Hi Logan, Logan Gunthorpe <log...@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 <log...@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))