Re: [PATCH 1/2] riscv: Register System RAM as iomem resources

[Nick Kossifidis]

ÎÏÎÏ 2020-07-09 21:27, Palmer Dabbelt ÎÎÏÎÏÎ:
> On Tue, 16 Jun 2020 00:45:46 PDT (-0700), zong.li@xxxxxxxxxx wrote:
> > Add System RAM to /proc/iomem, various tools expect it such as kdump.
> > It is also needed for page_is_ram API which checks the specified 
> > address
> > whether registered as System RAM in iomem_resource list.
> >
> > Signed-off-by: Zong Li <zong.li@xxxxxxxxxx>
> > ---
> >  arch/riscv/mm/init.c | 22 ++++++++++++++++++++++
> >  1 file changed, 22 insertions(+)
> >
> > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> > index f4adb3684f3d..bbe816e03b2f 100644
> > --- a/arch/riscv/mm/init.c
> > +++ b/arch/riscv/mm/init.c
> > @@ -517,6 +517,27 @@ void mark_rodata_ro(void)
> >  }
> >  #endif
> >
> > +void __init resource_init(void)
> > +{
> > +	struct memblock_region *region;
> > +
> > +	for_each_memblock(memory, region) {
> > +		struct resource *res;
> > +
> > +		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
> > +		if (!res)
> > +			panic("%s: Failed to allocate %zu bytes\n", __func__,
> > +			      sizeof(struct resource));
> > +
> > +		res->name = "System RAM";
> > +		res->start = 
> > __pfn_to_phys(memblock_region_memory_base_pfn(region));
> > +		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 
> > 1;
> > +		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
>
> Looks like everyone else is checking MEMBLOCK_NOMAP before registering 
> memory
> regions.  I've added that and put this on for-next.  Thanks!
>
> commit 11dc632bf515874c84887727614e8044452f1f28
> gpg: Signature made Thu 09 Jul 2020 11:24:08 AM PDT
> gpg:                using RSA key 
> 2B3C3747446843B24A943A7A2E1319F35FBB1889
> gpg:                issuer "palmer@xxxxxxxxxxx"
> gpg: Good signature from "Palmer Dabbelt <palmer@xxxxxxxxxxx>" 
> [ultimate]
> gpg:                 aka "Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>" 
> [ultimate]
> Author: Zong Li <zong.li@xxxxxxxxxx>
> Date:   Tue Jun 16 15:45:46 2020 +0800
>
>    riscv: Register System RAM as iomem resources
>       Add System RAM to /proc/iomem, various tools expect it such as 
> kdump.
>    It is also needed for page_is_ram API which checks the specified 
> address
>    whether registered as System RAM in iomem_resource list.
>       Signed-off-by: Zong Li <zong.li@xxxxxxxxxx>
>    [Palmer: check MEMBLOCK_NOMAP]
>    Signed-off-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index f4adb3684f3d..8b78fd23713e 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -517,6 +517,32 @@ void mark_rodata_ro(void)
> }
> #endif
>
> +void __init resource_init(void)
> +{
> +	struct memblock_region *region;
> +
> +	for_each_memblock(memory, region) {
> +		struct resource *res;
> +
> +		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
> +		if (!res)
> +			panic("%s: Failed to allocate %zu bytes\n", __func__,
> +			      sizeof(struct resource));
> +
> +		if (memblock_is_nomap(region) {
> +			res->name = "reserved";
> +			res->flags = IORESOURCE_MEM;
> +		} else {
> +			res->name = "System RAM";
> +			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
> +		}
> +		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
> +		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 
> 1;
> +
> +		request_resource(&iomem_resource, res);
> +	}
> +}
> +
> void __init paging_init(void)
> {
> 	setup_vm_final();
> @@ -524,6 +550,7 @@ void __init paging_init(void)
> 	sparse_init();
> 	setup_zero_page();
> 	zone_sizes_init();
> +	resource_init();
> }
>
> #ifdef CONFIG_SPARSEMEM_VMEMMAP
>
>
> > +
> > +		request_resource(&iomem_resource, res);
> > +	}
> > +}
> > +
> >  void __init paging_init(void)
> >  {
> >  	setup_vm_final();
> > @@ -524,6 +545,7 @@ void __init paging_init(void)
> >  	sparse_init();
> >  	setup_zero_page();
> >  	zone_sizes_init();
> > +	resource_init();
> >  }
> >
> >  #ifdef CONFIG_SPARSEMEM_VMEMMAP
>
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Zong Li sent a newer version of this series without this patch, since 
I'm handling this on the kexec/kdump series as well where other sections 
needed for kdump are also registered.