/*
先说 CONFIG_PGTABLE_LEVEL = 3 的情况吧.
这个 映射层级 kernel 会自己计算的:
1:
Page size (4KB) --->
Virtual address space size (39-bit) --->
Symbol: PGTABLE_LEVELS [=3]
Defined at arch/arm64/Kconfig:224
它就是获取 pmd表的项嘛, 就是 pte表的起始地址.
其算法还是基地址 + 偏移量
偏移量就是 pmd_index(), 下面说说 基地址 .
*/
static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}
static inline unsigned long pmd_index(unsigned long address)
{
return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}
kdump -- Linux Kernel 欣赏
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转载自blog.csdn.net/leesagacious/article/details/107549061
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