<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/bus/mhi/ep/ring.c, branch master</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses</title>
<updated>2026-02-22T16:26:33+00:00</updated>
<author>
<name>Kees Cook</name>
<email>kees@kernel.org</email>
</author>
<published>2026-02-22T07:46:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=189f164e573e18d9f8876dbd3ad8fcbe11f93037'/>
<id>189f164e573e18d9f8876dbd3ad8fcbe11f93037</id>
<content type='text'>
Conversion performed via this Coccinelle script:

  // SPDX-License-Identifier: GPL-2.0-only
  // Options: --include-headers-for-types --all-includes --include-headers --keep-comments
  virtual patch

  @gfp depends on patch &amp;&amp; !(file in "tools") &amp;&amp; !(file in "samples")@
  identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex,
 		    kzalloc_obj,kzalloc_objs,kzalloc_flex,
		    kvmalloc_obj,kvmalloc_objs,kvmalloc_flex,
		    kvzalloc_obj,kvzalloc_objs,kvzalloc_flex};
  @@

  	ALLOC(...
  -		, GFP_KERNEL
  	)

  $ make coccicheck MODE=patch COCCI=gfp.cocci

Build and boot tested x86_64 with Fedora 42's GCC and Clang:

Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01
Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01

Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conversion performed via this Coccinelle script:

  // SPDX-License-Identifier: GPL-2.0-only
  // Options: --include-headers-for-types --all-includes --include-headers --keep-comments
  virtual patch

  @gfp depends on patch &amp;&amp; !(file in "tools") &amp;&amp; !(file in "samples")@
  identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex,
 		    kzalloc_obj,kzalloc_objs,kzalloc_flex,
		    kvmalloc_obj,kvmalloc_objs,kvmalloc_flex,
		    kvzalloc_obj,kvzalloc_objs,kvzalloc_flex};
  @@

  	ALLOC(...
  -		, GFP_KERNEL
  	)

  $ make coccicheck MODE=patch COCCI=gfp.cocci

Build and boot tested x86_64 with Fedora 42's GCC and Clang:

Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01
Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01

Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Replace kmalloc with kmalloc_obj for non-scalar types</title>
<updated>2026-02-21T09:02:28+00:00</updated>
<author>
<name>Kees Cook</name>
<email>kees@kernel.org</email>
</author>
<published>2026-02-21T07:49:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=69050f8d6d075dc01af7a5f2f550a8067510366f'/>
<id>69050f8d6d075dc01af7a5f2f550a8067510366f</id>
<content type='text'>
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 &lt;kees@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;kees@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bus: mhi: ep: Update read pointer only after buffer is written</title>
<updated>2025-04-24T05:04:51+00:00</updated>
<author>
<name>Sumit Kumar</name>
<email>quic_sumk@quicinc.com</email>
</author>
<published>2025-04-09T10:47:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6f18d174b73d0ceeaa341f46c0986436b3aefc9a'/>
<id>6f18d174b73d0ceeaa341f46c0986436b3aefc9a</id>
<content type='text'>
Inside mhi_ep_ring_add_element, the read pointer (rd_offset) is updated
before the buffer is written, potentially causing race conditions where
the host sees an updated read pointer before the buffer is actually
written. Updating rd_offset prematurely can lead to the host accessing
an uninitialized or incomplete element, resulting in data corruption.

Invoke the buffer write before updating rd_offset to ensure the element
is fully written before signaling its availability.

Fixes: bbdcba57a1a2 ("bus: mhi: ep: Add support for ring management")
cc: stable@vger.kernel.org
Co-developed-by: Youssef Samir &lt;quic_yabdulra@quicinc.com&gt;
Signed-off-by: Youssef Samir &lt;quic_yabdulra@quicinc.com&gt;
Signed-off-by: Sumit Kumar &lt;quic_sumk@quicinc.com&gt;
Reviewed-by: Jeff Hugo &lt;jeff.hugo@oss.qualcomm.com&gt;
Reviewed-by: Krishna Chaitanya Chundru &lt;krishna.chundru@oss.qualcomm.com&gt;
Reviewed-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
Link: https://patch.msgid.link/20250409-rp_fix-v1-1-8cf1fa22ed28@quicinc.com
Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Inside mhi_ep_ring_add_element, the read pointer (rd_offset) is updated
before the buffer is written, potentially causing race conditions where
the host sees an updated read pointer before the buffer is actually
written. Updating rd_offset prematurely can lead to the host accessing
an uninitialized or incomplete element, resulting in data corruption.

Invoke the buffer write before updating rd_offset to ensure the element
is fully written before signaling its availability.

