1 files changed, 307 insertions, 0 deletions
diff --git a/arch/loongarch/mm/tlb.c b/arch/loongarch/mm/tlb.c
new file mode 100644
index 000000000..da3681f13
--- /dev/null
+++ b/arch/loongarch/mm/tlb.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/export.h>
+
+#include <asm/cpu.h>
+#include <asm/bootinfo.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/tlb.h>
+
+void local_flush_tlb_all(void)
+{
+	invtlb_all(INVTLB_CURRENT_ALL, 0, 0);
+}
+EXPORT_SYMBOL(local_flush_tlb_all);
+
+void local_flush_tlb_user(void)
+{
+	invtlb_all(INVTLB_CURRENT_GFALSE, 0, 0);
+}
+EXPORT_SYMBOL(local_flush_tlb_user);
+
+void local_flush_tlb_kernel(void)
+{
+	invtlb_all(INVTLB_CURRENT_GTRUE, 0, 0);
+}
+EXPORT_SYMBOL(local_flush_tlb_kernel);
+
+/*
+ * All entries common to a mm share an asid. To effectively flush
+ * these entries, we just bump the asid.
+ */
+void local_flush_tlb_mm(struct mm_struct *mm)
+{
+	int cpu;
+
+	preempt_disable();
+
+	cpu = smp_processor_id();
+
+	if (asid_valid(mm, cpu))
+		drop_mmu_context(mm, cpu);
+	else
+		cpumask_clear_cpu(cpu, mm_cpumask(mm));
+
+	preempt_enable();
+}
+
+void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+	unsigned long end)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	int cpu = smp_processor_id();
+
+	if (asid_valid(mm, cpu)) {
+		unsigned long size, flags;
+
+		local_irq_save(flags);
+		start = round_down(start, PAGE_SIZE << 1);
+		end = round_up(end, PAGE_SIZE << 1);
+		size = (end - start) >> (PAGE_SHIFT + 1);
+		if (size <= (current_cpu_data.tlbsizestlbsets ?
+			     current_cpu_data.tlbsize / 8 :
+			     current_cpu_data.tlbsize / 2)) {
+			int asid = cpu_asid(cpu, mm);
+
+			while (start < end) {
+				invtlb(INVTLB_ADDR_GFALSE_AND_ASID, asid, start);
+				start += (PAGE_SIZE << 1);
+			}
+		} else {
+			drop_mmu_context(mm, cpu);
+		}
+		local_irq_restore(flags);
+	} else {
+		cpumask_clear_cpu(cpu, mm_cpumask(mm));
+	}
+}
+
+void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+	unsigned long size, flags;
+
+	local_irq_save(flags);
+	size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
+	size = (size + 1) >> 1;
+	if (size <= (current_cpu_data.tlbsizestlbsets ?
+		     current_cpu_data.tlbsize / 8 :
+		     current_cpu_data.tlbsize / 2)) {
+
+		start &= (PAGE_MASK << 1);
+		end += ((PAGE_SIZE << 1) - 1);
+		end &= (PAGE_MASK << 1);
+
+		while (start < end) {
+			invtlb_addr(INVTLB_ADDR_GTRUE_OR_ASID, 0, start);
+			start += (PAGE_SIZE << 1);
+		}
+	} else {
+		local_flush_tlb_kernel();
+	}
+	local_irq_restore(flags);
+}
+
+void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+	int cpu = smp_processor_id();
+
+	if (asid_valid(vma->vm_mm, cpu)) {
+		int newpid;
+
+		newpid = cpu_asid(cpu, vma->vm_mm);
+		page &= (PAGE_MASK << 1);
+		invtlb(INVTLB_ADDR_GFALSE_AND_ASID, newpid, page);
+	} else {
+		cpumask_clear_cpu(cpu, mm_cpumask(vma->vm_mm));
+	}
+}
+
+/*
+ * This one is only used for pages with the global bit set so we don't care
+ * much about the ASID.
