[PATCH V2 0/5] mm: Rework generic PTDUMP configs

[PATCH V2 0/5] mm: Rework generic PTDUMP configs

[Anshuman Khandual]

The series reworks generic PTDUMP configs before eventually renaming them
after some basic clean ups first. This is derived after splitting changes
from the following patch.

https://lore.kernel.org/all/20250205050039.1506377-1-anshuman.khandual@arm.com/

This series applies on v6.14-rc3 and has been tested on arm64. Although it
also builds on other platforms as well.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: kvmarm@lists.linux.dev
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org

Changes in V2:

- Dropped the patch "mm: Make GENERIC_PTDUMP dependent on MMU"
- Dropped GENERIC_PTDUMP from mpc885_ads_defconfig
- Dropped PTDUMP config options from ptdump.rst

Changes in V1:

https://lore.kernel.org/all/20250213040934.3245750-1-anshuman.khandual@arm.com/

Anshuman Khandual (5):
  configs: Drop GENERIC_PTDUMP from debug.config
  arch/powerpc: Drop GENERIC_PTDUMP from mpc885_ads_defconfig
  docs: arm64: Drop PTDUMP config options from ptdump.rst
  mm: Make DEBUG_WX depdendent on GENERIC_PTDUMP
  mm: Rename GENERIC_PTDUMP and PTDUMP_CORE

 Documentation/arch/arm64/ptdump.rst       |  2 --
 arch/arm64/Kconfig                        |  2 +-
 arch/arm64/include/asm/ptdump.h           |  4 ++--
 arch/arm64/kvm/Kconfig                    |  4 ++--
 arch/arm64/mm/Makefile                    |  2 +-
 arch/powerpc/Kconfig                      |  2 +-
 arch/powerpc/configs/mpc885_ads_defconfig |  1 -
 arch/powerpc/mm/Makefile                  |  2 +-
 arch/riscv/Kconfig                        |  2 +-
 arch/riscv/mm/Makefile                    |  2 +-
 arch/s390/Kconfig                         |  2 +-
 arch/s390/mm/Makefile                     |  2 +-
 arch/x86/Kconfig                          |  2 +-
 arch/x86/Kconfig.debug                    |  2 +-
 arch/x86/mm/Makefile                      |  2 +-
 kernel/configs/debug.config               |  1 -
 mm/Kconfig.debug                          | 11 ++++++-----
 mm/Makefile                               |  2 +-
 18 files changed, 22 insertions(+), 25 deletions(-)

-- 
2.25.1

[PATCH V2 1/5] configs: Drop GENERIC_PTDUMP from debug.config

[Anshuman Khandual]

The platforms that support GENERIC_PTDUMP select the config explicitly. But
enabling this feature on platforms that don't really support - does nothing
or might cause a build failure. Hence just drop GENERIC_PTDUMP from generic
debug.config

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 kernel/configs/debug.config | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/configs/debug.config b/kernel/configs/debug.config
index 20552f163930..8aafd050b754 100644
--- a/kernel/configs/debug.config
+++ b/kernel/configs/debug.config
@@ -73,7 +73,6 @@ CONFIG_DEBUG_VM=y
 CONFIG_DEBUG_VM_PGFLAGS=y
 CONFIG_DEBUG_VM_RB=y
 CONFIG_DEBUG_VM_VMACACHE=y
-CONFIG_GENERIC_PTDUMP=y
 CONFIG_KASAN=y
 CONFIG_KASAN_GENERIC=y
 CONFIG_KASAN_INLINE=y
-- 
2.25.1

[PATCH V2 2/5] arch/powerpc: Drop GENERIC_PTDUMP from mpc885_ads_defconfig

[Anshuman Khandual]

GENERIC_PTDUMP gets selected on powerpc explicitly and hence can be dropped
off from mpc885_ads_defconfig.

Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
Just wondering - Should CONFIG_PTDUMP_DEBUGFS be added instead ?

 arch/powerpc/configs/mpc885_ads_defconfig | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/configs/mpc885_ads_defconfig b/arch/powerpc/configs/mpc885_ads_defconfig
index 77306be62e9e..ea6f836407d2 100644
--- a/arch/powerpc/configs/mpc885_ads_defconfig
+++ b/arch/powerpc/configs/mpc885_ads_defconfig
@@ -78,4 +78,3 @@ CONFIG_DEBUG_VM_PGTABLE=y
 CONFIG_DETECT_HUNG_TASK=y
 CONFIG_BDI_SWITCH=y
 CONFIG_PPC_EARLY_DEBUG=y
-CONFIG_GENERIC_PTDUMP=y
-- 
2.25.1

