUOUS_ALLOCATION =
+ GPU_BUDDY_CONTIGUOUS_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_CLEAR_ALLOCATION = GPU_BUDDY_CLEAR_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_CLEARED = GPU_BUDDY_CLEARED;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_TRIM_DISABLE = GPU_BUDDY_TRIM_DISABLE;
+#endif
+
#if IS_ENABLED(CONFIG_ANDROID_BINDER_IPC_RUST)
#include "../../drivers/android/binder/rust_binder.h"
#include "../../drivers/android/binder/rust_binder_events.h"
diff --git a/rust/helpers/gpu.c b/rust/helpers/gpu.c
new file mode 100644
index 000000000000..38b1a4e6bef8
--- /dev/null
+++ b/rust/helpers/gpu.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/gpu_buddy.h>
+
+#ifdef CONFIG_GPU_BUDDY
+
+__rust_helper u64 rust_helper_gpu_buddy_block_offset(const struct gpu_buddy_block *block)
+{
+ return gpu_buddy_block_offset(block);
+}
+
+__rust_helper unsigned int rust_helper_gpu_buddy_block_order(struct gpu_buddy_block *block)
+{
+ return gpu_buddy_block_order(block);
+}
+
+__rust_helper u64 rust_helper_gpu_buddy_block_size(struct gpu_buddy *mm,
+ struct gpu_buddy_block *block)
+{
+ return gpu_buddy_block_size(mm, block);
+}
+
+#endif /* CONFIG_GPU_BUDDY */
diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
index 724fcb8240ac..a53929ce52a3 100644
--- a/rust/helpers/helpers.c
+++ b/rust/helpers/helpers.c
@@ -32,6 +32,7 @@
#include "err.c"
#include "irq.c"
#include "fs.c"
+#include "gpu.c"
#include "io.c"
#include "jump_label.c"
#include "kunit.c"
diff --git a/rust/kernel/gpu/buddy.rs b/rust/kernel/gpu/buddy.rs
new file mode 100644
index 000000000000..082dc79ab247
--- /dev/null
+++ b/rust/kernel/gpu/buddy.rs
@@ -0,0 +1,611 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! GPU buddy allocator bindings.
+//!
+//! C header: [`include/linux/gpu_buddy.h`](srctree/include/linux/gpu_buddy.h)
+//!
+//! This module provides Rust abstractions over the Linux kernel's GPU buddy
+//! allocator, which implements a binary buddy memory allocator.
+//!
+//! The buddy allocator manages a contiguous address space and allocates blocks
+//! in power-of-two sizes, useful for GPU physical memory management.
+//!
+//! # Examples
+//!
+//! Create a buddy allocator and perform a basic range allocation:
+//!
+//! ```
+//! use kernel::{
+//! gpu::buddy::{GpuBuddy, GpuBuddyAllocMode, GpuBuddyAllocFlags, GpuBuddyParams},
+//! prelude::*,
+//! ptr::Alignment,
+//! sizes::*, //
+//! };
+//!
+//! // Create a 1GB buddy allocator with 4KB minimum chunk size.
+//! let buddy = GpuBuddy::new(GpuBuddyParams {
+//! base_offset: 0,
+//! physical_memory_size: SZ_1G as u64,
+//! chunk_size: SZ_4K,
+//! })?;
+//!
+//! assert_eq!(buddy.size(), SZ_1G as u64);
+//! assert_eq!(buddy.chunk_size(), SZ_4K);
+//! let initial_free = buddy.free_memory();
+//!
+//! // Allocate 16MB, results in a single 16MB block at offset 0.
+//! let allocated = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::Range { start: 0, end: 0 },
+//! SZ_16M,
+//! Alignment::new::<SZ_16M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_16M as u64);
+//!
+//! let block = allocated.iter().next().expect("expected one block");
+//! assert_eq!(block.offset(), 0);
+//! assert_eq!(block.order(), 12); // 2^12 pages = 16MB
+//! assert_eq!(block.size(), SZ_16M);
+//!
+//! // Dropping the allocation returns the memory to the buddy allocator.
+//! drop(allocated);
+//! assert_eq!(buddy.free_memory(), initial_free);
+//! # Ok::<(), Error>(())
+//! ```
+//!
+//! Top-down allocation allocates from the highest addresses:
+//!
+//! ```
+//! # use kernel::{
+//! # gpu::buddy::{GpuBuddy, GpuBuddyAllocMode, GpuBuddyAllocFlags, GpuBuddyParams},
+//! # prelude::*,
+//! # ptr::Alignment,
+//! # sizes::*, //
+//! # };
+//! # let buddy = GpuBuddy::new(GpuBuddyParams {
+//! # base_offset: 0,
+//! # physical_memory_size: SZ_1G as u64,
+//! # chunk_size: SZ_4K,
+//! # })?;
+//! # let initial_free = buddy.free_memory();
+//! let topdown = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::TopDown,
+//! SZ_16M,
+//! Alignment::new::<SZ_16M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_16M as u64);
+//!
+//! let block = topdown.iter().next().expect("expected one block");
+//! assert_eq!(block.offset(), (SZ_1G - SZ_16M) as u64);
+//! assert_eq!(block.order(), 12);
+//! assert_eq!(block.size(), SZ_16M);
+//!
+//! // Dropping the allocation returns the memory to the buddy allocator.
+//! drop(topdown);
+//! assert_eq!(buddy.free_memory(), initial_free);
+//! # Ok::<(), Error>(())
+//! ```
+//!
+//! Non-contiguous allocation can fill fragmented memory by returning multiple
+//! blocks:
+//!
+//! ```
+//! # use kernel::{
+//! # gpu::buddy::{
+//! # GpuBuddy, GpuBuddyAllocFlags, GpuBuddyAllocMode, GpuBuddyParams,
+//! # },
+//! # prelude::*,
+//! # ptr::Alignment,
+//! # sizes::*, //
+//! # };
+//! # let buddy = GpuBuddy::new(GpuBuddyParams {
+//! # base_offset: 0,
+//! # physical_memory_size: SZ_1G as u64,
+//! # chunk_size: SZ_4K,
+//! # })?;
+//! # let initial_free = buddy.free_memory();
+//! // Create fragmentation by allocating 4MB blocks at [0,4M) and [8M,12M).
+//! let frag1 = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::Range { start: 0, end: SZ_4M as u64 },
+//! SZ_4M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_4M as u64);
+//!
+//! let frag2 = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::Range {
+//! start: SZ_8M as u64,
+//! end: (SZ_8M + SZ_4M) as u64,
+//! },
+//! SZ_4M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_8M as u64);
+//!
+//! // Allocate 8MB, this returns 2 blocks from the holes.
+//! let fragmented = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::Range { start: 0, end: SZ_16M as u64 },
+//! SZ_8M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_16M as u64);
+//!
+//! let (mut count, mut total) = (0u32, 0usize);
+//! for block in fragmented.iter() {
+//! assert_eq!(block.size(), SZ_4M);
+//! total += block.size();
+//! count += 1;
+//! }
+//! assert_eq!(total, SZ_8M);
+//! assert_eq!(count, 2);
+//! # Ok::<(), Error>(())
+//! ```
+//!
+//! Contiguous allocation fails when only fragmented space is available:
+//!
+//! ```
+//! # use kernel::{
+//! # gpu::buddy::{
+//! # GpuBuddy, GpuBuddyAllocFlag, GpuBuddyAllocMode, GpuBuddyParams,
+//! # },
+//! # prelude::*,
+//! # ptr::Alignment,
+//! # sizes::*, //
+//! # };
+//! // Create a small 16MB buddy allocator with fragmented memory.
+//! let small = GpuBuddy::new(GpuBuddyParams {
+//! base_offset: 0,
+//! physical_memory_size: SZ_16M as u64,
+//! chunk_size: SZ_4K,
+//! })?;
+//!
+//! let _hole1 = KBox::pin_init(
+//! small.alloc_blocks(
+//! GpuBuddyAllocMode::Range { start: 0, end: SZ_4M as u64 },
+//! SZ_4M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//!
+//! let _hole2 = KBox::pin_init(
+//! small.alloc_blocks(
+//! GpuBuddyAllocMode::Range {
+//! start: SZ_8M as u64,
+//! end: (SZ_8M + SZ_4M) as u64,
+//! },
+//! SZ_4M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//!
+//! // 8MB contiguous should fail, only two non-contiguous 4MB holes exist.
+//! let result = KBox::pin_init(
+//! small.alloc_blocks(
+//! GpuBuddyAllocMode::Simple,
+//! SZ_8M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyAllocFlag::Contiguous.into(),
+//! ),
+//! GFP_KERNEL,
+//! );
+//! assert!(result.is_err());
+//! # Ok::<(), Error>(())
+//! ```
+
+use crate::{
+ bindings,
+ clist_create,
+ error::to_result,
+ interop::list::CListHead,
+ new_mutex,
+ prelude::*,
+ ptr::Alignment,
+ sync::{
+ lock::mutex::MutexGuard,
+ Arc,
+ Mutex, //
+ },
+ types::Opaque, //
+};
+
+/// Allocation mode for the GPU buddy allocator.
+///
+/// The mode determines the primary allocation strategy. Modes are mutually
+/// exclusive: an allocation is either simple, range-constrained, or top-down.
+///
+/// Orthogonal modifier flags (e.g., contiguous, clear) are specified separately
+/// via [`GpuBuddyAllocFlags`].
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub enum GpuBuddyAllocMode {
+ /// Simple allocation without constraints.
+ Simple,
+ /// Range-based allocation between `start` and `end` addresses.
+ Range {
+ /// Start of the allocation range.
+ start: u64,
+ /// End of the allocation range.
+ end: u64,
+ },
+ /// Allocate from top of address space downward.
+ TopDown,
+}
+
+impl GpuBuddyAllocMode {
+ // Returns the C flags corresponding to the allocation mode.
+ fn into_flags(self) -> usize {
+ match self {
+ Self::Simple => 0,
+ Self::Range { .. } => bindings::GPU_BUDDY_RANGE_ALLOCATION as usize,
+ Self::TopDown => bindings::GPU_BUDDY_TOPDOWN_ALLOCATION as usize,
+ }
+ }
+
+ // Extracts the range start/end, defaulting to (0, 0) for non-range modes.
+ fn range(self) -> (u64, u64) {
+ match self {
+ Self::Range { start, end } => (start, end),
+ _ => (0, 0),
+ }
+ }
+}
+
+crate::impl_flags!(
+ /// Modifier flags for GPU buddy allocation.
+ ///
+ /// These flags can be combined with any [`GpuBuddyAllocMode`] to control
+ /// additional allocation behavior.
+ #[derive(Clone, Copy, Default, PartialEq, Eq)]
+ pub struct GpuBuddyAllocFlags(u32);
+
+ /// Individual modifier flag for GPU buddy allocation.
+ #[derive(Clone, Copy, PartialEq, Eq)]
+ pub enum GpuBuddyAllocFlag {
+ /// Allocate physically contiguous blocks.
+ Contiguous = bindings::GPU_BUDDY_CONTIGUOUS_ALLOCATION as u32,
+
+ /// Request allocation from cleared (zeroed) memory.
+ Clear = bindings::GPU_BUDDY_CLEAR_ALLOCATION as u32,
+
+ /// Disable trimming of partially used blocks.
+ TrimDisable = bindings::GPU_BUDDY_TRIM_DISABLE as u32,
+ }
+);
+
+/// Parameters for creating a GPU buddy allocator.
+pub struct GpuBuddyParams {
+ /// Base offset (in bytes) where the managed memory region starts.
+ /// Allocations will be offset by this value.
+ pub base_offset: u64,
+ /// Total physical memory size (in bytes) managed by the allocator.
+ pub physical_memory_size: u64,
+ /// Minimum allocation unit / chunk size (in bytes), must be >= 4KB.
+ pub chunk_size: usize,
+}
+
+/// Inner structure holding the actual buddy allocator.
+///
+/// # Synchronization
+///
+/// The C `gpu_buddy` API requires synchronization (see `include/linux/gpu_buddy.h`).
+/// [`GpuBuddyGuard`] ensures that the lock is held for all
+/// allocator and free operations, preventing races between concurrent allocations
+/// and the freeing that occurs when [`AllocatedBlocks`] is dropped.
+///
+/// # Invariants
+///
+/// The inner [`Opaque`] contains an initialized buddy allocator.
+#[pin_data(PinnedDrop)]
+struct GpuBuddyInner {
+ #[pin]
+ inner: Opaque<bindings::gpu_buddy>,
+
+ // TODO: Replace `Mutex<()>` with `Mutex<Opaque<..>>` once `Mutex::new()`
+ // accepts `impl PinInit<T>`.
+ #[pin]
+ lock: Mutex<()>,
+ /// Cached creation parameters (do not change after init).
+ params: GpuBuddyParams,
+}
+
+impl GpuBuddyInner {
+ /// Create a pin-initializer for the buddy allocator.
+ fn new(params: GpuBuddyParams) -> impl PinInit<Self, Error> {
+ let size = params.physical_memory_size;
+ let chunk_size = params.chunk_size;
+
+ // INVARIANT: `gpu_buddy_init` returns 0 on success, at which point the
+ // `gpu_buddy` structure is initialized and ready for use with all
+ // `gpu_buddy_*` APIs. `try_pin_init!` only completes if all fields succeed,
+ // so the invariant holds when construction finishes.
+ try_pin_init!(Self {
+ inner <- Opaque::try_ffi_init(|ptr| {
+ // SAFETY: `ptr` points to valid uninitialized memory from the pin-init
+ // infrastructure. `gpu_buddy_init` will initialize the structure.
+ to_result(unsafe { bindings::gpu_buddy_init(ptr, size, chunk_size as u64) })
+ }),
+ lock <- new_mutex!(()),
+ params,
+ })
+ }
+
+ /// Lock the mutex and return a guard for accessing the allocator.
+ fn lock(&self) -> GpuBuddyGuard<'_> {
+ GpuBuddyGuard {
+ inner: self,
+ _guard: self.lock.lock(),
+ }
+ }
+}
+
+#[pinned_drop]
+impl PinnedDrop for GpuBuddyInner {
+ fn drop(self: Pin<&mut Self>) {
+ let guard = self.lock();
+
+ // SAFETY: Per the type invariant, `inner` contains an initialized
+ // allocator. `guard` provides exclusive access.
+ unsafe {
+ bindings::gpu_buddy_fini(guard.as_raw());
+ }
+ }
+}
+
+// SAFETY: GpuBuddyInner can be sent between threads.
+unsafe impl Send for GpuBuddyInner {}
+
+// SAFETY: `GpuBuddyInner` is `Sync` because `GpuBuddyInner::lock`
+// serializes all access to the C allocator, preventing data races.
+unsafe impl Sync for GpuBuddyInner {}
+
+// Guard that proves the lock is held, enabling access to the allocator.
+// The `_guard` holds the lock for the duration of this guard's lifetime.
+struct GpuBuddyGuard<'a> {
+ inner: &'a GpuBuddyInner,
+ _guard: MutexGuard<'a, ()>,
+}
+
+impl GpuBuddyGuard<'_> {
+ /// Get a raw pointer to the underlying C `gpu_buddy` structure.
