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fbe765680d
Setting the cpu restart parameters is done in three different fashions: - directly setting the four parameters individually - copying the four parameters with memcpy (using 4 * sizeof(long)) - copying the four parameters using a private structure In addition code in entry*.S relies on a certain order of the restart members of struct _lowcore. Make all of this more robust to future changes by adding a mem_absolute_assign(dest, val) define, which assigns val to dest using absolute addressing mode. Also the load multiple instructions in entry*.S have been split into separate load instruction so the order of the struct _lowcore members doesn't matter anymore. In addition move the prototypes of memcpy_real/absolute from uaccess.h to processor.h. These memcpy* variants are not related to uaccess at all. string.h doesn't seem to match as well, so lets use processor.h. Also replace the eight byte array in struct _lowcore which represents a misaliged u64 with a u64. The compiler will always create code that handles the misaligned u64 correctly. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
168 lines
3.9 KiB
C
168 lines
3.9 KiB
C
/*
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* OS info memory interface
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*
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* Copyright IBM Corp. 2012
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* Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
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*/
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#define KMSG_COMPONENT "os_info"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/crash_dump.h>
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#include <linux/kernel.h>
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#include <asm/checksum.h>
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#include <asm/lowcore.h>
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#include <asm/os_info.h>
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/*
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* OS info structure has to be page aligned
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*/
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static struct os_info os_info __page_aligned_data;
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/*
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* Compute checksum over OS info structure
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*/
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u32 os_info_csum(struct os_info *os_info)
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{
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int size = sizeof(*os_info) - offsetof(struct os_info, version_major);
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return csum_partial(&os_info->version_major, size, 0);
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}
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/*
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* Add crashkernel info to OS info and update checksum
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*/
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void os_info_crashkernel_add(unsigned long base, unsigned long size)
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{
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os_info.crashkernel_addr = (u64)(unsigned long)base;
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os_info.crashkernel_size = (u64)(unsigned long)size;
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os_info.csum = os_info_csum(&os_info);
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}
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/*
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* Add OS info entry and update checksum
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*/
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void os_info_entry_add(int nr, void *ptr, u64 size)
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{
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os_info.entry[nr].addr = (u64)(unsigned long)ptr;
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os_info.entry[nr].size = size;
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os_info.entry[nr].csum = csum_partial(ptr, size, 0);
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os_info.csum = os_info_csum(&os_info);
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}
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/*
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* Initialize OS info struture and set lowcore pointer
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*/
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void __init os_info_init(void)
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{
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void *ptr = &os_info;
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os_info.version_major = OS_INFO_VERSION_MAJOR;
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os_info.version_minor = OS_INFO_VERSION_MINOR;
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os_info.magic = OS_INFO_MAGIC;
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os_info.csum = os_info_csum(&os_info);
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mem_assign_absolute(S390_lowcore.os_info, (unsigned long) ptr);
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}
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#ifdef CONFIG_CRASH_DUMP
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static struct os_info *os_info_old;
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/*
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* Allocate and copy OS info entry from oldmem
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*/
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static void os_info_old_alloc(int nr, int align)
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{
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unsigned long addr, size = 0;
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char *buf, *buf_align, *msg;
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u32 csum;
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addr = os_info_old->entry[nr].addr;
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if (!addr) {
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msg = "not available";
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goto fail;
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}
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size = os_info_old->entry[nr].size;
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buf = kmalloc(size + align - 1, GFP_KERNEL);
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if (!buf) {
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msg = "alloc failed";
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goto fail;
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}
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buf_align = PTR_ALIGN(buf, align);
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if (copy_from_oldmem(buf_align, (void *) addr, size)) {
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msg = "copy failed";
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goto fail_free;
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}
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csum = csum_partial(buf_align, size, 0);
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if (csum != os_info_old->entry[nr].csum) {
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msg = "checksum failed";
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goto fail_free;
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}
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os_info_old->entry[nr].addr = (u64)(unsigned long)buf_align;
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msg = "copied";
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goto out;
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fail_free:
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kfree(buf);
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fail:
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os_info_old->entry[nr].addr = 0;
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out:
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pr_info("entry %i: %s (addr=0x%lx size=%lu)\n",
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nr, msg, addr, size);
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}
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/*
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* Initialize os info and os info entries from oldmem
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*/
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static void os_info_old_init(void)
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{
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static int os_info_init;
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unsigned long addr;
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if (os_info_init)
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return;
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if (!OLDMEM_BASE)
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goto fail;
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if (copy_from_oldmem(&addr, &S390_lowcore.os_info, sizeof(addr)))
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goto fail;
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if (addr == 0 || addr % PAGE_SIZE)
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goto fail;
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os_info_old = kzalloc(sizeof(*os_info_old), GFP_KERNEL);
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if (!os_info_old)
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goto fail;
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if (copy_from_oldmem(os_info_old, (void *) addr, sizeof(*os_info_old)))
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goto fail_free;
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if (os_info_old->magic != OS_INFO_MAGIC)
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goto fail_free;
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if (os_info_old->csum != os_info_csum(os_info_old))
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goto fail_free;
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if (os_info_old->version_major > OS_INFO_VERSION_MAJOR)
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goto fail_free;
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os_info_old_alloc(OS_INFO_VMCOREINFO, 1);
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os_info_old_alloc(OS_INFO_REIPL_BLOCK, 1);
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pr_info("crashkernel: addr=0x%lx size=%lu\n",
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(unsigned long) os_info_old->crashkernel_addr,
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(unsigned long) os_info_old->crashkernel_size);
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os_info_init = 1;
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return;
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fail_free:
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kfree(os_info_old);
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fail:
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os_info_init = 1;
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os_info_old = NULL;
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}
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/*
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* Return pointer to os infor entry and its size
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*/
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void *os_info_old_entry(int nr, unsigned long *size)
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{
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os_info_old_init();
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if (!os_info_old)
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return NULL;
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if (!os_info_old->entry[nr].addr)
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return NULL;
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*size = (unsigned long) os_info_old->entry[nr].size;
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return (void *)(unsigned long)os_info_old->entry[nr].addr;
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}
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#endif
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