From patchwork Sun May 24 08:52:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11567179 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5188A913 for ; Sun, 24 May 2020 08:54:36 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2D71620787 for ; Sun, 24 May 2020 08:54:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="qb1PgvjA" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2D71620787 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ghiti.fr Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+patchwork-linux-riscv=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-Id:Date :Subject:To:From:Reply-To:Content-Type:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=AcPMbE94/eKHJetlA4W7Vj+PvW719re/F44/cr6atYI=; b=qb1PgvjA1hpCXc 2U7+Vv9s1enmRrNzfm6gRejhnOOZ/NjSeIILozmwJS3t8t4ZMREuGfvNQXdmXlxe3osOpmid3ixS7 6kxx2gBkpCBLDWV4Gr57/CNVndaNhD13N9T71vzv+tjwFmGS/oYCnDSQImTZEBYMjVD0XQF6VyHpV 0vgcNkgid88RgmmTN32klkPLF3mIwm+um9rvlZFQwp5L97Zf0gElV9hCfcbx2fvNvZWCXM0Apderc 9qg7/1acy324QiNGv6DiuyqtbztG9DwEyAGHjUBJ9TNlgdm6Cc4PHuSomSPGuR86y4wTCiQqyPkBq QalAZZShJe8FTF3D1t9g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jcmOu-0006by-Dx; Sun, 24 May 2020 08:54:32 +0000 Received: from relay10.mail.gandi.net ([217.70.178.230]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jcmOq-0006bG-Sh for linux-riscv@lists.infradead.org; Sun, 24 May 2020 08:54:31 +0000 Received: from localhost.localdomain (lfbn-gre-1-325-105.w90-112.abo.wanadoo.fr [90.112.45.105]) (Authenticated sender: alex@ghiti.fr) by relay10.mail.gandi.net (Postfix) with ESMTPSA id 88A61240003; Sun, 24 May 2020 08:54:19 +0000 (UTC) From: Alexandre Ghiti To: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Paul Walmsley , Palmer Dabbelt , Albert Ou , Anup Patel , Atish Patra , Zong Li , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org Subject: [PATCH v3 1/3] riscv: Move kernel mapping to vmalloc zone Date: Sun, 24 May 2020 04:52:57 -0400 Message-Id: <20200524085259.24784-2-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200524085259.24784-1-alex@ghiti.fr> References: <20200524085259.24784-1-alex@ghiti.fr> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200524_015429_199874_1AB292E5 X-CRM114-Status: GOOD ( 18.44 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at https://www.dnswl.org/, low trust [217.70.178.230 listed in list.dnswl.org] 0.0 SPF_NONE SPF: sender does not publish an SPF Record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexandre Ghiti Sender: "linux-riscv" Errors-To: linux-riscv-bounces+patchwork-linux-riscv=patchwork.kernel.org@lists.infradead.org This is a preparatory patch for relocatable kernel. The kernel used to be linked at PAGE_OFFSET address and used to be loaded physically at the beginning of the main memory. Therefore, we could use the linear mapping for the kernel mapping. But the relocated kernel base address will be different from PAGE_OFFSET and since in the linear mapping, two different virtual addresses cannot point to the same physical address, the kernel mapping needs to lie outside the linear mapping. In addition, because modules and BPF must be close to the kernel (inside +-2GB window), the kernel is placed at the end of the vmalloc zone minus 2GB, which leaves room for modules and BPF. The kernel could not be placed at the beginning of the vmalloc zone since other vmalloc allocations from the kernel could get all the +-2GB window around the kernel which would prevent new modules and BPF programs to be loaded. Signed-off-by: Alexandre Ghiti Reported-by: kbuild test robot --- arch/riscv/boot/loader.lds.S | 3 +- arch/riscv/include/asm/page.h | 10 +++++- arch/riscv/include/asm/pgtable.h | 37 +++++++++++++------- arch/riscv/kernel/head.S | 3 +- arch/riscv/kernel/module.c | 4 +-- arch/riscv/kernel/vmlinux.lds.S | 3 +- arch/riscv/mm/init.c | 58 +++++++++++++++++++++++++------- arch/riscv/mm/physaddr.c | 2 +- 8 files changed, 87 insertions(+), 33 deletions(-) diff --git a/arch/riscv/boot/loader.lds.S b/arch/riscv/boot/loader.lds.S index 47a5003c2e28..62d94696a19c 100644 --- a/arch/riscv/boot/loader.lds.S +++ b/arch/riscv/boot/loader.lds.S @@ -1,13 +1,14 @@ /* SPDX-License-Identifier: GPL-2.0 */ #include +#include OUTPUT_ARCH(riscv) ENTRY(_start) SECTIONS { - . = PAGE_OFFSET; + . = KERNEL_LINK_ADDR; .payload : { *(.payload) diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h index 2d50f76efe48..48bb09b6a9b7 100644 --- a/arch/riscv/include/asm/page.h +++ b/arch/riscv/include/asm/page.h @@ -90,18 +90,26 @@ typedef struct page *pgtable_t; #ifdef