From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B216C77B76 for ; Tue, 18 Apr 2023 13:11:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232361AbjDRNLU (ORCPT ); Tue, 18 Apr 2023 09:11:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232383AbjDRNLR (ORCPT ); Tue, 18 Apr 2023 09:11:17 -0400 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.154.123]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E433515A25 for ; Tue, 18 Apr 2023 06:11:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1681823473; x=1713359473; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=15bpy74ikNgMqPIM0raKdUnUd0of9O0foBfRD2t7dAs=; b=eUmhsLw6F1iYlayfJyWbspjfENVW86wJRCgZgynKpb0tEt8i0fpQuOTj GHeVslR/7p9YQ1F6+5Es/+TDs07T3aBjgdjsTu406eLwRrZBLufsSWpYO WoaZpzs0ZUyDupxxvKKsj4k129NuzcbHziu+ct7xVOCG0SW7REmgMnFKW IZBT3tUqqAtC2rdMxXCJ/MAMiYGHmethrSYKeFx1FNACM3oJeUfJglV1g m2agdVPzpvhFqo4kT2L1HOnTe0qqdibOCBagD7Ccoqzjj5ly5Q8IM2ft+ A7xLCTdmys5tkw9L7TeN6ixM/Los96/tKi7Ie8D3sJuLSH/aQYN4R60ak g==; X-IronPort-AV: E=Sophos;i="5.99,207,1677567600"; d="asc'?scan'208";a="211013692" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa2.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 18 Apr 2023 06:11:12 -0700 Received: from chn-vm-ex04.mchp-main.com (10.10.85.152) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Tue, 18 Apr 2023 06:11:11 -0700 Received: from wendy (10.10.115.15) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21 via Frontend Transport; Tue, 18 Apr 2023 06:11:10 -0700 Date: Tue, 18 Apr 2023 14:10:54 +0100 From: Conor Dooley To: Greg Kroah-Hartman CC: , , Alexandre Ghiti , Palmer Dabbelt , Sasha Levin Subject: Re: [PATCH 6.1 129/134] riscv: Move early dtb mapping into the fixmap region Message-ID: <20230418-tactile-cocoa-4242e87bf994@wendy> References: <20230418120313.001025904@linuxfoundation.org> <20230418120317.673170852@linuxfoundation.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="HQeLRL0T/HY+c+fT" Content-Disposition: inline In-Reply-To: <20230418120317.673170852@linuxfoundation.org> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org --HQeLRL0T/HY+c+fT Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Apr 18, 2023 at 02:23:05PM +0200, Greg Kroah-Hartman wrote: > From: Alexandre Ghiti >=20 > [ Upstream commit ef69d2559fe91f23d27a3d6fd640b5641787d22e ] Hey Greg, Please check out (I can't find a lore link for stable-commit@vger stuff) as I am not sure whether it is okay to backport this in isolation. Cheers, Conor. >=20 > riscv establishes 2 virtual mappings: >=20 > - early_pg_dir maps the kernel which allows to discover the system > memory > - swapper_pg_dir installs the final mapping (linear mapping included) >=20 > We used to map the dtb in early_pg_dir using DTB_EARLY_BASE_VA, and this > mapping was not carried over in swapper_pg_dir. It happens that > early_init_fdt_scan_reserved_mem() must be called before swapper_pg_dir is > setup otherwise we could allocate reserved memory defined in the dtb. > And this function initializes reserved_mem variable with addresses that > lie in the early_pg_dir dtb mapping: when those addresses are reused > with swapper_pg_dir, this mapping does not exist and then we trap. >=20 > The previous "fix" was incorrect as early_init_fdt_scan_reserved_mem() > must be called before swapper_pg_dir is set up otherwise we could > allocate in reserved memory defined in the dtb. >=20 > So