98d5c21c81
The powerpc kernel maintains information about logical memory blocks in the lmb.memory structure, which is initialized and updated at boot time, but not when memory is added or removed while the kernel is running. This adds a hotplug memory notifier which updates lmb.memory when memory is added or removed. This information is useful for eHEA driver to find out the memory layout and holes. NOTE: No special locking is needed for lmb_add() and lmb_remove(). Calls to these are serialized by caller. (pSeries_reconfig_chain). Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
141 lines
3.3 KiB
C
141 lines
3.3 KiB
C
/*
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* pseries Memory Hotplug infrastructure.
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*
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* Copyright (C) 2008 Badari Pulavarty, IBM Corporation
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/of.h>
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#include <linux/lmb.h>
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#include <asm/firmware.h>
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#include <asm/machdep.h>
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#include <asm/pSeries_reconfig.h>
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static int pseries_remove_memory(struct device_node *np)
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{
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const char *type;
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const unsigned int *my_index;
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const unsigned int *regs;
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u64 start_pfn, start;
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struct zone *zone;
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int ret = -EINVAL;
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/*
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* Check to see if we are actually removing memory
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*/
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type = of_get_property(np, "device_type", NULL);
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if (type == NULL || strcmp(type, "memory") != 0)
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return 0;
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/*
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* Find the memory index and size of the removing section
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*/
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my_index = of_get_property(np, "ibm,my-drc-index", NULL);
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if (!my_index)
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return ret;
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regs = of_get_property(np, "reg", NULL);
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if (!regs)
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return ret;
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start_pfn = section_nr_to_pfn(*my_index & 0xffff);
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zone = page_zone(pfn_to_page(start_pfn));
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/*
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* Remove section mappings and sysfs entries for the
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* section of the memory we are removing.
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*
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* NOTE: Ideally, this should be done in generic code like
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* remove_memory(). But remove_memory() gets called by writing
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* to sysfs "state" file and we can't remove sysfs entries
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* while writing to it. So we have to defer it to here.
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*/
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ret = __remove_pages(zone, start_pfn, regs[3] >> PAGE_SHIFT);
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if (ret)
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return ret;
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/*
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* Update memory regions for memory remove
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*/
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lmb_remove(start_pfn << PAGE_SHIFT, regs[3]);
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/*
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* Remove htab bolted mappings for this section of memory
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*/
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start = (unsigned long)__va(start_pfn << PAGE_SHIFT);
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ret = remove_section_mapping(start, start + regs[3]);
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return ret;
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}
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static int pseries_add_memory(struct device_node *np)
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{
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const char *type;
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const unsigned int *my_index;
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const unsigned int *regs;
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u64 start_pfn;
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int ret = -EINVAL;
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/*
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* Check to see if we are actually adding memory
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*/
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type = of_get_property(np, "device_type", NULL);
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if (type == NULL || strcmp(type, "memory") != 0)
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return 0;
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/*
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* Find the memory index and size of the added section
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*/
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my_index = of_get_property(np, "ibm,my-drc-index", NULL);
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if (!my_index)
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return ret;
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regs = of_get_property(np, "reg", NULL);
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if (!regs)
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return ret;
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start_pfn = section_nr_to_pfn(*my_index & 0xffff);
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/*
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* Update memory region to represent the memory add
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*/
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lmb_add(start_pfn << PAGE_SHIFT, regs[3]);
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return 0;
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}
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static int pseries_memory_notifier(struct notifier_block *nb,
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unsigned long action, void *node)
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{
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int err = NOTIFY_OK;
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switch (action) {
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case PSERIES_RECONFIG_ADD:
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if (pseries_add_memory(node))
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err = NOTIFY_BAD;
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break;
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case PSERIES_RECONFIG_REMOVE:
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if (pseries_remove_memory(node))
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err = NOTIFY_BAD;
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break;
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default:
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err = NOTIFY_DONE;
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break;
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}
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return err;
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}
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static struct notifier_block pseries_mem_nb = {
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.notifier_call = pseries_memory_notifier,
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};
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static int __init pseries_memory_hotplug_init(void)
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{
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if (firmware_has_feature(FW_FEATURE_LPAR))
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pSeries_reconfig_notifier_register(&pseries_mem_nb);
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return 0;
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}
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machine_device_initcall(pseries, pseries_memory_hotplug_init);
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