+ fn as_raw(&self) -> *mut bindings::gpu_buddy {
+ self.inner.inner.get()
+ }
+}
+
+/// GPU buddy allocator instance.
+///
+/// This structure wraps the C `gpu_buddy` allocator using reference counting.
+/// The allocator is automatically cleaned up when all references are dropped.
+///
+/// Refer to the module-level documentation for usage examples.
+pub struct GpuBuddy(Arc<GpuBuddyInner>);
+
+impl GpuBuddy {
+ /// Create a new buddy allocator.
+ ///
+ /// Creates a buddy allocator that manages a contiguous address space of the given
+ /// size, with the specified minimum allocation unit (chunk_size must be at least 4KB).
+ pub fn new(params: GpuBuddyParams) -> Result<Self> {
+ Ok(Self(Arc::pin_init(GpuBuddyInner::new(params), GFP_KERNEL)?))
+ }
+
+ /// Get the base offset for allocations.
+ pub fn base_offset(&self) -> u64 {
+ self.0.params.base_offset
+ }
+
+ /// Get the chunk size (minimum allocation unit).
+ pub fn chunk_size(&self) -> usize {
+ self.0.params.chunk_size
+ }
+
+ /// Get the total managed size.
+ pub fn size(&self) -> u64 {
+ self.0.params.physical_memory_size
+ }
+
+ /// Get the available (free) memory in bytes.
+ pub fn free_memory(&self) -> u64 {
+ let guard = self.0.lock();
+
+ // SAFETY: Per the type invariant, `inner` contains an initialized allocator.
+ // `guard` provides exclusive access.
+ unsafe { (*guard.as_raw()).avail }
+ }
+
+ /// Allocate blocks from the buddy allocator.
+ ///
+ /// Returns a pin-initializer for [`AllocatedBlocks`].
+ ///
+ /// Takes `&self` instead of `&mut self` because the internal [`Mutex`] provides
+ /// synchronization - no external `&mut` exclusivity needed.
+ pub fn alloc_blocks(
+ &self,
+ mode: GpuBuddyAllocMode,
+ size: usize,
+ min_block_size: Alignment,
+ flags: GpuBuddyAllocFlags,
+ ) -> impl PinInit<AllocatedBlocks, Error> {
+ let buddy_arc = Arc::clone(&self.0);
+ let (start, end) = mode.range();
+ let mode_flags = mode.into_flags();
+ let modifier_flags = u32::from(flags) as usize;
+
+ // Create pin-initializer that initializes list and allocates blocks.
+ try_pin_init!(AllocatedBlocks {
+ buddy: buddy_arc,
+ list <- CListHead::new(),
+ _: {
+ // Lock while allocating to serialize with concurrent frees.
+ let guard = buddy.lock();
+
+ // SAFETY: Per the type invariant, `inner` contains an initialized
+ // allocator. `guard` provides exclusive access.
+ to_result(unsafe {
+ bindings::gpu_buddy_alloc_blocks(
+ guard.as_raw(),
+ start,
+ end,
+ size as u64,
+ min_block_size.as_usize() as u64,
+ list.as_raw(),
+ mode_flags | modifier_flags,
+ )
+ })?
+ }
+ })
+ }
+}
+
+/// Allocated blocks from the buddy allocator with automatic cleanup.
+///
+/// This structure owns a list of allocated blocks and ensures they are
+/// automatically freed when dropped. Use `iter()` to iterate over all
+/// allocated blocks.
+///
+/// # Invariants
+///
+/// - `list` is an initialized, valid list head containing allocated blocks.
+#[pin_data(PinnedDrop)]
+pub struct AllocatedBlocks {
+ #[pin]
+ list: CListHead,
+ buddy: Arc<GpuBuddyInner>,
+}
+
+impl AllocatedBlocks {
+ /// Check if the block list is empty.
+ pub fn is_empty(&self) -> bool {
+ // An empty list head points to itself.
+ !self.list.is_linked()
+ }
+
+ /// Iterate over allocated blocks.
+ ///
+ /// Returns an iterator yielding [`AllocatedBlock`] values. Each [`AllocatedBlock`]
+ /// borrows `self` and is only valid for the duration of that borrow.
+ pub fn iter(&self) -> impl Iterator<Item = AllocatedBlock<'_>> + '_ {
+ // SAFETY:
+ // - Per the type invariant, `list` is an initialized sentinel `list_head`
+ // and is not concurrently modified (we hold a `&self` borrow).
+ // - The list contains `gpu_buddy_block` items linked via
+ // `__bindgen_anon_1.link`.
+ // - `Block` is `#[repr(transparent)]` over `gpu_buddy_block`.
+ let clist = clist_create!(unsafe {
+ self.list.as_raw(),
+ Block,
+ bindings::gpu_buddy_block,
+ __bindgen_anon_1.link
+ });
+
+ clist
+ .iter()
+ .map(|this| AllocatedBlock { this, blocks: self })
+ }
+}
+
+#[pinned_drop]
+impl PinnedDrop for AllocatedBlocks {
+ fn drop(self: Pin<&mut Self>) {
+ let guard = self.buddy.lock();
+
+ // SAFETY:
+ // - list is valid per the type's invariants.
+ // - guard provides exclusive access to the allocator.
+ unsafe {
+ bindings::gpu_buddy_free_list(guard.as_raw(), self.list.as_raw(), 0);
+ }
+ }
+}
+
+/// A GPU buddy block.
+///
+/// Transparent wrapper over C `gpu_buddy_block` structure. This type is returned
+/// as references during iteration over [`AllocatedBlocks`].
+///
+/// # Invariants
+///
+/// The inner [`Opaque`] contains a valid, allocated `gpu_buddy_block`.
+#[repr(transparent)]
+struct Block(Opaque<bindings::gpu_buddy_block>);
+
+impl Block {
+ /// Get a raw pointer to the underlying C block.
+ fn as_raw(&self) -> *mut bindings::gpu_buddy_block {
+ self.0.get()
+ }
+
+ /// Get the block's raw offset in the buddy address space (without base offset).
+ fn offset(&self) -> u64 {
+ // SAFETY: `self.as_raw()` is valid per the type's invariants.
+ unsafe { bindings::gpu_buddy_block_offset(self.as_raw()) }
+ }
+
+ /// Get the block order.
+ fn order(&self) -> u32 {
+ // SAFETY: `self.as_raw()` is valid per the type's invariants.
+ unsafe { bindings::gpu_buddy_block_order(self.as_raw()) }
+ }
+}
+
+// SAFETY: `Block` is a wrapper around `gpu_buddy_block` which can be
+// sent across threads safely.
+unsafe impl Send for Block {}
+
+// SAFETY: `Block` is only accessed through shared references after
+// allocation, and thus safe to access concurrently across threads.
+unsafe impl Sync for Block {}
+
+/// A buddy block paired with its owning [`AllocatedBlocks`] context.
+///
+/// Unlike a raw block, which only knows its offset within the buddy address
+/// space, an [`AllocatedBlock`] also has access to the allocator's `base_offset`
+/// and `chunk_size`, enabling it to compute absolute offsets and byte sizes.
+///
+/// Returned by [`AllocatedBlocks::iter()`].
+pub struct AllocatedBlock<'a> {
+ this: &'a Block,
+ blocks: &'a AllocatedBlocks,
+}
+
+impl AllocatedBlock<'_> {
+ /// Get the block's offset in the address space.
+ ///
+ /// Returns the absolute offset including the allocator's base offset.
+ /// This is the actual address to use for accessing the allocated memory.
+ pub fn offset(&self) -> u64 {
+ self.blocks.buddy.params.base_offset + self.this.offset()
+ }
+
+ /// Get the block order (size = chunk_size << order).
+ pub fn order(&self) -> u32 {
+ self.this.order()
+ }
+
+ /// Get the block's size in bytes.
+ pub fn size(&self) -> usize {
+ self.blocks.buddy.params.chunk_size << self.this.order()
+ }
+}
diff --git a/rust/kernel/gpu/mod.rs b/rust/kernel/gpu/mod.rs
new file mode 100644
index 000000000000..8f25e6367edc
--- /dev/null
+++ b/rust/kernel/gpu/mod.rs
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! GPU subsystem abstractions.
+
+pub mod buddy;
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index bb741f1e0dfd..63e3f656eb6c 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -98,6 +98,8 @@
pub mod firmware;
pub mod fmt;
pub mod fs;
+#[cfg(CONFIG_GPU_BUDDY = "y")]
+pub mod gpu;
#[cfg(CONFIG_I2C = "y")]
pub mod i2c;
pub mod id_pool;
--
2.34.1
^ permalink raw reply related
* [PATCH v12 0/1] Rust GPU buddy allocator bindings
From: Joel Fernandes @ 2026-03-08 18:04 UTC (permalink / raw)
To: linux-kernel
Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Dave Airlie, Daniel Almeida, Koen Koning,
dri-devel, nouveau, rust-for-linux, Nikola Djukic,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Jonathan Corbet, Alex Deucher,
Christian König, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi,
Tvrtko Ursulin, Huang Rui, Matthew Auld, Matthew Brost,
Lucas De Marchi, Thomas Hellström, Helge Deller, Alex Gaynor,
Boqun Feng, John Hubbard, Alistair Popple, Timur Tabi, Edwin Peer,
Alexandre Courbot, Andrea Righi, Andy Ritger, Zhi Wang,
Balbir Singh, Philipp Stanner, Elle Rhumsaa, alexeyi,
Eliot Courtney, joel, linux-doc, amd-gfx, intel-gfx, intel-xe,
linux-fbdev, Joel Fernandes
This patch adds safe Rust abstractions over the Linux kernel's GPU buddy
allocator for physical memory management. The prerequisite infrastructure
patches (DRM buddy code movement and the uninitialized buddy fix) have been
absorbed into upstream -next, so this is now a standalone patch.
The series along with all dependencies, including clist and nova-core mm
patches, are available at:
git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux.git (tag: nova-mm-current-3-8)
This patch is also here:
https://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux.git/commit/?id=gpu-buddy-bindings-v12
Change log:
Changes from v11 to v12:
- Rebased on linux-next his is now a standalone single patch as dependencies
are absorbed (but not clist is a prequisite)
- Redesigned allocation API (Alexandre Courbot) for better Rust ergonomics.
- Split single long example into 4 self-contained examples (Alexandre Courbot).
- Several safety and invariant comment changes (Danilo).
- MAINTAINERS changes (Arun, Mathew, Danilo, Dave).
- Fixed `#[cfg(CONFIG_GPU_BUDDY)]` to `#[cfg(CONFIG_GPU_BUDDY = "y")]` (Danilo Krummrich).
- Updated `ffi::clist::CListHead` to `interop::list::CListHead`.
Changes from v10 to v11:
- Dropped "rust: ffi: Convert pub use to pub mod and create ffi module" patch;
the ffi module restructuring will go through a different path.
- Dropped "rust: clist: Add support to interface with C linked lists" patch;
the clist module will be submitted separately.
- Dropped "nova-core: Kconfig: Sort select statements alphabetically" cosmetic
patch.
- Patches 1-3 (DRM buddy movement and fix) are included as reference only;
they are already being pulled into upstream via drm-misc-next.
- Removed clist patches as those can go in independently (Alice).
- Moved the Kconfig GPU_BUDDY selection patch to nova-core mm series to enable
it when it is actually used.
- Various nits to comments, etc.
Changes from v9 to v10:
- Absorbed the DRM buddy code movement patches into this series as patches 1-2.
Dave Airlie reworked these into two parts for better git history.
- Added "gpu: Fix uninitialized buddy for built-in drivers" fix by Koen Koning,
using subsys_initcall instead of module_init to fix NULL pointer dereference
when built-in drivers use the buddy allocator before initialization.
- Added "rust: ffi: Convert pub use to pub mod and create ffi module" to prepare
the ffi module for hosting clist as a sub-module.
- Moved clist from rust/kernel/clist.rs to rust/kernel/ffi/.
- Added "nova-core: Kconfig: Sort select statements alphabetically" (Danilo).
Changes from v8 to v9:
- Updated nova-core Kconfig patch: addressed sorting of Kconfig options.
- Added Daniel Almeida's Reviewed-by tag to clist patch.
- Minor refinements to GPU buddy bindings.
Changes from v7 to v8:
- Added nova-core Kconfig patch to select GPU_BUDDY for VRAM allocation.
- Various changes suggested by Danilo Krummrich, Gary Guo, and Daniel Almeida.
- Added Acked-by: Gary Guo for clist patch.
Changes from v6 to v7:
- Major restructuring: split the large 26-patch v6 RFC series. v7 only contains
the Rust infrastructure patches (clist + GPU buddy bindings), extracted from
the full nova-core MM series. The nova-core MM patches follow separately.
- Rebased on linux-next.
Changes from v5 to v6:
- Rebased on drm-rust-kernel/drm-rust-next.
- Expanded from 6 to 26 patches with full nova-core MM infrastructure including
page table walker, VMM, BAR1 user interface, TLB flush, and GpuMm manager.
Changes from v4 to v5:
- Added PRAMIN aperture support with documentation and self-tests.
- Improved buddy allocator bindings (fewer lines of code).
- Based on drm-rust-next instead of linux-next.
Changes from v3 to v4:
- Combined the clist and DRM buddy series into a single coherent series.
- Added DRM buddy allocator movement from drivers/gpu/drm/ up to drivers/gpu/,
renaming API from drm_buddy to gpu_buddy.
- Added Rust bindings for the GPU buddy allocator.
Changes from v2 to v3:
- Squashed 3 clist patches into one due to inter-dependencies.
- Changed Clist to Clist<'a, T> using const generic offset (Alex Courbot).
- Simplified C helpers to only list_add_tail (Alex Courbot, John Hubbard).
- Added init_list_head() Rust function (Alex Courbot).
- Added FusedIterator, PartialEq/Eq impls.
- Added MAINTAINERS entry (Miguel Ojeda).
Changes from v1 (RFC) to v2:
- Dropped DRM buddy allocator patches; series focuses solely on clist module.
- Dropped sample modules, replaced with doctests.
- Added proper lifetime management similar to scatterlist.
- Split clist into 3 separate patches.
