| Message ID | 20200917223716.2300238-2-atish.patra@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add UEFI support for RISC-V | expand |
Atish Patra <atish.patra@wdc.com> 於 2020年9月18日 週五 上午6:37寫道： > > From: Anup Patel <anup.patel@wdc.com> > > Currently, RISC-V reserves 1MB of fixmap memory for device tree. However, > it maps only single PMD (2MB) space for fixmap which leaves only < 1MB space > left for other kernel features such as early ioremap which requires fixmap > as well. The fixmap size can be increased by another 2MB but it brings > additional complexity and changes the virtual memory layout as well. > If we require some additional feature requiring fixmap again, it has to be > moved again. > > Technically, DT doesn't need a fixmap as the memory occupied by the DT is > only used during boot. That's why, We map device tree in early page table > using two consecutive PGD mappings at lower addresses (< PAGE_OFFSET). > This frees lot of space in fixmap and also makes maximum supported > device tree size supported as PGDIR_SIZE. Thus, init memory section can be used > for the same purpose as well. This simplifies fixmap implementation. > > Signed-off-by: Anup Patel <anup.patel@wdc.com> > Signed-off-by: Atish Patra <atish.patra@wdc.com> > Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> > Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> > --- > arch/riscv/include/asm/fixmap.h | 3 --- > arch/riscv/include/asm/pgtable.h | 1 + > arch/riscv/kernel/head.S | 1 - > arch/riscv/kernel/head.h | 2 -- > arch/riscv/kernel/setup.c | 9 +++++++-- > arch/riscv/mm/init.c | 26 ++++++++++++-------------- > 6 files changed, 20 insertions(+), 22 deletions(-) > > diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h > index 1ff075a8dfc7..11613f38228a 100644 > --- a/arch/riscv/include/asm/fixmap.h > +++ b/arch/riscv/include/asm/fixmap.h > @@ -22,9 +22,6 @@ > */ > enum fixed_addresses { > FIX_HOLE, > -#define FIX_FDT_SIZE SZ_1M > - FIX_FDT_END, > - FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1, > FIX_PTE, > FIX_PMD, > FIX_TEXT_POKE1, > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index eaea1f717010..815f8c959dd4 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -464,6 +464,7 @@ static inline void __kernel_map_pages(struct page *page, int numpages, int enabl > #define kern_addr_valid(addr) (1) /* FIXME */ > > extern void *dtb_early_va; > +extern uintptr_t dtb_early_pa; > void setup_bootmem(void); > void paging_init(void); > > diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S > index 0a4e81b8dc79..c6a37e8231a8 100644 > --- a/arch/riscv/kernel/head.S > +++ b/arch/riscv/kernel/head.S > @@ -259,7 +259,6 @@ clear_bss_done: > #endif > /* Start the kernel */ > call soc_early_init > - call parse_dtb > tail start_kernel > > .Lsecondary_start: > diff --git a/arch/riscv/kernel/head.h b/arch/riscv/kernel/head.h > index 105fb0496b24..b48dda3d04f6 100644 > --- a/arch/riscv/kernel/head.h > +++ b/arch/riscv/kernel/head.h > @@ -16,6 +16,4 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa); > extern void *__cpu_up_stack_pointer[]; > extern void *__cpu_up_task_pointer[]; > > -void __init parse_dtb(void); > - > #endif /* __ASM_HEAD_H */ > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c > index 2c6dd329312b..edea7ef88402 100644 > --- a/arch/riscv/kernel/setup.c > +++ b/arch/riscv/kernel/setup.c > @@ -48,8 +48,9 @@ atomic_t hart_lottery __section(.sdata); > unsigned long boot_cpu_hartid; > static DEFINE_PER_CPU(struct cpu, cpu_devices); > > -void __init parse_dtb(void) > +static void __init parse_dtb(void) > { > + /* Early scan of device tree from init memory */ > if (early_init_dt_scan(dtb_early_va)) > return; > > @@ -62,6 +63,7 @@ void __init parse_dtb(void) > > void __init setup_arch(char **cmdline_p) > { > + parse_dtb(); > init_mm.start_code = (unsigned long) _stext; > init_mm.end_code = (unsigned long) _etext; > init_mm.end_data = (unsigned long) _edata; > @@ -76,7 +78,10 @@ void __init setup_arch(char **cmdline_p) > #if IS_ENABLED(CONFIG_BUILTIN_DTB) > unflatten_and_copy_device_tree(); > #else > - unflatten_device_tree(); > + if (early_init_dt_verify(__va(dtb_early_pa))) > + unflatten_device_tree(); > + else > + pr_err("No DTB found in kernel mappings\n"); > #endif > > #ifdef CONFIG_SWIOTLB > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index 787c75f751a5..2b651f63f5c4 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -28,7 +28,9 @@ unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] > EXPORT_SYMBOL(empty_zero_page); > > extern char _start[]; > -void *dtb_early_va; > +#define DTB_EARLY_BASE_VA PGDIR_SIZE > +void *dtb_early_va __initdata; > +uintptr_t dtb_early_pa __initdata; > > static void __init zone_sizes_init(void) > { > @@ -141,8 +143,6 @@ static void __init setup_initrd(void) > } > #endif /* CONFIG_BLK_DEV_INITRD */ > > -static phys_addr_t dtb_early_pa __initdata; > - > void __init setup_bootmem(void) > { > struct memblock_region *reg; > @@ -399,7 +399,7 @@ static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) > > asmlinkage void __init setup_vm(uintptr_t dtb_pa) > { > - uintptr_t va, end_va; > + uintptr_t va, pa, end_va; > uintptr_t load_pa = (uintptr_t)(&_start); > uintptr_t load_sz = (uintptr_t)(&_end) - load_pa; > uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE); > @@ -448,16 +448,13 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > load_pa + (va - PAGE_OFFSET), > map_size, PAGE_KERNEL_EXEC); > > - /* Create fixed mapping for early FDT parsing */ > - end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE; > - for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE) > - create_pte_mapping(fixmap_pte, va, > - dtb_pa + (va - __fix_to_virt(FIX_FDT)), > - PAGE_SIZE, PAGE_KERNEL); > - > - /* Save pointer to DTB for early FDT parsing */ > - dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK); > - /* Save physical address for memblock reservation */ > + /* Create two consecutive PGD mappings for FDT early scan */ > + pa = dtb_pa & ~(PGDIR_SIZE - 1); > + create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA, > + pa, PGDIR_SIZE, PAGE_KERNEL); Hi Anup, I hit a booting failure case in Unleashed board in v5.10-rc2. After debugging, it looks like something wrong in this patch. It will create 0x40000000 as a VA start address for this mapping in rv64 here. #define DTB_EARLY_BASE_VA PGDIR_SIZE but using __va(dtb_early_pa) to get the virtual address? if (early_init_dt_verify(__va(dtb_early_pa))) unflatten_device_tree(); Would you please to take a look at it? I am not sure if I misunderstand something. Thank you. :)
On Mon, Nov 9, 2020 at 1:14 PM Greentime Hu <greentime.hu@sifive.com> wrote: > > Atish Patra <atish.patra@wdc.com> 於 2020年9月18日 週五 上午6:37寫道： > > > > From: Anup Patel <anup.patel@wdc.com> > > > > Currently, RISC-V reserves 1MB of fixmap memory for device tree. However, > > it maps only single PMD (2MB) space for fixmap which leaves only < 1MB space > > left for other kernel features such as early ioremap which requires fixmap > > as well. The fixmap size can be increased by another 2MB but it brings > > additional complexity and changes the virtual memory layout as well. > > If we require some additional feature requiring fixmap again, it has to be > > moved again. > > > > Technically, DT doesn't