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a27d76f451
... Make sure CMA zones do not straddle the emulated NUMA nodes ... Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
73 lines
1.3 KiB
C
73 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Simple NUMA emulation.
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*
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* Copyright © 2024 Raspberry Pi Ltd
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*
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* Author: Maíra Canal <mcanal@igalia.com>
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* Author: Tvrtko Ursulin <tursulin@igalia.com>
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*/
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#include <linux/cma.h>
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#include <linux/memblock.h>
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#include "numa_emulation.h"
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static unsigned int emu_nodes;
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int __init numa_emu_cmdline(char *str)
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{
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int ret;
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ret = kstrtouint(str, 10, &emu_nodes);
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if (ret)
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return ret;
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if (emu_nodes > MAX_NUMNODES) {
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pr_notice("numa=fake=%u too large, reducing to %u\n",
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emu_nodes, MAX_NUMNODES);
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emu_nodes = MAX_NUMNODES;
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}
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return 0;
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}
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int __init numa_emu_init(void)
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{
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phys_addr_t start, end;
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unsigned long size;
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unsigned int i;
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int ret;
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if (!emu_nodes)
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return -EINVAL;
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start = memblock_start_of_DRAM();
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end = memblock_end_of_DRAM() - 1;
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size = DIV_ROUND_DOWN_ULL(end - start + 1, emu_nodes);
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size = PAGE_ALIGN_DOWN(size);
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for (i = 0; i < emu_nodes; i++) {
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u64 s, e;
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s = start + i * size;
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e = s + size - 1;
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if (i == (emu_nodes - 1) && e != end)
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e = end;
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ret = cma_check_range(&s, &e);
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if (ret)
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return ret;
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pr_info("Faking a node at [mem %pap-%pap]\n", &s, &e);
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ret = numa_add_memblk(i, s, e + 1);
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if (ret) {
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pr_err("Failed to add fake NUMA node %d!\n", i);
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break;
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}
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}
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return ret;
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}
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