Link to v11: https://lore.kernel.org/all/20260224224005.3232841-1-joelagnelf@nvidia.com/
Joel Fernandes (1):
rust: gpu: Add GPU buddy allocator bindings
MAINTAINERS | 6 +-
rust/bindings/bindings_helper.h | 11 +
rust/helpers/gpu.c | 23 ++
rust/helpers/helpers.c | 1 +
rust/kernel/gpu/buddy.rs | 611 ++++++++++++++++++++++++++++++++
rust/kernel/gpu/mod.rs | 5 +
rust/kernel/lib.rs | 2 +
7 files changed, 658 insertions(+), 1 deletion(-)
create mode 100644 rust/helpers/gpu.c
create mode 100644 rust/kernel/gpu/buddy.rs
create mode 100644 rust/kernel/gpu/mod.rs
--
2.34.1
^ permalink raw reply
* Re: [PATCH] staging: sm750fb: add missing const qualifier to char pointer array
From: kernel test robot @ 2026-03-08 1:45 UTC (permalink / raw)
To: Oskar Ray-Frayssinet, sudipm.mukherjee, teddy.wang, gregkh
Cc: llvm, oe-kbuild-all, linux-fbdev, linux-staging, linux-kernel,
Oskar Ray-Frayssinet
In-Reply-To: <20260307131833.1138-1-rayfraytech@gmail.com>
Hi Oskar,
kernel test robot noticed the following build errors:
[auto build test ERROR on staging/staging-testing]
url: https://github.com/intel-lab-lkp/linux/commits/Oskar-Ray-Frayssinet/staging-sm750fb-add-missing-const-qualifier-to-char-pointer-array/20260307-212030
base: staging/staging-testing
patch link: https://lore.kernel.org/r/20260307131833.1138-1-rayfraytech%40gmail.com
patch subject: [PATCH] staging: sm750fb: add missing const qualifier to char pointer array
config: i386-buildonly-randconfig-003-20260308 (https://download.01.org/0day-ci/archive/20260308/202603080944.rMPCAhoj-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260308/202603080944.rMPCAhoj-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202603080944.rMPCAhoj-lkp@intel.com/
All errors (new ones prefixed by >>):
>> drivers/staging/sm750fb/sm750.c:782:19: error: cannot assign to variable 'g_fbmode' with const-qualified type 'const char *const[2]'
782 | g_fbmode[index] = g_def_fbmode;
| ~~~~~~~~~~~~~~~ ^
drivers/staging/sm750fb/sm750.c:36:27: note: variable 'g_fbmode' declared const here
36 | static const char * const g_fbmode[] = {NULL, NULL};
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/staging/sm750fb/sm750.c:784:20: error: cannot assign to variable 'g_fbmode' with const-qualified type 'const char *const[2]'
784 | g_fbmode[index] = g_fbmode[0];
| ~~~~~~~~~~~~~~~ ^
drivers/staging/sm750fb/sm750.c:36:27: note: variable 'g_fbmode' declared const here
36 | static const char * const g_fbmode[] = {NULL, NULL};
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/staging/sm750fb/sm750.c:893:17: error: cannot assign to variable 'g_fbmode' with const-qualified type 'const char *const[2]'
893 | g_fbmode[0] = opt;
| ~~~~~~~~~~~ ^
drivers/staging/sm750fb/sm750.c:36:27: note: variable 'g_fbmode' declared const here
36 | static const char * const g_fbmode[] = {NULL, NULL};
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/staging/sm750fb/sm750.c:897:17: error: cannot assign to variable 'g_fbmode' with const-qualified type 'const char *const[2]'
897 | g_fbmode[1] = opt;
| ~~~~~~~~~~~ ^
drivers/staging/sm750fb/sm750.c:36:27: note: variable 'g_fbmode' declared const here
36 | static const char * const g_fbmode[] = {NULL, NULL};
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
4 errors generated.
vim +782 drivers/staging/sm750fb/sm750.c
81dee67e215b23f Sudip Mukherjee 2015-03-03 716
81dee67e215b23f Sudip Mukherjee 2015-03-03 717 static int lynxfb_set_fbinfo(struct fb_info *info, int index)
81dee67e215b23f Sudip Mukherjee 2015-03-03 718 {
81dee67e215b23f Sudip Mukherjee 2015-03-03 719 int i;
81dee67e215b23f Sudip Mukherjee 2015-03-03 720 struct lynxfb_par *par;
e359b6a863e19f2 Mike Rapoport 2015-10-26 721 struct sm750_dev *sm750_dev;
81dee67e215b23f Sudip Mukherjee 2015-03-03 722 struct lynxfb_crtc *crtc;
81dee67e215b23f Sudip Mukherjee 2015-03-03 723 struct lynxfb_output *output;
81dee67e215b23f Sudip Mukherjee 2015-03-03 724 struct fb_var_screeninfo *var;
81dee67e215b23f Sudip Mukherjee 2015-03-03 725 struct fb_fix_screeninfo *fix;
81dee67e215b23f Sudip Mukherjee 2015-03-03 726
81dee67e215b23f Sudip Mukherjee 2015-03-03 727 const struct fb_videomode *pdb[] = {
81dee67e215b23f Sudip Mukherjee 2015-03-03 728 lynx750_ext, NULL, vesa_modes,
81dee67e215b23f Sudip Mukherjee 2015-03-03 729 };
81dee67e215b23f Sudip Mukherjee 2015-03-03 730 int cdb[] = {ARRAY_SIZE(lynx750_ext), 0, VESA_MODEDB_SIZE};
8c475735085a7db Tim Wassink 2025-12-21 731 static const char *fix_id[2] = {
81dee67e215b23f Sudip Mukherjee 2015-03-03 732 "sm750_fb1", "sm750_fb2",
81dee67e215b23f Sudip Mukherjee 2015-03-03 733 };
81dee67e215b23f Sudip Mukherjee 2015-03-03 734
81dee67e215b23f Sudip Mukherjee 2015-03-03 735 int ret, line_length;
81dee67e215b23f Sudip Mukherjee 2015-03-03 736
81dee67e215b23f Sudip Mukherjee 2015-03-03 737 ret = 0;
81dee67e215b23f Sudip Mukherjee 2015-03-03 738 par = (struct lynxfb_par *)info->par;
e359b6a863e19f2 Mike Rapoport 2015-10-26 739 sm750_dev = par->dev;
81dee67e215b23f Sudip Mukherjee 2015-03-03 740 crtc = &par->crtc;
81dee67e215b23f Sudip Mukherjee 2015-03-03 741 output = &par->output;
81dee67e215b23f Sudip Mukherjee 2015-03-03 742 var = &info->var;
81dee67e215b23f Sudip Mukherjee 2015-03-03 743 fix = &info->fix;
81dee67e215b23f Sudip Mukherjee 2015-03-03 744
81dee67e215b23f Sudip Mukherjee 2015-03-03 745 /* set index */
81dee67e215b23f Sudip Mukherjee 2015-03-03 746 par->index = index;
81dee67e215b23f Sudip Mukherjee 2015-03-03 747 output->channel = &crtc->channel;
81dee67e215b23f Sudip Mukherjee 2015-03-03 748 sm750fb_set_drv(par);
81dee67e215b23f Sudip Mukherjee 2015-03-03 749
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 750 /*
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 751 * set current cursor variable and proc pointer,
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 752 * must be set after crtc member initialized
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 753 */
fdc234d85210d91 Benjamin Philip 2021-07-28 754 crtc->cursor.offset = crtc->o_screen + crtc->vidmem_size - 1024;
e359b6a863e19f2 Mike Rapoport 2015-10-26 755 crtc->cursor.mmio = sm750_dev->pvReg +
e359b6a863e19f2 Mike Rapoport 2015-10-26 756 0x800f0 + (int)crtc->channel * 0x140;
81dee67e215b23f Sudip Mukherjee 2015-03-03 757
cd33da26036ea54 Christopher Carbone 2022-08-23 758 crtc->cursor.max_h = 64;
cd33da26036ea54 Christopher Carbone 2022-08-23 759 crtc->cursor.max_w = 64;
39f9137268ee3df Benjamin Philip 2021-07-26 760 crtc->cursor.size = crtc->cursor.max_h * crtc->cursor.max_w * 2 / 8;
e359b6a863e19f2 Mike Rapoport 2015-10-26 761 crtc->cursor.vstart = sm750_dev->pvMem + crtc->cursor.offset;
81dee67e215b23f Sudip Mukherjee 2015-03-03 762
3de08a2d14ff8c7 Lorenzo Stoakes 2015-03-20 763 memset_io(crtc->cursor.vstart, 0, crtc->cursor.size);
f7c8a046577e09d Thomas Zimmermann 2023-11-27 764 if (!g_hwcursor)
52d0744d751d8f1 Arnd Bergmann 2016-11-09 765 sm750_hw_cursor_disable(&crtc->cursor);
81dee67e215b23f Sudip Mukherjee 2015-03-03 766
81dee67e215b23f Sudip Mukherjee 2015-03-03 767 /* set info->fbops, must be set before fb_find_mode */
e359b6a863e19f2 Mike Rapoport 2015-10-26 768 if (!sm750_dev->accel_off) {
81dee67e215b23f Sudip Mukherjee 2015-03-03 769 /* use 2d acceleration */
f7c8a046577e09d Thomas Zimmermann 2023-11-27 770 if (!g_hwcursor)
f7c8a046577e09d Thomas Zimmermann 2023-11-27 771 info->fbops = &lynxfb_ops_accel;
f7c8a046577e09d Thomas Zimmermann 2023-11-27 772 else
f7c8a046577e09d Thomas Zimmermann 2023-11-27 773 info->fbops = &lynxfb_ops_accel_with_cursor;
f7c8a046577e09d Thomas Zimmermann 2023-11-27 774 } else {
f7c8a046577e09d Thomas Zimmermann 2023-11-27 775 if (!g_hwcursor)
81dee67e215b23f Sudip Mukherjee 2015-03-03 776 info->fbops = &lynxfb_ops;
f7c8a046577e09d Thomas Zimmermann 2023-11-27 777 else
f7c8a046577e09d Thomas Zimmermann 2023-11-27 778 info->fbops = &lynxfb_ops_with_cursor;
f7c8a046577e09d Thomas Zimmermann 2023-11-27 779 }
81dee67e215b23f Sudip Mukherjee 2015-03-03 780
81dee67e215b23f Sudip Mukherjee 2015-03-03 781 if (!g_fbmode[index]) {
81dee67e215b23f Sudip Mukherjee 2015-03-03 @782 g_fbmode[index] = g_def_fbmode;
81dee67e215b23f Sudip Mukherjee 2015-03-03 783 if (index)
81dee67e215b23f Sudip Mukherjee 2015-03-03 784 g_fbmode[index] = g_fbmode[0];
81dee67e215b23f Sudip Mukherjee 2015-03-03 785 }
81dee67e215b23f Sudip Mukherjee 2015-03-03 786
81dee67e215b23f Sudip Mukherjee 2015-03-03 787 for (i = 0; i < 3; i++) {
81dee67e215b23f Sudip Mukherjee 2015-03-03 788 ret = fb_find_mode(var, info, g_fbmode[index],
81dee67e215b23f Sudip Mukherjee 2015-03-03 789 pdb[i], cdb[i], NULL, 8);
81dee67e215b23f Sudip Mukherjee 2015-03-03 790
db7fb3588ab4920 Artem Lytkin 2026-02-23 791 if (ret == 1 || ret == 2)
81dee67e215b23f Sudip Mukherjee 2015-03-03 792 break;
81dee67e215b23f Sudip Mukherjee 2015-03-03 793 }
81dee67e215b23f Sudip Mukherjee 2015-03-03 794
81dee67e215b23f Sudip Mukherjee 2015-03-03 795 /* set par */
81dee67e215b23f Sudip Mukherjee 2015-03-03 796 par->info = info;
81dee67e215b23f Sudip Mukherjee 2015-03-03 797
81dee67e215b23f Sudip Mukherjee 2015-03-03 798 /* set info */
e3a3f9f5123683b Mike Rapoport 2015-10-26 799 line_length = ALIGN((var->xres_virtual * var->bits_per_pixel / 8),
e3a3f9f5123683b Mike Rapoport 2015-10-26 800 crtc->line_pad);
81dee67e215b23f Sudip Mukherjee 2015-03-03 801
81dee67e215b23f Sudip Mukherjee 2015-03-03 802 info->pseudo_palette = &par->pseudo_palette[0];
cc59bde1c920ab6 Benjamin Philip 2021-07-28 803 info->screen_base = crtc->v_screen;
81dee67e215b23f Sudip Mukherjee 2015-03-03 804 info->screen_size = line_length * var->yres_virtual;
81dee67e215b23f Sudip Mukherjee 2015-03-03 805
81dee67e215b23f Sudip Mukherjee 2015-03-03 806 /* set info->fix */
81dee67e215b23f Sudip Mukherjee 2015-03-03 807 fix->type = FB_TYPE_PACKED_PIXELS;
81dee67e215b23f Sudip Mukherjee 2015-03-03 808 fix->type_aux = 0;
81dee67e215b23f Sudip Mukherjee 2015-03-03 809 fix->xpanstep = crtc->xpanstep;
81dee67e215b23f Sudip Mukherjee 2015-03-03 810 fix->ypanstep = crtc->ypanstep;
81dee67e215b23f Sudip Mukherjee 2015-03-03 811 fix->ywrapstep = crtc->ywrapstep;
81dee67e215b23f Sudip Mukherjee 2015-03-03 812 fix->accel = FB_ACCEL_SMI;
81dee67e215b23f Sudip Mukherjee 2015-03-03 813
8c475735085a7db Tim Wassink 2025-12-21 814 strscpy(fix->id, fix_id[index], sizeof(fix->id));
81dee67e215b23f Sudip Mukherjee 2015-03-03 815
fdc234d85210d91 Benjamin Philip 2021-07-28 816 fix->smem_start = crtc->o_screen + sm750_dev->vidmem_start;
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 817 /*
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 818 * according to mmap experiment from user space application,
81dee67e215b23f Sudip Mukherjee 2015-03-03 819 * fix->mmio_len should not larger than virtual size
81dee67e215b23f Sudip Mukherjee 2015-03-03 820 * (xres_virtual x yres_virtual x ByPP)
81dee67e215b23f Sudip Mukherjee 2015-03-03 821 * Below line maybe buggy when user mmap fb dev node and write
81dee67e215b23f Sudip Mukherjee 2015-03-03 822 * data into the bound over virtual size
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 823 */
81dee67e215b23f Sudip Mukherjee 2015-03-03 824 fix->smem_len = crtc->vidmem_size;
81dee67e215b23f Sudip Mukherjee 2015-03-03 825 info->screen_size = fix->smem_len;
81dee67e215b23f Sudip Mukherjee 2015-03-03 826 fix->line_length = line_length;
e359b6a863e19f2 Mike Rapoport 2015-10-26 827 fix->mmio_start = sm750_dev->vidreg_start;
e359b6a863e19f2 Mike Rapoport 2015-10-26 828 fix->mmio_len = sm750_dev->vidreg_size;
b610e1193a917f4 Matej Dujava 2020-04-30 829
b610e1193a917f4 Matej Dujava 2020-04-30 830 lynxfb_set_visual_mode(info);
81dee67e215b23f Sudip Mukherjee 2015-03-03 831
81dee67e215b23f Sudip Mukherjee 2015-03-03 832 /* set var */
81dee67e215b23f Sudip Mukherjee 2015-03-03 833 var->activate = FB_ACTIVATE_NOW;
81dee67e215b23f Sudip Mukherjee 2015-03-03 834 var->accel_flags = 0;
81dee67e215b23f Sudip Mukherjee 2015-03-03 835 var->vmode = FB_VMODE_NONINTERLACED;
81dee67e215b23f Sudip Mukherjee 2015-03-03 836
61c507cf652da1b Michel von Czettritz 2015-03-26 837 ret = fb_alloc_cmap(&info->cmap, 256, 0);
