[PATCH 6/6] Revert "arch: introduce set_direct_map_valid_noflush()"

["Mike Rapoport (Microsoft)" <rppt@kernel.org>]

Commit 0c6378a71574 ("arch: introduce set_direct_map_valid_noflush()")
added set_direct_map_valid_noflush() to allow updating the direct map
for a physically contiguous range in execmem.

As Brendan recently pointed out [1], this API is confusing because on
arm64 it means that is sets VALID bit in ptes, while on other
architectures it is an analog of set_direct_map_default_noflush().

The only user of set_direct_map_valid_noflush() was execmem's ROX cache
freeing path and it was switched to utilize VM_FLUSH_RESET_PERMS for
resetting permissions of the direct map alias.

With the last user gone and with set_direct_map_{invalid,default}_noflush()
accepting number of pages as a parameter, set_direct_map_valid_noflush()
become a copy of set_memory_valid() on arm64 and a duplicate of
set_direct_map_{invalid,default}_noflush() on other architecture, it is
safe to remove set_direct_map_valid_noflush().

Also drop a stale comment in arm64::__kernel_map_pages() that Linus
bothered to add when merging changes containing set_direct_map_valid_noflush()
to his tree.

This reverts commit 0c6378a71574daa6cd1534ad42a956e3262756c7.

[1] https://lore.kernel.org/all/DJ69RCVRBO0Y.3JCYSW50IC4RC@linux.dev

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 arch/arm64/include/asm/set_memory.h     |  1 -
 arch/arm64/mm/pageattr.c                | 16 ----------------
 arch/loongarch/include/asm/set_memory.h |  1 -
 arch/loongarch/mm/pageattr.c            | 19 -------------------
 arch/riscv/include/asm/set_memory.h     |  1 -
 arch/riscv/mm/pageattr.c                | 15 ---------------
 arch/s390/include/asm/set_memory.h      |  1 -
 arch/s390/mm/pageattr.c                 | 12 ------------
 arch/x86/include/asm/set_memory.h       |  1 -
 arch/x86/mm/pat/set_memory.c            |  8 --------
 include/linux/set_memory.h              |  6 ------
 11 files changed, 81 deletions(-)

diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h
index b07fd4e026ea..0091ba12200e 100644
--- a/arch/arm64/include/asm/set_memory.h
+++ b/arch/arm64/include/asm/set_memory.h
@@ -13,7 +13,6 @@ int set_memory_valid(unsigned long addr, int numpages, int enable);
 
 int set_direct_map_invalid_noflush(struct page *page, unsigned int numpages);
 int set_direct_map_default_noflush(struct page *page, unsigned int numpages);
-int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid);
 bool kernel_page_present(struct page *page);
 
 int set_memory_encrypted(unsigned long addr, int numpages);
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index db8d60a84d14..132938b32eb1 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -355,23 +355,7 @@ int realm_register_memory_enc_ops(void)
 	return arm64_mem_crypt_ops_register(&realm_crypt_ops);
 }
 
-int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
-{
-	unsigned long addr = (unsigned long)page_address(page);
-
-	if (!can_set_direct_map())
-		return 0;
-
-	return set_memory_valid(addr, nr, valid);
-}
-
 #ifdef CONFIG_DEBUG_PAGEALLOC
-/*
- * This is - apart from the return value - doing the same
- * thing as the new set_direct_map_valid_noflush() function.
- *
- * Unify? Explain the conceptual differences?
- */
 void __kernel_map_pages(struct page *page, int numpages, int enable)
 {
 	if (!can_set_direct_map())
diff --git a/arch/loongarch/include/asm/set_memory.h b/arch/loongarch/include/asm/set_memory.h
index 563aab92896e..4bb01172fbc2 100644
--- a/arch/loongarch/include/asm/set_memory.h
+++ b/arch/loongarch/include/asm/set_memory.h
@@ -17,6 +17,5 @@ int set_memory_rw(unsigned long addr, int numpages);
 bool kernel_page_present(struct page *page);
 int set_direct_map_default_noflush(struct page *page, unsigned int nr);
 int set_direct_map_invalid_noflush(struct page *page, unsigned int nr);
-int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid);
 