[PATCH V2 3/5] docs: arm64: Drop PTDUMP config options from ptdump.rst

[Anshuman Khandual]

Both GENERIC_PTDUMP and PTDUMP_CORE are not user selectable config options.
Just drop these from documentation.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: Steven Price <steven.price@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 Documentation/arch/arm64/ptdump.rst | 2 --
 1 file changed, 2 deletions(-)

diff --git a/Documentation/arch/arm64/ptdump.rst b/Documentation/arch/arm64/ptdump.rst
index 5dcfc5d7cddf..51eb902ba41a 100644
--- a/Documentation/arch/arm64/ptdump.rst
+++ b/Documentation/arch/arm64/ptdump.rst
@@ -22,8 +22,6 @@ offlining of memory being accessed by the ptdump code.
 In order to dump the kernel page tables, enable the following
 configurations and mount debugfs::
 
- CONFIG_GENERIC_PTDUMP=y
- CONFIG_PTDUMP_CORE=y
  CONFIG_PTDUMP_DEBUGFS=y
 
  mount -t debugfs nodev /sys/kernel/debug
-- 
2.25.1

[PATCH V2 4/5] mm: Make DEBUG_WX depdendent on GENERIC_PTDUMP

[Anshuman Khandual]

DEBUG_WX selects PTDUMP_CORE without even ensuring that the given platform
implements GENERIC_PTDUMP. This problem has been latent until now, as all
the platforms subscribing ARCH_HAS_DEBUG_WX also subscribe GENERIC_PTDUMP.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 mm/Kconfig.debug | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index 41a58536531d..a51a1149909a 100644
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -186,6 +186,7 @@ config ARCH_HAS_DEBUG_WX
 config DEBUG_WX
 	bool "Warn on W+X mappings at boot"
 	depends on ARCH_HAS_DEBUG_WX
+	depends on GENERIC_PTDUMP
 	depends on MMU
 	select PTDUMP_CORE
 	help
-- 
2.25.1

[PATCH V2 5/5] mm: Rename GENERIC_PTDUMP and PTDUMP_CORE

[Anshuman Khandual]

Platforms subscribe into generic ptdump implementation via GENERIC_PTDUMP.
But generic ptdump gets enabled via PTDUMP_CORE. These configs combination
is confusing as they sound very similar and does not differentiate between
platform's feature subscription and feature enablement for ptdump. Rename
the configs as ARCH_HAS_PTDUMP and PTDUMP making it more clear and improve
readability.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: kvmarm@lists.linux.dev
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/arm64/Kconfig              |  2 +-
 arch/arm64/include/asm/ptdump.h |  4 ++--
 arch/arm64/kvm/Kconfig          |  4 ++--
 arch/arm64/mm/Makefile          |  2 +-
 arch/powerpc/Kconfig            |  2 +-
 arch/powerpc/mm/Makefile        |  2 +-
 arch/riscv/Kconfig              |  2 +-
 arch/riscv/mm/Makefile          |  2 +-
 arch/s390/Kconfig               |  2 +-
 arch/s390/mm/Makefile           |  2 +-
 arch/x86/Kconfig                |  2 +-
 arch/x86/Kconfig.debug          |  2 +-
 arch/x86/mm/Makefile            |  2 +-
 mm/Kconfig.debug                | 12 ++++++------
 mm/Makefile                     |  2 +-
 15 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 940343beb3d4..5cf688ee01b7 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -41,6 +41,7 @@ config ARM64
 	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
+	select ARCH_HAS_PTDUMP
 	select ARCH_HAS_PTE_DEVMAP
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_HW_PTE_YOUNG
@@ -157,7 +158,6 @@ config ARM64
 	select GENERIC_IRQ_SHOW_LEVEL
 	select GENERIC_LIB_DEVMEM_IS_ALLOWED
 	select GENERIC_PCI_IOMAP
-	select GENERIC_PTDUMP
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
index 6cf4aae05219..b2931d1ae0fb 100644
--- a/arch/arm64/include/asm/ptdump.h
+++ b/arch/arm64/include/asm/ptdump.h
@@ -7,7 +7,7 @@
 
