diff mbox series

[3/3] riscv: convert pgtable_l4_enabled to static key

Message ID 20220125165036.987-4-jszhang@kernel.org (mailing list archive)
State New, archived
Headers show
Series unified way to use static key and optimize pgtable_l4_enabled | expand

Commit Message

Jisheng Zhang Jan. 25, 2022, 4:50 p.m. UTC 
On a specific HW platform, pgtable_l4_enabled won't change after
boot, and the check sits at hot code path, this characteristic make it
suitable for optimization with static key.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
 arch/riscv/include/asm/cpufeature.h |  6 ++++++
 arch/riscv/include/asm/pgalloc.h    |  8 ++++----
 arch/riscv/include/asm/pgtable-64.h | 21 ++++++++++-----------
 arch/riscv/include/asm/pgtable.h    |  3 +--
 arch/riscv/kernel/cpu.c             |  2 +-
 arch/riscv/mm/init.c                | 23 ++++++++++-------------
 arch/riscv/mm/kasan_init.c          |  6 +++---
 arch/riscv/tools/cpucaps            |  1 +
 8 files changed, 36 insertions(+), 34 deletions(-)

Comments

kernel test robot Jan. 25, 2022, 9:30 p.m. UTC | #1 
Hi Jisheng,

I love your patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v5.17-rc1 next-20220125]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jisheng-Zhang/unified-way-to-use-static-key-and-optimize-pgtable_l4_enabled/20220126-010230
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git a08b41ab9e2e468647f78eb17c28e29b93006394
config: riscv-randconfig-r012-20220124 (https://download.01.org/0day-ci/archive/20220126/202201260555.SwYGWcoq-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 997e128e2a78f5a5434fc75997441ae1ee76f8a4)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/0day-ci/linux/commit/6822380e5bcac6d3edfa5d0723d829db8ec28405
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jisheng-Zhang/unified-way-to-use-static-key-and-optimize-pgtable_l4_enabled/20220126-010230
        git checkout 6822380e5bcac6d3edfa5d0723d829db8ec28405
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash arch/riscv/mm/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> arch/riscv/mm/init.c:691:6: error: implicit declaration of function 'system_supports_sv48' [-Werror,-Wimplicit-function-declaration]
           if (system_supports_sv48()) {
               ^
   arch/riscv/mm/init.c:721:13: warning: no previous prototype for function 'pt_ops_set_early' [-Wmissing-prototypes]
   void __init pt_ops_set_early(void)
               ^
   arch/riscv/mm/init.c:721:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void __init pt_ops_set_early(void)
   ^
   static 
   arch/riscv/mm/init.c:741:13: warning: no previous prototype for function 'pt_ops_set_fixmap' [-Wmissing-prototypes]
   void __init pt_ops_set_fixmap(void)
               ^
   arch/riscv/mm/init.c:741:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void __init pt_ops_set_fixmap(void)
   ^
   static 
   arch/riscv/mm/init.c:757:13: warning: no previous prototype for function 'pt_ops_set_late' [-Wmissing-prototypes]
   void __init pt_ops_set_late(void)
               ^
   arch/riscv/mm/init.c:757:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void __init pt_ops_set_late(void)
   ^
   static 
   3 warnings and 1 error generated.


