mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-08 04:26:40 +07:00
44e5ddc4e9
This patch makes the create_mem_hole() function more readable and fixes some minor bugs (e.g. off-by-one problems). Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
146 lines
3.7 KiB
C
146 lines
3.7 KiB
C
/*
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* Copyright IBM Corp. 2008, 2009
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*
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* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <asm/ipl.h>
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#include <asm/sclp.h>
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#include <asm/setup.h>
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#define ADDR2G (1ULL << 31)
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static void find_memory_chunks(struct mem_chunk chunk[])
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{
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unsigned long long memsize, rnmax, rzm;
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unsigned long addr = 0, size;
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int i = 0, type;
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rzm = sclp_get_rzm();
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rnmax = sclp_get_rnmax();
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memsize = rzm * rnmax;
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if (!rzm)
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rzm = 1ULL << 17;
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if (sizeof(long) == 4) {
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rzm = min(ADDR2G, rzm);
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memsize = memsize ? min(ADDR2G, memsize) : ADDR2G;
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}
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do {
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size = 0;
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type = tprot(addr);
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do {
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size += rzm;
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if (memsize && addr + size >= memsize)
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break;
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} while (type == tprot(addr + size));
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if (type == CHUNK_READ_WRITE || type == CHUNK_READ_ONLY) {
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chunk[i].addr = addr;
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chunk[i].size = size;
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chunk[i].type = type;
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i++;
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}
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addr += size;
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} while (addr < memsize && i < MEMORY_CHUNKS);
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}
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void detect_memory_layout(struct mem_chunk chunk[])
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{
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unsigned long flags, cr0;
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memset(chunk, 0, MEMORY_CHUNKS * sizeof(struct mem_chunk));
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/* Disable IRQs, DAT and low address protection so tprot does the
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* right thing and we don't get scheduled away with low address
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* protection disabled.
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*/
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flags = __arch_local_irq_stnsm(0xf8);
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__ctl_store(cr0, 0, 0);
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__ctl_clear_bit(0, 28);
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find_memory_chunks(chunk);
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__ctl_load(cr0, 0, 0);
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arch_local_irq_restore(flags);
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}
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EXPORT_SYMBOL(detect_memory_layout);
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/*
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* Move memory chunks array from index "from" to index "to"
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*/
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static void mem_chunk_move(struct mem_chunk chunk[], int to, int from)
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{
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int cnt = MEMORY_CHUNKS - to;
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memmove(&chunk[to], &chunk[from], cnt * sizeof(struct mem_chunk));
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}
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/*
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* Initialize memory chunk
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*/
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static void mem_chunk_init(struct mem_chunk *chunk, unsigned long addr,
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unsigned long size, int type)
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{
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chunk->type = type;
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chunk->addr = addr;
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chunk->size = size;
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}
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/*
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* Create memory hole with given address, size, and type
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*/
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void create_mem_hole(struct mem_chunk chunk[], unsigned long addr,
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unsigned long size, int type)
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{
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unsigned long lh_start, lh_end, lh_size, ch_start, ch_end, ch_size;
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int i, ch_type;
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for (i = 0; i < MEMORY_CHUNKS; i++) {
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if (chunk[i].size == 0)
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continue;
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/* Define chunk properties */
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ch_start = chunk[i].addr;
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ch_size = chunk[i].size;
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ch_end = ch_start + ch_size - 1;
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ch_type = chunk[i].type;
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/* Is memory chunk hit by memory hole? */
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if (addr + size <= ch_start)
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continue; /* No: memory hole in front of chunk */
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if (addr > ch_end)
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continue; /* No: memory hole after chunk */
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/* Yes: Define local hole properties */
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lh_start = max(addr, chunk[i].addr);
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lh_end = min(addr + size - 1, ch_end);
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lh_size = lh_end - lh_start + 1;
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if (lh_start == ch_start && lh_end == ch_end) {
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/* Hole covers complete memory chunk */
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mem_chunk_init(&chunk[i], lh_start, lh_size, type);
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} else if (lh_end == ch_end) {
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/* Hole starts in memory chunk and convers chunk end */
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mem_chunk_move(chunk, i + 1, i);
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mem_chunk_init(&chunk[i], ch_start, ch_size - lh_size,
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ch_type);
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mem_chunk_init(&chunk[i + 1], lh_start, lh_size, type);
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i += 1;
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} else if (lh_start == ch_start) {
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/* Hole ends in memory chunk */
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mem_chunk_move(chunk, i + 1, i);
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mem_chunk_init(&chunk[i], lh_start, lh_size, type);
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mem_chunk_init(&chunk[i + 1], lh_end + 1,
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ch_size - lh_size, ch_type);
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break;
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} else {
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/* Hole splits memory chunk */
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mem_chunk_move(chunk, i + 2, i);
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mem_chunk_init(&chunk[i], ch_start,
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lh_start - ch_start, ch_type);
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mem_chunk_init(&chunk[i + 1], lh_start, lh_size, type);
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mem_chunk_init(&chunk[i + 2], lh_end + 1,
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ch_end - lh_end, ch_type);
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break;
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}
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}
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}
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