61c507cf652da1b Michel von Czettritz 2015-03-26 838 if (ret < 0) {
fbab250eb51d6d6 Artem Lytkin 2026-02-07 839 dev_err(info->device, "Could not allocate memory for cmap.\n");
81dee67e215b23f Sudip Mukherjee 2015-03-03 840 goto exit;
81dee67e215b23f Sudip Mukherjee 2015-03-03 841 }
81dee67e215b23f Sudip Mukherjee 2015-03-03 842
81dee67e215b23f Sudip Mukherjee 2015-03-03 843 exit:
81dee67e215b23f Sudip Mukherjee 2015-03-03 844 lynxfb_ops_check_var(var, info);
81dee67e215b23f Sudip Mukherjee 2015-03-03 845 return ret;
81dee67e215b23f Sudip Mukherjee 2015-03-03 846 }
81dee67e215b23f Sudip Mukherjee 2015-03-03 847
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply
* Re: [PATCH] staging: sm750fb: add missing const qualifier to char pointer array
From: kernel test robot @ 2026-03-07 23:05 UTC (permalink / raw)
To: Oskar Ray-Frayssinet, sudipm.mukherjee, teddy.wang, gregkh
Cc: oe-kbuild-all, linux-fbdev, linux-staging, linux-kernel,
Oskar Ray-Frayssinet
In-Reply-To: <20260307131833.1138-1-rayfraytech@gmail.com>
Hi Oskar,
kernel test robot noticed the following build errors:
[auto build test ERROR on staging/staging-testing]
url: https://github.com/intel-lab-lkp/linux/commits/Oskar-Ray-Frayssinet/staging-sm750fb-add-missing-const-qualifier-to-char-pointer-array/20260307-212030
base: staging/staging-testing
patch link: https://lore.kernel.org/r/20260307131833.1138-1-rayfraytech%40gmail.com
patch subject: [PATCH] staging: sm750fb: add missing const qualifier to char pointer array
config: parisc-randconfig-r073-20260308 (https://download.01.org/0day-ci/archive/20260308/202603080719.feszwgV8-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 13.4.0
smatch: v0.5.0-9004-gb810ac53
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260308/202603080719.feszwgV8-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202603080719.feszwgV8-lkp@intel.com/
All errors (new ones prefixed by >>):
drivers/staging/sm750fb/sm750.c: In function 'lynxfb_set_fbinfo':
>> drivers/staging/sm750fb/sm750.c:782:33: error: assignment of read-only location 'g_fbmode[index]'
782 | g_fbmode[index] = g_def_fbmode;
| ^
drivers/staging/sm750fb/sm750.c:784:41: error: assignment of read-only location 'g_fbmode[index]'
784 | g_fbmode[index] = g_fbmode[0];
| ^
drivers/staging/sm750fb/sm750.c: In function 'sm750fb_setup':
>> drivers/staging/sm750fb/sm750.c:893:45: error: assignment of read-only location 'g_fbmode[0]'
893 | g_fbmode[0] = opt;
| ^
drivers/staging/sm750fb/sm750.c:897:45: error: assignment of read-only location 'g_fbmode[1]'
897 | g_fbmode[1] = opt;
| ^
vim +782 drivers/staging/sm750fb/sm750.c
81dee67e215b23 Sudip Mukherjee 2015-03-03 716
81dee67e215b23 Sudip Mukherjee 2015-03-03 717 static int lynxfb_set_fbinfo(struct fb_info *info, int index)
81dee67e215b23 Sudip Mukherjee 2015-03-03 718 {
81dee67e215b23 Sudip Mukherjee 2015-03-03 719 int i;
81dee67e215b23 Sudip Mukherjee 2015-03-03 720 struct lynxfb_par *par;
e359b6a863e19f Mike Rapoport 2015-10-26 721 struct sm750_dev *sm750_dev;
81dee67e215b23 Sudip Mukherjee 2015-03-03 722 struct lynxfb_crtc *crtc;
81dee67e215b23 Sudip Mukherjee 2015-03-03 723 struct lynxfb_output *output;
81dee67e215b23 Sudip Mukherjee 2015-03-03 724 struct fb_var_screeninfo *var;
81dee67e215b23 Sudip Mukherjee 2015-03-03 725 struct fb_fix_screeninfo *fix;
81dee67e215b23 Sudip Mukherjee 2015-03-03 726
81dee67e215b23 Sudip Mukherjee 2015-03-03 727 const struct fb_videomode *pdb[] = {
81dee67e215b23 Sudip Mukherjee 2015-03-03 728 lynx750_ext, NULL, vesa_modes,
81dee67e215b23 Sudip Mukherjee 2015-03-03 729 };
81dee67e215b23 Sudip Mukherjee 2015-03-03 730 int cdb[] = {ARRAY_SIZE(lynx750_ext), 0, VESA_MODEDB_SIZE};
8c475735085a7d Tim Wassink 2025-12-21 731 static const char *fix_id[2] = {
81dee67e215b23 Sudip Mukherjee 2015-03-03 732 "sm750_fb1", "sm750_fb2",
81dee67e215b23 Sudip Mukherjee 2015-03-03 733 };
81dee67e215b23 Sudip Mukherjee 2015-03-03 734
81dee67e215b23 Sudip Mukherjee 2015-03-03 735 int ret, line_length;
81dee67e215b23 Sudip Mukherjee 2015-03-03 736
81dee67e215b23 Sudip Mukherjee 2015-03-03 737 ret = 0;
81dee67e215b23 Sudip Mukherjee 2015-03-03 738 par = (struct lynxfb_par *)info->par;
e359b6a863e19f Mike Rapoport 2015-10-26 739 sm750_dev = par->dev;
81dee67e215b23 Sudip Mukherjee 2015-03-03 740 crtc = &par->crtc;
81dee67e215b23 Sudip Mukherjee 2015-03-03 741 output = &par->output;
81dee67e215b23 Sudip Mukherjee 2015-03-03 742 var = &info->var;
81dee67e215b23 Sudip Mukherjee 2015-03-03 743 fix = &info->fix;
81dee67e215b23 Sudip Mukherjee 2015-03-03 744
81dee67e215b23 Sudip Mukherjee 2015-03-03 745 /* set index */
81dee67e215b23 Sudip Mukherjee 2015-03-03 746 par->index = index;
81dee67e215b23 Sudip Mukherjee 2015-03-03 747 output->channel = &crtc->channel;
81dee67e215b23 Sudip Mukherjee 2015-03-03 748 sm750fb_set_drv(par);
81dee67e215b23 Sudip Mukherjee 2015-03-03 749
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 750 /*
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 751 * set current cursor variable and proc pointer,
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 752 * must be set after crtc member initialized
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 753 */
fdc234d85210d9 Benjamin Philip 2021-07-28 754 crtc->cursor.offset = crtc->o_screen + crtc->vidmem_size - 1024;
e359b6a863e19f Mike Rapoport 2015-10-26 755 crtc->cursor.mmio = sm750_dev->pvReg +
e359b6a863e19f Mike Rapoport 2015-10-26 756 0x800f0 + (int)crtc->channel * 0x140;
81dee67e215b23 Sudip Mukherjee 2015-03-03 757
cd33da26036ea5 Christopher Carbone 2022-08-23 758 crtc->cursor.max_h = 64;
cd33da26036ea5 Christopher Carbone 2022-08-23 759 crtc->cursor.max_w = 64;
39f9137268ee3d Benjamin Philip 2021-07-26 760 crtc->cursor.size = crtc->cursor.max_h * crtc->cursor.max_w * 2 / 8;
e359b6a863e19f Mike Rapoport 2015-10-26 761 crtc->cursor.vstart = sm750_dev->pvMem + crtc->cursor.offset;
81dee67e215b23 Sudip Mukherjee 2015-03-03 762
3de08a2d14ff8c Lorenzo Stoakes 2015-03-20 763 memset_io(crtc->cursor.vstart, 0, crtc->cursor.size);
f7c8a046577e09 Thomas Zimmermann 2023-11-27 764 if (!g_hwcursor)
52d0744d751d8f Arnd Bergmann 2016-11-09 765 sm750_hw_cursor_disable(&crtc->cursor);
81dee67e215b23 Sudip Mukherjee 2015-03-03 766
81dee67e215b23 Sudip Mukherjee 2015-03-03 767 /* set info->fbops, must be set before fb_find_mode */
e359b6a863e19f Mike Rapoport 2015-10-26 768 if (!sm750_dev->accel_off) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 769 /* use 2d acceleration */
f7c8a046577e09 Thomas Zimmermann 2023-11-27 770 if (!g_hwcursor)
f7c8a046577e09 Thomas Zimmermann 2023-11-27 771 info->fbops = &lynxfb_ops_accel;
f7c8a046577e09 Thomas Zimmermann 2023-11-27 772 else
f7c8a046577e09 Thomas Zimmermann 2023-11-27 773 info->fbops = &lynxfb_ops_accel_with_cursor;
f7c8a046577e09 Thomas Zimmermann 2023-11-27 774 } else {
f7c8a046577e09 Thomas Zimmermann 2023-11-27 775 if (!g_hwcursor)
81dee67e215b23 Sudip Mukherjee 2015-03-03 776 info->fbops = &lynxfb_ops;
f7c8a046577e09 Thomas Zimmermann 2023-11-27 777 else
f7c8a046577e09 Thomas Zimmermann 2023-11-27 778 info->fbops = &lynxfb_ops_with_cursor;
f7c8a046577e09 Thomas Zimmermann 2023-11-27 779 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 780
81dee67e215b23 Sudip Mukherjee 2015-03-03 781 if (!g_fbmode[index]) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 @782 g_fbmode[index] = g_def_fbmode;
81dee67e215b23 Sudip Mukherjee 2015-03-03 783 if (index)
81dee67e215b23 Sudip Mukherjee 2015-03-03 784 g_fbmode[index] = g_fbmode[0];
81dee67e215b23 Sudip Mukherjee 2015-03-03 785 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 786
81dee67e215b23 Sudip Mukherjee 2015-03-03 787 for (i = 0; i < 3; i++) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 788 ret = fb_find_mode(var, info, g_fbmode[index],
81dee67e215b23 Sudip Mukherjee 2015-03-03 789 pdb[i], cdb[i], NULL, 8);
81dee67e215b23 Sudip Mukherjee 2015-03-03 790
db7fb3588ab492 Artem Lytkin 2026-02-23 791 if (ret == 1 || ret == 2)
81dee67e215b23 Sudip Mukherjee 2015-03-03 792 break;
81dee67e215b23 Sudip Mukherjee 2015-03-03 793 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 794
81dee67e215b23 Sudip Mukherjee 2015-03-03 795 /* set par */
81dee67e215b23 Sudip Mukherjee 2015-03-03 796 par->info = info;
81dee67e215b23 Sudip Mukherjee 2015-03-03 797
81dee67e215b23 Sudip Mukherjee 2015-03-03 798 /* set info */
e3a3f9f5123683 Mike Rapoport 2015-10-26 799 line_length = ALIGN((var->xres_virtual * var->bits_per_pixel / 8),
e3a3f9f5123683 Mike Rapoport 2015-10-26 800 crtc->line_pad);
81dee67e215b23 Sudip Mukherjee 2015-03-03 801
81dee67e215b23 Sudip Mukherjee 2015-03-03 802 info->pseudo_palette = &par->pseudo_palette[0];
cc59bde1c920ab Benjamin Philip 2021-07-28 803 info->screen_base = crtc->v_screen;
81dee67e215b23 Sudip Mukherjee 2015-03-03 804 info->screen_size = line_length * var->yres_virtual;
81dee67e215b23 Sudip Mukherjee 2015-03-03 805
81dee67e215b23 Sudip Mukherjee 2015-03-03 806 /* set info->fix */
81dee67e215b23 Sudip Mukherjee 2015-03-03 807 fix->type = FB_TYPE_PACKED_PIXELS;
81dee67e215b23 Sudip Mukherjee 2015-03-03 808 fix->type_aux = 0;
81dee67e215b23 Sudip Mukherjee 2015-03-03 809 fix->xpanstep = crtc->xpanstep;
81dee67e215b23 Sudip Mukherjee 2015-03-03 810 fix->ypanstep = crtc->ypanstep;
81dee67e215b23 Sudip Mukherjee 2015-03-03 811 fix->ywrapstep = crtc->ywrapstep;
81dee67e215b23 Sudip Mukherjee 2015-03-03 812 fix->accel = FB_ACCEL_SMI;
81dee67e215b23 Sudip Mukherjee 2015-03-03 813
8c475735085a7d Tim Wassink 2025-12-21 814 strscpy(fix->id, fix_id[index], sizeof(fix->id));
81dee67e215b23 Sudip Mukherjee 2015-03-03 815
fdc234d85210d9 Benjamin Philip 2021-07-28 816 fix->smem_start = crtc->o_screen + sm750_dev->vidmem_start;
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 817 /*
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 818 * according to mmap experiment from user space application,
81dee67e215b23 Sudip Mukherjee 2015-03-03 819 * fix->mmio_len should not larger than virtual size
81dee67e215b23 Sudip Mukherjee 2015-03-03 820 * (xres_virtual x yres_virtual x ByPP)
81dee67e215b23 Sudip Mukherjee 2015-03-03 821 * Below line maybe buggy when user mmap fb dev node and write
81dee67e215b23 Sudip Mukherjee 2015-03-03 822 * data into the bound over virtual size
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 823 */
81dee67e215b23 Sudip Mukherjee 2015-03-03 824 fix->smem_len = crtc->vidmem_size;
81dee67e215b23 Sudip Mukherjee 2015-03-03 825 info->screen_size = fix->smem_len;
81dee67e215b23 Sudip Mukherjee 2015-03-03 826 fix->line_length = line_length;
e359b6a863e19f Mike Rapoport 2015-10-26 827 fix->mmio_start = sm750_dev->vidreg_start;
e359b6a863e19f Mike Rapoport 2015-10-26 828 fix->mmio_len = sm750_dev->vidreg_size;
b610e1193a917f Matej Dujava 2020-04-30 829
b610e1193a917f Matej Dujava 2020-04-30 830 lynxfb_set_visual_mode(info);
81dee67e215b23 Sudip Mukherjee 2015-03-03 831
81dee67e215b23 Sudip Mukherjee 2015-03-03 832 /* set var */
81dee67e215b23 Sudip Mukherjee 2015-03-03 833 var->activate = FB_ACTIVATE_NOW;
81dee67e215b23 Sudip Mukherjee 2015-03-03 834 var->accel_flags = 0;
81dee67e215b23 Sudip Mukherjee 2015-03-03 835 var->vmode = FB_VMODE_NONINTERLACED;
81dee67e215b23 Sudip Mukherjee 2015-03-03 836
61c507cf652da1 Michel von Czettritz 2015-03-26 837 ret = fb_alloc_cmap(&info->cmap, 256, 0);
61c507cf652da1 Michel von Czettritz 2015-03-26 838 if (ret < 0) {
fbab250eb51d6d Artem Lytkin 2026-02-07 839 dev_err(info->device, "Could not allocate memory for cmap.\n");
81dee67e215b23 Sudip Mukherjee 2015-03-03 840 goto exit;
81dee67e215b23 Sudip Mukherjee 2015-03-03 841 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 842
81dee67e215b23 Sudip Mukherjee 2015-03-03 843 exit:
81dee67e215b23 Sudip Mukherjee 2015-03-03 844 lynxfb_ops_check_var(var, info);
81dee67e215b23 Sudip Mukherjee 2015-03-03 845 return ret;
81dee67e215b23 Sudip Mukherjee 2015-03-03 846 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 847
81dee67e215b23 Sudip Mukherjee 2015-03-03 848 /* chip specific g_option configuration routine */
