54 lines
1.2 KiB
D
54 lines
1.2 KiB
D
/**
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* A1 memory allocator.
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*/
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module hulk.hurl.a1;
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import hulk.hurl;
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import hulk.hippo;
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import hulk.util;
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import hulk.pagetable;
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/**
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* The A1 memory allocator is a one-shot memory allocator for kernel memory
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* that is allocated but never freed.
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*/
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struct A1
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{
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/**
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* Number of bytes allocated in the A1 region so far.
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*/
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private static __gshared size_t allocated;
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/**
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* Allocate memory.
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*
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* @param size
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* Size of memory to allocate.
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*
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* @return Address of allocated memory. This address will always be aligned
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* to a multiple of 16 bytes.
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*/
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public static void * allocate(size_t size)
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{
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/* Round size up to a multiple of 16. */
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size = round_up_power_2(size, 16u);
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ulong address = Hurl.A1_BASE + allocated;
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ulong mapped_limit = round_up_power_2(address, PAGE_SIZE);
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allocated += size;
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ulong desired_limit = round_up_power_2(Hurl.A1_BASE + allocated, PAGE_SIZE);
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while (desired_limit > mapped_limit)
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{
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void * page = Hippo.allocate_page();
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Hurl.map(Hurl.A1_BASE + mapped_limit, page, PT_WRITABLE);
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mapped_limit += PAGE_SIZE;
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}
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return cast(void *)address;
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}
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}
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