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From: Huacai Chen <chenhuacai@loongson.cn>
To: Andrew Morton <akpm@linux-foundation.org>,
	Huacai Chen <chenhuacai@kernel.org>
Cc: loongarch@lists.linux.dev,
	linux-mm@kvack.org,
	Xuefeng Li <lixuefeng@loongson.cn>,
	Guo Ren <guoren@kernel.org>,
	Xuerui Wang <kernel@xen0n.name>,
	Jiaxun Yang <jiaxun.yang@flygoat.com>,
	linux-kernel@vger.kernel.org,
	loongson-kernel@lists.loongnix.cn,
	Huacai Chen <chenhuacai@loongson.cn>
Subject: [PATCH 2/3] LoongArch: Make {virt, phys, page, pfn} translation work with KFENCE
Date: Thu,  4 Apr 2024 21:36:35 +0800
Message-ID: <20240404133642.971583-3-chenhuacai@loongson.cn>
In-Reply-To: <20240404133642.971583-1-chenhuacai@loongson.cn>
References: <20240404133642.971583-1-chenhuacai@loongson.cn>
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KFENCE changes virt_to_page() to be able to translate tlb mapped virtual
addresses, but forget to change virt_to_phys()/phys_to_virt() and other
translation functions as well. This patch fix it, otherwise some drivers
(such as nvme and virtio-blk) cannot work with KFENCE.

All {virt, phys, page, pfn} translation functions are updated:
1, virt_to_pfn()/pfn_to_virt();
2, virt_to_page()/page_to_virt();
3, virt_to_phys()/phys_to_virt().

DMW/TLB mapped addresses are distinguished by comparing the vaddress
with vm_map_base in virt_to_xyz(), and we define WANT_PAGE_VIRTUAL in
the KFENCE case for the reverse translations, xyz_to_virt().

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---
 arch/loongarch/include/asm/io.h     | 20 +++++++++++++++-----
 arch/loongarch/include/asm/kfence.h |  9 +++++++++
 arch/loongarch/include/asm/page.h   | 26 +++++++++++++++++++++++++-
 arch/loongarch/mm/pgtable.c         |  4 ++--
 4 files changed, 51 insertions(+), 8 deletions(-)

diff --git a/arch/loongarch/include/asm/io.h b/arch/loongarch/include/asm/io.h
index 4a8adcca329b..c2f9979b2979 100644
--- a/arch/loongarch/include/asm/io.h
+++ b/arch/loongarch/include/asm/io.h
@@ -14,11 +14,6 @@
 #include <asm/pgtable-bits.h>
 #include <asm/string.h>
 
-/*
- * Change "struct page" to physical address.
- */
-#define page_to_phys(page)	((phys_addr_t)page_to_pfn(page) << PAGE_SHIFT)
-
 extern void __init __iomem *early_ioremap(u64 phys_addr, unsigned long size);
 extern void __init early_iounmap(void __iomem *addr, unsigned long size);
 
@@ -73,6 +68,21 @@ extern void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t
 
 #define __io_aw() mmiowb()
 
+#ifdef CONFIG_KFENCE
+#define virt_to_phys(kaddr)								\
+({											\
+	(likely((unsigned long)kaddr < vm_map_base)) ? __pa((unsigned long)kaddr) :	\
+	page_to_phys(tlb_virt_to_page((unsigned long)kaddr)) + offset_in_page((unsigned long)kaddr);\
+})
+
+#define phys_to_virt(paddr)								\
+({											\
+	extern char *__kfence_pool;							\
+	(unlikely(__kfence_pool == NULL)) ? __va((unsigned long)paddr) :		\
+	page_address(phys_to_page((unsigned long)paddr)) + offset_in_page((unsigned long)paddr);\
+})
+#endif
+
 #include <asm-generic/io.h>
 
