[merged mm-nonmm-stable] riscv-kexec-add-support-for-crashkernel-cma-reservation.patch removed from -mm tree

[merged mm-nonmm-stable] riscv-kexec-add-support-for-crashkernel-cma-reservation.patch removed from -mm tree

[Andrew Morton]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 5559 bytes --]


The quilt patch titled
     Subject: riscv: kexec: add support for crashkernel CMA reservation
has been removed from the -mm tree.  Its filename was
     riscv-kexec-add-support-for-crashkernel-cma-reservation.patch

This patch was dropped because it was merged into the mm-nonmm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Jinjie Ruan <ruanjinjie@huawei.com>
Subject: riscv: kexec: add support for crashkernel CMA reservation
Date: Mon, 26 Jan 2026 16:07:38 +0800

Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the crashkernel=
command line option") and commit ab475510e042 ("kdump: implement
reserve_crashkernel_cma") added CMA support for kdump crashkernel
reservation.  This allows the kernel to dynamically allocate contiguous
memory for crash dumping when needed, rather than permanently reserving a
fixed region at boot time.

So extend crashkernel CMA reservation support to riscv.  The following
changes are made to enable CMA reservation:

- Parse and obtain the CMA reservation size along with other crashkernel
  parameters.
- Call reserve_crashkernel_cma() to allocate the CMA region for kdump.
- Include the CMA-reserved ranges for kdump kernel to use.
- Exclude the CMA-reserved ranges from the crash kernel memory to
  prevent them from being exported through /proc/vmcore.

Update kernel-parameters.txt to document CMA support for crashkernel on
riscv architecture.

Link: https://lkml.kernel.org/r/20260126080738.696723-1-ruanjinjie@huawei.com
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Björn Töpel <bjorn@rivosinc.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Breno Leitao <leitao@debian.org>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <kees@kernel.org>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Marco Elver <elver@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Samuel Holland <samuel.holland@sifive.com>
Cc: Song Shuai <songshuaishuai@tinylab.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Yunhui Cui <cuiyunhui@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 Documentation/admin-guide/kernel-parameters.txt |    2 -
 arch/riscv/kernel/machine_kexec_file.c          |   17 ++++++++++++--
 arch/riscv/mm/init.c                            |    5 ++--
 3 files changed, 19 insertions(+), 5 deletions(-)

--- a/arch/riscv/kernel/machine_kexec_file.c~riscv-kexec-add-support-for-crashkernel-cma-reservation
+++ a/arch/riscv/kernel/machine_kexec_file.c
@@ -59,9 +59,9 @@ static int prepare_elf_headers(void **ad
 {
 	struct crash_mem *cmem;
 	unsigned int nr_ranges;
-	int ret;
+	int ret, i;
 
-	nr_ranges = 1; /* For exclusion of crashkernel region */
+	nr_ranges = 1 + crashk_cma_cnt; /* For exclusion of crashkernel region */
 	walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
 
 	cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL);
@@ -74,11 +74,24 @@ static int prepare_elf_headers(void **ad
 	if (ret)
 		goto out;
 
+	for (i = 0; i < crashk_cma_cnt; i++) {
+		cmem->ranges[cmem->nr_ranges].start = crashk_cma_ranges[i].start;
+		cmem->ranges[cmem->nr_ranges].end = crashk_cma_ranges[i].end;
+		cmem->nr_ranges++;
+	}
+
 	/* Exclude crashkernel region */
 	ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
 	if (!ret)
 		ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
 
+	for (i = 0; i < crashk_cma_cnt; ++i) {
+		ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
+					      crashk_cma_ranges[i].end);
+		if (ret)
+			goto out;
+	}
+
 out:
 	kfree(cmem);
 	return ret;
--- a/arch/riscv/mm/init.c~riscv-kexec-add-support-for-crashkernel-cma-reservation
+++ a/arch/riscv/mm/init.c
@@ -1404,7 +1404,7 @@ static inline void setup_vm_final(void)
  */
 static void __init arch_reserve_crashkernel(void)
 {
-	unsigned long long low_size = 0;
+	unsigned long long low_size = 0, cma_size = 0;
 	unsigned long long crash_base, crash_size;
 	bool high = false;
 	int ret;
@@ -1414,11 +1414,12 @@ static void __init arch_reserve_crashker
 
