On Fri, 2013-12-20 at 15:43 +0800, Kevin Hao wrote:
> On Wed, Dec 18, 2013 at 05:48:25PM -0600, Scott Wood wrote:
> > On Wed, Aug 07, 2013 at 09:18:31AM +0800, Kevin Hao wrote:
> > > This is based on the codes in the head_44x.S. The difference is that
> > > the init tlb size we used is 64M. With this patch we can only load the
> > > kernel at address between memstart_addr ~ memstart_addr + 64M. We will
> > > fix this restriction in the following patches.
> >
> > Which following patch fixes the restriction? With all seven patches
> > applied, I was still only successful booting within 64M of memstart_addr.
>
> There is bug in this patch series when booting above the 64M. It seems
> that I missed to test this previously. Sorry for that. With the following
> change I can boot the kernel at 0x5000000.
I tried v4 and it still doesn't work for me over 64M (without increasing
the start of memory). I pulled the following out of the log buffer when
booting at 0x5000000 (after cleaning up the binary goo -- is that
something new?):
Unable to handle kernel paging request for data at address 0xbffe4008
Faulting instruction address: 0xc16ee934
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=8
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 3.13.0-rc1-00065-g422752a #12
task: c18f2340 ti: c192c000 task.ti: c192c000
NIP: c16ee934 LR: c16d1860 CTR: c100e96c
REGS: c192dee0 TRAP: 0300 Not tainted (3.13.0-rc1-00065-g422752a)
MSR: 00021002 <CE,ME> CR: 42044022 XER: 20000000
DEAR: bffe4008 ESR: 00000000
GPR00: c16d1860 c192df90 c18f2340 c16eec58 00000000 00000000 05000000 00000000
GPR08: 00000000 bffe4000 00000000 bc000000 00000000 0570ad40 ffffffff 7ffb0aec
GPR16: 00000000 00000000 7fe4dd70 00000000 7fe4ddb0 00000000 c192c000 00000007
GPR24: 00000000 c1940000 c16eec58 00000000 ffffffff 03fe4000 00000000 c18f0000
NIP [c16ee934] of_scan_flat_dt+0x28/0x148
LR [c16d1860] early_get_first_memblock_info+0x38/0x84
Call Trace:
[c192dfc0] [c16d1860] early_get_first_memblock_info+0x38/0x84
[c192dfd0] [c16d4888] relocate_init+0x98/0x160
[c192dff0] [c100045c] set_ivor+0x144/0x190
Instruction dump:
7c0803a6 4e800020 9421ffd0 7c0802a6 bee1000c 3f20c194 8139a45c 7c7a1b78
90010034 7c9b2378 3b80ffff 3ae00007 <83e90008> 3b00fff8 7fe9fa14 48000008
---[ end trace 41ed10ed80b8d831 ]---
Kernel panic - not syncing: Attempted to kill the idle task!
> diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
> index 048d716ae706..ce0c7d7db6c3 100644
> --- a/arch/powerpc/mm/fsl_booke_mmu.c
> +++ b/arch/powerpc/mm/fsl_booke_mmu.c
> @@ -171,11 +171,10 @@ unsigned long calc_cam_sz(unsigned long ram, unsigned
> long virt,
> return 1UL << camsize;
> }
>
> -unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
> +static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long
> virt,
> + unsigned long ram, int max_cam_idx)
> {
> int i;
> - unsigned long virt = PAGE_OFFSET;
> - phys_addr_t phys = memstart_addr;
> unsigned long amount_mapped = 0;
>
> /* Calculate CAM values */
> @@ -195,6 +194,14 @@ unsigned long map_mem_in_cams(unsigned long ram, int
> max_cam_idx)
> return amount_mapped;
> }
>
> +unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
> +{
> + unsigned long virt = PAGE_OFFSET;
> + phys_addr_t phys = memstart_addr;
> +
> + return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx);
> +}
> +
> #ifdef CONFIG_PPC32
>
> #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >=
> NUM_TLBCAMS)
> @@ -289,7 +296,11 @@ notrace void __init relocate_init(u64 dt_ptr,
> phys_addr_t start)
> is_second_reloc = 1;
> n = switch_to_as1();
> /* map a 64M area for the second relocation */
> - map_mem_in_cams(0x4000000UL, CONFIG_LOWMEM_CAM_NUM);
> + if (memstart_addr > start)
> + map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM);
> + else
> + map_mem_in_cams_addr(start, PAGE_OFFSET - offset,
> + 0x4000000, CONFIG_LOWMEM_CAM_NUM);
> restore_to_as0(n, offset, __va(dt_ptr));
> /* We should never reach here */
> panic("Relocation error");
>
I'm having a hard time following the logic here. What is PAGE_OFFSET -
offset supposed to be? Why would we map anything belowe PAGE_OFFSET?
-Scott
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