+ */
+void local_flush_tlb_one(unsigned long page)
+{
+	page &= (PAGE_MASK << 1);
+	invtlb_addr(INVTLB_ADDR_GTRUE_OR_ASID, 0, page);
+}
+
+static void __update_hugetlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
+{
+#ifdef CONFIG_HUGETLB_PAGE
+	int idx;
+	unsigned long lo;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	address &= (PAGE_MASK << 1);
+	write_csr_entryhi(address);
+	tlb_probe();
+	idx = read_csr_tlbidx();
+	write_csr_pagesize(PS_HUGE_SIZE);
+	lo = pmd_to_entrylo(pte_val(*ptep));
+	write_csr_entrylo0(lo);
+	write_csr_entrylo1(lo + (HPAGE_SIZE >> 1));
+
+	if (idx < 0)
+		tlb_write_random();
+	else
+		tlb_write_indexed();
+	write_csr_pagesize(PS_DEFAULT_SIZE);
+
+	local_irq_restore(flags);
+#endif
+}
+
+void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
+{
+	int idx;
+	unsigned long flags;
+
+	/*
+	 * Handle debugger faulting in for debugee.
+	 */
+	if (current->active_mm != vma->vm_mm)
+		return;
+
+	if (pte_val(*ptep) & _PAGE_HUGE) {
+		__update_hugetlb(vma, address, ptep);
+		return;
+	}
+
+	local_irq_save(flags);
+
+	if ((unsigned long)ptep & sizeof(pte_t))
+		ptep--;
+
+	address &= (PAGE_MASK << 1);
+	write_csr_entryhi(address);
+	tlb_probe();
+	idx = read_csr_tlbidx();
+	write_csr_pagesize(PS_DEFAULT_SIZE);
+	write_csr_entrylo0(pte_val(*ptep++));
+	write_csr_entrylo1(pte_val(*ptep));
+	if (idx < 0)
+		tlb_write_random();
+	else
+		tlb_write_indexed();
+
+	local_irq_restore(flags);
+}
+
+static void setup_ptwalker(void)
+{
+	unsigned long pwctl0, pwctl1;
+	unsigned long pgd_i = 0, pgd_w = 0;
+	unsigned long pud_i = 0, pud_w = 0;
+	unsigned long pmd_i = 0, pmd_w = 0;
+	unsigned long pte_i = 0, pte_w = 0;
+
+	pgd_i = PGDIR_SHIFT;
+	pgd_w = PAGE_SHIFT - 3;
+#if CONFIG_PGTABLE_LEVELS > 3
+	pud_i = PUD_SHIFT;
+	pud_w = PAGE_SHIFT - 3;
+#endif
+#if CONFIG_PGTABLE_LEVELS > 2
+	pmd_i = PMD_SHIFT;
+	pmd_w = PAGE_SHIFT - 3;
+#endif
+	pte_i = PAGE_SHIFT;
+	pte_w = PAGE_SHIFT - 3;
+
+	pwctl0 = pte_i | pte_w << 5 | pmd_i << 10 | pmd_w << 15 | pud_i << 20 | pud_w << 25;
+	pwctl1 = pgd_i | pgd_w << 6;
+
+	csr_write64(pwctl0, LOONGARCH_CSR_PWCTL0);
+	csr_write64(pwctl1, LOONGARCH_CSR_PWCTL1);
+	csr_write64((long)swapper_pg_dir, LOONGARCH_CSR_PGDH);
+	csr_write64((long)invalid_pg_dir, LOONGARCH_CSR_PGDL);
+	csr_write64((long)smp_processor_id(), LOONGARCH_CSR_TMID);
+}
+
+static void output_pgtable_bits_defines(void)
+{
+#define pr_define(fmt, ...)					\
+	pr_debug("#define " fmt, ##__VA_ARGS__)