need a fixmap as the memory occupied by the DT is > > only used during boot. That's why, We map device tree in early page table > > using two consecutive PGD mappings at lower addresses (< PAGE_OFFSET). > > This frees lot of space in fixmap and also makes maximum supported > > device tree size supported as PGDIR_SIZE. Thus, init memory section can be used > > for the same purpose as well. This simplifies fixmap implementation. > > > > Signed-off-by: Anup Patel <anup.patel@wdc.com> > > Signed-off-by: Atish Patra <atish.patra@wdc.com> > > Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> > > Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> > > --- > > arch/riscv/include/asm/fixmap.h | 3 --- > > arch/riscv/include/asm/pgtable.h | 1 + > > arch/riscv/kernel/head.S | 1 - > > arch/riscv/kernel/head.h | 2 -- > > arch/riscv/kernel/setup.c | 9 +++++++-- > > arch/riscv/mm/init.c | 26 ++++++++++++-------------- > > 6 files changed, 20 insertions(+), 22 deletions(-) > > > > diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h > > index 1ff075a8dfc7..11613f38228a 100644 > > --- a/arch/riscv/include/asm/fixmap.h > > +++ b/arch/riscv/include/asm/fixmap.h > > @@ -22,9 +22,6 @@ > > */ > > enum fixed_addresses { > > FIX_HOLE, > > -#define FIX_FDT_SIZE SZ_1M > > - FIX_FDT_END, > > - FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1, > > FIX_PTE, > > FIX_PMD, > > FIX_TEXT_POKE1, > > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > > index eaea1f717010..815f8c959dd4 100644 > > --- a/arch/riscv/include/asm/pgtable.h > > +++ b/arch/riscv/include/asm/pgtable.h > > @@ -464,6 +464,7 @@ static inline void __kernel_map_pages(struct page *page, int numpages, int enabl > > #define kern_addr_valid(addr) (1) /* FIXME */ > > > > extern void *dtb_early_va; > > +extern uintptr_t dtb_early_pa; > > void setup_bootmem(void); > > void paging_init(void); > > > > diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S > > index 0a4e81b8dc79..c6a37e8231a8 100644 > > --- a/arch/riscv/kernel/head.S > > +++ b/arch/riscv/kernel/head.S > > @@ -259,7 +259,6 @@ clear_bss_done: > > #endif > > /* Start the kernel */ > > call soc_early_init > > - call parse_dtb > > tail start_kernel > > > > .Lsecondary_start: > > diff --git a/arch/riscv/kernel/head.h b/arch/riscv/kernel/head.h > > index 105fb0496b24..b48dda3d04f6 100644 > > --- a/arch/riscv/kernel/head.h > > +++ b/arch/riscv/kernel/head.h > > @@ -16,6 +16,4 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa); > > extern void *__cpu_up_stack_pointer[]; > > extern void *__cpu_up_task_pointer[]; > > > > -void __init parse_dtb(void); > > - > > #endif /* __ASM_HEAD_H */ > > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c > > index 2c6dd329312b..edea7ef88402 100644 > > --- a/arch/riscv/kernel/setup.c > > +++ b/arch/riscv/kernel/setup.c > > @@ -48,8 +48,9 @@ atomic_t hart_lottery __section(.sdata); > > unsigned long boot_cpu_hartid; > > static DEFINE_PER_CPU(struct cpu, cpu_devices); > > > > -void __init parse_dtb(void) > > +static void __init parse_dtb(void) > > { > > + /* Early scan of device tree from init memory */ > > if (early_init_dt_scan(dtb_early_va)) > > return; > > > > @@ -62,6 +63,7 @@ void __init parse_dtb(void) > > > > void __init setup_arch(char **cmdline_p) > > { > > + parse_dtb(); > > init_mm.start_code = (unsigned long) _stext; > > init_mm.end_code = (unsigned long) _etext; > > init_mm.end_data = (unsigned long) _edata; > > @@ -76,7 +78,10 @@ void __init setup_arch(char **cmdline_p) > > #if IS_ENABLED(CONFIG_BUILTIN_DTB) > > unflatten_and_copy_device_tree(); > > #else > > - unflatten_device_tree(); > > + if (early_init_dt_verify(__va(dtb_early_pa))) > > + unflatten_device_tree(); > > + else > > + pr_err("No DTB found in kernel mappings\n"); > > #endif > > > > #ifdef CONFIG_SWIOTLB > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > > index 787c75f751a5..2b651f63f5c4 100644 > > --- a/arch/riscv/mm/init.c > > +++ b/arch/riscv/mm/init.c > > @@ -28,7 +28,9 @@ unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] > > EXPORT_SYMBOL(empty_zero_page); > > > > extern char _start[]; > > -void *dtb_early_va; > > +#define DTB_EARLY_BASE_VA PGDIR_SIZE > > +void *dtb_early_va __initdata; > > +uintptr_t dtb_early_pa __initdata; > > > > static void __init zone_sizes_init(void) > > { > > @@ -141,8 +143,6 @@ static void __init setup_initrd(void) > > } > > #endif /* CONFIG_BLK_DEV_INITRD */ > > > > -static phys_addr_t dtb_early_pa __initdata; > > - > > void __init setup_bootmem(void) > > { > > struct memblock_region *reg; > > @@ -399,7 +399,7 @@ static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) > > > > asmlinkage void __init setup_vm(uintptr_t dtb_pa) > > { > > - uintptr_t va, end_va; > > + uintptr_t va, pa, end_va; > > uintptr_t load_pa = (uintptr_t)(&_start); > > uintptr_t load_sz = (uintptr_t)(&_end) - load_pa; > > uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE); > > @@ -448,16 +448,13 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > > load_pa + (va - PAGE_OFFSET), > > map_size, PAGE_KERNEL_EXEC); > > > > - /* Create fixed mapping for early FDT parsing */ > > - end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE; > > - for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE) > > - create_pte_mapping(fixmap_pte, va, > > - dtb_pa + (va - __fix_to_virt(FIX_FDT)), > > - PAGE_SIZE, PAGE_KERNEL); > > - > > - /* Save pointer to DTB for early FDT parsing */ > > - dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK); > > - /* Save physical address for memblock reservation */ > > + /* Create two consecutive PGD mappings for FDT early scan */ > > + pa = dtb_pa & ~(PGDIR_SIZE - 1); > > + create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA, > > + pa, PGDIR_SIZE, PAGE_KERNEL); > Hi Anup, > > I hit a booting failure case in Unleashed board in v5.10-rc2. > > After debugging, it looks like something wrong in this patch. > It will create 0x40000000 as a VA start address for this mapping in rv64 here. > #define DTB_EARLY_BASE_VA PGDIR_SIZE > > but using __va(dtb_early_pa) to get the virtual address? > if (early_init_dt_verify(__va(dtb_early_pa))) > unflatten_device_tree(); > > Would you please to take a look at it? I am not sure if I > misunderstand something. > Thank you. :) This has been already fixed in v5.10-rc3 by following patch: https://lkml.org/lkml/2020/11/4/34 Please try v5.10-rc3 at your end. Regards, Anup
diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h index 1ff075a8dfc7..11613f38228a 100644 --- a/arch/riscv/include/asm/fixmap.h +++ b/arch/riscv/include/asm/fixmap.h @@ -22,9 +22,6 @@ */ enum fixed_addresses { FIX_HOLE, -#define FIX_FDT_SIZE SZ_1M - FIX_FDT_END, - FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1, FIX_PTE, FIX_PMD, FIX_TEXT_POKE1, diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index eaea1f717010..815f8c959dd4 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -464,6 +464,7 @@ static inline void __kernel_map_pages(struct page *page, int numpages, int enabl #define kern_addr_valid(addr) (1) /* FIXME */ extern void *dtb_early_va; +extern uintptr_t dtb_early_pa; void setup_bootmem(void); void paging_init(void); diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 0a4e81b8dc79..c6a37e8231a8 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -259,7 +259,6 @@ clear_bss_done: #endif /* Start the kernel */ call soc_early_init - call parse_dtb tail start_kernel .Lsecondary_start: diff --git a/arch/riscv/kernel/head.h b/arch/riscv/kernel/head.h index 105fb0496b24..b48dda3d04f6 100644 --- a/arch/riscv/kernel/head.h +++ b/arch/riscv/kernel/head.h @@ -16,6 +16,4 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa); extern void *__cpu_up_stack_pointer[]; extern void *__cpu_up_task_pointer[]; -void __init parse_dtb(void); - #endif /* __ASM_HEAD_H */ diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 2c6dd329312b..edea7ef88402 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -48,8 +48,9 @@ atomic_t hart_lottery __section(.sdata); unsigned long boot_cpu_hartid; static DEFINE_PER_CPU(struct cpu, cpu_devices); -void __init parse_dtb(void) +static void __init parse_dtb(void) { + /* Early scan of device tree from init memory */ if (early_init_dt_scan(dtb_early_va)) return; @@ -62,6 +63,7 @@ void __init parse_dtb(void) void __init setup_arch(char **cmdline_p) { + parse_dtb(); init_mm.start_code = (unsigned long) _stext; init_mm.end_code = (unsigned long) _etext; init_mm.end_data = (unsigned long) _edata; @@ -76,7 +78,10 @@ void __init setup_arch(char **cmdline_p) #if IS_ENABLED(CONFIG_BUILTIN_DTB) unflatten_and_copy_device_tree(); #else - unflatten_device_tree(); + if (early_init_dt_verify(__va(dtb_early_pa))) + unflatten_device_tree(); + else + pr_err("No DTB found in kernel mappings\n"); #endif #ifdef CONFIG_SWIOTLB diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 787c75f751a5..2b651f63f5c4 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -28,7 +28,9 @@ unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] EXPORT_SYMBOL(empty_zero_page); extern char _start[]; -void *dtb_early_va; +#define DTB_EARLY_BASE_VA PGDIR_SIZE +void *dtb_early_va __initdata; +uintptr_t dtb_early_pa __initdata; static void __init zone_sizes_init(void) { @@ -141,8 +143,6 @@ static void __init setup_initrd(void) } #endif /* CONFIG_BLK_DEV_INITRD */ -static phys_addr_t dtb_early_pa __initdata; - void __init setup_bootmem(void) { struct memblock_region *reg; @@ -399,7 +399,7 @@ static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) asmlinkage void __init setup_vm(uintptr_t dtb_pa) { - uintptr_t va, end_va; + uintptr_t va, pa, end_va; uintptr_t load_pa = (uintptr_t)(&_start); uintptr_t load_sz = (uintptr_t)(&_end) - load_pa; uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE); @@ -448,16 +448,13 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) load_pa + (va - PAGE_OFFSET), map_size, PAGE_KERNEL_EXEC); - /* Create fixed mapping for early FDT parsing */ - end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE; - for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE) - create_pte_mapping(fixmap_pte, va, - dtb_pa + (va - __fix_to_virt(FIX_FDT)), - PAGE_SIZE, PAGE_KERNEL); - - /* Save pointer to DTB for early FDT parsing */ - dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK); - /* Save physical address for memblock reservation */ + /* Create two consecutive PGD mappings for FDT early scan */ + pa = dtb_pa & ~(PGDIR_SIZE - 1); + create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA, + pa, PGDIR_SIZE, PAGE_KERNEL); + create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA + PGDIR_SIZE, + pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL); + dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PGDIR_SIZE - 1)); dtb_early_pa = dtb_pa; } @@ -516,6 +513,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) #else dtb_early_va = (void *)dtb_pa; #endif + dtb_early_pa = dtb_pa; } static inline void setup_vm_final(void)