 #include <linux/ptdump.h>
 
-#ifdef CONFIG_PTDUMP_CORE
+#ifdef CONFIG_PTDUMP
 
 #include <linux/mm_types.h>
 #include <linux/seq_file.h>
@@ -70,6 +70,6 @@ static inline void ptdump_debugfs_register(struct ptdump_info *info,
 #else
 static inline void note_page(struct ptdump_state *pt_st, unsigned long addr,
 			     int level, u64 val) { }
-#endif /* CONFIG_PTDUMP_CORE */
+#endif /* CONFIG_PTDUMP */
 
 #endif /* __ASM_PTDUMP_H */
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index ead632ad01b4..096e45acadb2 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -71,8 +71,8 @@ config PTDUMP_STAGE2_DEBUGFS
 	depends on KVM
 	depends on DEBUG_KERNEL
 	depends on DEBUG_FS
-	depends on GENERIC_PTDUMP
-	select PTDUMP_CORE
+	depends on ARCH_HAS_PTDUMP
+	select PTDUMP
 	default n
 	help
 	  Say Y here if you want to show the stage-2 kernel pagetables
diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile
index fc92170a8f37..c26489cf96cd 100644
--- a/arch/arm64/mm/Makefile
+++ b/arch/arm64/mm/Makefile
@@ -5,7 +5,7 @@ obj-y				:= dma-mapping.o extable.o fault.o init.o \
 				   context.o proc.o pageattr.o fixmap.o
 obj-$(CONFIG_ARM64_CONTPTE)	+= contpte.o
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
-obj-$(CONFIG_PTDUMP_CORE)	+= ptdump.o
+obj-$(CONFIG_PTDUMP)		+= ptdump.o
 obj-$(CONFIG_PTDUMP_DEBUGFS)	+= ptdump_debugfs.o
 obj-$(CONFIG_TRANS_TABLE)	+= trans_pgd.o
 obj-$(CONFIG_TRANS_TABLE)	+= trans_pgd-asm.o
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 424f188e62d9..6f1ae41dcf85 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -148,6 +148,7 @@ config PPC
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_PMEM_API
 	select ARCH_HAS_PREEMPT_LAZY
+	select ARCH_HAS_PTDUMP
 	select ARCH_HAS_PTE_DEVMAP		if PPC_BOOK3S_64
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64
@@ -206,7 +207,6 @@ config PPC
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_SHOW_LEVEL
 	select GENERIC_PCI_IOMAP		if PCI
-	select GENERIC_PTDUMP
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_VDSO_TIME_NS
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index 0fe2f085c05a..8c1582b2987d 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -15,5 +15,5 @@ obj-$(CONFIG_NUMA) += numa.o
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
 obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o
 obj-$(CONFIG_PPC_COPRO_BASE)	+= copro_fault.o
-obj-$(CONFIG_PTDUMP_CORE)	+= ptdump/
+obj-$(CONFIG_PTDUMP)		+= ptdump/
 obj-$(CONFIG_KASAN)		+= kasan/
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 7612c52e9b1e..5aef2aa4103c 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -43,6 +43,7 @@ config RISCV
 	select ARCH_HAS_PMEM_API
 	select ARCH_HAS_PREEMPT_LAZY
 	select ARCH_HAS_PREPARE_SYNC_CORE_CMD
+	select ARCH_HAS_PTDUMP
 	select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_DIRECT_MAP if MMU
@@ -112,7 +113,6 @@ config RISCV
 	select GENERIC_IRQ_SHOW_LEVEL
 	select GENERIC_LIB_DEVMEM_IS_ALLOWED
 	select GENERIC_PCI_IOMAP
-	select GENERIC_PTDUMP if MMU
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
index cbe4d775ef56..b916a68d324a 100644
--- a/arch/riscv/mm/Makefile
+++ b/arch/riscv/mm/Makefile
@@ -19,7 +19,7 @@ obj-y += context.o
 obj-y += pmem.o
 
 obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
-obj-$(CONFIG_PTDUMP_CORE) += ptdump.o
+obj-$(CONFIG_PTDUMP) += ptdump.o
 obj-$(CONFIG_KASAN)   += kasan_init.o
 
