linux.git/kernel/irq/matrix.c, branch v7.0

Convert 'alloc_flex' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This is the exact same thing as the 'alloc_obj()' version, only much
smaller because there are a lot fewer users of the *alloc_flex()
interface.

As with alloc_obj() version, this was done entirely with mindless brute
force, using the same script, except using 'flex' in the pattern rather
than 'objs*'.

Signed-off-by: Linus Torvalds

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook

treewide: Update email address

2026-01-11T16:09:11+00:00

In a vain attempt to consolidate the email zoo switch everything to the
kernel.org account.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Linus Torvalds

genirq/matrix: Dynamic bitmap allocation

2024-02-23T09:18:44+00:00

A future user of the matrix allocator, does not know the size of the matrix
bitmaps at compile time.

To avoid wasting memory on unnecessary large bitmaps, size the bitmap at
matrix allocation time.

Signed-off-by: Björn Töpel 
Signed-off-by: Anup Patel 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240222094006.1030709-11-apatel@ventanamicro.com

genirq/matrix: Exclude managed interrupts in irq_matrix_allocated()

2023-10-25T15:25:57+00:00

When a CPU is about to be offlined, x86 validates that all active
interrupts which are targeted to this CPU can be migrated to the remaining
online CPUs. If not, the offline operation is aborted.

The validation uses irq_matrix_allocated() to retrieve the number of
vectors which are allocated on the outgoing CPU. The returned number of
allocated vectors includes also vectors which are associated to managed
interrupts.

That's overaccounting because managed interrupts are:

  - not migrated when the affinity mask of the interrupt targets only
    the outgoing CPU

  - migrated to another CPU, but in that case the vector is already
    pre-allocated on the potential target CPUs and must not be taken into
    account.

As a consequence the check whether the remaining online CPUs have enough
capacity for migrating the allocated vectors from the outgoing CPU might
fail incorrectly.

Let irq_matrix_allocated() return only the number of allocated non-managed
interrupts to make this validation check correct.

[ tglx: Amend changelog and fixup kernel-doc comment ]

Fixes: 2f75d9e1c905 ("genirq: Implement bitmap matrix allocator")
Reported-by: Wendy Wang 
Signed-off-by: Chen Yu 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20231020072522.557846-1-yu.c.chen@intel.com

genirq/matrix: Remove redundant assignment to variable 'end'

2022-04-25T13:02:57+00:00

Variable end is being initialized with a value that is never read, it
is being re-assigned later with the same value. The initialization is
redundant and can be removed.

Cleans up clang scan build warning:
kernel/irq/matrix.c:289:25: warning: Value stored to 'end' during its
initialization is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Tom Rix 
Link: https://lore.kernel.org/r/20220422110418.1264778-1-colin.i.king@gmail.com

genirq/matrix: Fix kernel doc warnings for irq_matrix_alloc_managed()

2021-08-10T20:50:07+00:00

Describe the arguments correctly.

Fixes the following W=1 kernel build warning(s):

kernel/irq/matrix.c:287: warning: Function parameter or
 member 'msk' not described in 'irq_matrix_alloc_managed'
kernel/irq/matrix.c:287: warning: Function parameter or
 member 'mapped_cpu' not described in 'irq_matrix_alloc_managed'
kernel/irq/matrix.c:287: warning: Excess function
 parameter 'cpu' description in 'irq_matrix_alloc_managed'

Signed-off-by: Baokun Li 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20210605063413.684085-1-libaokun1@huawei.com

genirq/matrix: Prevent allocation counter corruption

2021-03-19T21:52:11+00:00

When irq_matrix_free() is called for an unallocated vector the
managed_allocated and total_allocated counters get out of sync with the
real state of the matrix. Later, when the last interrupt is freed, these
counters will underflow resulting in UINTMAX because the counters are
unsigned.

While this is certainly a problem of the calling code, this can be catched
in the allocator by checking the allocation bit for the to be freed vector
which simplifies debugging.

An example of the problem described above:
https://lore.kernel.org/lkml/20210318192819.636943062@linutronix.de/

Add the missing sanity check and emit a warning when it triggers.

Suggested-by: Thomas Gleixner 
Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20210319111823.1105248-1-vkuznets@redhat.com

irq: Simplify condition in irq_matrix_reserve()

2021-03-17T20:44:01+00:00

The if condition in irq_matrix_reserve() can be much simpler.

While at it fix a typo in the comment.

Signed-off-by: Juergen Gross 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20210211070953.5914-1-jgross@suse.com

genirq: Fix typos and misspellings in comments

2021-03-16T14:08:29+00:00

No functional change.

Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20210316100205.23492-1-krzysztof.kozlowski@canonical.com