LoongArch: Add memory management

Add memory management support for LoongArch, including: cache and tlb
management, page fault handling and ioremap/mmap support.

Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

arch/loongarch/include/asm/cache.h

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_CACHE_H
+#define _ASM_CACHE_H
+
+#define L1_CACHE_SHIFT		CONFIG_L1_CACHE_SHIFT
+#define L1_CACHE_BYTES		(1 << L1_CACHE_SHIFT)
+
+#define __read_mostly __section(".data..read_mostly")
+
+#endif /* _ASM_CACHE_H */

arch/loongarch/include/asm/cacheflush.h

@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_CACHEFLUSH_H
+#define _ASM_CACHEFLUSH_H
+
+#include <linux/mm.h>
+#include <asm/cpu-features.h>
+#include <asm/cacheops.h>
+
+extern void local_flush_icache_range(unsigned long start, unsigned long end);
+
+#define flush_icache_range	local_flush_icache_range
+#define flush_icache_user_range	local_flush_icache_range
+
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
+
+#define flush_cache_all()				do { } while (0)
+#define flush_cache_mm(mm)				do { } while (0)
+#define flush_cache_dup_mm(mm)				do { } while (0)
+#define flush_cache_range(vma, start, end)		do { } while (0)
+#define flush_cache_page(vma, vmaddr, pfn)		do { } while (0)
+#define flush_cache_vmap(start, end)			do { } while (0)
+#define flush_cache_vunmap(start, end)			do { } while (0)
+#define flush_icache_page(vma, page)			do { } while (0)
+#define flush_icache_user_page(vma, page, addr, len)	do { } while (0)
+#define flush_dcache_page(page)				do { } while (0)
+#define flush_dcache_mmap_lock(mapping)			do { } while (0)
+#define flush_dcache_mmap_unlock(mapping)		do { } while (0)
+
+#define cache_op(op, addr)						\
+	__asm__ __volatile__(						\
+	"	cacop	%0, %1					\n"	\
+	:								\
+	: "i" (op), "ZC" (*(unsigned char *)(addr)))
+
+static inline void flush_icache_line_indexed(unsigned long addr)
+{
+	cache_op(Index_Invalidate_I, addr);
+}
+
+static inline void flush_dcache_line_indexed(unsigned long addr)
+{
+	cache_op(Index_Writeback_Inv_D, addr);
+}
+
+static inline void flush_vcache_line_indexed(unsigned long addr)
+{
+	cache_op(Index_Writeback_Inv_V, addr);
+}
+
+static inline void flush_scache_line_indexed(unsigned long addr)
+{
+	cache_op(Index_Writeback_Inv_S, addr);
+}
+
+static inline void flush_icache_line(unsigned long addr)
+{
+	cache_op(Hit_Invalidate_I, addr);
+}
+
+static inline void flush_dcache_line(unsigned long addr)
+{
+	cache_op(Hit_Writeback_Inv_D, addr);
+}
+
+static inline void flush_vcache_line(unsigned long addr)
+{
+	cache_op(Hit_Writeback_Inv_V, addr);
+}
+
+static inline void flush_scache_line(unsigned long addr)
+{
+	cache_op(Hit_Writeback_Inv_S, addr);
+}
+
+#include <asm-generic/cacheflush.h>
+
+#endif /* _ASM_CACHEFLUSH_H */