 ifdef CONFIG_KASAN
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 9c9ec08d78c7..dd9dd2f8e673 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -96,6 +96,7 @@ config S390
 	select ARCH_HAS_MEM_ENCRYPT
 	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
 	select ARCH_HAS_PREEMPT_LAZY
+	select ARCH_HAS_PTDUMP
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SCALED_CPUTIME
 	select ARCH_HAS_SET_DIRECT_MAP
@@ -163,7 +164,6 @@ config S390
 	select GENERIC_CPU_VULNERABILITIES
 	select GENERIC_ENTRY
 	select GENERIC_GETTIMEOFDAY
-	select GENERIC_PTDUMP
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_VDSO_TIME_NS
diff --git a/arch/s390/mm/Makefile b/arch/s390/mm/Makefile
index f6c2db7a8669..9726b91fe7e4 100644
--- a/arch/s390/mm/Makefile
+++ b/arch/s390/mm/Makefile
@@ -9,6 +9,6 @@ obj-y		+= page-states.o pageattr.o pgtable.o pgalloc.o extable.o
 obj-$(CONFIG_CMM)		+= cmm.o
 obj-$(CONFIG_DEBUG_VIRTUAL)	+= physaddr.o
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
-obj-$(CONFIG_PTDUMP_CORE)	+= dump_pagetables.o
+obj-$(CONFIG_PTDUMP)		+= dump_pagetables.o
 obj-$(CONFIG_PGSTE)		+= gmap.o
 obj-$(CONFIG_PFAULT)		+= pfault.o
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index be2c311f5118..39ecafffc7e3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -26,6 +26,7 @@ config X86_64
 	depends on 64BIT
 	# Options that are inherently 64-bit kernel only:
 	select ARCH_HAS_GIGANTIC_PAGE
+	select ARCH_HAS_PTDUMP
 	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
 	select ARCH_SUPPORTS_PER_VMA_LOCK
 	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
@@ -174,7 +175,6 @@ config X86
 	select GENERIC_IRQ_RESERVATION_MODE
 	select GENERIC_IRQ_SHOW
 	select GENERIC_PENDING_IRQ		if SMP
-	select GENERIC_PTDUMP
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 1eb4d23cdaae..c95c3aaadf97 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -59,7 +59,7 @@ config EARLY_PRINTK_USB_XDBC
 config EFI_PGT_DUMP
 	bool "Dump the EFI pagetable"
 	depends on EFI
-	select PTDUMP_CORE
+	select PTDUMP
 	help
 	  Enable this if you want to dump the EFI page table before
 	  enabling virtual mode. This can be used to debug miscellaneous
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 690fbf48e853..e0c99a8760ca 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -39,7 +39,7 @@ CFLAGS_fault.o := -I $(src)/../include/asm/trace
 obj-$(CONFIG_X86_32)		+= pgtable_32.o iomap_32.o
 
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
-obj-$(CONFIG_PTDUMP_CORE)	+= dump_pagetables.o
+obj-$(CONFIG_PTDUMP)		+= dump_pagetables.o
 obj-$(CONFIG_PTDUMP_DEBUGFS)	+= debug_pagetables.o
 
 obj-$(CONFIG_HIGHMEM)		+= highmem_32.o
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index a51a1149909a..32b65073d0cc 100644
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -186,9 +186,9 @@ config ARCH_HAS_DEBUG_WX
 config DEBUG_WX
 	bool "Warn on W+X mappings at boot"
 	depends on ARCH_HAS_DEBUG_WX
-	depends on GENERIC_PTDUMP
+	depends on ARCH_HAS_PTDUMP
 	depends on MMU
-	select PTDUMP_CORE
+	select PTDUMP
 	help
 	  Generate a warning if any W+X mappings are found at boot.
 
@@ -213,18 +213,18 @@ config DEBUG_WX
 
 	  If in doubt, say "Y".
 
-config GENERIC_PTDUMP
+config ARCH_HAS_PTDUMP
 	bool
 
-config PTDUMP_CORE
+config PTDUMP
 	bool
 
 config PTDUMP_DEBUGFS
 	bool "Export kernel pagetable layout to userspace via debugfs"
 	depends on DEBUG_KERNEL
 	depends on DEBUG_FS
-	depends on GENERIC_PTDUMP
-	select PTDUMP_CORE
+	depends on ARCH_HAS_PTDUMP
+	select PTDUMP
 	help
 	  Say Y here if you want to show the kernel pagetable layout in a
 	  debugfs file. This information is only useful for kernel developers
diff --git a/mm/Makefile b/mm/Makefile
index 850386a67b3e..26dfecd4d396 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -138,7 +138,7 @@ obj-$(CONFIG_ZONE_DEVICE) += memremap.o
 obj-$(CONFIG_HMM_MIRROR) += hmm.o
 obj-$(CONFIG_MEMFD_CREATE) += memfd.o
 obj-$(CONFIG_MAPPING_DIRTY_HELPERS) += mapping_dirty_helpers.o
-obj-$(CONFIG_PTDUMP_CORE) += ptdump.o
+obj-$(CONFIG_PTDUMP) += ptdump.o
 obj-$(CONFIG_PAGE_REPORTING) += page_reporting.o
 obj-$(CONFIG_IO_MAPPING) += io-mapping.o
 obj-$(CONFIG_HAVE_BOOTMEM_INFO_NODE) += bootmem_info.o
-- 
2.25.1