 #endif /* _ASM_LOONGARCH_SET_MEMORY_H */
diff --git a/arch/loongarch/mm/pageattr.c b/arch/loongarch/mm/pageattr.c
index 43ad2a104f19..a7dcff40f759 100644
--- a/arch/loongarch/mm/pageattr.c
+++ b/arch/loongarch/mm/pageattr.c
@@ -217,22 +217,3 @@ int set_direct_map_invalid_noflush(struct page *page, unsigned int nr)
 
 	return __set_memory(addr, nr, __pgprot(0), __pgprot(_PAGE_PRESENT | _PAGE_VALID));
 }
-
-int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
-{
-	unsigned long addr = (unsigned long)page_address(page);
-	pgprot_t set, clear;
-
-	if (addr < vm_map_base)
-		return 0;
-
-	if (valid) {
-		set = PAGE_KERNEL;
-		clear = __pgprot(0);
-	} else {
-		set = __pgprot(0);
-		clear = __pgprot(_PAGE_PRESENT | _PAGE_VALID);
-	}
-
-	return __set_memory(addr, nr, set, clear);
-}
diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h
index db1d0ed82b69..e9f9960c1947 100644
--- a/arch/riscv/include/asm/set_memory.h
+++ b/arch/riscv/include/asm/set_memory.h
@@ -42,7 +42,6 @@ static inline int set_kernel_memory(char *startp, char *endp,
 
 int set_direct_map_invalid_noflush(struct page *page, unsigned int nr);
 int set_direct_map_default_noflush(struct page *page, unsigned int nr);
-int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid);
 bool kernel_page_present(struct page *page);
 
 #endif /* __ASSEMBLER__ */
diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
index 20ef95b1d0c3..5b3cf326455d 100644
--- a/arch/riscv/mm/pageattr.c
+++ b/arch/riscv/mm/pageattr.c
@@ -386,21 +386,6 @@ int set_direct_map_default_noflush(struct page *page, unsigned int nr)
 			    PAGE_KERNEL, __pgprot(_PAGE_EXEC));
 }
 
-int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
-{
-	pgprot_t set, clear;
-
-	if (valid) {
-		set = PAGE_KERNEL;
-		clear = __pgprot(_PAGE_EXEC);
-	} else {
-		set = __pgprot(0);
-		clear = __pgprot(_PAGE_PRESENT);
-	}
-
-	return __set_memory((unsigned long)page_address(page), nr, set, clear);
-}
-
 #ifdef CONFIG_DEBUG_PAGEALLOC
 static int debug_pagealloc_set_page(pte_t *pte, unsigned long addr, void *data)
 {
diff --git a/arch/s390/include/asm/set_memory.h b/arch/s390/include/asm/set_memory.h
index 6b0aa9147ed8..e3562bf0c1aa 100644
--- a/arch/s390/include/asm/set_memory.h
+++ b/arch/s390/include/asm/set_memory.h
@@ -62,7 +62,6 @@ __SET_MEMORY_FUNC(set_memory_4k, SET_MEMORY_4K)
 
 int set_direct_map_invalid_noflush(struct page *page, unsigned int nr);
 int set_direct_map_default_noflush(struct page *page, unsigned int nr);
-int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid);
 bool kernel_page_present(struct page *page);
 
 #endif
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index 02d992b251cb..f46a666bc5c7 100644
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -397,18 +397,6 @@ int set_direct_map_default_noflush(struct page *page, unsigned int nr)
 	return __set_memory((unsigned long)page_to_virt(page), nr, SET_MEMORY_DEF);
 }
 
-int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
-{
-	unsigned long flags;
-
-	if (valid)
-		flags = SET_MEMORY_DEF;
-	else
-		flags = SET_MEMORY_INV;
-
-	return __set_memory((unsigned long)page_to_virt(page), nr, flags);
-}
-
 bool kernel_page_present(struct page *page)
 {
 	unsigned long addr;
diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index 0c4235d159f4..39271a5ea925 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -88,7 +88,6 @@ int set_pages_rw(struct page *page, int numpages);
 
 int set_direct_map_invalid_noflush(struct page *page, unsigned int nr);
 int set_direct_map_default_noflush(struct page *page, unsigned int nr);
-int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid);
 bool kernel_page_present(struct page *page);
 
 extern int kernel_set_to_readonly;
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 9022354e26e9..a6b2912a4837 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -2683,14 +2683,6 @@ int set_direct_map_default_noflush(struct page *page, unsigned int nr)
 	return __set_pages_p(page, nr);
 }
 
-int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
-{
-	if (valid)
-		return __set_pages_p(page, nr);
-
-	return __set_pages_np(page, nr);
-}
-
 #ifdef CONFIG_DEBUG_PAGEALLOC
 void __kernel_map_pages(struct page *page, int numpages, int enable)
 {
diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h
index 0b77f1d7d8b9..3fe293cfed8c 100644
--- a/include/linux/set_memory.h
+++ b/include/linux/set_memory.h
@@ -36,12 +36,6 @@ static inline int set_direct_map_default_noflush(struct page *page,
 	return 0;
 }
 
-static inline int set_direct_map_valid_noflush(struct page *page,
-					       unsigned nr, bool valid)
-{
-	return 0;
-}
-
 static inline bool kernel_page_present(struct page *page)
 {
 	return true;

-- 
2.53.0