From: Greentime Hu <greentime.hu@sifive.com>
To: Atish Patra <atish.patra@wdc.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Anup Patel <anup.patel@wdc.com>,
Palmer Dabbelt <palmerdabbelt@google.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Alistair Francis <alistair.francis@wdc.com>,
Andrew Morton <akpm@linux-foundation.org>,
Ard Biesheuvel <ardb@kernel.org>,
Arvind Sankar <nivedita@alum.mit.edu>,
Borislav Petkov <bp@suse.de>, Heiko Carstens <hca@linux.ibm.com>,
Ingo Molnar <mingo@kernel.org>, Kees Cook <keescook@chromium.org>,
linux-efi@vger.kernel.org,
linux-riscv <linux-riscv@lists.infradead.org>,
Masahiro Yamada <masahiroy@kernel.org>,
Maxim Uvarov <maxim.uvarov@linaro.org>,
Michal Simek <michal.simek@xilinx.com>,
Mike Rapoport <rppt@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Thomas Gleixner <tglx@linutronix.de>,
Zong Li <zong.li@sifive.com>
Subject: Re: [PATCH v8 1/7] RISC-V: Move DT mapping outof fixmap
Date: Mon, 9 Nov 2020 15:44:03 +0800 [thread overview]
Message-ID: <CAHCEehJVEJzUrAsYqiZCZ7_qtJ+uXBrdbj6LQkZW-v87CRiH=Q@mail.gmail.com> (raw)
In-Reply-To: <20200917223716.2300238-2-atish.patra@wdc.com>
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. :)
next prev parent reply other threads:[~2020-11-09 7:44 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-17 22:37 [PATCH v8 0/7] Add UEFI support for RISC-V Atish Patra
2020-09-17 22:37 ` [PATCH v8 1/7] RISC-V: Move DT mapping outof fixmap Atish Patra
2020-11-09 7:44 ` Greentime Hu [this message]
2020-11-09 8:19 ` Anup Patel
2020-09-17 22:37 ` [PATCH v8 2/7] RISC-V: Add early ioremap support Atish Patra
2020-09-17 22:37 ` [PATCH v8 3/7] RISC-V: Implement late mapping page table allocation functions Atish Patra
2020-09-17 22:37 ` [PATCH v8 4/7] RISC-V: Add PE/COFF header for EFI stub Atish Patra
2020-09-17 22:37 ` [PATCH v8 5/7] RISC-V: Add EFI stub support Atish Patra
2020-09-17 22:37 ` [PATCH v8 6/7] RISC-V: Add EFI runtime services Atish Patra
2020-09-17 22:37 ` [PATCH v8 7/7] RISC-V: Add page table dump support for uefi Atish Patra
2020-10-02 21:38 ` [PATCH v8 0/7] Add UEFI support for RISC-V Palmer Dabbelt
Reply instructions:
You may reply publicly 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='CAHCEehJVEJzUrAsYqiZCZ7_qtJ+uXBrdbj6LQkZW-v87CRiH=Q@mail.gmail.com' \
--to=greentime.hu@sifive.com \
--cc=akpm@linux-foundation.org \
--cc=alistair.francis@wdc.com \
--cc=anup.patel@wdc.com \
--cc=aou@eecs.berkeley.edu \
--cc=ardb@kernel.org \
--cc=atish.patra@wdc.com \
--cc=bp@suse.de \
--cc=hca@linux.ibm.com \
--cc=keescook@chromium.org \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=masahiroy@kernel.org \
--cc=maxim.uvarov@linaro.org \
--cc=michal.simek@xilinx.com \
--cc=mingo@kernel.org \
--cc=ndesaulniers@google.com \
--cc=nivedita@alum.mit.edu \
--cc=palmer@dabbelt.com \
--cc=palmerdabbelt@google.com \
--cc=paul.walmsley@sifive.com \
--cc=rppt@kernel.org \
--cc=tglx@linutronix.de \
--cc=zong.li@sifive.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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).