move the dtb mapping in the fixmap region which is established in > early_pg_dir and handed over to swapper_pg_dir. >=20 > Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blo= b") > Fixes: 8f3a2b4a96dc ("RISC-V: Move DT mapping outof fixmap") > Fixes: 50e63dd8ed92 ("riscv: fix reserved memory setup") > Reported-by: Conor Dooley > Link: https://lore.kernel.org/all/f8e67f82-103d-156c-deb0-d6d6e2756f5e@mi= crochip.com/ > Signed-off-by: Alexandre Ghiti > Reviewed-by: Conor Dooley > Tested-by: Conor Dooley > Link: https://lore.kernel.org/r/20230329081932.79831-2-alexghiti@rivosinc= =2Ecom > Cc: stable@vger.kernel.org > Signed-off-by: Palmer Dabbelt > Signed-off-by: Sasha Levin > --- > Documentation/riscv/vm-layout.rst | 6 +-- > arch/riscv/include/asm/fixmap.h | 8 ++++ > arch/riscv/include/asm/pgtable.h | 8 +++- > arch/riscv/kernel/setup.c | 1 - > arch/riscv/mm/init.c | 61 +++++++++++++++++-------------- > 5 files changed, 51 insertions(+), 33 deletions(-) >=20 > diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-l= ayout.rst > index 3be44e74ec5d6..5462c84f4723f 100644 > --- a/Documentation/riscv/vm-layout.rst > +++ b/Documentation/riscv/vm-layout.rst > @@ -47,7 +47,7 @@ RISC-V Linux Kernel SV39 > | Kernel-s= pace virtual memory, shared between all processes: > ____________________________________________________________|_________= __________________________________________________ > | | | | > - ffffffc6fee00000 | -228 GB | ffffffc6feffffff | 2 MB | fixmap > + ffffffc6fea00000 | -228 GB | ffffffc6feffffff | 6 MB | fixmap > ffffffc6ff000000 | -228 GB | ffffffc6ffffffff | 16 MB | PCI io > ffffffc700000000 | -228 GB | ffffffc7ffffffff | 4 GB | vmemmap > ffffffc800000000 | -224 GB | ffffffd7ffffffff | 64 GB | vmalloc/= ioremap space > @@ -83,7 +83,7 @@ RISC-V Linux Kernel SV48 > | Kernel-s= pace virtual memory, shared between all processes: > ____________________________________________________________|_________= __________________________________________________ > | | | | > - ffff8d7ffee00000 | -114.5 TB | ffff8d7ffeffffff | 2 MB | fixmap > + ffff8d7ffea00000 | -114.5 TB | ffff8d7ffeffffff | 6 MB | fixmap > ffff8d7fff000000 | -114.5 TB | ffff8d7fffffffff | 16 MB | PCI io > ffff8d8000000000 | -114.5 TB | ffff8f7fffffffff | 2 TB | vmemmap > ffff8f8000000000 | -112.5 TB | ffffaf7fffffffff | 32 TB | vmalloc/= ioremap space > @@ -119,7 +119,7 @@ RISC-V Linux Kernel SV57 > | Kernel-s= pace virtual memory, shared between all processes: > ____________________________________________________________|_________= __________________________________________________ > | | | | > - ff1bfffffee00000 | -57 PB | ff1bfffffeffffff | 2 MB | fixmap > + ff1bfffffea00000 | -57 PB | ff1bfffffeffffff | 6 MB | fixmap > ff1bffffff000000 | -57 PB | ff1bffffffffffff | 16 MB | PCI io > ff1c000000000000 | -57 PB | ff1fffffffffffff | 1 PB | vmemmap > ff20000000000000 | -56 PB | ff5fffffffffffff | 16 PB | vmalloc/= ioremap space > diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fix= map.h > index 5c3e7b97fcc6f..0a55099bb7349 100644 > --- a/arch/riscv/include/asm/fixmap.h > +++ b/arch/riscv/include/asm/fixmap.h > @@ -22,6 +22,14 @@ > */ > enum fixed_addresses { > FIX_HOLE, > + /* > + * The fdt fixmap mapping must be PMD aligned and will be mapped > + * using PMD entries in fixmap_pmd in 64-bit and a PGD entry in 32-bit. > + */ > + FIX_FDT_END, > + FIX_FDT =3D FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1, > + > + /* Below fixmaps will be mapped using fixmap_pte */ > FIX_PTE, > FIX_PMD, > FIX_PUD, > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pg= table.h > index 92ec2d9d7273f..2aeaf8e3a4ab0 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -87,9 +87,13 @@ > =20 > #define FIXADDR_TOP PCI_IO_START > #ifdef CONFIG_64BIT > -#define FIXADDR_SIZE PMD_SIZE > +#define MAX_FDT_SIZE PMD_SIZE > +#define FIX_FDT_SIZE (MAX_FDT_SIZE + SZ_2M) > +#define FIXADDR_SIZE (PMD_SIZE + FIX_FDT_SIZE) > #else > -#define FIXADDR_SIZE PGDIR_SIZE > +#define MAX_FDT_SIZE PGDIR_SIZE > +#define FIX_FDT_SIZE MAX_FDT_SIZE > +#define FIXADDR_SIZE (PGDIR_SIZE + FIX_FDT_SIZE) > #endif > #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) > =20 > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c > index d4a12233e728d..2acf51c235673 100644 > --- a/arch/riscv/kernel/setup.c > +++ b/arch/riscv/kernel/setup.c > @@ -280,7 +280,6 @@ void __init setup_arch(char **cmdline_p) > #else > unflatten_device_tree(); > #endif > - early_init_fdt_scan_reserved_mem(); > misc_mem_init(); > =20 > init_resources(); > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index 50a1b6edd4918..5570c52deb0b5 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -57,7 +57,6 @@ unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsign= ed long)] > EXPORT_SYMBOL(empty_zero_page); > =20 > extern char _start[]; > -#define DTB_EARLY_BASE_VA PGDIR_SIZE > void *_dtb_early_va __initdata; > uintptr_t _dtb_early_pa __initdata; > =20 > @@ -236,6 +235,14 @@ static void __init setup_bootmem(void) > set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET); > =20 > reserve_initrd_mem(); > + > + /* > + * No allocation should be done before reserving the memory as defined > + * in the device tree, otherwise the allocation could end up in a > + * reserved region. > + */ > + early_init_fdt_scan_reserved_mem(); > + > /* > * If DTB is built in, no need to reserve its memblock. > * Otherwise, do reserve it but avoid using > @@ -279,9 +286,6 @@ pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_= bss; > static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; > =20 > pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); > -static p4d_t __maybe_unused early_dtb_p4d[PTRS_PER_P4D] __initdata __ali= gned(PAGE_SIZE); > -static pud_t __maybe_unused early_dtb_pud[PTRS_PER_PUD] __initdata __ali= gned(PAGE_SIZE); > -static pmd_t __maybe_unused early_dtb_pmd[PTRS_PER_PMD] __initdata __ali= gned(PAGE_SIZE); > =20 > #ifdef CONFIG_XIP_KERNEL > #define pt_ops (*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops)) > @@ -626,9 +630,6 @@ static void __init create_p4d_mapping(p4d_t *p4dp, > #define trampoline_pgd_next (pgtable_l5_enabled ? \ > (uintptr_t)trampoline_p4d : (pgtable_l4_enabled ? \ > (uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd)) > -#define early_dtb_pgd_next (pgtable_l5_enabled ? \ > - (uintptr_t)early_dtb_p4d : (pgtable_l4_enabled ? \ > - (uintptr_t)early_dtb_pud : (uintptr_t)early_dtb_pmd)) > #else > #define pgd_next_t pte_t > #define alloc_pgd_next(__va) pt_ops.alloc_pte(__va) > @@ -636,7 +637,6 @@ static void __init create_p4d_mapping(p4d_t *p4dp, > #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ > create_pte_mapping(__nextp, __va, __pa, __sz, __prot) > #define fixmap_pgd_next ((uintptr_t)fixmap_pte) > -#define early_dtb_pgd_next ((uintptr_t)early_dtb_pmd) > #define create_p4d_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while= (0) > #define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while= (0) > #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while= (0) > @@ -859,32 +859,28 @@ static void __init create_kernel_page_table(pgd_t *= pgdir, bool early) > * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PG= DIR > * entry. > */ > -static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t d= tb_pa) > +static void __init create_fdt_early_page_table(pgd_t *pgdir, > + uintptr_t fix_fdt_va, > + uintptr_t dtb_pa) > { > -#ifndef CONFIG_BUILTIN_DTB > uintptr_t pa =3D dtb_pa & ~(PMD_SIZE - 1); > =20 > - create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA, > - IS_ENABLED(CONFIG_64BIT) ? early_dtb_pgd_next : pa, > - PGDIR_SIZE, > - IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL); > - > - if (pgtable_l5_enabled) > - create_p4d_mapping(early_dtb_p4d, DTB_EARLY_BASE_VA, > - (uintptr_t)early_dtb_pud, P4D_SIZE, PAGE_TABLE); > - > - if (pgtable_l4_enabled) > - create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA, > - (uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE); > +#ifndef CONFIG_BUILTIN_DTB > + /* Make sure the fdt fixmap address is always aligned on PMD size */ > + BUILD_BUG_ON(FIX_FDT % (PMD_SIZE / PAGE_SIZE)); > =20 > - if (IS_ENABLED(CONFIG_64BIT)) { > - create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA, > + /* In 32-bit only, the fdt lies in its own PGD */ > + if (!IS_ENABLED(CONFIG_64BIT)) { > + create_pgd_mapping(early_pg_dir, fix_fdt_va, > + pa, MAX_FDT_SIZE, PAGE_KERNEL); > + } else { > + create_pmd_mapping(fixmap_pmd, fix_fdt_va, > pa, PMD_SIZE, PAGE_KERNEL); > - create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE, > + create_pmd_mapping(fixmap_pmd, fix_fdt_va + PMD_SIZE, > pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL); > } > =20 > - dtb_early_va =3D (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1)); > + dtb_early_va =3D (void *)fix_fdt_va + (dtb_pa & (PMD_SIZE - 1)); > #else > /* > * For 64-bit kernel, __va can't be used since it would return a linear > @@ -1054,7 +1050,8 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > create_kernel_page_table(early_pg_dir, true); > =20 > /* Setup early mapping for FDT early scan */ > - create_fdt_early_page_table(early_pg_dir, dtb_pa); > + create_fdt_early_page_table(early_pg_dir, > + __fix_to_virt(FIX_FDT), dtb_pa); > =20 > /* > * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap > @@ -1096,6 +1093,16 @@ static void __init setup_vm_final(void) > u64 i; > =20 > /* Setup swapper PGD for fixmap */ > +#if !defined(CONFIG_64BIT) > + /* > + * In 32-bit, the device tree lies in a pgd entry, so it must be copied > + * directly in swapper_pg_dir in addition to the pgd entry that points > + * to fixmap_pte. > + */ > + unsigned long idx =3D pgd_index(__fix_to_virt(FIX_FDT)); > + > + set_pgd(&swapper_pg_dir[idx], early_pg_dir[idx]); > +#endif > create_pgd_mapping(swapper_pg_dir, FIXADDR_START, > __pa_symbol(fixmap_pgd_next), > PGDIR_SIZE, PAGE_TABLE); > --=20 > 2.39.2 >=20 >=20 >=20 --HQeLRL0T/HY+c+fT Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZD6W3gAKCRB4tDGHoIJi 0n4jAPkBNaJEves6c2aFFfaQoy01w5IEzTZCiboSdHzHtltGhwD/e/RxwhujiNIj wan4iSgCySfeg2ph6P9aBV+F+n8vVwk= =DP/c -----END PGP SIGNATURE----- --HQeLRL0T/HY+c+fT--