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100 lines
2.1 KiB
100 lines
2.1 KiB
/*
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* Copyright IBM Corp. 2008
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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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static int memory_fast_detect(struct mem_chunk *chunk)
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{
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unsigned long val0 = 0;
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unsigned long val1 = 0xc;
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int rc = -EOPNOTSUPP;
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if (ipl_flags & IPL_NSS_VALID)
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return -EOPNOTSUPP;
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asm volatile(
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" diag %1,%2,0x260\n"
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"0: lhi %0,0\n"
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"1:\n"
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EX_TABLE(0b,1b)
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: "+d" (rc), "+d" (val0), "+d" (val1) : : "cc");
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if (rc || val0 != val1)
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return -EOPNOTSUPP;
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chunk->size = val0 + 1;
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return 0;
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}
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static inline int tprot(unsigned long addr)
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{
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int rc = -EFAULT;
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asm volatile(
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" tprot 0(%1),0\n"
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"0: ipm %0\n"
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" srl %0,28\n"
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"1:\n"
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EX_TABLE(0b,1b)
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: "+d" (rc) : "a" (addr) : "cc");
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return rc;
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}
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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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if (memory_fast_detect(&chunk[0]) == 0)
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return;
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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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