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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>
This commit is contained in:
Peter Tyser 2009-12-18 16:50:37 -06:00 committed by Kumar Gala
parent fa644298eb
commit d1d47ec6e6
1 changed files with 19 additions and 2 deletions
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21
arch/powerpc/platforms/85xx/smp.c
View File

@ -46,6 +46,7 @@ smp_85xx_kick_cpu(int nr)
__iomem u32 *bptr_vaddr;
struct device_node *np;
int n = 0;
int ioremappable;
WARN_ON (nr < 0 || nr >= NR_CPUS);
@ -59,21 +60,37 @@ smp_85xx_kick_cpu(int 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 */
bptr_vaddr = ioremap(*cpu_rel_addr, SIZE_BOOT_ENTRY);
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);
iounmap(bptr_vaddr);
if (ioremappable)
iounmap(bptr_vaddr);
pr_debug("waited %d msecs for CPU #%d.\n", n, nr);
}