vim +/system_supports_sv48 +691 arch/riscv/mm/init.c

   675	
   676	/*
   677	 * Setup a 4MB mapping that encompasses the device tree: for 64-bit kernel,
   678	 * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR
   679	 * entry.
   680	 */
   681	static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
   682	{
   683	#ifndef CONFIG_BUILTIN_DTB
   684		uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);
   685	
   686		create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
   687				   IS_ENABLED(CONFIG_64BIT) ? early_dtb_pgd_next : pa,
   688				   PGDIR_SIZE,
   689				   IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL);
   690	
 > 691		if (system_supports_sv48()) {
   692			create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA,
   693					   (uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE);
   694		}
   695	
   696		if (IS_ENABLED(CONFIG_64BIT)) {
   697			create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
   698					   pa, PMD_SIZE, PAGE_KERNEL);
   699			create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE,
   700					   pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
   701		}
   702	
   703		dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1));
   704	#else
   705		/*
   706		 * For 64-bit kernel, __va can't be used since it would return a linear
   707		 * mapping address whereas dtb_early_va will be used before
   708		 * setup_vm_final installs the linear mapping. For 32-bit kernel, as the
   709		 * kernel is mapped in the linear mapping, that makes no difference.
   710		 */
   711		dtb_early_va = kernel_mapping_pa_to_va(XIP_FIXUP(dtb_pa));
   712	#endif
   713	
   714		dtb_early_pa = dtb_pa;
   715	}
   716	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
kernel test robot Jan. 26, 2022, 2:42 a.m. UTC | #2 
Hi Jisheng,

I love your patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v5.17-rc1 next-20220125]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jisheng-Zhang/unified-way-to-use-static-key-and-optimize-pgtable_l4_enabled/20220126-010230
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git a08b41ab9e2e468647f78eb17c28e29b93006394
config: riscv-randconfig-p001-20220124 (https://download.01.org/0day-ci/archive/20220126/202201261008.l5nSsAdd-lkp@intel.com/config)
compiler: riscv32-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/6822380e5bcac6d3edfa5d0723d829db8ec28405
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jisheng-Zhang/unified-way-to-use-static-key-and-optimize-pgtable_l4_enabled/20220126-010230
        git checkout 6822380e5bcac6d3edfa5d0723d829db8ec28405
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=riscv SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   arch/riscv/mm/init.c: In function 'create_fdt_early_page_table':
>> arch/riscv/mm/init.c:691:13: error: implicit declaration of function 'system_supports_sv48' [-Werror=implicit-function-declaration]
     691 |         if (system_supports_sv48()) {
         |             ^~~~~~~~~~~~~~~~~~~~
   arch/riscv/mm/init.c: At top level:
   arch/riscv/mm/init.c:721:13: warning: no previous prototype for 'pt_ops_set_early' [-Wmissing-prototypes]
     721 | void __init pt_ops_set_early(void)
         |             ^~~~~~~~~~~~~~~~
   arch/riscv/mm/init.c:741:13: warning: no previous prototype for 'pt_ops_set_fixmap' [-Wmissing-prototypes]
     741 | void __init pt_ops_set_fixmap(void)
         |             ^~~~~~~~~~~~~~~~~
   arch/riscv/mm/init.c:757:13: warning: no previous prototype for 'pt_ops_set_late' [-Wmissing-prototypes]
     757 | void __init pt_ops_set_late(void)
         |             ^~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +/system_supports_sv48 +691 arch/riscv/mm/init.c

   675	
   676	/*
   677	 * Setup a 4MB mapping that encompasses the device tree: for 64-bit kernel,
   678	 * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR
   679	 * entry.
   680	 */
   681	static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
   682	{
   683	#ifndef CONFIG_BUILTIN_DTB
   684		uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);
   685	
   686		create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
   687				   IS_ENABLED(CONFIG_64BIT) ? early_dtb_pgd_next : pa,
   688				   PGDIR_SIZE,
   689				   IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL);
   690	
 > 691		if (system_supports_sv48()) {
   692			create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA,
   693					   (uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE);
   694		}
   695	
   696		if (IS_ENABLED(CONFIG_64BIT)) {
   697			create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
   698					   pa, PMD_SIZE, PAGE_KERNEL);
   699			create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE,
   700					   pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
   701		}
   702	
   703		dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1));
   704	#else
   705		/*
   706		 * For 64-bit kernel, __va can't be used since it would return a linear
   707		 * mapping address whereas dtb_early_va will be used before
   708		 * setup_vm_final installs the linear mapping. For 32-bit kernel, as the
   709		 * kernel is mapped in the linear mapping, that makes no difference.
   710		 */
   711		dtb_early_va = kernel_mapping_pa_to_va(XIP_FIXUP(dtb_pa));
   712	#endif
   713	
   714		dtb_early_pa = dtb_pa;
   715	}
   716	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff mbox series