700591a9adc8b1 Mike Rapoport 2015-10-26 849 static void sm750fb_setup(struct sm750_dev *sm750_dev, char *src)
81dee67e215b23 Sudip Mukherjee 2015-03-03 850 {
81dee67e215b23 Sudip Mukherjee 2015-03-03 851 char *opt;
81dee67e215b23 Sudip Mukherjee 2015-03-03 852 int swap;
81dee67e215b23 Sudip Mukherjee 2015-03-03 853
81dee67e215b23 Sudip Mukherjee 2015-03-03 854 swap = 0;
81dee67e215b23 Sudip Mukherjee 2015-03-03 855
cc34db609ff98c Madhumitha Sundar 2026-01-27 856 sm750_dev->init_parm.chip_clk = 0;
cc34db609ff98c Madhumitha Sundar 2026-01-27 857 sm750_dev->init_parm.mem_clk = 0;
cc34db609ff98c Madhumitha Sundar 2026-01-27 858 sm750_dev->init_parm.master_clk = 0;
cc34db609ff98c Madhumitha Sundar 2026-01-27 859 sm750_dev->init_parm.powerMode = 0;
cc34db609ff98c Madhumitha Sundar 2026-01-27 860 sm750_dev->init_parm.setAllEngOff = 0;
cc34db609ff98c Madhumitha Sundar 2026-01-27 861 sm750_dev->init_parm.resetMemory = 1;
81dee67e215b23 Sudip Mukherjee 2015-03-03 862
81dee67e215b23 Sudip Mukherjee 2015-03-03 863 /* defaultly turn g_hwcursor on for both view */
81dee67e215b23 Sudip Mukherjee 2015-03-03 864 g_hwcursor = 3;
81dee67e215b23 Sudip Mukherjee 2015-03-03 865
81dee67e215b23 Sudip Mukherjee 2015-03-03 866 if (!src || !*src) {
c56de0967a658c Elise Lennion 2016-10-31 867 dev_warn(&sm750_dev->pdev->dev, "no specific g_option.\n");
81dee67e215b23 Sudip Mukherjee 2015-03-03 868 goto NO_PARAM;
81dee67e215b23 Sudip Mukherjee 2015-03-03 869 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 870
0fa96e39279988 Sudip Mukherjee 2015-03-10 871 while ((opt = strsep(&src, ":")) != NULL && *opt != 0) {
c56de0967a658c Elise Lennion 2016-10-31 872 dev_info(&sm750_dev->pdev->dev, "opt=%s\n", opt);
c56de0967a658c Elise Lennion 2016-10-31 873 dev_info(&sm750_dev->pdev->dev, "src=%s\n", src);
81dee67e215b23 Sudip Mukherjee 2015-03-03 874
144634a6b42146 Katie Dunne 2017-02-19 875 if (!strncmp(opt, "swap", strlen("swap"))) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 876 swap = 1;
144634a6b42146 Katie Dunne 2017-02-19 877 } else if (!strncmp(opt, "nocrt", strlen("nocrt"))) {
1757d106a9ce8c Mike Rapoport 2015-10-26 878 sm750_dev->nocrt = 1;
144634a6b42146 Katie Dunne 2017-02-19 879 } else if (!strncmp(opt, "36bit", strlen("36bit"))) {
1757d106a9ce8c Mike Rapoport 2015-10-26 880 sm750_dev->pnltype = sm750_doubleTFT;
144634a6b42146 Katie Dunne 2017-02-19 881 } else if (!strncmp(opt, "18bit", strlen("18bit"))) {
1757d106a9ce8c Mike Rapoport 2015-10-26 882 sm750_dev->pnltype = sm750_dualTFT;
144634a6b42146 Katie Dunne 2017-02-19 883 } else if (!strncmp(opt, "24bit", strlen("24bit"))) {
1757d106a9ce8c Mike Rapoport 2015-10-26 884 sm750_dev->pnltype = sm750_24TFT;
144634a6b42146 Katie Dunne 2017-02-19 885 } else if (!strncmp(opt, "nohwc0", strlen("nohwc0"))) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 886 g_hwcursor &= ~0x1;
144634a6b42146 Katie Dunne 2017-02-19 887 } else if (!strncmp(opt, "nohwc1", strlen("nohwc1"))) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 888 g_hwcursor &= ~0x2;
144634a6b42146 Katie Dunne 2017-02-19 889 } else if (!strncmp(opt, "nohwc", strlen("nohwc"))) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 890 g_hwcursor = 0;
144634a6b42146 Katie Dunne 2017-02-19 891 } else {
81dee67e215b23 Sudip Mukherjee 2015-03-03 892 if (!g_fbmode[0]) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 @893 g_fbmode[0] = opt;
cee9ba1c30d051 Abdul Rauf 2017-01-08 894 dev_info(&sm750_dev->pdev->dev,
cee9ba1c30d051 Abdul Rauf 2017-01-08 895 "find fbmode0 : %s\n", g_fbmode[0]);
81dee67e215b23 Sudip Mukherjee 2015-03-03 896 } else if (!g_fbmode[1]) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 897 g_fbmode[1] = opt;
cee9ba1c30d051 Abdul Rauf 2017-01-08 898 dev_info(&sm750_dev->pdev->dev,
cee9ba1c30d051 Abdul Rauf 2017-01-08 899 "find fbmode1 : %s\n", g_fbmode[1]);
81dee67e215b23 Sudip Mukherjee 2015-03-03 900 } else {
c56de0967a658c Elise Lennion 2016-10-31 901 dev_warn(&sm750_dev->pdev->dev, "How many view you wann set?\n");
81dee67e215b23 Sudip Mukherjee 2015-03-03 902 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 903 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 904 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 905
81dee67e215b23 Sudip Mukherjee 2015-03-03 906 NO_PARAM:
e359b6a863e19f Mike Rapoport 2015-10-26 907 if (sm750_dev->revid != SM750LE_REVISION_ID) {
a3f92cc94c6126 Mike Rapoport 2016-01-17 908 if (sm750_dev->fb_count > 1) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 909 if (swap)
1757d106a9ce8c Mike Rapoport 2015-10-26 910 sm750_dev->dataflow = sm750_dual_swap;
81dee67e215b23 Sudip Mukherjee 2015-03-03 911 else
1757d106a9ce8c Mike Rapoport 2015-10-26 912 sm750_dev->dataflow = sm750_dual_normal;
81dee67e215b23 Sudip Mukherjee 2015-03-03 913 } else {
81dee67e215b23 Sudip Mukherjee 2015-03-03 914 if (swap)
1757d106a9ce8c Mike Rapoport 2015-10-26 915 sm750_dev->dataflow = sm750_simul_sec;
81dee67e215b23 Sudip Mukherjee 2015-03-03 916 else
1757d106a9ce8c Mike Rapoport 2015-10-26 917 sm750_dev->dataflow = sm750_simul_pri;
81dee67e215b23 Sudip Mukherjee 2015-03-03 918 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 919 } else {
81dee67e215b23 Sudip Mukherjee 2015-03-03 920 /* SM750LE only have one crt channel */
1757d106a9ce8c Mike Rapoport 2015-10-26 921 sm750_dev->dataflow = sm750_simul_sec;
81dee67e215b23 Sudip Mukherjee 2015-03-03 922 /* sm750le do not have complex attributes */
1757d106a9ce8c Mike Rapoport 2015-10-26 923 sm750_dev->nocrt = 0;
81dee67e215b23 Sudip Mukherjee 2015-03-03 924 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 925 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 926
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply
* Re: [GIT PULL] fbdev fix for v7.0-rc3
From: pr-tracker-bot @ 2026-03-07 21:24 UTC (permalink / raw)
To: Helge Deller
Cc: Linus Torvalds, linux-kernel, linux-fbdev, dri-devel,
Uwe Kleine-König
In-Reply-To: <aayOLznDX70UUs6T@carbonx1>
The pull request you sent on Sat, 7 Mar 2026 21:44:31 +0100:
> http://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev.git tags/fbdev-for-7.0-rc3
has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/fb07430e6f98ccff61f6f1a06d01d7f12e29c6d3
Thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/prtracker.html
^ permalink raw reply
* [GIT PULL] fbdev fix for v7.0-rc3
From: Helge Deller @ 2026-03-07 20:44 UTC (permalink / raw)
To: Linus Torvalds, linux-kernel, linux-fbdev, dri-devel
Cc: Uwe Kleine-König
Hi Linus,
please pull one patch for the au1100fb driver to
fix a build error reported by the kernel test robot.
Thanks!
Helge
----------------------------------------------------------------
The following changes since commit 11439c4635edd669ae435eec308f4ab8a0804808:
Linux 7.0-rc2 (2026-03-01 15:39:31 -0800)
are available in the Git repository at:
http://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev.git tags/fbdev-for-7.0-rc3
for you to fetch changes up to e31a374a99f5026df6ebff2a1c49492276e776fd:
fbdev: au1100fb: Fix build on MIPS64 (2026-03-05 17:35:12 +0100)
----------------------------------------------------------------
fbdev fixes for kernel v7.0-rc3:
Silence build error in au1100fb driver found by kernel test robot
----------------------------------------------------------------
Helge Deller (1):
fbdev: au1100fb: Fix build on MIPS64
drivers/video/fbdev/au1100fb.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
^ permalink raw reply
* [PATCH] staging: sm750fb: add missing const qualifier to char pointer array
From: Oskar Ray-Frayssinet @ 2026-03-07 13:18 UTC (permalink / raw)
To: sudipm.mukherjee, teddy.wang, gregkh
Cc: linux-fbdev, linux-staging, linux-kernel, Oskar Ray-Frayssinet
Add missing 'const' qualifier to g_fbmode pointer array declaration
to make both the pointers and the strings they point to immutable.
Signed-off-by: Oskar Ray-Frayssinet <rayfraytech@gmail.com>
---
drivers/staging/sm750fb/sm750.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c
index dec1f6b88a7d..08d4979c6755 100644
--- a/drivers/staging/sm750fb/sm750.c
+++ b/drivers/staging/sm750fb/sm750.c
@@ -33,7 +33,7 @@
static int g_hwcursor = 1;
static int g_noaccel;
static int g_nomtrr;
-static const char *g_fbmode[] = {NULL, NULL};
+static const char * const g_fbmode[] = {NULL, NULL};
static const char *g_def_fbmode = "1024x768-32@60";
static char *g_settings;
static int g_dualview;
--
2.43.0
^ permalink raw reply related
* [PATCH v12 1/1] rust: interop: Add list module for C linked list interface
From: Joel Fernandes @ 2026-03-06 20:36 UTC (permalink / raw)
To: linux-kernel
Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Alex Gaynor, Danilo Krummrich, Dave Airlie, David Airlie,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann,
Simona Vetter, Daniel Almeida, Koen Koning, Nikola Djukic,
Alexandre Courbot, Philipp Stanner, Elle Rhumsaa, Jonathan Corbet,
Alex Deucher, Christian König, Jani Nikula, Joonas Lahtinen,
Rodrigo Vivi, Tvrtko Ursulin, Huang Rui, Matthew Auld,
Matthew Brost, Lucas De Marchi, Thomas Hellström,
Helge Deller, John Hubbard, Alistair Popple, Timur Tabi,
Edwin Peer, Andrea Righi, Andy Ritger, Zhi Wang, Balbir Singh,
alexeyi, Eliot Courtney, dri-devel, nouveau, rust-for-linux,
linux-doc, amd-gfx, intel-gfx, intel-xe, linux-fbdev,
Joel Fernandes, Miguel Ojeda
In-Reply-To: <20260306203648.1136554-1-joelagnelf@nvidia.com>
Add a new module `kernel::interop::list` for working with C's doubly
circular linked lists. Provide low-level iteration over list nodes.
Typed iteration over actual items is provided with a `clist_create`
macro to assist in creation of the `CList` type.
Cc: Nikola Djukic <ndjukic@nvidia.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Gary Guo <gary@garyguo.net>
Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
---
MAINTAINERS | 8 +
rust/helpers/helpers.c | 1 +
rust/helpers/list.c | 17 ++
rust/kernel/interop/list.rs | 338 ++++++++++++++++++++++++++++++++++++
rust/kernel/interop/mod.rs | 9 +
rust/kernel/lib.rs | 2 +
6 files changed, 375 insertions(+)
create mode 100644 rust/helpers/list.c
create mode 100644 rust/kernel/interop/list.rs
create mode 100644 rust/kernel/interop/mod.rs
diff --git a/MAINTAINERS b/MAINTAINERS
index 2842d7529a65..4c66f8261ff2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -23219,6 +23219,14 @@ T: git https://github.com/Rust-for-Linux/linux.git alloc-next
F: rust/kernel/alloc.rs
F: rust/kernel/alloc/
+RUST [INTEROP]
+M: Joel Fernandes <joelagnelf@nvidia.com>
+M: Alexandre Courbot <acourbot@nvidia.com>
+L: rust-for-linux@vger.kernel.org
+S: Maintained
+T: git https://github.com/Rust-for-Linux/linux.git interop-next
+F: rust/kernel/interop/
+
RUST [NUM]
M: Alexandre Courbot <acourbot@nvidia.com>
R: Yury Norov <yury.norov@gmail.com>
diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
index a3c42e51f00a..724fcb8240ac 100644
--- a/rust/helpers/helpers.c
+++ b/rust/helpers/helpers.c
@@ -35,6 +35,7 @@
#include "io.c"
#include "jump_label.c"
#include "kunit.c"
+#include "list.c"
#include "maple_tree.c"
#include "mm.c"
#include "mutex.c"
diff --git a/rust/helpers/list.c b/rust/helpers/list.c
new file mode 100644
index 000000000000..18095a5593c5
--- /dev/null
+++ b/rust/helpers/list.c
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Helpers for C circular doubly linked list implementation.
+ */
+
+#include <linux/list.h>
+
+__rust_helper void rust_helper_INIT_LIST_HEAD(struct list_head *list)
+{
+ INIT_LIST_HEAD(list);
+}
+
+__rust_helper void rust_helper_list_add_tail(struct list_head *new, struct list_head *head)
+{
+ list_add_tail(new, head);
+}
diff --git a/rust/kernel/interop/list.rs b/rust/kernel/interop/list.rs
new file mode 100644
index 000000000000..bd6409f8bca2
--- /dev/null
+++ b/rust/kernel/interop/list.rs
@@ -0,0 +1,338 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Rust interface for C doubly circular intrusive linked lists.
+//!
+//! This module provides Rust abstractions for iterating over C `list_head`-based
+//! linked lists. It should only be used for cases where C and Rust code share
+//! direct access to the same linked list through a C interop interface.