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 				&crash_size, &crash_base,
-				&low_size, NULL, &high);
+				&low_size, &cma_size, &high);
 	if (ret)
 		return;
 
 	reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
+	reserve_crashkernel_cma(cma_size);
 }
 
 void __init paging_init(void)
--- a/Documentation/admin-guide/kernel-parameters.txt~riscv-kexec-add-support-for-crashkernel-cma-reservation
+++ a/Documentation/admin-guide/kernel-parameters.txt
@@ -1119,7 +1119,7 @@ Kernel parameters
 			It will be ignored when crashkernel=X,high is not used
 			or memory reserved is below 4G.
 	crashkernel=size[KMG],cma
-			[KNL, X86, ppc] Reserve additional crash kernel memory from
+			[KNL, X86, RISCV, ppc] Reserve additional crash kernel memory from
 			CMA. This reservation is usable by the first system's
 			userspace memory and kernel movable allocations (memory
 			balloon, zswap). Pages allocated from this memory range
_

Patches currently in -mm which might be from ruanjinjie@huawei.com are

Re: [merged mm-nonmm-stable] riscv-kexec-add-support-for-crashkernel-cma-reservation.patch removed from -mm tree

[Mike Rapoport]

Hi Andrew,

On Sat, Jan 31, 2026 at 04:17:10PM -0800, Andrew Morton wrote:
> 
> The quilt patch titled
>      Subject: riscv: kexec: add support for crashkernel CMA reservation
> has been removed from the -mm tree.  Its filename was
>      riscv-kexec-add-support-for-crashkernel-cma-reservation.patch
> 
> This patch was dropped because it was merged into the mm-nonmm-stable branch
> of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> 
> ------------------------------------------------------
> From: Jinjie Ruan <ruanjinjie@huawei.com>
> Subject: riscv: kexec: add support for crashkernel CMA reservation
> Date: Mon, 26 Jan 2026 16:07:38 +0800

I commented on almost identical patch for arm64 

https://lore.kernel.org/all/20260126081334.699147-1-ruanjinjie@huawei.com/

about moving the exclusion of CMA regions into the core crash code.
The same comment applies to this one as well. Sorry I didn't mention that
more explicitly.
 
> Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the crashkernel=
> command line option") and commit ab475510e042 ("kdump: implement
> reserve_crashkernel_cma") added CMA support for kdump crashkernel
> reservation.  This allows the kernel to dynamically allocate contiguous
> memory for crash dumping when needed, rather than permanently reserving a
> fixed region at boot time.
> 
> So extend crashkernel CMA reservation support to riscv.  The following
> changes are made to enable CMA reservation:
> 
> - Parse and obtain the CMA reservation size along with other crashkernel
>   parameters.
> - Call reserve_crashkernel_cma() to allocate the CMA region for kdump.
> - Include the CMA-reserved ranges for kdump kernel to use.
> - Exclude the CMA-reserved ranges from the crash kernel memory to
>   prevent them from being exported through /proc/vmcore.
> 
> Update kernel-parameters.txt to document CMA support for crashkernel on
> riscv architecture.
> 
> Link: https://lkml.kernel.org/r/20260126080738.696723-1-ruanjinjie@huawei.com
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> Cc: Albert Ou <aou@eecs.berkeley.edu>
> Cc: Alexandre Ghiti <alex@ghiti.fr>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Björn Töpel <bjorn@rivosinc.com>
> Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
> Cc: Breno Leitao <leitao@debian.org>
> Cc: Frank van der Linden <fvdl@google.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Kees Cook <kees@kernel.org>
> Cc: Kevin Brodsky <kevin.brodsky@arm.com>
> Cc: Li RongQing <lirongqing@baidu.com>
> Cc: Marco Elver <elver@google.com>
> Cc: Mike Rapoport <rppt@kernel.org>
> Cc: Palmer Dabbelt <palmer@dabbelt.com>
> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
> Cc: Randy Dunlap <rdunlap@infradead.org>
> Cc: Samuel Holland <samuel.holland@sifive.com>
> Cc: Song Shuai <songshuaishuai@tinylab.org>
> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> Cc: Yunhui Cui <cuiyunhui@bytedance.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>  Documentation/admin-guide/kernel-parameters.txt |    2 -
>  arch/riscv/kernel/machine_kexec_file.c          |   17 ++++++++++++--
>  arch/riscv/mm/init.c                            |    5 ++--
>  3 files changed, 19 insertions(+), 5 deletions(-)
> 
> --- a/arch/riscv/kernel/machine_kexec_file.c~riscv-kexec-add-support-for-crashkernel-cma-reservation
> +++ a/arch/riscv/kernel/machine_kexec_file.c
> @@ -59,9 +59,9 @@ static int prepare_elf_headers(void **ad
>  {
>  	struct crash_mem *cmem;
>  	unsigned int nr_ranges;
> -	int ret;
> +	int ret, i;
>  
> -	nr_ranges = 1; /* For exclusion of crashkernel region */
> +	nr_ranges = 1 + crashk_cma_cnt; /* For exclusion of crashkernel region */
>  	walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
>  
>  	cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL);
> @@ -74,11 +74,24 @@ static int prepare_elf_headers(void **ad
>  	if (ret)
>  		goto out;
>  
> +	for (i = 0; i < crashk_cma_cnt; i++) {
> +		cmem->ranges[cmem->nr_ranges].start = crashk_cma_ranges[i].start;
> +		cmem->ranges[cmem->nr_ranges].end = crashk_cma_ranges[i].end;
> +		cmem->nr_ranges++;
> +	}
> +
>  	/* Exclude crashkernel region */
>  	ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
>  	if (!ret)
>  		ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
>  
> +	for (i = 0; i < crashk_cma_cnt; ++i) {
> +		ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
> +					      crashk_cma_ranges[i].end);
> +		if (ret)
> +			goto out;
> +	}
> +
>  out:
>  	kfree(cmem);
>  	return ret;
> --- a/arch/riscv/mm/init.c~riscv-kexec-add-support-for-crashkernel-cma-reservation
> +++ a/arch/riscv/mm/init.c
> @@ -1404,7 +1404,7 @@ static inline void setup_vm_final(void)
>   */
>  static void __init arch_reserve_crashkernel(void)
>  {
> -	unsigned long long low_size = 0;
> +	unsigned long long low_size = 0, cma_size = 0;
>  	unsigned long long crash_base, crash_size;
>  	bool high = false;
>  	int ret;
> @@ -1414,11 +1414,12 @@ static void __init arch_reserve_crashker
>  
>  	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
>  				&crash_size, &crash_base,
> -				&low_size, NULL, &high);
> +				&low_size, &cma_size, &high);
>  	if (ret)
>  		return;
>  
>  	reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
> +	reserve_crashkernel_cma(cma_size);
>  }
>  
>  void __init paging_init(void)
> --- a/Documentation/admin-guide/kernel-parameters.txt~riscv-kexec-add-support-for-crashkernel-cma-reservation
> +++ a/Documentation/admin-guide/kernel-parameters.txt
> @@ -1119,7 +1119,7 @@ Kernel parameters
>  			It will be ignored when crashkernel=X,high is not used
>  			or memory reserved is below 4G.
>  	crashkernel=size[KMG],cma
> -			[KNL, X86, ppc] Reserve additional crash kernel memory from
> +			[KNL, X86, RISCV, ppc] Reserve additional crash kernel memory from
>  			CMA. This reservation is usable by the first system's
>  			userspace memory and kernel movable allocations (memory
>  			balloon, zswap). Pages allocated from this memory range
> _
> 
> Patches currently in -mm which might be from ruanjinjie@huawei.com are
> 
> 

-- 
Sincerely yours,
Mike.