Patch

diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
index 634a653c7fa2..10af83d6fb2a 100644
--- a/arch/riscv/include/asm/cpufeature.h
+++ b/arch/riscv/include/asm/cpufeature.h
@@ -96,4 +96,10 @@  static inline bool system_supports_fpu(void)
 	return IS_ENABLED(CONFIG_FPU) && !cpus_have_final_cap(RISCV_HAS_NO_FPU);
 }
 
+static inline bool system_supports_sv48(void)
+{
+	return IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL) &&
+		!cpus_have_const_cap(RISCV_HAS_NO_SV48);
+}
+
 #endif
diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
index 11823004b87a..cd37f3777ff1 100644
--- a/arch/riscv/include/asm/pgalloc.h
+++ b/arch/riscv/include/asm/pgalloc.h
@@ -41,7 +41,7 @@  static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 
 static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
 {
-	if (pgtable_l4_enabled) {
+	if (system_supports_sv48()) {
 		unsigned long pfn = virt_to_pfn(pud);
 
 		set_p4d(p4d, __p4d((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
@@ -51,7 +51,7 @@  static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
 static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d,
 				     pud_t *pud)
 {
-	if (pgtable_l4_enabled) {
+	if (system_supports_sv48()) {
 		unsigned long pfn = virt_to_pfn(pud);
 
 		set_p4d_safe(p4d,
@@ -62,7 +62,7 @@  static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d,
 #define pud_alloc_one pud_alloc_one
 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		return __pud_alloc_one(mm, addr);
 
 	return NULL;
@@ -71,7 +71,7 @@  static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
 #define pud_free pud_free
 static inline void pud_free(struct mm_struct *mm, pud_t *pud)
 {
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		__pud_free(mm, pud);
 }
 
diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
index bbbdd66e5e2f..5ad4311f9c6e 100644
--- a/arch/riscv/include/asm/pgtable-64.h
+++ b/arch/riscv/include/asm/pgtable-64.h
@@ -7,14 +7,13 @@ 
 #define _ASM_RISCV_PGTABLE_64_H
 
 #include <linux/const.h>
-
-extern bool pgtable_l4_enabled;
+#include <asm/cpufeature.h>
 
 #define PGDIR_SHIFT_L3  30
 #define PGDIR_SHIFT_L4  39
 #define PGDIR_SIZE_L3   (_AC(1, UL) << PGDIR_SHIFT_L3)
 
-#define PGDIR_SHIFT     (pgtable_l4_enabled ? PGDIR_SHIFT_L4 : PGDIR_SHIFT_L3)
+#define PGDIR_SHIFT     (system_supports_sv48() ? PGDIR_SHIFT_L4 : PGDIR_SHIFT_L3)
 /* Size of region mapped by a page global directory */
 #define PGDIR_SIZE      (_AC(1, UL) << PGDIR_SHIFT)
 #define PGDIR_MASK      (~(PGDIR_SIZE - 1))
@@ -102,7 +101,7 @@  static inline struct page *pud_page(pud_t pud)
 #define mm_pud_folded  mm_pud_folded
 static inline bool mm_pud_folded(struct mm_struct *mm)
 {
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		return false;
 
 	return true;
@@ -130,7 +129,7 @@  static inline unsigned long _pmd_pfn(pmd_t pmd)
 
 static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
 {
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		*p4dp = p4d;
 	else
 		set_pud((pud_t *)p4dp, (pud_t){ p4d_val(p4d) });
@@ -138,7 +137,7 @@  static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
 
