65 lines
1.5 KiB
C
65 lines
1.5 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 = __raw_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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__raw_local_irq_ssm(flags);
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}
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EXPORT_SYMBOL(detect_memory_layout);
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