Hi Paul,
On Thu, Aug 30, 2018 at 02:48:57PM -0700, Paul Burton wrote:
> Hi Mike,
>
> On Mon, Aug 27, 2018 at 10:59:35AM +0300, Mike Rapoport wrote:
> > MIPS already has memblock support and all the memory is already registered
> > with it.
> >
> > This patch replaces bootmem memory reservations with memblock ones and
> > removes the bootmem initialization.
> >
> > Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
> > ---
> >
> > arch/mips/Kconfig | 1 +
> > arch/mips/kernel/setup.c | 89 +++++-----------------------------
> > arch/mips/loongson64/loongson-3/numa.c | 34 ++++++-------
> > arch/mips/sgi-ip27/ip27-memory.c | 11 ++---
> > 4 files changed, 33 insertions(+), 102 deletions(-)
>
> Thanks for working on this. Unfortunately it breaks boot for at least a
> 32r6el_defconfig kernel on QEMU:
>
> $ qemu-system-mips64el \
> -M boston \
> -kernel arch/mips/boot/vmlinux.gz.itb \
> -serial stdio \
> -append "earlycon=uart8250,mmio32,0x17ffe000,115200 console=ttyS0,115200 debug memblock=debug mminit_loglevel=4"
> [ 0.000000] Linux version 4.19.0-rc1-00008-g82d0f342eecd (pburton@pburton-laptop) (gcc version 8.1.0 (GCC)) #23 SMP Thu Aug 30 14:38:06 PDT 2018
> [ 0.000000] CPU0 revision is: 0001a900 (MIPS I6400)
> [ 0.000000] FPU revision is: 20f30300
> [ 0.000000] MSA revision is: 00000300
> [ 0.000000] MIPS: machine is img,boston
> [ 0.000000] Determined physical RAM map:
> [ 0.000000] memory: 10000000 @ 00000000 (usable)
> [ 0.000000] memory: 30000000 @ 90000000 (usable)
> [ 0.000000] earlycon: uart8250 at MMIO32 0x17ffe000 (options '115200')
> [ 0.000000] bootconsole [uart8250] enabled
> [ 0.000000] memblock_reserve: [0x00000000-0x009a8fff] setup_arch+0x224/0x718
> [ 0.000000] memblock_reserve: [0x01360000-0x01361ca7] setup_arch+0x3d8/0x718
> [ 0.000000] Initrd not found or empty - disabling initrd
> [ 0.000000] memblock_virt_alloc_try_nid: 7336 bytes align=0x40 nid=-1 from=0x00000000 max_addr=0x00000000 early_init_dt_alloc_memory_arch+0x20/0x2c
> [ 0.000000] memblock_reserve: [0xbfffe340-0xbfffffe7] memblock_virt_alloc_internal+0x120/0x1ec
> <hang>
>
> It looks like we took a TLB store exception after calling memset() with
> a bogus address from memblock_virt_alloc_try_nid() or something inlined
> into it.
Memblock tries to allocate from the top and the resulting address ends up
in the high memory.
With the hunk below I was able to get to "VFS: Cannot open root device"
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 4114d3c..4a9b0f7 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -577,6 +577,8 @@ static void __init bootmem_init(void)
* Reserve initrd memory if needed.
*/
finalize_initrd();
+
+ memblock_set_bottom_up(true);
}
#endif /* CONFIG_SGI_IP27 */
> This was with your patch applied atop the mips-next branch from [1],
> which is currently at commit 35d017947401 ("MIPS: ralink: Add rt3352
> SPI_CS1 pinmux").
>
> Thanks,
> Paul
>
> [1] git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux.git
>
--
Sincerely yours,
Mike.