 static inline int p4d_none(p4d_t p4d)
 {
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		return (p4d_val(p4d) == 0);
 
 	return 0;
@@ -146,7 +145,7 @@  static inline int p4d_none(p4d_t p4d)
 
 static inline int p4d_present(p4d_t p4d)
 {
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		return (p4d_val(p4d) & _PAGE_PRESENT);
 
 	return 1;
@@ -154,7 +153,7 @@  static inline int p4d_present(p4d_t p4d)
 
 static inline int p4d_bad(p4d_t p4d)
 {
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		return !p4d_present(p4d);
 
 	return 0;
@@ -162,13 +161,13 @@  static inline int p4d_bad(p4d_t p4d)
 
 static inline void p4d_clear(p4d_t *p4d)
 {
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		set_p4d(p4d, __p4d(0));
 }
 
 static inline pud_t *p4d_pgtable(p4d_t p4d)
 {
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		return (pud_t *)pfn_to_virt(p4d_val(p4d) >> _PAGE_PFN_SHIFT);
 
 	return (pud_t *)pud_pgtable((pud_t) { p4d_val(p4d) });
@@ -184,7 +183,7 @@  static inline struct page *p4d_page(p4d_t p4d)
 #define pud_offset pud_offset
 static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
 {
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		return p4d_pgtable(*p4d) + pud_index(address);
 
 	return (pud_t *)p4d;
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 7e949f25c933..40d999950e5b 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -62,7 +62,7 @@ 
  * position vmemmap directly below the VMALLOC region.
  */
 #ifdef CONFIG_64BIT
-#define VA_BITS		(pgtable_l4_enabled ? 48 : 39)
+#define VA_BITS		(system_supports_sv48() ? 48 : 39)
 #else
 #define VA_BITS		32
 #endif
@@ -735,7 +735,6 @@  extern uintptr_t _dtb_early_pa;
 #define dtb_early_pa	_dtb_early_pa
 #endif /* CONFIG_XIP_KERNEL */
 extern u64 satp_mode;
-extern bool pgtable_l4_enabled;
 
 void paging_init(void);
 void misc_mem_init(void);
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index ad0a7e9f828b..ce38319232ec 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -79,7 +79,7 @@  static void print_mmu(struct seq_file *f)
 #if defined(CONFIG_32BIT)
 	strncpy(sv_type, "sv32", 5);
 #elif defined(CONFIG_64BIT)
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		strncpy(sv_type, "sv48", 5);
 	else
 		strncpy(sv_type, "sv39", 5);
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 35586688a1b6..8a84606f99f0 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -44,9 +44,6 @@  u64 satp_mode __ro_after_init = SATP_MODE_32;
 #endif
 EXPORT_SYMBOL(satp_mode);
 
-bool pgtable_l4_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
-EXPORT_SYMBOL(pgtable_l4_enabled);
-
 phys_addr_t phys_ram_base __ro_after_init;
 EXPORT_SYMBOL(phys_ram_base);
 
