Hi Logan,
On Thu, Aug 15, 2019 at 6:21 AM Logan Gunthorpe <log...@deltatee.com> wrote:
>
> Hey,
>
> On 2019-08-14 7:35 a.m., Greentime Hu wrote:
> > How about this fix? Not sure if it is good for everyone.
>
> I applied your fix to the patch and it seems ok. But it doesn't seem to
> work on a recent version of the kernel. Have you got it working on v5.3?
> It seems the following patch breaks things:
>
> 671f9a3e2e24 ("RISC-V: Setup initial page tables in two stages")
>
> I don't really have time right now to debug this any further.
>
I just tried v5.3-rc4 and it failed. I try to debug this case.
I found it failed might be because of an unmapped virtual address is used
in memblocks_present() -> memblock_alloc ().
In this commit 671f9a3e2e24 ("RISC-V: Setup initial page tables in two
stages"), it finishes all the VA/PA mapping after setup_vm_final() is
called.
So we have to call memblocks_present() and sparse_init() right after
setup_vm_final().
Here is my patch and I tested with memory-with-hole.
It can boot normally in Unleashed board after applying this patch.
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 27d1d847fb2d..35aacb0c93e5 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -138,8 +138,6 @@ void __init setup_bootmem(void)
PFN_PHYS(end_pfn - start_pfn),
&memblock.memory, 0);
}
- memblocks_present();
- sparse_init();
}
unsigned long va_pa_offset;
@@ -452,6 +450,8 @@ static void __init setup_vm_final(void)
void __init paging_init(void)
{
setup_vm_final();
+ memblocks_present();
+ sparse_init();
setup_zero_page();
zone_sizes_init();
}
Test case:
memory@80000000 {
device_type = "memory";
reg = <0x0 0x80000000 0x0 0x80000000>;
};
memory@180000000 {
device_type = "memory";
reg = <0x1 0x80000000 0x0 0x40000000>;
};
# cat /proc/meminfo
MemTotal: 3003496 kB
MemFree: 2986584 kB
MemAvailable: 2970176 kB
Buffers: 0 kB
Cached: 3540 kB
SwapCached: 0 kB
Active: 3920 kB
Inactive: 68 kB
Active(anon): 3920 kB
Inactive(anon): 68 kB
Active(file): 0 kB
Inactive(file): 0 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 0 kB
SwapFree: 0 kB
Dirty: 0 kB
Writeback: 0 kB
AnonPages: 528 kB
Mapped: 1984 kB
Shmem: 3540 kB
KReclaimable: 688 kB
Slab: 5700 kB
SReclaimable: 688 kB
SUnreclaim: 5012 kB
KernelStack: 424 kB
PageTables: 80 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 1501748 kB
Committed_AS: 3200 kB
VmallocTotal: 67108863 kB
VmallocUsed: 12 kB
VmallocChunk: 0 kB
Percpu: 272 kB
# uname -a
Linux buildroot 5.3.0-rc4-00001-g44404421c481-dirty #10 SMP Thu Aug 15
16:28:24 DST 2019 riscv64 GNU/Lin[ 2352.443621] random: fast init done
ux
# zcat /proc/config.gz |grep SPARSE
CONFIG_SPARSE_IRQ=y
CONFIG_ARCH_SPARSEMEM_ENABLE=y
CONFIG_SPARSEMEM_MANUAL=y
CONFIG_SPARSEMEM=y
CONFIG_SPARSEMEM_EXTREME=y
CONFIG_SPARSEMEM_VMEMMAP_ENABLE=y
CONFIG_SPARSEMEM_VMEMMAP=y
# CONFIG_INPUT_SPARSEKMAP is not set