+//!
+//! Note: This *must not* be used by Rust components that just need a linked list
+//! primitive. Use [`kernel::list::List`] instead.
+//!
+//! # Examples
+//!
+//! ```
+//! use kernel::{
+//! bindings,
+//! clist_create,
+//! types::Opaque,
+//! };
+//! # // Create test list with values (0, 10, 20) - normally done by C code but it is
+//! # // emulated here for doctests using the C bindings.
+//! # use core::mem::MaybeUninit;
+//! #
+//! # /// C struct with embedded `list_head` (typically will be allocated by C code).
+//! # #[repr(C)]
+//! # pub struct SampleItemC {
+//! # pub value: i32,
+//! # pub link: bindings::list_head,
+//! # }
+//! #
+//! # let mut head = MaybeUninit::<bindings::list_head>::uninit();
+//! #
+//! # let head = head.as_mut_ptr();
+//! # // SAFETY: head and all the items are test objects allocated in this scope.
+//! # unsafe { bindings::INIT_LIST_HEAD(head) };
+//! #
+//! # let mut items = [
+//! # MaybeUninit::<SampleItemC>::uninit(),
+//! # MaybeUninit::<SampleItemC>::uninit(),
+//! # MaybeUninit::<SampleItemC>::uninit(),
+//! # ];
+//! #
+//! # for (i, item) in items.iter_mut().enumerate() {
+//! # let ptr = item.as_mut_ptr();
+//! # // SAFETY: `ptr` points to a valid `MaybeUninit<SampleItemC>`.
+//! # unsafe { (*ptr).value = i as i32 * 10 };
+//! # // SAFETY: `&raw mut` creates a pointer valid for `INIT_LIST_HEAD`.
+//! # unsafe { bindings::INIT_LIST_HEAD(&raw mut (*ptr).link) };
+//! # // SAFETY: `link` was just initialized and `head` is a valid list head.
+//! # unsafe { bindings::list_add_tail(&mut (*ptr).link, head) };
+//! # }
+//!
+//! // Rust wrapper for the C struct.
+//! // The list item struct in this example is defined in C code as:
+//! // struct SampleItemC {
+//! // int value;
+//! // struct list_head link;
+//! // };
+//! //
+//! #[repr(transparent)]
+//! pub struct Item(Opaque<SampleItemC>);
+//!
+//! impl Item {
+//! pub fn value(&self) -> i32 {
+//! // SAFETY: [`Item`] has same layout as [`SampleItemC`].
+//! unsafe { (*self.0.get()).value }
+//! }
+//! }
+//!
+//! // Create typed [`CList`] from sentinel head.
+//! // SAFETY: head is valid and initialized, items are `SampleItemC` with
+//! // embedded `link` field, and `Item` is `#[repr(transparent)]` over `SampleItemC`.
+//! let list = clist_create!(unsafe { head, Item, SampleItemC, link });
+//!
+//! // Iterate directly over typed items.
+//! let mut found_0 = false;
+//! let mut found_10 = false;
+//! let mut found_20 = false;
+//!
+//! for item in list.iter() {
+//! let val = item.value();
+//! if val == 0 { found_0 = true; }
+//! if val == 10 { found_10 = true; }
+//! if val == 20 { found_20 = true; }
+//! }
+//!
+//! assert!(found_0 && found_10 && found_20);
+//! ```
+
+use core::{
+ iter::FusedIterator,
+ marker::PhantomData, //
+};
+
+use crate::{
+ bindings,
+ types::Opaque, //
+};
+
+use pin_init::{
+ pin_data,
+ pin_init,
+ PinInit, //
+};
+
+/// FFI wrapper for a C `list_head` object used in intrusive linked lists.
+///
+/// # Invariants
+///
+/// - The underlying `list_head` has been initialized (e.g. via `INIT_LIST_HEAD()`) and its
+/// `next`/`prev` pointers are valid and non-NULL.
+#[pin_data]
+#[repr(transparent)]
+pub struct CListHead {
+ #[pin]
+ inner: Opaque<bindings::list_head>,
+}
+
+impl CListHead {
+ /// Create a `&CListHead` reference from a raw `list_head` pointer.
+ ///
+ /// # Safety
+ ///
+ /// - `ptr` must be a valid pointer to an initialized `list_head` (e.g. via
+ /// `INIT_LIST_HEAD()`), with valid non-NULL `next`/`prev` pointers.
+ /// - `ptr` must remain valid for the lifetime `'a`.
+ /// - The list and all linked `list_head` nodes must not be modified from
+ /// anywhere for the lifetime `'a`, unless done so via any [`CListHead`] APIs.
+ #[inline]
+ pub unsafe fn from_raw<'a>(ptr: *mut bindings::list_head) -> &'a Self {
+ // SAFETY:
+ // - [`CListHead`] has same layout as `list_head`.
+ // - `ptr` is valid and unmodified for 'a per caller guarantees.
+ unsafe { &*ptr.cast() }
+ }
+
+ /// Get the raw `list_head` pointer.
+ #[inline]
+ pub fn as_raw(&self) -> *mut bindings::list_head {
+ self.inner.get()
+ }
+
+ /// Get the next [`CListHead`] in the list.
+ #[inline]
+ pub fn next(&self) -> &Self {
+ let raw = self.as_raw();
+ // SAFETY:
+ // - `self.as_raw()` is valid and initialized per type invariants.
+ // - The `next` pointer is valid and non-NULL per type invariants
+ // (initialized via `INIT_LIST_HEAD()` or equivalent).
+ unsafe { Self::from_raw((*raw).next) }
+ }
+
+ /// Check if this node is linked in a list (not isolated).
+ #[inline]
+ pub fn is_linked(&self) -> bool {
+ let raw = self.as_raw();
+ // SAFETY: self.as_raw() is valid per type invariants.
+ unsafe { (*raw).next != raw && (*raw).prev != raw }
+ }
+
+ /// Pin-initializer that initializes the list head.
+ pub fn new() -> impl PinInit<Self> {
+ pin_init!(Self {
+ // SAFETY: `INIT_LIST_HEAD` initializes `slot` to a valid empty list.
+ inner <- Opaque::ffi_init(|slot| unsafe { bindings::INIT_LIST_HEAD(slot) }),
+ })
+ }
+}
+
+// SAFETY: `list_head` contains no thread-bound state; it only holds
+// `next`/`prev` pointers.
+unsafe impl Send for CListHead {}
+
+// SAFETY: `CListHead` can be shared among threads as modifications are
+// not allowed at the moment.
+unsafe impl Sync for CListHead {}
+
+impl PartialEq for CListHead {
+ #[inline]
+ fn eq(&self, other: &Self) -> bool {
+ core::ptr::eq(self, other)
+ }
+}
+
+impl Eq for CListHead {}
+
+/// Low-level iterator over `list_head` nodes.
+///
+/// An iterator used to iterate over a C intrusive linked list (`list_head`). Caller has to
+/// perform conversion of returned [`CListHead`] to an item (using `container_of` macro or similar).
+///
+/// # Invariants
+///
+/// [`CListHeadIter`] is iterating over an initialized and valid list.
+struct CListHeadIter<'a> {
+ /// Current position in the list.
+ current: &'a CListHead,
+ /// The sentinel head (used to detect end of iteration).
+ sentinel: &'a CListHead,
+}
+
+impl<'a> Iterator for CListHeadIter<'a> {
+ type Item = &'a CListHead;
+
+ #[inline]
+ fn next(&mut self) -> Option<Self::Item> {
+ // Check if we've reached the sentinel (end of list).
+ if self.current == self.sentinel {
+ return None;
+ }
+
+ let item = self.current;
+ self.current = item.next();
+ Some(item)
+ }
+}
+
+impl<'a> FusedIterator for CListHeadIter<'a> {}
+
+/// A typed C linked list with a sentinel head intended for FFI use-cases where
+/// C subsystem manages a linked list that Rust code needs to read. Generally
+/// required only for special cases.
+///
+/// A sentinel head [`CListHead`] represents the entire linked list and can be used
+/// for iteration over items of type `T`, it is not associated with a specific item.
+///
+/// The const generic `OFFSET` specifies the byte offset of the `list_head` field within
+/// the struct that `T` wraps.
+///
+/// # Invariants
+///
+/// - The sentinel [`CListHead`] has been initialized (e.g. via `INIT_LIST_HEAD()`) with valid
+/// non-NULL `next`/`prev` pointers.
+/// - `OFFSET` is the byte offset of the `list_head` field within the struct that `T` wraps.
+/// - All the list's `list_head` nodes have been initialized with valid non-NULL `next`/`prev`
+/// pointers.
+#[repr(transparent)]
+pub struct CList<T, const OFFSET: usize>(CListHead, PhantomData<T>);
+
+impl<T, const OFFSET: usize> CList<T, OFFSET> {
+ /// Create a typed [`CList`] reference from a raw sentinel `list_head` pointer.
+ ///
+ /// # Safety
+ ///
+ /// - `ptr` must be a valid pointer to an initialized sentinel `list_head` (e.g. via
+ /// `INIT_LIST_HEAD()`), with valid non-NULL `next`/`prev` pointers.
+ /// - `ptr` must remain valid for the lifetime `'a`.
+ /// - The list and all linked nodes must not be concurrently modified for the lifetime `'a`.
+ /// - The list must contain items where the `list_head` field is at byte offset `OFFSET`.
+ /// - `T` must be `#[repr(transparent)]` over the C struct.
+ #[inline]
+ pub unsafe fn from_raw<'a>(ptr: *mut bindings::list_head) -> &'a Self {
+ // SAFETY:
+ // - [`CList`] has same layout as [`CListHead`] due to repr(transparent).
+ // - Caller guarantees `ptr` is a valid, sentinel `list_head` object.
+ unsafe { &*ptr.cast() }
+ }
+
+ /// Check if the list is empty.
+ #[inline]
+ pub fn is_empty(&self) -> bool {
+ !self.0.is_linked()
+ }
+
+ /// Create an iterator over typed items.
+ #[inline]
+ pub fn iter(&self) -> CListIter<'_, T, OFFSET> {
+ let head = &self.0;
+ CListIter {
+ head_iter: CListHeadIter {
+ current: head.next(),
+ sentinel: head,
+ },
+ _phantom: PhantomData,
+ }
+ }
+}
+
+/// High-level iterator over typed list items.
+pub struct CListIter<'a, T, const OFFSET: usize> {
+ head_iter: CListHeadIter<'a>,
+ _phantom: PhantomData<&'a T>,
+}
+
+impl<'a, T, const OFFSET: usize> Iterator for CListIter<'a, T, OFFSET> {
+ type Item = &'a T;
+
+ #[inline]
+ fn next(&mut self) -> Option<Self::Item> {
+ let head = self.head_iter.next()?;
+
+ // Convert to item using OFFSET.
+ // SAFETY: The pointer calculation is valid because `OFFSET` is derived
+ // from `offset_of!` per type invariants.
+ Some(unsafe { &*head.as_raw().byte_sub(OFFSET).cast::<T>() })
+ }
+}
+
+impl<'a, T, const OFFSET: usize> FusedIterator for CListIter<'a, T, OFFSET> {}
+
+/// Create a C doubly-circular linked list interface `CList` from a raw `list_head` pointer.
+///
+/// This macro creates a `CList<T, OFFSET>` that can iterate over items of type `$rust_type`
+/// linked via the `$field` field in the underlying C struct `$c_type`.
+///
+/// # Arguments
+///
+/// - `$head`: Raw pointer to the sentinel `list_head` object (`*mut bindings::list_head`).
+/// - `$rust_type`: Each item's rust wrapper type.
+/// - `$c_type`: Each item's C struct type that contains the embedded `list_head`.
+/// - `$field`: The name of the `list_head` field within the C struct.
+///
+/// # Safety
+///
+/// The caller must ensure:
+///
+/// - `$head` is a valid, initialized sentinel `list_head` (e.g. via `INIT_LIST_HEAD()`)
+/// pointing to a list that is not concurrently modified for the lifetime of the `CList`.
+/// - The list contains items of type `$c_type` linked via an embedded `$field`.
+/// - `$rust_type` is `#[repr(transparent)]` over `$c_type` or has compatible layout.
+///
+/// # Examples
+///
+/// Refer to the examples in this module's documentation.
+#[macro_export]
+macro_rules! clist_create {
+ (unsafe { $head:expr, $rust_type:ty, $c_type:ty, $($field:tt).+ }) => {{
+ // Compile-time check that field path is a list_head.
+ let _: fn(*const $c_type) -> *const $crate::bindings::list_head =
+ |p| unsafe { &raw const (*p).$($field).+ };
+
+ // Calculate offset and create `CList`.
+ const OFFSET: usize = ::core::mem::offset_of!($c_type, $($field).+);
+ // SAFETY: The caller of this macro is responsible for ensuring safety.
+ unsafe { $crate::interop::list::CList::<$rust_type, OFFSET>::from_raw($head) }
+ }};
+}
diff --git a/rust/kernel/interop/mod.rs b/rust/kernel/interop/mod.rs
new file mode 100644
index 000000000000..b88140cf76dc
--- /dev/null
+++ b/rust/kernel/interop/mod.rs
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Infrastructure for interfacing Rust code with C kernel subsystems.
+//!
+//! This module is intended for low-level, unsafe Rust infrastructure code
+//! that interoperates between Rust and C. It is NOT for use directly in
+//! Rust drivers.
+
+pub mod list;
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 3da92f18f4ee..bb741f1e0dfd 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -28,6 +28,7 @@
#![feature(lint_reasons)]
//
// Stable since Rust 1.82.0.
+#![feature(offset_of_nested)]
#![feature(raw_ref_op)]
//
// Stable since Rust 1.83.0.
@@ -103,6 +104,7 @@
#[doc(hidden)]
pub mod impl_flags;
pub mod init;
+pub mod interop;
pub mod io;
pub mod ioctl;
pub mod iommu;
--
2.34.1
^ permalink raw reply related
* [PATCH v12 0/1] rust: interop: Add list module for C linked list interface
From: Joel Fernandes @ 2026-03-06 20:36 UTC (permalink / raw)
To: linux-kernel
Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Alex Gaynor, Danilo Krummrich, Dave Airlie, David Airlie,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann,
Simona Vetter, Daniel Almeida, Koen Koning, Nikola Djukic,
Alexandre Courbot, Philipp Stanner, Elle Rhumsaa, Jonathan Corbet,
Alex Deucher, Christian König, Jani Nikula, Joonas Lahtinen,
Rodrigo Vivi, Tvrtko Ursulin, Huang Rui, Matthew Auld,
Matthew Brost, Lucas De Marchi, Thomas Hellström,
Helge Deller, John Hubbard, Alistair Popple, Timur Tabi,
Edwin Peer, Andrea Righi, Andy Ritger, Zhi Wang, Balbir Singh,
alexeyi, Eliot Courtney, dri-devel, nouveau, rust-for-linux,
linux-doc, amd-gfx, intel-gfx, intel-xe, linux-fbdev,
Joel Fernandes
The interop/list module provides Rust abstractions for iterating over C
list_head-based linked lists. The primary use-case right now is iterating
over GPU buddy allocator blocks.