@@ -459,19 +456,19 @@  static void __init create_pud_mapping(pud_t *pudp,
 }
 
 #define pgd_next_t		pud_t
-#define alloc_pgd_next(__va)	(pgtable_l4_enabled ?			\
+#define alloc_pgd_next(__va)	(system_supports_sv48() ?			\
 		pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va))
-#define get_pgd_next_virt(__pa)	(pgtable_l4_enabled ?			\
+#define get_pgd_next_virt(__pa)	(system_supports_sv48() ?			\
 		pt_ops.get_pud_virt(__pa) : (pgd_next_t *)pt_ops.get_pmd_virt(__pa))
 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
-				(pgtable_l4_enabled ?			\
+				(system_supports_sv48() ?			\
 		create_pud_mapping(__nextp, __va, __pa, __sz, __prot) :	\
 		create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot))
-#define fixmap_pgd_next		(pgtable_l4_enabled ?			\
+#define fixmap_pgd_next		(system_supports_sv48() ?			\
 		(uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd)
-#define trampoline_pgd_next	(pgtable_l4_enabled ?			\
+#define trampoline_pgd_next	(system_supports_sv48() ?			\
 		(uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd)
-#define early_dtb_pgd_next	(pgtable_l4_enabled ?			\
+#define early_dtb_pgd_next	(system_supports_sv48() ?			\
 		(uintptr_t)early_dtb_pud : (uintptr_t)early_dtb_pmd)
 #else
 #define pgd_next_t		pte_t
@@ -575,7 +572,7 @@  static __init pgprot_t pgprot_from_va(uintptr_t va)
 #ifdef CONFIG_64BIT
 static void __init disable_pgtable_l4(void)
 {
-	pgtable_l4_enabled = false;
+	cpus_set_cap(RISCV_HAS_NO_SV48);
 	kernel_map.page_offset = PAGE_OFFSET_L3;
 	satp_mode = SATP_MODE_39;
 }
@@ -691,7 +688,7 @@  static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
 			   PGDIR_SIZE,
 			   IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL);
 
-	if (pgtable_l4_enabled) {
+	if (system_supports_sv48()) {
 		create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA,
 				   (uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE);
 	}
@@ -819,7 +816,7 @@  asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 
 #ifndef __PAGETABLE_PMD_FOLDED
 	/* Setup fixmap PUD and PMD */
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		create_pud_mapping(fixmap_pud, FIXADDR_START,
 				   (uintptr_t)fixmap_pmd, PUD_SIZE, PAGE_TABLE);
 	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
@@ -827,7 +824,7 @@  asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 	/* Setup trampoline PGD and PMD */
 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
 			   trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE);
-	if (pgtable_l4_enabled)
+	if (system_supports_sv48())
 		create_pud_mapping(trampoline_pud, kernel_map.virt_addr,
 				   (uintptr_t)trampoline_pmd, PUD_SIZE, PAGE_TABLE);
 #ifdef CONFIG_XIP_KERNEL
diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
index f61f7ca6fe0f..3d456c5b55c8 100644
--- a/arch/riscv/mm/kasan_init.c
+++ b/arch/riscv/mm/kasan_init.c
@@ -149,11 +149,11 @@  static void __init kasan_populate_pud(pgd_t *pgd,
 		set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(base_pud)), PAGE_TABLE));
 }
 
-#define kasan_early_shadow_pgd_next			(pgtable_l4_enabled ?	\
+#define kasan_early_shadow_pgd_next		(system_supports_sv48() ?	\
 				(uintptr_t)kasan_early_shadow_pud :		\
 				(uintptr_t)kasan_early_shadow_pmd)
 #define kasan_populate_pgd_next(pgdp, vaddr, next, early)			\
-		(pgtable_l4_enabled ?						\
+		(system_supports_sv48() ?					\
 			kasan_populate_pud(pgdp, vaddr, next, early) :		\
 			kasan_populate_pmd((pud_t *)pgdp, vaddr, next))
 
@@ -211,7 +211,7 @@  asmlinkage void __init kasan_early_init(void)
 				(__pa((uintptr_t)kasan_early_shadow_pte)),
 				PAGE_TABLE));
 
-	if (pgtable_l4_enabled) {
+	if (system_supports_sv48()) {
 		for (i = 0; i < PTRS_PER_PUD; ++i)
 			set_pud(kasan_early_shadow_pud + i,
 				pfn_pud(PFN_DOWN
diff --git a/arch/riscv/tools/cpucaps b/arch/riscv/tools/cpucaps
index cb1ff2747859..1aea959f225d 100644
--- a/arch/riscv/tools/cpucaps
+++ b/arch/riscv/tools/cpucaps
@@ -3,3 +3,4 @@ 
 # Internal CPU capabilities constants, keep this list sorted
 
 HAS_NO_FPU
+HAS_NO_SV48