Re: [PATCH V2 5/5] mm: Rename GENERIC_PTDUMP and PTDUMP_CORE

[Christophe Leroy]

Le 17/02/2025 à 05:22, Anshuman Khandual a écrit :
> Platforms subscribe into generic ptdump implementation via GENERIC_PTDUMP.
> But generic ptdump gets enabled via PTDUMP_CORE. These configs combination
> is confusing as they sound very similar and does not differentiate between
> platform's feature subscription and feature enablement for ptdump. Rename
> the configs as ARCH_HAS_PTDUMP and PTDUMP making it more clear and improve
> readability.
> 
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Nicholas Piggin <npiggin@gmail.com>
> Cc: Paul Walmsley <paul.walmsley@sifive.com>
> Cc: Palmer Dabbelt <palmer@dabbelt.com>
> Cc: Heiko Carstens <hca@linux.ibm.com>
> Cc: Vasily Gorbik <gor@linux.ibm.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-doc@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: kvmarm@lists.linux.dev
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-riscv@lists.infradead.org
> Cc: linux-s390@vger.kernel.org
> Cc: linux-mm@kvack.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 7612c52e9b1e..5aef2aa4103c 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -43,6 +43,7 @@ config RISCV
>   	select ARCH_HAS_PMEM_API
>   	select ARCH_HAS_PREEMPT_LAZY
>   	select ARCH_HAS_PREPARE_SYNC_CORE_CMD
> +	select ARCH_HAS_PTDUMP

Is it OK to drop the 'if MMU' from below ?

>   	select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU
>   	select ARCH_HAS_PTE_SPECIAL
>   	select ARCH_HAS_SET_DIRECT_MAP if MMU
> @@ -112,7 +113,6 @@ config RISCV
>   	select GENERIC_IRQ_SHOW_LEVEL
>   	select GENERIC_LIB_DEVMEM_IS_ALLOWED
>   	select GENERIC_PCI_IOMAP
> -	select GENERIC_PTDUMP if MMU
>   	select GENERIC_SCHED_CLOCK
>   	select GENERIC_SMP_IDLE_THREAD
>   	select GENERIC_TIME_VSYSCALL if MMU && 64BIT

Re: [PATCH V2 2/5] arch/powerpc: Drop GENERIC_PTDUMP from mpc885_ads_defconfig

[Christophe Leroy]

Le 17/02/2025 à 05:22, Anshuman Khandual a écrit :
> GENERIC_PTDUMP gets selected on powerpc explicitly and hence can be dropped
> off from mpc885_ads_defconfig.
> 
> Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Nicholas Piggin <npiggin@gmail.com>
> Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> Just wondering - Should CONFIG_PTDUMP_DEBUGFS be added instead ?

Yes please do that as a fix to commit e084728393a5 ("powerpc/ptdump: 
Convert powerpc to GENERIC_PTDUMP")

> 
>   arch/powerpc/configs/mpc885_ads_defconfig | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/arch/powerpc/configs/mpc885_ads_defconfig b/arch/powerpc/configs/mpc885_ads_defconfig
> index 77306be62e9e..ea6f836407d2 100644
> --- a/arch/powerpc/configs/mpc885_ads_defconfig
> +++ b/arch/powerpc/configs/mpc885_ads_defconfig
> @@ -78,4 +78,3 @@ CONFIG_DEBUG_VM_PGTABLE=y
>   CONFIG_DETECT_HUNG_TASK=y
>   CONFIG_BDI_SWITCH=y
>   CONFIG_PPC_EARLY_DEBUG=y
> -CONFIG_GENERIC_PTDUMP=y

Re: [PATCH V2 2/5] arch/powerpc: Drop GENERIC_PTDUMP from mpc885_ads_defconfig

[Anshuman Khandual]

On 2/24/25 17:34, Christophe Leroy wrote:
> 
> 
> Le 17/02/2025 à 05:22, Anshuman Khandual a écrit :
>> GENERIC_PTDUMP gets selected on powerpc explicitly and hence can be dropped
>> off from mpc885_ads_defconfig.
>>
>> Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: Nicholas Piggin <npiggin@gmail.com>
>> Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
>> Cc: linuxppc-dev@lists.ozlabs.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>> Just wondering - Should CONFIG_PTDUMP_DEBUGFS be added instead ?
> 
> Yes please do that as a fix to commit e084728393a5 ("powerpc/ptdump: Convert powerpc to GENERIC_PTDUMP")

Sure, does the following updated commit message look okay ?

arch/powerpc: Drop GENERIC_PTDUMP from mpc885_ads_defconfig

GENERIC_PTDUMP gets selected on powerpc explicitly and hence can be dropped
off from mpc885_ads_defconfig. Just add CONFIG_PTDUMP_DEBUGFS instead.

