From: Atish Patra <atish.patra@wdc.com> To: linux-kernel@vger.kernel.org Cc: Anup Patel <anup.patel@wdc.com>, Atish Patra <atish.patra@wdc.com>, Palmer Dabbelt <palmerdabbelt@google.com>, Alistair Francis <alistair.francis@wdc.com>, Ard Biesheuvel <ardb@kernel.org>, Arvind Sankar <nivedita@alum.mit.edu>, Greentime Hu <greentime.hu@sifive.com>, Ingo Molnar <mingo@kernel.org>, linux-efi@vger.kernel.org, linux-riscv@lists.infradead.org, Masahiro Yamada <masahiroy@kernel.org>, Mike Rapoport <rppt@kernel.org>, Nick Desaulniers <ndesaulniers@google.com>, Palmer Dabbelt <palmer@dabbelt.com>, Paul Walmsley <paul.walmsley@sifive.com> Subject: [PATCH v7 1/9] RISC-V: Move DT mapping outof fixmap Date: Fri, 28 Aug 2020 10:20:28 -0700 [thread overview] Message-ID: <20200828172036.8056-2-atish.patra@wdc.com> (raw) In-Reply-To: <20200828172036.8056-1-atish.patra@wdc.com> 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> --- 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); + 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) -- 2.24.0
WARNING: multiple messages have this Message-ID (diff)
From: Atish Patra <atish.patra@wdc.com> To: linux-kernel@vger.kernel.org Cc: Anup Patel <anup.patel@wdc.com>, Palmer Dabbelt <palmer@dabbelt.com>, Masahiro Yamada <masahiroy@kernel.org>, Palmer Dabbelt <palmerdabbelt@google.com>, Nick Desaulniers <ndesaulniers@google.com>, Ingo Molnar <mingo@kernel.org>, Atish Patra <atish.patra@wdc.com>, Arvind Sankar <nivedita@alum.mit.edu>, linux-efi@vger.kernel.org, Alistair Francis <alistair.francis@wdc.com>, Paul Walmsley <paul.walmsley@sifive.com>, Greentime Hu <greentime.hu@sifive.com>, linux-riscv@lists.infradead.org, Ard Biesheuvel <ardb@kernel.org>, Mike Rapoport <rppt@kernel.org> Subject: [PATCH v7 1/9] RISC-V: Move DT mapping outof fixmap Date: Fri, 28 Aug 2020 10:20:28 -0700 [thread overview] Message-ID: <20200828172036.8056-2-atish.patra@wdc.com> (raw) In-Reply-To: <20200828172036.8056-1-atish.patra@wdc.com> 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> --- 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); + 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) -- 2.24.0 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2020-08-28 17:21 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-08-28 17:20 [PATCH v7 0/9] Add UEFI support for RISC-V Atish Patra 2020-08-28 17:20 ` Atish Patra 2020-08-28 17:20 ` Atish Patra [this message] 2020-08-28 17:20 ` [PATCH v7 1/9] RISC-V: Move DT mapping outof fixmap Atish Patra 2020-08-28 17:20 ` [PATCH v7 2/9] RISC-V: Add early ioremap support Atish Patra 2020-08-28 17:20 ` Atish Patra 2020-08-28 17:20 ` [PATCH v7 3/9] RISC-V: Implement late mapping page table allocation functions Atish Patra 2020-08-28 17:20 ` Atish Patra 2020-08-28 17:20 ` [PATCH v7 4/9] include: pe.h: Add RISC-V related PE definition Atish Patra 2020-08-28 17:20 ` Atish Patra 2020-08-28 17:20 ` [PATCH v7 5/9] RISC-V: Add PE/COFF header for EFI stub Atish Patra 2020-08-28 17:20 ` Atish Patra 2020-09-11 13:09 ` Ard Biesheuvel 2020-09-11 13:09 ` Ard Biesheuvel 2020-09-12 2:04 ` Atish Patra 2020-09-12 2:04 ` Atish Patra 2020-09-14 18:32 ` Ard Biesheuvel 2020-09-14 18:32 ` Ard Biesheuvel 2020-08-28 17:20 ` [PATCH v7 6/9] RISC-V: Add EFI stub support Atish Patra 2020-08-28 17:20 ` Atish Patra 2020-08-28 17:20 ` [PATCH v7 7/9] efi: Rename arm-init to efi-init common for all arch Atish Patra 2020-08-28 17:20 ` Atish Patra 2020-08-28 17:20 ` [PATCH v7 8/9] RISC-V: Add EFI runtime services Atish Patra 2020-08-28 17:20 ` Atish Patra 2020-08-28 17:20 ` [PATCH v7 9/9] RISC-V: Add page table dump support for uefi Atish Patra 2020-08-28 17:20 ` Atish Patra 2020-09-09 1:16 ` [PATCH v7 0/9] Add UEFI support for RISC-V Palmer Dabbelt 2020-09-09 1:16 ` Palmer Dabbelt 2020-09-09 7:29 ` Ard Biesheuvel 2020-09-09 7:29 ` Ard Biesheuvel
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