kernel/drivers/misc/cxl/main.c, branch linux-6.18.y

cxl: Remove driver

2025-03-16T11:04:27Z

Remove the cxl driver that provides support for the IBM Coherent Accelerator Processor Interface. Revert or clean up associated code in arch/powerpc that is no longer necessary. cxl has received minimal maintenance for several years, and is not supported on the Power10 processor. We aren't aware of any users who are likely to be using recent kernels. Thanks to Mikey Neuling, Ian Munsie, Daniel Axtens, Frederic Barrat, Christophe Lombard, Philippe Bergheaud, Vaibhav Jain and Alastair D'Silva for their work on this driver over the years. Signed-off-by: Andrew Donnellan Acked-by: Frederic Barrat Acked-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20250219070007.177725-2-ajd@linux.ibm.com

cxl/ocxl: Prepare cleanup of powerpc's asm/prom.h

2022-05-11T13:06:39Z

powerpc's asm/prom.h brings some headers that it doesn't need itself. In order to clean it up, first add missing headers in users of asm/prom.h Signed-off-by: Christophe Leroy Acked-by: Frederic Barrat Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/a2bae89b280e7a7cb87889635d9911d6a245e780.1648833388.git.christophe.leroy@csgroup.eu

powerpc/64s/radix: introduce options to disable use of the tlbie instruction

2019-09-05T04:22:41Z

Introduce two options to control the use of the tlbie instruction. A boot time option which completely disables the kernel using the instruction, this is currently incompatible with HASH MMU, KVM, and coherent accelerators. And a debugfs option can be switched at runtime and avoids using tlbie for invalidating CPU TLBs for normal process and kernel address mappings. Coherent accelerators are still managed with tlbie, as will KVM partition scope translations. Cross-CPU TLB flushing is implemented with IPIs and tlbiel. This is a basic implementation which does not attempt to make any optimisation beyond the tlbie implementation. This is useful for performance testing among other things. For example in certain situations on large systems, using IPIs may be faster than tlbie as they can be directed rather than broadcast. Later we may also take advantage of the IPIs to do more interesting things such as trim the mm cpumask more aggressively. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190902152931.17840-7-npiggin@gmail.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

cxl: Fix wrong comparison in cxl_adapter_context_get()

2018-07-19T11:58:11Z

Function atomic_inc_unless_negative() returns a bool to indicate success/failure. However cxl_adapter_context_get() wrongly compares the return value against '>=0' which will always be true. The patch fixes this comparison to '==0' there by also fixing this compile time warning: drivers/misc/cxl/main.c:290 cxl_adapter_context_get() warn: 'atomic_inc_unless_negative(&adapter->contexts_num)' is unsigned Fixes: 70b565bbdb91 ("cxl: Prevent adapter reset if an active context exists") Cc: stable@vger.kernel.org # v4.9+ Reported-by: Dan Carpenter Signed-off-by: Vaibhav Jain Acked-by: Andrew Donnellan Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman

Revert "cxl: Allow a default context to be associated with an external pci_dev"

2018-07-02T13:54:33Z

Remove abandonned capi support for the Mellanox CX4. This reverts commit a19bd79e31769626d288cc016e21a31b6f47bf6f. Signed-off-by: Frederic Barrat Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman

Revert "cxl: Add preliminary workaround for CX4 interrupt limitation"

2018-07-02T13:54:31Z

Remove abandonned capi support for the Mellanox CX4. This reverts commit cbce0917e2e47d4bf5aa3b5fd6b1247f33e1a126. Signed-off-by: Alastair D'Silva Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman

Revert "cxl: Add support for interrupts on the Mellanox CX4"

2018-07-02T13:54:30Z

Remove abandonned capi support for the Mellanox CX4. This reverts commit a2f67d5ee8d950caaa7a6144cf0bfb256500b73e. Signed-off-by: Alastair D'Silva Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman

cxl: Fixes for Coherent Accelerator Interface Architecture 2.0

2017-06-23T06:26:23Z

A previous set of patches "cxl: Add support for Coherent Accelerator Interface Architecture 2.0" has introduced a new support for the CAPI cards. These patches have been tested on Simulation environment and quite a bit of them have been tested on real hardware. This patch brings new fixes after a series of tests carried out on new equipment: - Add POWER9 definition. - Re-enable any masked interrupts when the AFU is not activated after resetting the AFU. - Remove the api cxl_is_psl8/9 which is no longer useful. - Do not dump CAPI1 registers. - Rewrite cxl_is_page_fault() function. - Do not register slb callack on P9. Fixes: f24be42aab37 ("cxl: Add psl9 specific code") Signed-off-by: Christophe Lombard Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman

cxl: Keep track of mm struct associated with a context

2017-04-13T13:34:29Z

The mm_struct corresponding to the current task is acquired each time an interrupt is raised. So to simplify the code, we only get the mm_struct when attaching an AFU context to the process. The mm_count reference is increased to ensure that the mm_struct can't be freed. The mm_struct will be released when the context is detached. A reference on mm_users is not kept to avoid a circular dependency if the process mmaps its cxl mmio and forget to unmap before exiting. The field glpid (pid of the group leader associated with the pid), of the structure cxl_context, is removed because it's no longer useful. Signed-off-by: Christophe Lombard Reviewed-by: Andrew Donnellan Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman