Linux-RISC-V Archive on lore.kernel.org
 help / color / Atom feed
From: Greentime Hu <green.hu@gmail.com>
To: Logan Gunthorpe <logang@deltatee.com>
Cc: Rob Herring <robh@kernel.org>, Albert Ou <aou@eecs.berkeley.edu>,
	Andrew Waterman <andrew@sifive.com>,
	Palmer Dabbelt <palmer@sifive.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Stephen Bates <sbates@raithlin.com>, Zong Li <zong@andestech.com>,
	paul.walmsley@sifive.com, Olof Johansson <olof@lixom.net>,
	greentime.hu@sifive.com, linux-riscv@lists.infradead.org,
	Michael Clark <michaeljclark@mac.com>,
	Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v4 2/2] RISC-V: Implement sparsemem
Date: Mon, 12 Aug 2019 12:01:49 +0800
Message-ID: <CAEbi=3d7_xefYaVXEnMJW49Bzdbbmc2+UOwXWrCiBo7YkTAihg@mail.gmail.com> (raw)
In-Reply-To: <e2603558-7b2c-2e5f-e28c-f01782dc4e66@deltatee.com>

Hi Logan,

Logan Gunthorpe <logang@deltatee.com> 於 2019年8月10日 週六 上午3:03寫道:
>
>
>
> On 2019-08-09 11:01 a.m., Greentime Hu wrote:
> > Hi Logan,
> >
> > Logan Gunthorpe <logang@deltatee.com> 於 2019年8月9日 週五 下午11:47寫道:
> >>
> >>
> >>
> >> On 2019-08-08 10:23 p.m., Greentime Hu wrote:
> >>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> >>> index 3f12b069af1d..208b3e14ccd8 100644
> >>> --- a/arch/riscv/Kconfig
> >>> +++ b/arch/riscv/Kconfig
> >>> @@ -116,7 +116,8 @@ config PGTABLE_LEVELS
> >>>         default 2
> >>>
> >>>  config HAVE_ARCH_PFN_VALID
> >>> -       def_bool y
> >>> +       bool
> >>> +       default !SPARSEMEM_VMEMMAP
> >>>
> >>>  menu "Platform type"
> >>>
> >>> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
> >>> index 8ddb6c7fedac..6991f7a5a4a7 100644
> >>> --- a/arch/riscv/include/asm/page.h
> >>> +++ b/arch/riscv/include/asm/page.h
> >>> @@ -93,16 +93,20 @@ extern unsigned long min_low_pfn;
> >>>  #define virt_to_pfn(vaddr)     (phys_to_pfn(__pa(vaddr)))
> >>>  #define pfn_to_virt(pfn)       (__va(pfn_to_phys(pfn)))
> >>>
> >>> +#if !defined(CONFIG_SPARSEMEM_VMEMMAP)
> >>> +#define pfn_valid(pfn) \
> >>> +       (((pfn) >= pfn_base) && (((pfn)-pfn_base) < max_mapnr))
> >>>  #define virt_to_page(vaddr)    (pfn_to_page(virt_to_pfn(vaddr)))
> >>>  #define page_to_virt(page)     (pfn_to_virt(page_to_pfn(page)))
> >>> +#else
> >>> +#define virt_to_page(vaddr)    ((struct page *)((((u64)vaddr -
> >>> va_pa_offset) / PAGE_SIZE) * sizeof(struct page) + VMEMMAP_START))
> >>> +#define page_to_virt(pg)       ((void *)(((((u64)pg - VMEMMAP_START) /
> >>> sizeof(struct page)) * PAGE_SIZE) + va_pa_offset))
> >>> +#endif
> >>
> >> This doesn't make sense to me at all. It should always use pfn_to_page()
> >> for virt_to_page() and the generic pfn_to_page()/page_to_pfn()
> >> implementations essentially already do what you are doing in a cleaner
> >> way. So I'd be really surprised if this does anything at all.
> >>
> >
> > Thank you for point me out that. I just checked the generic
> > implementation and I should use that one.
> > Sorry I didn't check the generic one and just implement it again.
> > I think the only patch we need is the first part to use generic
> > pfn_valid(). I just tested it and yes it can boot successfully in dts
> > with hole.
> >
> > It will fail in this check ((pfn)-pfn_base) < max_mapnr.
>
> Sounds to me like max_mapnr is not set correctly. See the code in
> setup_bootmem(). Seems like 'mem_size' should be set to the largest
> memory block, not just the one that contains the kernel...
>
>
> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> > index 3f12b069af1d..208b3e14ccd8 100644
> > --- a/arch/riscv/Kconfig
> > +++ b/arch/riscv/Kconfig
> > @@ -116,7 +116,8 @@ config PGTABLE_LEVELS
> >         default 2
> >
> >  config HAVE_ARCH_PFN_VALID
> > -       def_bool y
> > +       bool
> > +       default !SPARSEMEM_VMEMMAP
> >
> >  menu "Platform type"
> >
> > diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
> > index 8ddb6c7fedac..80d28fa1e2eb 100644
> > --- a/arch/riscv/include/asm/page.h
> > +++ b/arch/riscv/include/asm/page.h
> > @@ -100,8 +100,10 @@ extern unsigned long min_low_pfn;
> >  #define page_to_bus(page)      (page_to_phys(page))
> >  #define phys_to_page(paddr)    (pfn_to_page(phys_to_pfn(paddr)))
> >
> > +#if !defined(CONFIG_SPARSEMEM_VMEMMAP)
> >  #define pfn_valid(pfn) \
> >         (((pfn) >= pfn_base) && (((pfn)-pfn_base) < max_mapnr))
> > +#endif
> >
> >  #define ARCH_PFN_OFFSET                (pfn_base)
>
>
> This patch still makes no sense. I'm not sure why we have an arch
> specific pfn_valid() because it's very similar to the generic one. But
> my guess is there's a reason for it and it's not doing what it is
> supposed when you remove it for the sparsemem case.

It will use another pfn_valid() implementation in
include/linux/mmzone.h if CONFIG_SPARSEMEM and
!CONFIG_HAVE_ARCH_PFN_VALID
It will be this one.

static inline int pfn_valid(unsigned long pfn)
{
        if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
                return 0;
        return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
}

This generic pfn_valid() API can check the pfn is valid or not even if
there a hole in the memory.
For example:
A hole is between 0x100000000 to 0x180000000 (4GB-6GB) in my dts test case.

[    0.000000] In setup_bootmem, pfn_valid(0x180000)=1
[    0.000000] In setup_bootmem, pfn_valid(0x80000)=1
[    0.000000] In setup_bootmem, pfn_valid(0x80200)=1
[    0.000000] In setup_bootmem, pfn_valid(0x80300)=1
[    0.000000] In setup_bootmem, pfn_valid(0x160000)=0
[    0.000000] In setup_bootmem, pfn_valid(0x17ffff)=0
[    0.000000] In setup_bootmem, pfn_valid(0x120000)=0
[    0.000000] In setup_bootmem, pfn_valid(0x100000)=0
[    0.000000] In setup_bootmem, pfn_valid(0xfffff)=1

This generic pfn_valid() could tell the pfn is valid or not.


I think this one is only available for flatmem.
#define pfn_valid(pfn)  (((pfn) >= pfn_base) && (((pfn)-pfn_base) < max_mapnr))

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

  reply index

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-09 20:39 [PATCH v4 0/2] [PATCH v2 0/6] sparsemem support for RISC-V Logan Gunthorpe
2019-01-09 20:39 ` [PATCH v4 1/2] sh: mm: make use of new memblocks_present() helper Logan Gunthorpe
2019-01-15 13:58   ` Christoph Hellwig
2019-01-15 17:30     ` Logan Gunthorpe
2019-01-09 20:39 ` [PATCH v4 2/2] RISC-V: Implement sparsemem Logan Gunthorpe
2019-01-15 13:58   ` Christoph Hellwig
2019-07-31  6:30   ` Greentime Hu
2019-07-31 17:07     ` Logan Gunthorpe
2019-08-01  3:34       ` Greentime Hu
     [not found]         ` <CAEbi=3eZcgWevpX9VO9ohgxVDFVprk_t52Xbs3-TdtZ+js3NVA@mail.gmail.com>
2019-08-09 15:46           ` Logan Gunthorpe
2019-08-09 17:01             ` Greentime Hu
2019-08-09 19:03               ` Logan Gunthorpe
2019-08-12  4:01                 ` Greentime Hu [this message]
2019-08-12 15:51                   ` Logan Gunthorpe
2019-08-13  6:04                     ` Greentime Hu
2019-08-13 16:14                       ` Logan Gunthorpe
2019-08-13 16:39                         ` Paul Walmsley
2019-08-13 16:48                           ` Paul Walmsley
2019-08-13 16:49                           ` Logan Gunthorpe
2019-08-14 13:35                             ` Greentime Hu
2019-08-14 16:56                               ` Logan Gunthorpe
2019-08-14 17:40                                 ` Paul Walmsley
2019-08-14 17:46                                   ` Logan Gunthorpe
2019-08-14 20:09                                     ` Paul Walmsley
2019-08-14 22:21                               ` Logan Gunthorpe
2019-08-15  9:31                                 ` Greentime Hu
2019-08-15 16:20                                   ` Logan Gunthorpe
2019-08-16  2:07                                     ` Greentime Hu

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAEbi=3d7_xefYaVXEnMJW49Bzdbbmc2+UOwXWrCiBo7YkTAihg@mail.gmail.com' \
    --to=green.hu@gmail.com \
    --cc=andrew@sifive.com \
    --cc=aou@eecs.berkeley.edu \
    --cc=greentime.hu@sifive.com \
    --cc=hch@lst.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=logang@deltatee.com \
    --cc=michaeljclark@mac.com \
    --cc=olof@lixom.net \
    --cc=palmer@sifive.com \
    --cc=paul.walmsley@sifive.com \
    --cc=robh@kernel.org \
    --cc=sbates@raithlin.com \
    --cc=zong@andestech.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-RISC-V Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-riscv/0 linux-riscv/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-riscv linux-riscv/ https://lore.kernel.org/linux-riscv \
		linux-riscv@lists.infradead.org infradead-linux-riscv@archiver.kernel.org
	public-inbox-index linux-riscv


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-riscv


AGPL code for this site: git clone https://public-inbox.org/ public-inbox