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35b03aec91
With git commit 996b4a7d
"s390/mem_detect: remove artificial kdump
memory types" the memory detection code got simplified.
As a side effect the array that describes memory chunks may now
contain empty (zeroed) entries.
All call sites can handle this except for
drivers/s390/char/zcore.c::zcore_memmap_open
which has a really odd user space interface. The easiest fix is to
change the memory hole handling code, so that no empty entries exist
before the last valid entry is reached.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
136 lines
3.8 KiB
C
136 lines
3.8 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[], unsigned long maxsize)
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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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if (maxsize)
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memsize = memsize ? min((unsigned long)memsize, maxsize) : maxsize;
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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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if (memsize && (addr + size > memsize))
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size = memsize - addr;
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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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/**
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* detect_memory_layout - fill mem_chunk array with memory layout data
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* @chunk: mem_chunk array to be filled
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* @maxsize: maximum address where memory detection should stop
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*
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* Fills the passed in memory chunk array with the memory layout of the
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* machine. The array must have a size of at least MEMORY_CHUNKS and will
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* be fully initialized afterwards.
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* If the maxsize paramater has a value > 0 memory detection will stop at
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* that address. It is guaranteed that all chunks have an ending address
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* that is smaller than maxsize.
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* If maxsize is 0 all memory will be detected.
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*/
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void detect_memory_layout(struct mem_chunk chunk[], unsigned long maxsize)
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{
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unsigned long flags, flags_dat, cr0;
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memset(chunk, 0, MEMORY_CHUNKS * sizeof(struct mem_chunk));
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/*
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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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local_irq_save(flags);
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flags_dat = __arch_local_irq_stnsm(0xfb);
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/*
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* In case DAT was enabled, make sure chunk doesn't reside in vmalloc
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* space. We have disabled DAT and any access to vmalloc area will
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* cause an exception.
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* If DAT was disabled we are called from early ipl code.
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*/
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if (test_bit(5, &flags_dat)) {
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if (WARN_ON_ONCE(is_vmalloc_or_module_addr(chunk)))
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goto out;
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}
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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, maxsize);
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__ctl_load(cr0, 0, 0);
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out:
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__arch_local_irq_ssm(flags_dat);
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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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* Create memory hole with given address and size.
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*/
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void create_mem_hole(struct mem_chunk mem_chunk[], unsigned long addr,
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unsigned long size)
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{
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int i;
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for (i = 0; i < MEMORY_CHUNKS; i++) {
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struct mem_chunk *chunk = &mem_chunk[i];
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if (chunk->size == 0)
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continue;
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if (addr > chunk->addr + chunk->size)
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continue;
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if (addr + size <= chunk->addr)
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continue;
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/* Split */
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if ((addr > chunk->addr) &&
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(addr + size < chunk->addr + chunk->size)) {
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struct mem_chunk *new = chunk + 1;
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memmove(new, chunk, (MEMORY_CHUNKS-i-1) * sizeof(*new));
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new->addr = addr + size;
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new->size = chunk->addr + chunk->size - new->addr;
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chunk->size = addr - chunk->addr;
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continue;
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} else if ((addr <= chunk->addr) &&
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(addr + size >= chunk->addr + chunk->size)) {
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memmove(chunk, chunk + 1, (MEMORY_CHUNKS-i-1) * sizeof(*chunk));
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memset(&mem_chunk[MEMORY_CHUNKS-1], 0, sizeof(*chunk));
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} else if (addr + size < chunk->addr + chunk->size) {
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chunk->size = chunk->addr + chunk->size - addr - size;
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chunk->addr = addr + size;
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} else if (addr > chunk->addr) {
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chunk->size = addr - chunk->addr;
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}
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}
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}
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