From 6778948f9de86c3cfaf36725a7c87dcff9ba247f Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 08:20:59 +0000
Subject: [PATCH] kernel_5.10 no rt

---
 kernel/arch/csky/mm/highmem.c |   75 +++++++++++++++++++++++++++++++++++++
 1 files changed, 74 insertions(+), 1 deletions(-)

diff --git a/kernel/arch/csky/mm/highmem.c b/kernel/arch/csky/mm/highmem.c
index 4161df3..89c1080 100644
--- a/kernel/arch/csky/mm/highmem.c
+++ b/kernel/arch/csky/mm/highmem.c
@@ -9,6 +9,8 @@
 #include <asm/tlbflush.h>
 #include <asm/cacheflush.h>
 
+static pte_t *kmap_pte;
+
 unsigned long highstart_pfn, highend_pfn;
 
 void kmap_flush_tlb(unsigned long addr)
@@ -17,7 +19,67 @@
 }
 EXPORT_SYMBOL(kmap_flush_tlb);
 
-void __init kmap_init(void)
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
+{
+	unsigned long vaddr;
+	int idx, type;
+
+	type = kmap_atomic_idx_push();
+	idx = type + KM_TYPE_NR*smp_processor_id();
+	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+#ifdef CONFIG_DEBUG_HIGHMEM
+	BUG_ON(!pte_none(*(kmap_pte - idx)));
+#endif
+	set_pte(kmap_pte-idx, mk_pte(page, prot));
+	flush_tlb_one((unsigned long)vaddr);
+
+	return (void *)vaddr;
+}
+EXPORT_SYMBOL(kmap_atomic_high_prot);
+
+void kunmap_atomic_high(void *kvaddr)
+{
+	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
+	int idx;
+
+	if (vaddr < FIXADDR_START)
+		return;
+
+#ifdef CONFIG_DEBUG_HIGHMEM
+	idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
+
+	BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
+
+	pte_clear(&init_mm, vaddr, kmap_pte - idx);
+	flush_tlb_one(vaddr);
+#else
+	(void) idx; /* to kill a warning */
+#endif
+	kmap_atomic_idx_pop();
+}
+EXPORT_SYMBOL(kunmap_atomic_high);
+
+/*
+ * This is the same as kmap_atomic() but can map memory that doesn't
+ * have a struct page associated with it.
+ */
+void *kmap_atomic_pfn(unsigned long pfn)
+{
+	unsigned long vaddr;
+	int idx, type;
+
+	pagefault_disable();
+
+	type = kmap_atomic_idx_push();
+	idx = type + KM_TYPE_NR*smp_processor_id();
+	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+	set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
+	flush_tlb_one(vaddr);
+
+	return (void *) vaddr;
+}
+
+static void __init kmap_pages_init(void)
 {
 	unsigned long vaddr;
 	pgd_t *pgd;
@@ -34,3 +96,14 @@
 	pte = pte_offset_kernel(pmd, vaddr);
 	pkmap_page_table = pte;
 }
+
+void __init kmap_init(void)
+{
+	unsigned long vaddr;
+
+	kmap_pages_init();
+
+	vaddr = __fix_to_virt(FIX_KMAP_BEGIN);
+
+	kmap_pte = pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr);
+}

--
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