Re: [merged mm-nonmm-stable] riscv-kexec-add-support-for-crashkernel-cma-reservation.patch removed from -mm tree

[Andrew Morton]

On Sun, 1 Feb 2026 15:29:17 +0100 Mike Rapoport <rppt@kernel.org> wrote:

> > From: Jinjie Ruan <ruanjinjie@huawei.com>
> > Subject: riscv: kexec: add support for crashkernel CMA reservation
> > Date: Mon, 26 Jan 2026 16:07:38 +0800
> 
> I commented on almost identical patch for arm64 
> 
> https://lore.kernel.org/all/20260126081334.699147-1-ruanjinjie@huawei.com/
> 
> about moving the exclusion of CMA regions into the core crash code.
> The same comment applies to this one as well. Sorry I didn't mention that
> more explicitly.

Thanks.

So IIUC this patch is OK, but we should reduce the code duplication in
this area?

Re: [merged mm-nonmm-stable] riscv-kexec-add-support-for-crashkernel-cma-reservation.patch removed from -mm tree

[Mike Rapoport]

On Mon, Feb 02, 2026 at 12:54:04PM -0800, Andrew Morton wrote:
> On Sun, 1 Feb 2026 15:29:17 +0100 Mike Rapoport <rppt@kernel.org> wrote:
> 
> > > From: Jinjie Ruan <ruanjinjie@huawei.com>
> > > Subject: riscv: kexec: add support for crashkernel CMA reservation
> > > Date: Mon, 26 Jan 2026 16:07:38 +0800
> > 
> > I commented on almost identical patch for arm64 
> > 
> > https://lore.kernel.org/all/20260126081334.699147-1-ruanjinjie@huawei.com/
> > 
> > about moving the exclusion of CMA regions into the core crash code.
> > The same comment applies to this one as well. Sorry I didn't mention that
> > more explicitly.
> 
> Thanks.
> 
> So IIUC this patch is OK, but we should reduce the code duplication in
> this area?

The patch is Ok in the sense it does not break anything :)

I'd like to see series with PATCH 1/3 moving the duplicated code from x86
and powerpc to the crash_core.c and patches 2 and 3 adding arm64 and riscv
support for CMA.

Requiring refactoring upfront rather than fixing this afterwards makes
maintainers life easier ;-)

-- 
Sincerely yours,
Mike.

Re: [merged mm-nonmm-stable] riscv-kexec-add-support-for-crashkernel-cma-reservation.patch removed from -mm tree

[Andrew Morton]

On Tue, 3 Feb 2026 09:43:52 +0200 Mike Rapoport <rppt@kernel.org> wrote:

> On Mon, Feb 02, 2026 at 12:54:04PM -0800, Andrew Morton wrote:
> > On Sun, 1 Feb 2026 15:29:17 +0100 Mike Rapoport <rppt@kernel.org> wrote:
> > 
> > > > From: Jinjie Ruan <ruanjinjie@huawei.com>
> > > > Subject: riscv: kexec: add support for crashkernel CMA reservation
> > > > Date: Mon, 26 Jan 2026 16:07:38 +0800
> > > 
> > > I commented on almost identical patch for arm64 
> > > 
> > > https://lore.kernel.org/all/20260126081334.699147-1-ruanjinjie@huawei.com/
> > > 
> > > about moving the exclusion of CMA regions into the core crash code.
> > > The same comment applies to this one as well. Sorry I didn't mention that
> > > more explicitly.
> > 
> > Thanks.
> > 
> > So IIUC this patch is OK, but we should reduce the code duplication in
> > this area?
> 
> The patch is Ok in the sense it does not break anything :)

No probs, I've dropped "riscv: kexec: add support for crashkernel CMA
reservation" from mm.git.

> I'd like to see series with PATCH 1/3 moving the duplicated code from x86
> and powerpc to the crash_core.c and patches 2 and 3 adding arm64 and riscv
> support for CMA.

I'm not sure which kind soul will be doing this work!