This series provides the interop/list module required for GPU buddy bindings,
which is inturn required for nova-core memory memory management. This patch is
being sent separately from the rest of the preparatory patches (DRM buddy
movement, GPU buddy bindings, etc.) as it can go in independently.
The git tree with the patch can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux.git (tag: interop-v12-20260306)
Change log:
Changes from v11 to v12:
- Renamed module from ffi/clist to interop/list, reflecting community feedback
that 'interop' better describes the purpose than 'ffi' (credit to Boqun for
starting this idea.)
- Updated MAINTAINERS entry from "RUST [FFI HELPER]" to "RUST [INTEROP]"
and updated git tree reference.
- Added Acked-by from Miguel.
Changes from v10 to v11:
- Sending only the ffi/clist patches separately from the rest of the
preparatory series, as these can go in independently.
- MAINTAINERS entry: Renamed from "RUST TO C LIST INTERFACES" to
"RUST [FFI HELPER]" with (CLIST) scope annotations for maintainers,
following Danilo's suggestion. Note: There is still an ongoing
discussion about the MAINTAINER file entry naming between Miguel and
Danilo: https://lore.kernel.org/all/DGJXYEXCYIII.Z6FOAA8YYMAZ@kernel.org/
- Updated clist.rs module documentation per Danilo's review: generalized
the FFI usage description and added explicit note directing Rust-only
users to kernel::list::List instead.
- Implemented suggestions from Alice related to safety of CList wrt
concurrent modifications.
- Removed unnecessary trailing comment markers from example imports.
- Added feature guard for offset_of_nested (Eliot).
Changes from v9 to v10:
- Combined clist/ffi patches into the larger "Preparatory patches for
nova-core memory management" series (8 patches total).
- Added new ffi module patch: Convert pub use to pub mod and create
rust/kernel/ffi/mod.rs to host clist as a sub-module.
- Moved clist from rust/kernel/clist.rs to rust/kernel/ffi/clist.rs.
- Added Reviewed-by and Acked-by tags from Gary and Daniel.
Changes from v8 to v9:
- Added nova-core Kconfig change to select GPU_BUDDY.
- Minor fixups.
Changes from v7 to v8:
- Various changes suggested by Danilo, Gary, Daniel. Added tags.
Changes from v6 to v7:
- Extracted clist and GPU buddy patches from the larger RFC v6 nova-core
memory management series into a standalone series.
- Changes based on suggestions by Gary and Dave.
Changes from v5 to v6:
- Part of the larger RFC v6 nova-core memory management series
(26 patches).
Changes from v4 to v5:
- Part of the larger RFC v5 nova-core memory management series
(6 patches).
Changes from v3 to v4:
- Combined the clist and DRM buddy series back together.
- Added Rust bindings for the GPU buddy allocator.
- Moved DRM buddy allocator one level up to drivers/gpu/ so it can be
used by GPU drivers (e.g. nova-core) that have non-DRM usecases.
Changes from v2 to v3:
- Consolidated 3 patches into a single patch.
Changes from v1 to v2:
- Dropped the DRM buddy allocator patches. Series now focuses solely on
the clist module.
- Dropped samples and added doctests.
- Added proper lifetime management similar to scatterlist.
Link to v11: https://lore.kernel.org/all/20260224222734.3153931-1-joelagnelf@nvidia.com/
Link to v10: https://lore.kernel.org/all/20260218205507.689429-1-joelagnelf@nvidia.com/
Link to v9: https://lore.kernel.org/all/20260210233204.790524-1-joelagnelf@nvidia.com/
Link to v8: https://lore.kernel.org/all/20260209214246.2783990-1-joelagnelf@nvidia.com/
Link to v7: https://lore.kernel.org/all/20260206004110.1914814-1-joelagnelf@nvidia.com/
Joel Fernandes (1):
rust: interop: Add list module for C linked list interface
MAINTAINERS | 8 +
rust/helpers/helpers.c | 1 +
rust/helpers/list.c | 17 ++
rust/kernel/interop/list.rs | 338 ++++++++++++++++++++++++++++++++++++
rust/kernel/interop/mod.rs | 9 +
rust/kernel/lib.rs | 2 +
6 files changed, 375 insertions(+)
create mode 100644 rust/helpers/list.c
create mode 100644 rust/kernel/interop/list.rs
create mode 100644 rust/kernel/interop/mod.rs
base-commit: 877552aa875839314afad7154b5a561889e87ea9
--
2.34.1
^ permalink raw reply
* Re: (subset) [PATCH v2] backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()
From: Lee Jones @ 2026-03-06 14:21 UTC (permalink / raw)
To: daniel, Chen Ni
Cc: danielt, deller, dri-devel, jingoohan1, lee, linusw, linux-fbdev,
linux-kernel
In-Reply-To: <20260203021625.578678-1-nichen@iscas.ac.cn>
On Tue, 03 Feb 2026 10:16:25 +0800, Chen Ni wrote:
> The devm_gpiod_get_optional() function may return an ERR_PTR in case of
> genuine GPIO acquisition errors, not just NULL which indicates the
> legitimate absence of an optional GPIO.
>
> Add an IS_ERR() check after the call in sky81452_bl_parse_dt(). On
> error, return the error code to ensure proper failure handling rather
> than proceeding with invalid pointers.
>
> [...]
Applied, thanks!
[1/1] backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()
commit: 797cc011ae02bda26f93d25a4442d7a1a77d84df
--
Lee Jones [李琼斯]
^ permalink raw reply
* Re: [PATCH v2] backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()
From: Linus Walleij @ 2026-03-06 13:31 UTC (permalink / raw)
To: Chen Ni
Cc: daniel, danielt, deller, dri-devel, jingoohan1, lee, linux-fbdev,
linux-kernel
In-Reply-To: <20260203021625.578678-1-nichen@iscas.ac.cn>
On Tue, Feb 3, 2026 at 3:17 AM Chen Ni <nichen@iscas.ac.cn> wrote:
> The devm_gpiod_get_optional() function may return an ERR_PTR in case of
> genuine GPIO acquisition errors, not just NULL which indicates the
> legitimate absence of an optional GPIO.
>
> Add an IS_ERR() check after the call in sky81452_bl_parse_dt(). On
> error, return the error code to ensure proper failure handling rather
> than proceeding with invalid pointers.
>
> Fixes: e1915eec54a6 ("backlight: sky81452: Convert to GPIO descriptors")
> Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Yours,
Linus Walleij
^ permalink raw reply
* Re: [PATCH] fbdev: macfb: Replace deprecated strcpy with strscpy
From: Helge Deller @ 2026-03-06 9:20 UTC (permalink / raw)
To: Thorsten Blum; +Cc: linux-fbdev, dri-devel, linux-kernel
In-Reply-To: <20260305103919.158067-2-thorsten.blum@linux.dev>
On 3/5/26 11:39, Thorsten Blum wrote:
> strcpy() has been deprecated [1] because it performs no bounds checking
> on the destination buffer, which can lead to buffer overflows. Replace
> it with the safer strscpy(). No functional changes.
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strcpy [1]
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
> drivers/video/fbdev/macfb.c | 38 ++++++++++++++++++-------------------
> 1 file changed, 19 insertions(+), 19 deletions(-)
applied.
Thanks!
Helge
^ permalink raw reply
* Re: [PATCH v2 09/13] lib/fonts: Compare font data for equality with font_data_is_equal()
From: Nathan Chancellor @ 2026-03-05 20:12 UTC (permalink / raw)
To: Thomas Zimmermann
Cc: gregkh, deller, sam, linux-fbdev, dri-devel, linux-kernel
In-Reply-To: <4acb921b-6bce-4bbf-a607-cc3e991dfc3a@suse.de>
On Thu, Mar 05, 2026 at 10:31:13AM +0100, Thomas Zimmermann wrote:
> Thanks for testing. The attached patch fixes the problem for me. Could you
> please test?
Yeah, that appears to work for me as well.
Tested-by: Nathan Chancellor <nathan@kernel.org> # build
It seems like the asm/sections.h include can be dropped as well, since
that was only included for is_kernel_rodata() AFAICT.
> From 8dc48d2e676d1437584794f4df3dd20d08878655 Mon Sep 17 00:00:00 2001
> From: Thomas Zimmermann <tzimmermann@suse.de>
> Date: Thu, 5 Mar 2026 09:28:28 +0100
> Subject: [PATCH] test for internal fonts by refcount
>
> Internal font data is 'static const'. Hence test against the refcount
> being zero.
> ---
> lib/fonts/fonts.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/lib/fonts/fonts.c b/lib/fonts/fonts.c
> index 198aae869be2..b73d74b977ec 100644
> --- a/lib/fonts/fonts.c
> +++ b/lib/fonts/fonts.c
> @@ -45,14 +45,11 @@ static struct font_data *to_font_data_struct(font_data_t *fd)
>
> static bool font_data_is_internal(font_data_t *fd)
> {
> - return is_kernel_rodata((unsigned long)fd);
> + return !REFCOUNT(fd); /* internal fonts have no reference counting */
> }
>
> static void font_data_free(font_data_t *fd)
> {
> - if (WARN_ON(font_data_is_internal(fd)))
> - return;
> -
> kfree(to_font_data_struct(fd));
> }
>
> --
> 2.53.0
>
^ permalink raw reply
* [PATCH] fbdev: macfb: Replace deprecated strcpy with strscpy
From: Thorsten Blum @ 2026-03-05 10:39 UTC (permalink / raw)
To: Helge Deller; +Cc: Thorsten Blum, linux-fbdev, dri-devel, linux-kernel
strcpy() has been deprecated [1] because it performs no bounds checking
on the destination buffer, which can lead to buffer overflows. Replace
it with the safer strscpy(). No functional changes.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strcpy [1]
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
drivers/video/fbdev/macfb.c | 38 ++++++++++++++++++-------------------
1 file changed, 19 insertions(+), 19 deletions(-)
diff --git a/drivers/video/fbdev/macfb.c b/drivers/video/fbdev/macfb.c
index 887fffdccd24..ef3d2304e2f4 100644
--- a/drivers/video/fbdev/macfb.c
+++ b/drivers/video/fbdev/macfb.c
@@ -668,19 +668,19 @@ static int __init macfb_init(void)
switch(ndev->dr_hw) {
case NUBUS_DRHW_APPLE_MDC:
- strcpy(macfb_fix.id, "Mac Disp. Card");
+ strscpy(macfb_fix.id, "Mac Disp. Card");
macfb_setpalette = mdc_setpalette;
break;
case NUBUS_DRHW_APPLE_TFB:
- strcpy(macfb_fix.id, "Toby");
+ strscpy(macfb_fix.id, "Toby");
macfb_setpalette = toby_setpalette;
break;
case NUBUS_DRHW_APPLE_JET:
- strcpy(macfb_fix.id, "Jet");
+ strscpy(macfb_fix.id, "Jet");
macfb_setpalette = jet_setpalette;
break;
default:
- strcpy(macfb_fix.id, "Generic NuBus");
+ strscpy(macfb_fix.id, "Generic NuBus");
break;
}
}
@@ -707,7 +707,7 @@ static int __init macfb_init(void)
case MAC_MODEL_Q700:
case MAC_MODEL_Q900:
case MAC_MODEL_Q950:
- strcpy(macfb_fix.id, "DAFB");
+ strscpy(macfb_fix.id, "DAFB");
macfb_setpalette = dafb_setpalette;
dafb_cmap_regs = ioremap(DAFB_BASE, 0x1000);
break;
@@ -716,7 +716,7 @@ static int __init macfb_init(void)
* LC II uses the V8 framebuffer
*/
case MAC_MODEL_LCII:
- strcpy(macfb_fix.id, "V8");
+ strscpy(macfb_fix.id, "V8");
macfb_setpalette = v8_brazil_setpalette;
v8_brazil_cmap_regs = ioremap(DAC_BASE, 0x1000);
break;
@@ -729,7 +729,7 @@ static int __init macfb_init(void)
case MAC_MODEL_IIVI:
case MAC_MODEL_IIVX:
case MAC_MODEL_P600:
- strcpy(macfb_fix.id, "Brazil");
+ strscpy(macfb_fix.id, "Brazil");
macfb_setpalette = v8_brazil_setpalette;
v8_brazil_cmap_regs = ioremap(DAC_BASE, 0x1000);
break;
@@ -745,7 +745,7 @@ static int __init macfb_init(void)
case MAC_MODEL_P520:
case MAC_MODEL_P550:
case MAC_MODEL_P460:
- strcpy(macfb_fix.id, "Sonora");
+ strscpy(macfb_fix.id, "Sonora");
macfb_setpalette = v8_brazil_setpalette;
v8_brazil_cmap_regs = ioremap(DAC_BASE, 0x1000);
break;
@@ -757,7 +757,7 @@ static int __init macfb_init(void)
*/
case MAC_MODEL_IICI:
case MAC_MODEL_IISI:
- strcpy(macfb_fix.id, "RBV");
+ strscpy(macfb_fix.id, "RBV");
macfb_setpalette = rbv_setpalette;
rbv_cmap_regs = ioremap(DAC_BASE, 0x1000);
break;
@@ -767,7 +767,7 @@ static int __init macfb_init(void)
*/
case MAC_MODEL_Q840:
case MAC_MODEL_C660:
- strcpy(macfb_fix.id, "Civic");
+ strscpy(macfb_fix.id, "Civic");
macfb_setpalette = civic_setpalette;
civic_cmap_regs = ioremap(CIVIC_BASE, 0x1000);
break;
@@ -778,7 +778,7 @@ static int __init macfb_init(void)
* We think this may be like the LC II
*/
case MAC_MODEL_LC:
- strcpy(macfb_fix.id, "LC");
+ strscpy(macfb_fix.id, "LC");
if (vidtest) {
macfb_setpalette = v8_brazil_setpalette;
v8_brazil_cmap_regs =
@@ -790,7 +790,7 @@ static int __init macfb_init(void)
* We think this may be like the LC II
*/
case MAC_MODEL_CCL:
- strcpy(macfb_fix.id, "Color Classic");
+ strscpy(macfb_fix.id, "Color Classic");
if (vidtest) {
macfb_setpalette = v8_brazil_setpalette;
v8_brazil_cmap_regs =
@@ -802,7 +802,7 @@ static int __init macfb_init(void)
* And we *do* mean "weirdos"
*/
case MAC_MODEL_TV:
- strcpy(macfb_fix.id, "Mac TV");
+ strscpy(macfb_fix.id, "Mac TV");
break;
/*
@@ -810,7 +810,7 @@ static int __init macfb_init(void)
*/
case MAC_MODEL_SE30:
case MAC_MODEL_CLII:
- strcpy(macfb_fix.id, "Monochrome");
+ strscpy(macfb_fix.id, "Monochrome");
break;
/*
@@ -828,7 +828,7 @@ static int __init macfb_init(void)
case MAC_MODEL_PB140:
case MAC_MODEL_PB145:
case MAC_MODEL_PB170:
- strcpy(macfb_fix.id, "DDC");
+ strscpy(macfb_fix.id, "DDC");
break;
/*
@@ -840,7 +840,7 @@ static int __init macfb_init(void)
case MAC_MODEL_PB180:
case MAC_MODEL_PB210:
case MAC_MODEL_PB230:
- strcpy(macfb_fix.id, "GSC");
+ strscpy(macfb_fix.id, "GSC");
break;
/*
@@ -848,7 +848,7 @@ static int __init macfb_init(void)
*/
case MAC_MODEL_PB165C:
case MAC_MODEL_PB180C:
- strcpy(macfb_fix.id, "TIM");
+ strscpy(macfb_fix.id, "TIM");
break;
/*
@@ -860,13 +860,13 @@ static int __init macfb_init(void)
case MAC_MODEL_PB270C:
case MAC_MODEL_PB280:
case MAC_MODEL_PB280C:
- strcpy(macfb_fix.id, "CSC");
+ strscpy(macfb_fix.id, "CSC");
macfb_setpalette = csc_setpalette;
csc_cmap_regs = ioremap(CSC_BASE, 0x1000);
break;
default:
- strcpy(macfb_fix.id, "Unknown");
+ strscpy(macfb_fix.id, "Unknown");
break;
}
--
Thorsten Blum <thorsten.blum@linux.dev>
GPG: 1D60 735E 8AEF 3BE4 73B6 9D84 7336 78FD 8DFE EAD4
^ permalink raw reply related
* Re: [PATCH v2 09/13] lib/fonts: Compare font data for equality with font_data_is_equal()
From: Thomas Zimmermann @ 2026-03-05 9:31 UTC (permalink / raw)
To: Nathan Chancellor
Cc: gregkh, deller, sam, linux-fbdev, dri-devel, linux-kernel
In-Reply-To: <20260305002347.GA4102761@ax162>
[-- Attachment #1: Type: text/plain, Size: 1348 bytes --]
Hi
Am 05.03.26 um 01:23 schrieb Nathan Chancellor:
[...]
