forked from Minki/linux
4e21b94c9c
At console init, when the kernel tries to flush the log buffer the ePAPR byte-channel based console write fails silently, losing the buffered messages. This happens because The ePAPR para-virtualization init isn't done early enough so that the hcall instruction to be set, causing the byte-channel write hcall to be a nop. To fix, change the ePAPR para-virt init to use early device tree functions and move it in early init. Signed-off-by: Laurentiu Tudor <Laurentiu.Tudor@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
72 lines
1.8 KiB
C
72 lines
1.8 KiB
C
/*
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* ePAPR para-virtualization support.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* Copyright (C) 2012 Freescale Semiconductor, Inc.
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*/
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#include <linux/of.h>
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#include <asm/epapr_hcalls.h>
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#include <asm/cacheflush.h>
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#include <asm/code-patching.h>
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#include <asm/machdep.h>
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#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
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extern void epapr_ev_idle(void);
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extern u32 epapr_ev_idle_start[];
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#endif
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bool epapr_paravirt_enabled;
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static int __init early_init_dt_scan_epapr(unsigned long node,
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const char *uname,
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int depth, void *data)
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{
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const u32 *insts;
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unsigned long len;
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int i;
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insts = of_get_flat_dt_prop(node, "hcall-instructions", &len);
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if (!insts)
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return 0;
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if (len % 4 || len > (4 * 4))
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return -1;
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for (i = 0; i < (len / 4); i++) {
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patch_instruction(epapr_hypercall_start + i, insts[i]);
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#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
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patch_instruction(epapr_ev_idle_start + i, insts[i]);
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#endif
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}
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#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
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if (of_get_flat_dt_prop(node, "has-idle", NULL))
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ppc_md.power_save = epapr_ev_idle;
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#endif
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epapr_paravirt_enabled = true;
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return 1;
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}
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int __init epapr_paravirt_early_init(void)
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{
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of_scan_flat_dt(early_init_dt_scan_epapr, NULL);
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return 0;
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}
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