I've cc'ed Jinjie Ruan regarding "arm64: kexec: Add support for
crashkernel CMA reservation" and Sourabh Jain regarding "powerpc/kdump:
Add support for crashkernel CMA reservation".

Re: [merged mm-nonmm-stable] riscv-kexec-add-support-for-crashkernel-cma-reservation.patch removed from -mm tree

[Sourabh Jain]

On 03/02/26 21:57, Andrew Morton wrote:
> On Tue, 3 Feb 2026 09:43:52 +0200 Mike Rapoport <rppt@kernel.org> wrote:
>
>> On Mon, Feb 02, 2026 at 12:54:04PM -0800, Andrew Morton wrote:
>>> On Sun, 1 Feb 2026 15:29:17 +0100 Mike Rapoport <rppt@kernel.org> wrote:
>>>
>>>>> From: Jinjie Ruan <ruanjinjie@huawei.com>
>>>>> Subject: riscv: kexec: add support for crashkernel CMA reservation
>>>>> Date: Mon, 26 Jan 2026 16:07:38 +0800
>>>> I commented on almost identical patch for arm64
>>>>
>>>> https://lore.kernel.org/all/20260126081334.699147-1-ruanjinjie@huawei.com/
>>>>
>>>> about moving the exclusion of CMA regions into the core crash code.
>>>> The same comment applies to this one as well. Sorry I didn't mention that
>>>> more explicitly.
>>> Thanks.
>>>
>>> So IIUC this patch is OK, but we should reduce the code duplication in
>>> this area?
>> The patch is Ok in the sense it does not break anything :)
> No probs, I've dropped "riscv: kexec: add support for crashkernel CMA
> reservation" from mm.git.
>
>> I'd like to see series with PATCH 1/3 moving the duplicated code from x86
>> and powerpc to the crash_core.c and patches 2 and 3 adding arm64 and riscv
>> support for CMA.
> I'm not sure which kind soul will be doing this work!
>
> I've cc'ed Jinjie Ruan regarding "arm64: kexec: Add support for
> crashkernel CMA reservation" and Sourabh Jain regarding "powerpc/kdump:
> Add support for crashkernel CMA reservation".

I agree that we should avoid code duplication by handling CMA crashkernel
exclusion in a more generic way.

Would it make sense to handle the exclusion of all crash memory ranges
(including crashk_res, crashk_cma, and crashk_low) at the generic level?

Andrew, I can send the patch series you referred above.

- Sourabh

Re: [merged mm-nonmm-stable] riscv-kexec-add-support-for-crashkernel-cma-reservation.patch removed from -mm tree

[Jinjie Ruan]

On 2026/2/3 15:43, Mike Rapoport wrote:
> On Mon, Feb 02, 2026 at 12:54:04PM -0800, Andrew Morton wrote:
>> On Sun, 1 Feb 2026 15:29:17 +0100 Mike Rapoport <rppt@kernel.org> wrote:
>>
>>>> From: Jinjie Ruan <ruanjinjie@huawei.com>
>>>> Subject: riscv: kexec: add support for crashkernel CMA reservation
>>>> Date: Mon, 26 Jan 2026 16:07:38 +0800
>>>
>>> I commented on almost identical patch for arm64 
>>>
>>> https://lore.kernel.org/all/20260126081334.699147-1-ruanjinjie@huawei.com/
>>>
>>> about moving the exclusion of CMA regions into the core crash code.
>>> The same comment applies to this one as well. Sorry I didn't mention that
>>> more explicitly.
>>
>> Thanks.
>>
>> So IIUC this patch is OK, but we should reduce the code duplication in
>> this area?
> 
> The patch is Ok in the sense it does not break anything :)
> 
> I'd like to see series with PATCH 1/3 moving the duplicated code from x86
> and powerpc to the crash_core.c and patches 2 and 3 adding arm64 and riscv
> support for CMA.

I agree that we should eliminate this duplication; I can also try to
post a standalone patch that reduces the redundant code as suggested.

> 
> Requiring refactoring upfront rather than fixing this afterwards makes
> maintainers life easier ;-)
>