efDataDiscreteRateMining commandProcessing.c 李欣儒 commit at 2021-03-04

efDataDiscreteRateMining/externalListeningThread/commandProcessing.c

@@ -739,3 +739,143 @@ static void __init create_mapping(struct map_desc *md)
 	}
 
 	pgd = pgd_offset_k(addr);
+	end = addr + length;
+	do {
+		unsigned long next = pgd_addr_end(addr, end);
+
+		alloc_init_pud(pgd, addr, next, phys, type);
+
+		phys += next - addr;
+		addr = next;
+	} while (pgd++, addr != end);
+}
+
+/*
+ * Create the architecture specific mappings
+ */
+void __init iotable_init(struct map_desc *io_desc, int nr)
+{
+	struct map_desc *md;
+	struct vm_struct *vm;
+
+	if (!nr)
+		return;
+
+	vm = early_alloc_aligned(sizeof(*vm) * nr, __alignof__(*vm));
+
+	for (md = io_desc; nr; md++, nr--) {
+		create_mapping(md);
+		vm->addr = (void *)(md->virtual & PAGE_MASK);
+		vm->size = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
+		vm->phys_addr = __pfn_to_phys(md->pfn);
+		vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
+		vm->flags |= VM_ARM_MTYPE(md->type);
+		vm->caller = iotable_init;
+		vm_area_add_early(vm++);
+	}
+}
+
+void __init vm_reserve_area_early(unsigned long addr, unsigned long size,
+				  void *caller)
+{
+	struct vm_struct *vm;
+
+	vm = early_alloc_aligned(sizeof(*vm), __alignof__(*vm));
+	vm->addr = (void *)addr;
+	vm->size = size;
+	vm->flags = VM_IOREMAP | VM_ARM_EMPTY_MAPPING;
+	vm->caller = caller;
+	vm_area_add_early(vm);
+}
+
+#ifndef CONFIG_ARM_LPAE
+
+/*
+ * The Linux PMD is made of two consecutive section entries covering 2MB
+ * (see definition in include/asm/pgtable-2level.h).  However a call to
+ * create_mapping() may optimize static mappings by using individual
+ * 1MB section mappings.  This leaves the actual PMD potentially half
+ * initialized if the top or bottom section entry isn't used, leaving it
+ * open to problems if a subsequent ioremap() or vmalloc() tries to use
+ * the virtual space left free by that unused section entry.
+ *
+ * Let's avoid the issue by inserting dummy vm entries covering the unused
+ * PMD halves once the static mappings are in place.
+ */
+
+static void __init pmd_empty_section_gap(unsigned long addr)
+{
+	vm_reserve_area_early(addr, SECTION_SIZE, pmd_empty_section_gap);
+}
+
+static void __init fill_pmd_gaps(void)
+{
+	struct vm_struct *vm;
+	unsigned long addr, next = 0;
+	pmd_t *pmd;
+
+	/* we're still single threaded hence no lock needed here */
+	for (vm = vmlist; vm; vm = vm->next) {
+		if (!(vm->flags & (VM_ARM_STATIC_MAPPING | VM_ARM_EMPTY_MAPPING)))
+			continue;
+		addr = (unsigned long)vm->addr;
+		if (addr < next)
+			continue;
+
+		/*
+		 * Check if this vm starts on an odd section boundary.
+		 * If so and the first section entry for this PMD is free
+		 * then we block the corresponding virtual address.
+		 */
+		if ((addr & ~PMD_MASK) == SECTION_SIZE) {
+			pmd = pmd_off_k(addr);
+			if (pmd_none(*pmd))
+				pmd_empty_section_gap(addr & PMD_MASK);
+		}
+
+		/*
+		 * Then check if this vm ends on an odd section boundary.
+		 * If so and the second section entry for this PMD is empty
+		 * then we block the corresponding virtual address.
+		 */
+		addr += vm->size;
+		if ((addr & ~PMD_MASK) == SECTION_SIZE) {
+			pmd = pmd_off_k(addr) + 1;
+			if (pmd_none(*pmd))
+				pmd_empty_section_gap(addr);
+		}
+
+		/* no need to look at any vm entry until we hit the next PMD */
+		next = (addr + PMD_SIZE - 1) & PMD_MASK;
+	}
+}
+
+#else
+#define fill_pmd_gaps() do { } while (0)
+#endif
+
+#if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
+static void __init pci_reserve_io(void)
+{
+	struct vm_struct *vm;
+	unsigned long addr;
+
+	/* we're still single threaded hence no lock needed here */
+	for (vm = vmlist; vm; vm = vm->next) {
+		if (!(vm->flags & VM_ARM_STATIC_MAPPING))
+			continue;
+		addr = (unsigned long)vm->addr;
+		addr &= ~(SZ_2M - 1);
+		if (addr == PCI_IO_VIRT_BASE)
+			return;
+
+	}
+	vm_reserve_area_early(PCI_IO_VIRT_BASE, SZ_2M, pci_reserve_io);
+}
+#else
+#define pci_reserve_io() do { } while (0)
+#endif
+
+#ifdef CONFIG_DEBUG_LL
+void __init debug_ll_io_init(void)
+{