+
+	pr_debug("#include <asm/asm.h>\n");
+	pr_debug("#include <asm/regdef.h>\n");
+	pr_debug("\n");
+
+	pr_define("_PAGE_VALID_SHIFT %d\n", _PAGE_VALID_SHIFT);
+	pr_define("_PAGE_DIRTY_SHIFT %d\n", _PAGE_DIRTY_SHIFT);
+	pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT);
+	pr_define("_PAGE_GLOBAL_SHIFT %d\n", _PAGE_GLOBAL_SHIFT);
+	pr_define("_PAGE_PRESENT_SHIFT %d\n", _PAGE_PRESENT_SHIFT);
+	pr_define("_PAGE_WRITE_SHIFT %d\n", _PAGE_WRITE_SHIFT);
+	pr_define("_PAGE_NO_READ_SHIFT %d\n", _PAGE_NO_READ_SHIFT);
+	pr_define("_PAGE_NO_EXEC_SHIFT %d\n", _PAGE_NO_EXEC_SHIFT);
+	pr_define("_PFN_SHIFT %d\n", _PFN_SHIFT);
+	pr_debug("\n");
+}
+
+#ifdef CONFIG_NUMA
+static unsigned long pcpu_handlers[NR_CPUS];
+#endif
+extern long exception_handlers[VECSIZE * 128 / sizeof(long)];
+
+void setup_tlb_handler(int cpu)
+{
+	setup_ptwalker();
+	local_flush_tlb_all();
+
+	/* The tlb handlers are generated only once */
+	if (cpu == 0) {
+		memcpy((void *)tlbrentry, handle_tlb_refill, 0x80);
+		local_flush_icache_range(tlbrentry, tlbrentry + 0x80);
+		set_handler(EXCCODE_TLBI * VECSIZE, handle_tlb_load, VECSIZE);
+		set_handler(EXCCODE_TLBL * VECSIZE, handle_tlb_load, VECSIZE);
+		set_handler(EXCCODE_TLBS * VECSIZE, handle_tlb_store, VECSIZE);
+		set_handler(EXCCODE_TLBM * VECSIZE, handle_tlb_modify, VECSIZE);
+		set_handler(EXCCODE_TLBNR * VECSIZE, handle_tlb_protect, VECSIZE);
+		set_handler(EXCCODE_TLBNX * VECSIZE, handle_tlb_protect, VECSIZE);
+		set_handler(EXCCODE_TLBPE * VECSIZE, handle_tlb_protect, VECSIZE);
+	}
+#ifdef CONFIG_NUMA
+	else {
+		void *addr;
+		struct page *page;
+		const int vec_sz = sizeof(exception_handlers);
+
+		if (pcpu_handlers[cpu])
+			return;
+
+		page = alloc_pages_node(cpu_to_node(cpu), GFP_ATOMIC, get_order(vec_sz));
+		if (!page)
+			return;
+
+		addr = page_address(page);
+		pcpu_handlers[cpu] = (unsigned long)addr;
+		memcpy((void *)addr, (void *)eentry, vec_sz);
+		local_flush_icache_range((unsigned long)addr, (unsigned long)addr + vec_sz);
+		csr_write64(pcpu_handlers[cpu], LOONGARCH_CSR_EENTRY);
+		csr_write64(pcpu_handlers[cpu], LOONGARCH_CSR_MERRENTRY);
+		csr_write64(pcpu_handlers[cpu] + 80*VECSIZE, LOONGARCH_CSR_TLBRENTRY);
+	}
+#endif
+}
+
+void tlb_init(int cpu)
+{
+	write_csr_pagesize(PS_DEFAULT_SIZE);
+	write_csr_stlbpgsize(PS_DEFAULT_SIZE);
+	write_csr_tlbrefill_pagesize(PS_DEFAULT_SIZE);
+
+	setup_tlb_handler(cpu);
+	output_pgtable_bits_defines();
+}