arch/loongarch/include/asm/cacheops.h

@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Cache operations for the cache instruction.
+ *
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_CACHEOPS_H
+#define __ASM_CACHEOPS_H
+
+/*
+ * Most cache ops are split into a 2 bit field identifying the cache, and a 3
+ * bit field identifying the cache operation.
+ */
+#define CacheOp_Cache			0x03
+#define CacheOp_Op			0x1c
+
+#define Cache_I				0x00
+#define Cache_D				0x01
+#define Cache_V				0x02
+#define Cache_S				0x03
+
+#define Index_Invalidate		0x08
+#define Index_Writeback_Inv		0x08
+#define Hit_Invalidate			0x10
+#define Hit_Writeback_Inv		0x10
+#define CacheOp_User_Defined		0x18
+
+#define Index_Invalidate_I		(Cache_I | Index_Invalidate)
+#define Index_Writeback_Inv_D		(Cache_D | Index_Writeback_Inv)
+#define Index_Writeback_Inv_V		(Cache_V | Index_Writeback_Inv)
+#define Index_Writeback_Inv_S		(Cache_S | Index_Writeback_Inv)
+#define Hit_Invalidate_I		(Cache_I | Hit_Invalidate)
+#define Hit_Writeback_Inv_D		(Cache_D | Hit_Writeback_Inv)
+#define Hit_Writeback_Inv_V		(Cache_V | Hit_Writeback_Inv)
+#define Hit_Writeback_Inv_S		(Cache_S | Hit_Writeback_Inv)
+
+#endif	/* __ASM_CACHEOPS_H */

arch/loongarch/include/asm/fixmap.h

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * fixmap.h: compile-time virtual memory allocation
+ *
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#ifndef _ASM_FIXMAP_H
+#define _ASM_FIXMAP_H
+
+#define NR_FIX_BTMAPS 64
+
+#endif

arch/loongarch/include/asm/hugetlb.h

@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#ifndef __ASM_HUGETLB_H
+#define __ASM_HUGETLB_H
+
+#include <asm/page.h>
+
+uint64_t pmd_to_entrylo(unsigned long pmd_val);
+
+#define __HAVE_ARCH_PREPARE_HUGEPAGE_RANGE
+static inline int prepare_hugepage_range(struct file *file,
+					 unsigned long addr,
+					 unsigned long len)
+{
+	unsigned long task_size = STACK_TOP;
+	struct hstate *h = hstate_file(file);
+
+	if (len & ~huge_page_mask(h))
+		return -EINVAL;
+	if (addr & ~huge_page_mask(h))
+		return -EINVAL;
+	if (len > task_size)
+		return -ENOMEM;
+	if (task_size - len < addr)
+		return -EINVAL;
+	return 0;
+}
+
+#define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
+static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+					    unsigned long addr, pte_t *ptep)
+{
+	pte_t clear;
+	pte_t pte = *ptep;
+
+	pte_val(clear) = (unsigned long)invalid_pte_table;
+	set_pte_at(mm, addr, ptep, clear);
+	return pte;
+}
+
+#define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
+static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
+					  unsigned long addr, pte_t *ptep)
+{
+	pte_t pte;
+
+	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+	flush_tlb_page(vma, addr);
+	return pte;
+}
+
+#define __HAVE_ARCH_HUGE_PTE_NONE
+static inline int huge_pte_none(pte_t pte)
+{
+	unsigned long val = pte_val(pte) & ~_PAGE_GLOBAL;
+	return !val || (val == (unsigned long)invalid_pte_table);
+}
+
+#define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
+static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
+					     unsigned long addr,
+					     pte_t *ptep, pte_t pte,
+					     int dirty)
+{
+	int changed = !pte_same(*ptep, pte);
+
+	if (changed) {
+		set_pte_at(vma->vm_mm, addr, ptep, pte);
+		/*
+		 * There could be some standard sized pages in there,
+		 * get them all.
+		 */
+		flush_tlb_range(vma, addr, addr + HPAGE_SIZE);
+	}
+	return changed;
+}
+
+#include <asm-generic/hugetlb.h>
+
+#endif /* __ASM_HUGETLB_H */

arch/loongarch/include/asm/page.h

@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_PAGE_H
+#define _ASM_PAGE_H
+
+#include <linux/const.h>
+
+/*
+ * PAGE_SHIFT determines the page size
+ */
+#ifdef CONFIG_PAGE_SIZE_4KB
+#define PAGE_SHIFT	12
+#endif
+#ifdef CONFIG_PAGE_SIZE_16KB
+#define PAGE_SHIFT	14
+#endif
+#ifdef CONFIG_PAGE_SIZE_64KB
+#define PAGE_SHIFT	16
+#endif
+#define PAGE_SIZE	(_AC(1, UL) << PAGE_SHIFT)
+#define PAGE_MASK	(~(PAGE_SIZE - 1))
+
+#define HPAGE_SHIFT	(PAGE_SHIFT + PAGE_SHIFT - 3)
+#define HPAGE_SIZE	(_AC(1, UL) << HPAGE_SHIFT)
+#define HPAGE_MASK	(~(HPAGE_SIZE - 1))
+#define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
+
+#ifndef __ASSEMBLY__
+
+#include <linux/kernel.h>
+#include <linux/pfn.h>
+
+#define MAX_DMA32_PFN  (1UL << (32 - PAGE_SHIFT))
+
+/*
+ * It's normally defined only for FLATMEM config but it's
+ * used in our early mem init code for all memory models.
+ * So always define it.
+ */
+#define ARCH_PFN_OFFSET	PFN_UP(PHYS_OFFSET)
+
+extern void clear_page(void *page);
+extern void copy_page(void *to, void *from);
+
+#define clear_user_page(page, vaddr, pg)	clear_page(page)
+#define copy_user_page(to, from, vaddr, pg)	copy_page(to, from)
+
+extern unsigned long shm_align_mask;
+
+struct page;
+struct vm_area_struct;
+void copy_user_highpage(struct page *to, struct page *from,
+	      unsigned long vaddr, struct vm_area_struct *vma);
+
+#define __HAVE_ARCH_COPY_USER_HIGHPAGE
+
+typedef struct { unsigned long pte; } pte_t;
+#define pte_val(x)	((x).pte)
+#define __pte(x)	((pte_t) { (x) })
+typedef struct page *pgtable_t;
+
+typedef struct { unsigned long pgd; } pgd_t;
+#define pgd_val(x)	((x).pgd)
+#define __pgd(x)	((pgd_t) { (x) })
+
+/*
+ * Manipulate page protection bits
+ */
+typedef struct { unsigned long pgprot; } pgprot_t;
+#define pgprot_val(x)	((x).pgprot)
+#define __pgprot(x)	((pgprot_t) { (x) })
+#define pte_pgprot(x)	__pgprot(pte_val(x) & ~_PFN_MASK)
+
+#define ptep_buddy(x)	((pte_t *)((unsigned long)(x) ^ sizeof(pte_t)))
+
+/*
+ * __pa()/__va() should be used only during mem init.
+ */
+#define __pa(x)		PHYSADDR(x)
+#define __va(x)		((void *)((unsigned long)(x) + PAGE_OFFSET - PHYS_OFFSET))
+
+#define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
+
+#ifdef CONFIG_FLATMEM
+
+static inline int pfn_valid(unsigned long pfn)
+{
+	/* avoid <linux/mm.h> include hell */
+	extern unsigned long max_mapnr;
+	unsigned long pfn_offset = ARCH_PFN_OFFSET;
+
+	return pfn >= pfn_offset && pfn < max_mapnr;
+}
+
+#endif
+
+#define virt_to_pfn(kaddr)	PFN_DOWN(virt_to_phys((void *)(kaddr)))
+#define virt_to_page(kaddr)	pfn_to_page(virt_to_pfn(kaddr))
+
+extern int __virt_addr_valid(volatile void *kaddr);
+#define virt_addr_valid(kaddr)	__virt_addr_valid((volatile void *)(kaddr))
+
+#define VM_DATA_DEFAULT_FLAGS \
+	(VM_READ | VM_WRITE | \
+	 ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
+	 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+
+#include <asm-generic/memory_model.h>
+#include <asm-generic/getorder.h>
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_PAGE_H */