From d1d47ec6e62ab08d2ebb925fd9203abfad3adfbf Mon Sep 17 00:00:00 2001 From: Peter Tyser Date: Fri, 18 Dec 2009 16:50:37 -0600 Subject: [PATCH] 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 Signed-off-by: Nate Case Reported-by: Dipen Dudhat Tested-by: Dipen Dudhat Signed-off-by: Kumar Gala --- arch/powerpc/platforms/85xx/smp.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c index 04160a4cc699..a15f582300d8 100644 --- a/arch/powerpc/platforms/85xx/smp.c +++ b/arch/powerpc/platforms/85xx/smp.c @@ -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); } -- 2.20.1