linux_dsm_epyc7002/arch/powerpc/platforms/85xx/smp.c
Peter Tyser d1d47ec6e6 powerpc/85xx: Fix SMP when "cpu-release-addr" is in lowmem
Recent U-Boot commit 5ccd29c3679b3669b0bde5c501c1aa0f325a7acb caused
the "cpu-release-addr" device tree property to contain the physical RAM
location that secondary cores were spinning at.  Previously, the
"cpu-release-addr" property contained a value referencing the boot page
translation address range of 0xfffffxxx, which then indirectly accessed
RAM.

The "cpu-release-addr" is currently ioremapped and the secondary cores
kicked.  However, due to the recent change in "cpu-release-addr", it
sometimes points to a memory location in low memory that cannot be
ioremapped.  For example on a P2020-based board with 512MB of RAM the
following error occurs on bootup:

  <...>
  mpic: requesting IPIs ...
  __ioremap(): phys addr 0x1ffff000 is RAM lr c05df9a0
  Unable to handle kernel paging request for data at address 0x00000014
  Faulting instruction address: 0xc05df9b0
  Oops: Kernel access of bad area, sig: 11 [#1]
  SMP NR_CPUS=2 P2020 RDB
  Modules linked in:
  <... eventual kernel panic>

Adding logic to conditionally ioremap or access memory directly resolves
the issue.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: Nate Case <ncase@xes-inc.com>
Reported-by: Dipen Dudhat <B09055@freescale.com>
Tested-by: Dipen Dudhat <B09055@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2010-02-13 14:23:24 -06:00

126 lines
3.0 KiB
C

/*
* Author: Andy Fleming <afleming@freescale.com>
* Kumar Gala <galak@kernel.crashing.org>
*
* Copyright 2006-2008 Freescale Semiconductor Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <asm/machdep.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/mpic.h>
#include <asm/cacheflush.h>
#include <asm/dbell.h>
#include <sysdev/fsl_soc.h>
extern void __early_start(void);
#define BOOT_ENTRY_ADDR_UPPER 0
#define BOOT_ENTRY_ADDR_LOWER 1
#define BOOT_ENTRY_R3_UPPER 2
#define BOOT_ENTRY_R3_LOWER 3
#define BOOT_ENTRY_RESV 4
#define BOOT_ENTRY_PIR 5
#define BOOT_ENTRY_R6_UPPER 6
#define BOOT_ENTRY_R6_LOWER 7
#define NUM_BOOT_ENTRY 8
#define SIZE_BOOT_ENTRY (NUM_BOOT_ENTRY * sizeof(u32))
static void __init
smp_85xx_kick_cpu(int nr)
{
unsigned long flags;
const u64 *cpu_rel_addr;
__iomem u32 *bptr_vaddr;
struct device_node *np;
int n = 0;
int ioremappable;
WARN_ON (nr < 0 || nr >= NR_CPUS);
pr_debug("smp_85xx_kick_cpu: kick CPU #%d\n", nr);
np = of_get_cpu_node(nr, NULL);
cpu_rel_addr = of_get_property(np, "cpu-release-addr", NULL);
if (cpu_rel_addr == NULL) {
printk(KERN_ERR "No cpu-release-addr for cpu %d\n", nr);
return;
}
/*
* A secondary core could be in a spinloop in the bootpage
* (0xfffff000), somewhere in highmem, or somewhere in lowmem.
* The bootpage and highmem can be accessed via ioremap(), but
* we need to directly access the spinloop if its in lowmem.
*/
ioremappable = *cpu_rel_addr > virt_to_phys(high_memory);
/* Map the spin table */
if (ioremappable)
bptr_vaddr = ioremap(*cpu_rel_addr, SIZE_BOOT_ENTRY);
else
bptr_vaddr = phys_to_virt(*cpu_rel_addr);
local_irq_save(flags);
out_be32(bptr_vaddr + BOOT_ENTRY_PIR, nr);
out_be32(bptr_vaddr + BOOT_ENTRY_ADDR_LOWER, __pa(__early_start));
if (!ioremappable)
flush_dcache_range((ulong)bptr_vaddr,
(ulong)(bptr_vaddr + SIZE_BOOT_ENTRY));
/* Wait a bit for the CPU to ack. */
while ((__secondary_hold_acknowledge != nr) && (++n < 1000))
mdelay(1);
local_irq_restore(flags);
if (ioremappable)
iounmap(bptr_vaddr);
pr_debug("waited %d msecs for CPU #%d.\n", n, nr);
}
static void __init
smp_85xx_setup_cpu(int cpu_nr)
{
mpic_setup_this_cpu();
}
struct smp_ops_t smp_85xx_ops = {
.kick_cpu = smp_85xx_kick_cpu,
};
void __init mpc85xx_smp_init(void)
{
struct device_node *np;
np = of_find_node_by_type(NULL, "open-pic");
if (np) {
smp_85xx_ops.probe = smp_mpic_probe;
smp_85xx_ops.setup_cpu = smp_85xx_setup_cpu;
smp_85xx_ops.message_pass = smp_mpic_message_pass;
}
if (cpu_has_feature(CPU_FTR_DBELL))
smp_85xx_ops.message_pass = smp_dbell_message_pass;
BUG_ON(!smp_85xx_ops.message_pass);
smp_ops = &smp_85xx_ops;
}