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/mips/mm/highmem.c | 77 ++++++++++++++++++++++++++++++++++++++
1 files changed, 77 insertions(+), 0 deletions(-)
diff --git a/kernel/arch/mips/mm/highmem.c b/kernel/arch/mips/mm/highmem.c
index 57e2f08..5fec7f4 100644
--- a/kernel/arch/mips/mm/highmem.c
+++ b/kernel/arch/mips/mm/highmem.c
@@ -8,6 +8,8 @@
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
+static pte_t *kmap_pte;
+
unsigned long highstart_pfn, highend_pfn;
void kmap_flush_tlb(unsigned long addr)
@@ -15,3 +17,78 @@
flush_tlb_one(addr);
}
EXPORT_SYMBOL(kmap_flush_tlb);
+
+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));
+ local_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 type __maybe_unused;
+
+ if (vaddr < FIXADDR_START)
+ return;
+
+ type = kmap_atomic_idx();
+#ifdef CONFIG_DEBUG_HIGHMEM
+ {
+ int idx = type + KM_TYPE_NR * smp_processor_id();
+
+ BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
+
+ /*
+ * force other mappings to Oops if they'll try to access
+ * this pte without first remap it
+ */
+ pte_clear(&init_mm, vaddr, kmap_pte-idx);
+ local_flush_tlb_one(vaddr);
+ }
+#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;
+
+ preempt_disable();
+ 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;
+}
+
+void __init kmap_init(void)
+{
+ unsigned long kmap_vstart;
+
+ /* cache the first kmap pte */
+ kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
+ kmap_pte = virt_to_kpte(kmap_vstart);
+}
--
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