>>
>> +static bool font_data_is_internal(font_data_t *fd)
>> +{
>> + return is_kernel_rodata((unsigned long)fd);
>> +}
>> +
[...]
>>
>> This breaks the build when CONFIG_FONT_SUPPORT is a module.
>>
>> $ cat allno.config
>> CONFIG_MODULES=y
>> CONFIG_DRM=m
>> CONFIG_DRM_PANIC=y
>>
>> $ make -skj"$(nproc)" ARCH=x86_64 CROSS_COMPILE=x86_64-linux- KCONFIG_ALLCONFIG=1 allnoconfig all
>> ERROR: modpost: "__end_rodata" [lib/fonts/font.ko] undefined!
>> make[4]: *** [scripts/Makefile.modpost:147: Module.symvers] Error 1
>> ...
>>
>> $ scripts/config -s FONT_SUPPORT
>> m
Thanks for testing. The attached patch fixes the problem for me. Could
you please test?
Best regards
Thomas
>>
>> Cheers,
>> Nathan
>>
>>
>> + if (font_data_size(lhs) != font_data_size(rhs))
>> + return false;
>> + if (FNTSUM(lhs) && FNTSUM(rhs) && FNTSUM(lhs) != FNTSUM(rhs))
>> + return false;
>> +
>> + return !memcmp(lhs, rhs, FNTSIZE(lhs));
>> +}
>> +EXPORT_SYMBOL_GPL(font_data_is_equal);
>> +
>> /*
>> * Font lookup
>> */
>> --
>> 2.53.0
>>
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)
[-- Attachment #2: 0001-test-for-internal-fonts-by-refcount.patch --]
[-- Type: text/x-patch, Size: 927 bytes --]
From 8dc48d2e676d1437584794f4df3dd20d08878655 Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Thu, 5 Mar 2026 09:28:28 +0100
Subject: [PATCH] test for internal fonts by refcount
Internal font data is 'static const'. Hence test against the refcount
being zero.
---
lib/fonts/fonts.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/lib/fonts/fonts.c b/lib/fonts/fonts.c
index 198aae869be2..b73d74b977ec 100644
--- a/lib/fonts/fonts.c
+++ b/lib/fonts/fonts.c
@@ -45,14 +45,11 @@ static struct font_data *to_font_data_struct(font_data_t *fd)
static bool font_data_is_internal(font_data_t *fd)
{
- return is_kernel_rodata((unsigned long)fd);
+ return !REFCOUNT(fd); /* internal fonts have no reference counting */
}
static void font_data_free(font_data_t *fd)
{
- if (WARN_ON(font_data_is_internal(fd)))
- return;
-
kfree(to_font_data_struct(fd));
}
--
2.53.0
^ permalink raw reply related
* Re: [PATCH] fbdev: wmt_ge_rops: use devm_platform_ioremap_resource()
From: Helge Deller @ 2026-03-05 8:26 UTC (permalink / raw)
To: Amin GATTOUT, Alexey Charkov, Krzysztof Kozlowski
Cc: linux-arm-kernel, linux-fbdev, dri-devel, linux-kernel,
Thomas Zimmermann
In-Reply-To: <20260304-master-v1-1-2bfeb1b9559f@gmail.com>
On 3/4/26 18:10, Amin GATTOUT wrote:
> Replace the open-coded platform_get_resource() + ioremap() pair with
> devm_platform_ioremap_resource(), which requests the memory region and
> maps it in a single call, with automatic cleanup on device removal.
>
> Also reset regbase to NULL in remove() so that the single-instance
> guard in probe() works correctly if the device is re-probed.
>
> Signed-off-by: Amin GATTOUT <amin.gattout@gmail.com>
> ---
> drivers/video/fbdev/wmt_ge_rops.c | 18 ++++--------------
> 1 file changed, 4 insertions(+), 14 deletions(-)
applied to fbdev git tree.
Thanks!
Helge
^ permalink raw reply
* Re: [PATCH 6/6] staging: sm750fb: sm750_sw_i2c_init: return -EINVAL for invalid GPIO
From: Dan Carpenter @ 2026-03-05 5:48 UTC (permalink / raw)
To: Soham Kute
Cc: sudipm.mukherjee, teddy.wang, gregkh, linux-fbdev, linux-staging,
linux-kernel
In-Reply-To: <20260304173529.192067-6-officialsohamkute@gmail.com>
On Wed, Mar 04, 2026 at 11:05:29PM +0530, Soham Kute wrote:
> Return -EINVAL instead of -1 when the GPIO pin number is out of
> range. The caller ignores the return value.
>
> Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
> ---
> drivers/staging/sm750fb/ddk750_swi2c.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
> index c73943341f66..46599be8d6b9 100644
> --- a/drivers/staging/sm750fb/ddk750_swi2c.c
> +++ b/drivers/staging/sm750fb/ddk750_swi2c.c
> @@ -344,7 +344,7 @@ static unsigned char sw_i2c_read_byte(unsigned char ack)
> * data_gpio - The GPIO pin to be used as i2c SDA
> *
> * Return Value:
> - * -1 - Fail to initialize the i2c
> + * -EINVAL - Fail to initialize the i2c
> * 0 - Success
> */
> static long sm750le_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
This part needs to be done in the patch that changes
sw_i2c_read_byte().
regards,
dan carpenter
> @@ -382,7 +382,7 @@ static long sm750le_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
> * data_gpio - The GPIO pin to be used as i2c SDA
> *
> * Return Value:
> - * -1 - Fail to initialize the i2c
> + * -EINVAL - Fail to initialize the i2c
> * 0 - Success
> */
> long sm750_sw_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
> @@ -394,7 +394,7 @@ long sm750_sw_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
> * range is only from [0..63]
> */
> if ((clk_gpio > 31) || (data_gpio > 31))
> - return -1;
> + return -EINVAL;
>
> if (sm750_get_chip_type() == SM750LE)
> return sm750le_i2c_init(clk_gpio, data_gpio);
> --
> 2.34.1
>
^ permalink raw reply
* Re: [PATCH 2/6] staging: sm750fb: sm750_hw_fillrect: propagate de_wait() error
From: Dan Carpenter @ 2026-03-05 5:34 UTC (permalink / raw)
To: Soham Kute
Cc: sudipm.mukherjee, teddy.wang, gregkh, linux-fbdev, linux-staging,
linux-kernel
In-Reply-To: <20260304173529.192067-2-officialsohamkute@gmail.com>
On Wed, Mar 04, 2026 at 11:05:25PM +0530, Soham Kute wrote:
> Propagate the error from accel->de_wait() instead of returning -1.
> The caller treats all non-zero return values as failure.
No, the caller just ignores the errors.
regards,
dan carpenter
^ permalink raw reply
* Re: [PATCH 1/6] staging: sm750fb: hw_sm750le_de_wait: return -ETIMEDOUT on timeout
From: Dan Carpenter @ 2026-03-05 5:33 UTC (permalink / raw)
To: Soham Kute
Cc: sudipm.mukherjee, teddy.wang, gregkh, linux-fbdev, linux-staging,
linux-kernel
In-Reply-To: <20260304173529.192067-1-officialsohamkute@gmail.com>
On Wed, Mar 04, 2026 at 11:05:24PM +0530, Soham Kute wrote:
> Return -ETIMEDOUT instead of -1 when the DE engine poll loop
> times out. The callers check for non-zero return value and
> propagate the error code back to their callers.
>
They don't propagate the error back. The callers do:
drivers/staging/sm750fb/sm750_accel.c
87 int sm750_hw_fillrect(struct lynx_accel *accel,
88 u32 base, u32 pitch, u32 Bpp,
89 u32 x, u32 y, u32 width, u32 height,
90 u32 color, u32 rop)
91 {
92 u32 de_ctrl;
93
94 if (accel->de_wait() != 0) {
95 /*
96 * int time wait and always busy,seems hardware
97 * got something error
98 */
99 pr_debug("De engine always busy\n");
100 return -1;
101 }
They return -1. Propagating the errors means:
ret = accel->de_wait();
if (ret)
return ret;
Also this is a v3 patch, it needs v3 in the subject and a little
description of what changed.
https://staticthinking.wordpress.com/2022/07/27/how-to-send-a-v2-patch/
regards,
dan carpenter
^ permalink raw reply
* Re: [PATCH v2 09/13] lib/fonts: Compare font data for equality with font_data_is_equal()
From: Nathan Chancellor @ 2026-03-05 0:23 UTC (permalink / raw)
To: Thomas Zimmermann
Cc: gregkh, deller, sam, linux-fbdev, dri-devel, linux-kernel
In-Reply-To: <20260302141255.518657-10-tzimmermann@suse.de>
Hi Thomas,
On Mon, Mar 02, 2026 at 03:08:43PM +0100, Thomas Zimmermann wrote:
...
> diff --git a/lib/fonts/fonts.c b/lib/fonts/fonts.c
> index 8c9a6762061c..c9f6328d5dda 100644
> --- a/lib/fonts/fonts.c
> +++ b/lib/fonts/fonts.c
> @@ -12,18 +12,25 @@
> * for more details.
> */
>
> +#include <linux/font.h>
> #include <linux/module.h>
> -#include <linux/types.h>
> #include <linux/string.h>
> +#include <linux/types.h>
> +
> +#include <asm/sections.h>
> #if defined(__mc68000__)
> #include <asm/setup.h>
> #endif
> -#include <linux/font.h>
>
> /*
> * Helpers for font_data_t
> */
>
> +static bool font_data_is_internal(font_data_t *fd)
> +{
> + return is_kernel_rodata((unsigned long)fd);
> +}
> +
> /**
> * font_data_size - Return size of the font data in bytes
> * @fd: Font data
> @@ -37,6 +44,32 @@ unsigned int font_data_size(font_data_t *fd)
> }
> EXPORT_SYMBOL_GPL(font_data_size);
>
> +/**
> + * font_data_is_equal - Compares font data for equality
> + * @lhs: Left-hand side font data
> + * @rhs: Right-hand-size font data
> + *
> + * Font data is equal if is constain the same sequence of values. The
> + * helper also use the checksum, if both arguments contain it. Font data
> + * coming from different origins, internal or from user space, is never
> + * equal. Allowing this would break reference counting.
> + *
> + * Returns:
> + * True if the given font data is equal, false otherwise.
> + */
> +bool font_data_is_equal(font_data_t *lhs, font_data_t *rhs)
> +{
> + if (font_data_is_internal(lhs) != font_data_is_internal(rhs))
> + return false;
This breaks the build when CONFIG_FONT_SUPPORT is a module.
$ cat allno.config
CONFIG_MODULES=y
CONFIG_DRM=m
CONFIG_DRM_PANIC=y
$ make -skj"$(nproc)" ARCH=x86_64 CROSS_COMPILE=x86_64-linux- KCONFIG_ALLCONFIG=1 allnoconfig all
ERROR: modpost: "__end_rodata" [lib/fonts/font.ko] undefined!
make[4]: *** [scripts/Makefile.modpost:147: Module.symvers] Error 1
...
$ scripts/config -s FONT_SUPPORT
m
Cheers,
Nathan
> + if (font_data_size(lhs) != font_data_size(rhs))
> + return false;
> + if (FNTSUM(lhs) && FNTSUM(rhs) && FNTSUM(lhs) != FNTSUM(rhs))
> + return false;
> +
> + return !memcmp(lhs, rhs, FNTSIZE(lhs));
> +}
> +EXPORT_SYMBOL_GPL(font_data_is_equal);
> +
> /*
> * Font lookup
> */
> --
> 2.53.0
>
^ permalink raw reply
* [PATCH 6/6] staging: sm750fb: sm750_sw_i2c_init: return -EINVAL for invalid GPIO
From: Soham Kute @ 2026-03-04 17:35 UTC (permalink / raw)
To: sudipm.mukherjee, teddy.wang
Cc: gregkh, linux-fbdev, linux-staging, linux-kernel, dan.carpenter,
Soham Kute
In-Reply-To: <20260304173529.192067-1-officialsohamkute@gmail.com>
Return -EINVAL instead of -1 when the GPIO pin number is out of
range. The caller ignores the return value.
Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
drivers/staging/sm750fb/ddk750_swi2c.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
index c73943341f66..46599be8d6b9 100644
--- a/drivers/staging/sm750fb/ddk750_swi2c.c
+++ b/drivers/staging/sm750fb/ddk750_swi2c.c
@@ -344,7 +344,7 @@ static unsigned char sw_i2c_read_byte(unsigned char ack)
* data_gpio - The GPIO pin to be used as i2c SDA
*
* Return Value:
- * -1 - Fail to initialize the i2c
+ * -EINVAL - Fail to initialize the i2c
* 0 - Success
*/
static long sm750le_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
@@ -382,7 +382,7 @@ static long sm750le_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
* data_gpio - The GPIO pin to be used as i2c SDA
*
* Return Value:
- * -1 - Fail to initialize the i2c
+ * -EINVAL - Fail to initialize the i2c
* 0 - Success
*/
long sm750_sw_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
@@ -394,7 +394,7 @@ long sm750_sw_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
* range is only from [0..63]
*/
if ((clk_gpio > 31) || (data_gpio > 31))
- return -1;
+ return -EINVAL;
if (sm750_get_chip_type() == SM750LE)
return sm750le_i2c_init(clk_gpio, data_gpio);
--
2.34.1
^ permalink raw reply related
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