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From: Huang Pei <huangpei@loongson.cn>
To: Thomas Bogendoerfer <tsbogend@alpha.franken.de>, ambrosehua@gmail.com
Cc: Bibo Mao <maobibo@loongson.cn>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-mips@vger.kernel.org, linux-arch@vger.kernel.org,
	linux-mm@kvack.org, Jiaxun Yang <jiaxun.yang@flygoat.com>,
	Paul Burton <paulburton@kernel.org>,
	Li Xuefeng <lixuefeng@loongson.cn>,
	Yang Tiezhu <yangtiezhu@loongson.cn>,
	Gao Juxin <gaojuxin@loongson.cn>,
	Fuxin Zhang <zhangfx@lemote.com>, Huacai Chen <chenhc@lemote.com>
Subject: [PATCH v2] MIPS: make userspace mapping young by default
Date: Tue,  8 Sep 2020 10:16:47 +0800	[thread overview]
Message-ID: <20200908021647.21907-1-huangpei@loongson.cn> (raw)

MIPS page fault path take 3 exceptions (1 TLB Miss + 2 TLB Invalid), but
the second TLB Invalid exception is just triggered by __update_tlb from
do_page_fault writing tlb without _PAGE_VALID set. With this patch, it
only take 1 TLB Miss + 1 TLB Invalid exceptions

This version removes pte_sw_mkyoung without polluting MM code and makes
page fault delay of MIPS on par with other architecture and covers both
no-RIXI and RIXI MIPS CPUS

[1]: https://lkml.kernel.org/lkml/1591416169-26666-1-git-send-email
-maobibo@loongson.cn/

Co-developed-by: Huang Pei <huangpei@loongson.cn>
Signed-off-by: Huang Pei <huangpei@loongson.cn>
Co-developed-by: Bibo Mao <maobibo@loonson.cn>
---
V2:
- remove unused asm-generic definition of pte_sw_mkyoung following Mao's
advice
---
 arch/mips/include/asm/pgtable.h | 32 +++++++++++++++-----------------
 arch/mips/mm/cache.c            | 25 +++++++++++++------------
 include/linux/pgtable.h         |  8 --------
 mm/memory.c                     |  3 ---
 4 files changed, 28 insertions(+), 40 deletions(-)

diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index dd7a0f552cac..aaafe3d6a0a1 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -25,22 +25,22 @@
 struct mm_struct;
 struct vm_area_struct;
 
-#define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_NO_READ | \
-				 _page_cachable_default)
-#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_WRITE | \
-				 _page_cachable_default)
-#define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_NO_EXEC | \
-				 _page_cachable_default)
-#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | \
-				 _page_cachable_default)
-#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
-				 _PAGE_GLOBAL | _page_cachable_default)
-#define PAGE_KERNEL_NC	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
-				 _PAGE_GLOBAL | _CACHE_CACHABLE_NONCOHERENT)
-#define PAGE_USERIO	__pgprot(_PAGE_PRESENT | _PAGE_WRITE | \
-				 _page_cachable_default)
+#define PAGE_NONE      __pgprot(_PAGE_PRESENT | _PAGE_NO_READ | \
+                                _page_cachable_default)
+#define PAGE_SHARED    __pgprot(_PAGE_PRESENT | _PAGE_WRITE | \
+                                __READABLE | _page_cachable_default)
+#define PAGE_COPY      __pgprot(_PAGE_PRESENT | _PAGE_NO_EXEC | \
+                                __READABLE | _page_cachable_default)
+#define PAGE_READONLY  __pgprot(_PAGE_PRESENT |  __READABLE | \
+                                _page_cachable_default)
+#define PAGE_KERNEL    __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
+                                _PAGE_GLOBAL | _page_cachable_default)
+#define PAGE_KERNEL_NC __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
+                                _PAGE_GLOBAL | _CACHE_CACHABLE_NONCOHERENT)
+#define PAGE_USERIO    __pgprot(_PAGE_PRESENT | _PAGE_WRITE | \
+                                _page_cachable_default)
 #define PAGE_KERNEL_UNCACHED __pgprot(_PAGE_PRESENT | __READABLE | \
-			__WRITEABLE | _PAGE_GLOBAL | _CACHE_UNCACHED)
+                       __WRITEABLE | _PAGE_GLOBAL | _CACHE_UNCACHED)
 