Fixes: bbdcba57a1a2 ("bus: mhi: ep: Add support for ring management")
cc: stable@vger.kernel.org
Co-developed-by: Youssef Samir &lt;quic_yabdulra@quicinc.com&gt;
Signed-off-by: Youssef Samir &lt;quic_yabdulra@quicinc.com&gt;
Signed-off-by: Sumit Kumar &lt;quic_sumk@quicinc.com&gt;
Reviewed-by: Jeff Hugo &lt;jeff.hugo@oss.qualcomm.com&gt;
Reviewed-by: Krishna Chaitanya Chundru &lt;krishna.chundru@oss.qualcomm.com&gt;
Reviewed-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
Link: https://patch.msgid.link/20250409-rp_fix-v1-1-8cf1fa22ed28@quicinc.com
Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bus: mhi: ep: Rename read_from_host() and write_to_host() APIs</title>
<updated>2023-12-14T06:28:53+00:00</updated>
<author>
<name>Manivannan Sadhasivam</name>
<email>manivannan.sadhasivam@linaro.org</email>
</author>
<published>2023-11-27T08:27:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=927105244f8bc48e6841826a5644c6a961e03b5d'/>
<id>927105244f8bc48e6841826a5644c6a961e03b5d</id>
<content type='text'>
In the preparation for adding async API support, let's rename the existing
APIs to read_sync() and write_sync() to make it explicit that these APIs
are used for synchronous read/write.

Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In the preparation for adding async API support, let's rename the existing
APIs to read_sync() and write_sync() to make it explicit that these APIs
are used for synchronous read/write.

Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bus: mhi: ep: Pass mhi_ep_buf_info struct to read/write APIs</title>
<updated>2023-12-14T06:28:53+00:00</updated>
<author>
<name>Manivannan Sadhasivam</name>
<email>manivannan.sadhasivam@linaro.org</email>
</author>
<published>2023-08-17T17:54:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b08ded2ef2e98768d5ee5f71da8fe768b1f7774b'/>
<id>b08ded2ef2e98768d5ee5f71da8fe768b1f7774b</id>
<content type='text'>
In the preparation of DMA async support, let's pass the parameters to
read_from_host() and write_to_host() APIs using mhi_ep_buf_info structure.

No functional change.

Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In the preparation of DMA async support, let's pass the parameters to
read_from_host() and write_to_host() APIs using mhi_ep_buf_info structure.

No functional change.

Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bus: mhi: ep: Add support for interrupt moderation timer</title>
<updated>2023-12-14T06:28:49+00:00</updated>
<author>
<name>Manivannan Sadhasivam</name>
<email>manivannan.sadhasivam@linaro.org</email>
</author>
<published>2023-10-26T04:55:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=cea4bcbf997ab2f6c8d242f41785b21ea91d53c3'/>
<id>cea4bcbf997ab2f6c8d242f41785b21ea91d53c3</id>
<content type='text'>
MHI spec defines the interrupt moderation timer feature using which the
host can limit the number of interrupts being raised for an event ring by
the device. This feature allows the host to process multiple event ring
elements by a single IRQ from the device, thereby eliminating the need to
process IRQ for each element.

The INTMODT field in the event context array provides the value to be used
for delaying the IRQ generation from device. This value, along with the
Block Event Interrupt (BEI) flag of the TRE defines how IRQ is generated to
the host.

Support for interrupt moderation timer is implemented using delayed
workqueue in kernel. And a separate delayed work item is used for each
event ring.

Link: https://lore.kernel.org/r/20231026045513.12981-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
MHI spec defines the interrupt moderation timer feature using which the
host can limit the number of interrupts being raised for an event ring by
the device. This feature allows the host to process multiple event ring
elements by a single IRQ from the device, thereby eliminating the need to
process IRQ for each element.

The INTMODT field in the event context array provides the value to be used
for delaying the IRQ generation from device. This value, along with the
Block Event Interrupt (BEI) flag of the TRE defines how IRQ is generated to
the host.

Support for interrupt moderation timer is implemented using delayed
workqueue in kernel. And a separate delayed work item is used for each
event ring.

Link: https://lore.kernel.org/r/20231026045513.12981-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bus: mhi: ep: Add support for ring management</title>
<updated>2022-04-26T11:17:41+00:00</updated>
<author>
<name>Manivannan Sadhasivam</name>
<email>manivannan.sadhasivam@linaro.org</email>
</author>
<published>2022-04-05T13:57:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bbdcba57a1a26a4439a4f4ecdbfaf80a10fd8f34'/>
<id>bbdcba57a1a26a4439a4f4ecdbfaf80a10fd8f34</id>
<content type='text'>
Add support for managing the MHI ring. The MHI ring is a circular queue
of data structures used to pass the information between host and the
endpoint.

MHI support 3 types of rings:

1. Transfer ring
2. Event ring
3. Command ring

All rings reside inside the host memory and the MHI EP device maps it to
the device memory using blocks like PCIe iATU. The mapping is handled in
the MHI EP controller driver itself.

Reviewed-by: Alex Elder &lt;elder@linaro.org&gt;
Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
Link: https://lore.kernel.org/r/20220405135754.6622-6-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add support for managing the MHI ring. The MHI ring is a circular queue
of data structures used to pass the information between host and the
endpoint.

MHI support 3 types of rings:

1. Transfer ring
2. Event ring
3. Command ring

All rings reside inside the host memory and the MHI EP device maps it to
the device memory using blocks like PCIe iATU. The mapping is handled in
the MHI EP controller driver itself.

Reviewed-by: Alex Elder &lt;elder@linaro.org&gt;
Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
Link: https://lore.kernel.org/r/20220405135754.6622-6-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