 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
diff --git a/arch/loongarch/include/asm/kfence.h b/arch/loongarch/include/asm/kfence.h
index 6c82aea1c993..a6a5760da3a3 100644
--- a/arch/loongarch/include/asm/kfence.h
+++ b/arch/loongarch/include/asm/kfence.h
@@ -16,6 +16,7 @@
 static inline bool arch_kfence_init_pool(void)
 {
 	int err;
+	char *kaddr, *vaddr;
 	char *kfence_pool = __kfence_pool;
 	struct vm_struct *area;
 
@@ -35,6 +36,14 @@ static inline bool arch_kfence_init_pool(void)
 		return false;
 	}
 
+	kaddr = kfence_pool;
+	vaddr = __kfence_pool;
+	while (kaddr < kfence_pool + KFENCE_POOL_SIZE) {
+		set_page_address(virt_to_page(kaddr), vaddr);
+		kaddr += PAGE_SIZE;
+		vaddr += PAGE_SIZE;
+	}
+
 	return true;
 }
 
diff --git a/arch/loongarch/include/asm/page.h b/arch/loongarch/include/asm/page.h
index 44027060c54a..e85df33f11c7 100644
--- a/arch/loongarch/include/asm/page.h
+++ b/arch/loongarch/include/asm/page.h
@@ -78,7 +78,26 @@ typedef struct { unsigned long pgprot; } pgprot_t;
 struct page *dmw_virt_to_page(unsigned long kaddr);
 struct page *tlb_virt_to_page(unsigned long kaddr);
 
-#define virt_to_pfn(kaddr)	PFN_DOWN(PHYSADDR(kaddr))
+#define pfn_to_phys(pfn)	__pfn_to_phys(pfn)
+#define phys_to_pfn(paddr)	__phys_to_pfn(paddr)
+
+#define page_to_phys(page)	pfn_to_phys(page_to_pfn(page))
+#define phys_to_page(paddr)	pfn_to_page(phys_to_pfn(paddr))
+
+#ifndef CONFIG_KFENCE
+
+#define page_to_virt(page)	__va(page_to_phys(page))
+#define virt_to_page(kaddr)	phys_to_page(__pa(kaddr))
+
+#else
+
+#define WANT_PAGE_VIRTUAL
+
+#define page_to_virt(page)								\
+({											\
+	extern char *__kfence_pool;							\
+	(__kfence_pool == NULL) ? __va(page_to_phys(page)) : page_address(page);	\
+})
 
 #define virt_to_page(kaddr)								\
 ({											\
@@ -86,6 +105,11 @@ struct page *tlb_virt_to_page(unsigned long kaddr);
 	dmw_virt_to_page((unsigned long)kaddr) : tlb_virt_to_page((unsigned long)kaddr);\
 })
 
+#endif
+
+#define pfn_to_virt(pfn)	page_to_virt(pfn_to_page(pfn))
+#define virt_to_pfn(kaddr)	page_to_pfn(virt_to_page(kaddr))
+
 extern int __virt_addr_valid(volatile void *kaddr);
 #define virt_addr_valid(kaddr)	__virt_addr_valid((volatile void *)(kaddr))
 
diff --git a/arch/loongarch/mm/pgtable.c b/arch/loongarch/mm/pgtable.c
index 2aae72e63871..bda018150000 100644
--- a/arch/loongarch/mm/pgtable.c
+++ b/arch/loongarch/mm/pgtable.c
@@ -11,13 +11,13 @@
 
 struct page *dmw_virt_to_page(unsigned long kaddr)
 {
-	return pfn_to_page(virt_to_pfn(kaddr));
+	return phys_to_page(__pa(kaddr));
 }
 EXPORT_SYMBOL(dmw_virt_to_page);
 
 struct page *tlb_virt_to_page(unsigned long kaddr)
 {
-	return pfn_to_page(pte_pfn(*virt_to_kpte(kaddr)));
+	return phys_to_page(pfn_to_phys(pte_pfn(*virt_to_kpte(kaddr))));
 }
 EXPORT_SYMBOL(tlb_virt_to_page);
 
-- 
2.43.0