 /*
  * If _PAGE_NO_EXEC is not defined, we can't do page protection for
@@ -414,8 +414,6 @@ static inline pte_t pte_mkyoung(pte_t pte)
 	return pte;
 }
 
-#define pte_sw_mkyoung	pte_mkyoung
-
 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 static inline int pte_huge(pte_t pte)	{ return pte_val(pte) & _PAGE_HUGE; }
 
diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c
index 3e81ba000096..ed75f2871aad 100644
--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -159,22 +159,23 @@ static inline void setup_protection_map(void)
 {
 	if (cpu_has_rixi) {
 		protection_map[0]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
-		protection_map[1]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
+		protection_map[1]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE);
 		protection_map[2]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
-		protection_map[3]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
-		protection_map[4]  = __pgprot(_page_cachable_default | _PAGE_PRESENT);
-		protection_map[5]  = __pgprot(_page_cachable_default | _PAGE_PRESENT);
-		protection_map[6]  = __pgprot(_page_cachable_default | _PAGE_PRESENT);
-		protection_map[7]  = __pgprot(_page_cachable_default | _PAGE_PRESENT);
+		protection_map[3]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE);
+		protection_map[4]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE);
+		protection_map[5]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE);
+		protection_map[6]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE);
+		protection_map[7]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE);
 
 		protection_map[8]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
-		protection_map[9]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
+		protection_map[9]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE);
 		protection_map[10] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | _PAGE_NO_READ);
-		protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE);
-		protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
-		protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
-		protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE);
-		protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE);
+		protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | __READABLE);
+		protection_map[12]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE);
+		protection_map[13]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE);
+		protection_map[14]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE);
+		protection_map[15]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE);
+
 
 	} else {
 		protection_map[0] = PAGE_NONE;
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index e8cbc2e795d5..ef9c5fa8673e 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -377,14 +377,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
  * To be differentiate with macro pte_mkyoung, this macro is used on platforms
  * where software maintains page access bit.
  */
-#ifndef pte_sw_mkyoung
-static inline pte_t pte_sw_mkyoung(pte_t pte)
-{
-	return pte;
-}
-#define pte_sw_mkyoung	pte_sw_mkyoung
-#endif
-
 #ifndef pte_savedwrite
 #define pte_savedwrite pte_write
 #endif
diff --git a/mm/memory.c b/mm/memory.c
index 602f4283122f..5100ab5bcf77 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2705,7 +2705,6 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
 		}
 		flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte));
 		entry = mk_pte(new_page, vma->vm_page_prot);
-		entry = pte_sw_mkyoung(entry);
 		entry = maybe_mkwrite(pte_mkdirty(entry), vma);
 		/*
 		 * Clear the pte entry and flush it first, before updating the
@@ -3386,7 +3385,6 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 	__SetPageUptodate(page);
 
 	entry = mk_pte(page, vma->vm_page_prot);
-	entry = pte_sw_mkyoung(entry);
 	if (vma->vm_flags & VM_WRITE)
 		entry = pte_mkwrite(pte_mkdirty(entry));
 
@@ -3661,7 +3659,6 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct page *page)
 
 	flush_icache_page(vma, page);
 	entry = mk_pte(page, vma->vm_page_prot);
-	entry = pte_sw_mkyoung(entry);
 	if (write)
 		entry = maybe_mkwrite(pte_mkdirty(entry), vma);
 	/* copy-on-write page */
-- 
2.17.1


             reply	other threads:[~2020-09-08  2:17 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-08  2:16 Huang Pei [this message]
2020-09-18 14:13 ` [PATCH v2] MIPS: make userspace mapping young by default Thomas Bogendoerfer

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