Fixes: e084728393a5 ("powerpc/ptdump: Convert powerpc to GENERIC_PTDUMP")
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>

> 
>>
>>   arch/powerpc/configs/mpc885_ads_defconfig | 1 -
>>   1 file changed, 1 deletion(-)
>>
>> diff --git a/arch/powerpc/configs/mpc885_ads_defconfig b/arch/powerpc/configs/mpc885_ads_defconfig
>> index 77306be62e9e..ea6f836407d2 100644
>> --- a/arch/powerpc/configs/mpc885_ads_defconfig
>> +++ b/arch/powerpc/configs/mpc885_ads_defconfig
>> @@ -78,4 +78,3 @@ CONFIG_DEBUG_VM_PGTABLE=y
>>   CONFIG_DETECT_HUNG_TASK=y
>>   CONFIG_BDI_SWITCH=y
>>   CONFIG_PPC_EARLY_DEBUG=y
>> -CONFIG_GENERIC_PTDUMP=y
> 

Re: [PATCH V2 5/5] mm: Rename GENERIC_PTDUMP and PTDUMP_CORE

[Anshuman Khandual]

On 2/24/25 17:31, Christophe Leroy wrote:
> 
> 
> Le 17/02/2025 à 05:22, Anshuman Khandual a écrit :
>> Platforms subscribe into generic ptdump implementation via GENERIC_PTDUMP.
>> But generic ptdump gets enabled via PTDUMP_CORE. These configs combination
>> is confusing as they sound very similar and does not differentiate between
>> platform's feature subscription and feature enablement for ptdump. Rename
>> the configs as ARCH_HAS_PTDUMP and PTDUMP making it more clear and improve
>> readability.
>>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Will Deacon <will@kernel.org>
>> Cc: Jonathan Corbet <corbet@lwn.net>
>> Cc: Marc Zyngier <maz@kernel.org>
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: Nicholas Piggin <npiggin@gmail.com>
>> Cc: Paul Walmsley <paul.walmsley@sifive.com>
>> Cc: Palmer Dabbelt <palmer@dabbelt.com>
>> Cc: Heiko Carstens <hca@linux.ibm.com>
>> Cc: Vasily Gorbik <gor@linux.ibm.com>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Ingo Molnar <mingo@redhat.com>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: linux-arm-kernel@lists.infradead.org
>> Cc: linux-doc@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org
>> Cc: kvmarm@lists.linux.dev
>> Cc: linuxppc-dev@lists.ozlabs.org
>> Cc: linux-riscv@lists.infradead.org
>> Cc: linux-s390@vger.kernel.org
>> Cc: linux-mm@kvack.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
>> index 7612c52e9b1e..5aef2aa4103c 100644
>> --- a/arch/riscv/Kconfig
>> +++ b/arch/riscv/Kconfig
>> @@ -43,6 +43,7 @@ config RISCV
>>       select ARCH_HAS_PMEM_API
>>       select ARCH_HAS_PREEMPT_LAZY
>>       select ARCH_HAS_PREPARE_SYNC_CORE_CMD
>> +    select ARCH_HAS_PTDUMP
> 
> Is it OK to drop the 'if MMU' from below ?

Sure, will add it back.

> 
>>       select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU
>>       select ARCH_HAS_PTE_SPECIAL
>>       select ARCH_HAS_SET_DIRECT_MAP if MMU
>> @@ -112,7 +113,6 @@ config RISCV
>>       select GENERIC_IRQ_SHOW_LEVEL
>>       select GENERIC_LIB_DEVMEM_IS_ALLOWED
>>       select GENERIC_PCI_IOMAP
>> -    select GENERIC_PTDUMP if MMU
>>       select GENERIC_SCHED_CLOCK
>>       select GENERIC_SMP_IDLE_THREAD
>>       select GENERIC_TIME_VSYSCALL if MMU && 64BIT