CONFIG_MMU extern unsigned long va_pa_offset; +extern unsigned long va_kernel_pa_offset; extern unsigned long pfn_base; #define ARCH_PFN_OFFSET (pfn_base) #else #define va_pa_offset 0 +#define va_kernel_pa_offset 0 #define ARCH_PFN_OFFSET (PAGE_OFFSET >> PAGE_SHIFT) #endif /* CONFIG_MMU */ extern unsigned long max_low_pfn; extern unsigned long min_low_pfn; +extern unsigned long kernel_virt_addr; #define __pa_to_va_nodebug(x) ((void *)((unsigned long) (x) + va_pa_offset)) -#define __va_to_pa_nodebug(x) ((unsigned long)(x) - va_pa_offset) +#define linear_mapping_va_to_pa(x) ((unsigned long)(x) - va_pa_offset) +#define kernel_mapping_va_to_pa(x) \ + ((unsigned long)(x) - va_kernel_pa_offset) +#define __va_to_pa_nodebug(x) \ + (((x) >= PAGE_OFFSET) ? \ + linear_mapping_va_to_pa(x) : kernel_mapping_va_to_pa(x)) #ifdef CONFIG_DEBUG_VIRTUAL extern phys_addr_t __virt_to_phys(unsigned long x); diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 35b60035b6b0..25213cfaf680 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -11,23 +11,29 @@ #include -#ifndef __ASSEMBLY__ - -/* Page Upper Directory not used in RISC-V */ -#include -#include -#include -#include - -#ifdef CONFIG_MMU +#ifndef CONFIG_MMU +#define KERNEL_VIRT_ADDR PAGE_OFFSET +#define KERNEL_LINK_ADDR PAGE_OFFSET +#else +/* + * Leave 2GB for modules and BPF that must lie within a 2GB range around + * the kernel. + */ +#define KERNEL_VIRT_ADDR (VMALLOC_END - SZ_2G + 1) +#define KERNEL_LINK_ADDR KERNEL_VIRT_ADDR #define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1) #define VMALLOC_END (PAGE_OFFSET - 1) #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) #define BPF_JIT_REGION_SIZE (SZ_128M) -#define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE) -#define BPF_JIT_REGION_END (VMALLOC_END) +#define BPF_JIT_REGION_START (kernel_virt_addr) +#define BPF_JIT_REGION_END (kernel_virt_addr + BPF_JIT_REGION_SIZE) + +#ifdef CONFIG_64BIT +#define VMALLOC_MODULE_START BPF_JIT_REGION_END +#define VMALLOC_MODULE_END VMALLOC_END +#endif /* * Roughly size the vmemmap space to be large enough to fit enough @@ -57,9 +63,16 @@ #define FIXADDR_SIZE PGDIR_SIZE #endif #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) - #endif +#ifndef __ASSEMBLY__ + +/* Page Upper Directory not used in RISC-V */ +#include +#include +#include +#include + #ifdef CONFIG_64BIT #include #else diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 98a406474e7d..8f5bb7731327 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -49,7 +49,8 @@ ENTRY(_start) #ifdef CONFIG_MMU relocate: /* Relocate return address */ - li a1, PAGE_OFFSET + la a1, kernel_virt_addr + REG_L a1, 0(a1) la a2, _start sub a1, a1, a2 add ra, ra, a1 diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c index 8bbe5dbe1341..1a8fbe05accf 100644 --- a/arch/riscv/kernel/module.c +++ b/arch/riscv/kernel/module.c @@ -392,12 +392,10 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, } #if defined(CONFIG_MMU) && defined(CONFIG_64BIT) -#define VMALLOC_MODULE_START \ - max(PFN_ALIGN((unsigned long)&_end - SZ_2G), VMALLOC_START) void *module_alloc(unsigned long size) { return __vmalloc_node_range(size, 1, VMALLOC_MODULE_START, - VMALLOC_END, GFP_KERNEL, + VMALLOC_MODULE_END, GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, __builtin_return_address(0)); } diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S index 0339b6bbe11a..a9abde62909f 100644 --- a/arch/riscv/kernel/vmlinux.lds.S +++ b/arch/riscv/kernel/vmlinux.lds.S @@ -4,7 +4,8 @@ * Copyright (C) 2017 SiFive */ -#define LOAD_OFFSET PAGE_OFFSET +#include +#define LOAD_OFFSET KERNEL_LINK_ADDR #include #include #include diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 27a334106708..17f108baec4f 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -22,6 +22,9 @@ #include "../kernel/head.h" +unsigned long kernel_virt_addr = KERNEL_VIRT_ADDR; +EXPORT_SYMBOL(kernel_virt_addr); + unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss; EXPORT_SYMBOL(empty_zero_page); @@ -178,8 +181,12 @@ void __init setup_bootmem(void) } #ifdef CONFIG_MMU +/* Offset between linear mapping virtual address and kernel load address */ unsigned long va_pa_offset; EXPORT_SYMBOL(va_pa_offset); +/* Offset between kernel mapping virtual address and kernel load address */ +unsigned long va_kernel_pa_offset; +EXPORT_SYMBOL(va_kernel_pa_offset); unsigned long pfn_base; EXPORT_SYMBOL(pfn_base); @@ -271,7 +278,7 @@ static phys_addr_t __init alloc_pmd(uintptr_t va) if (mmu_enabled) return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); - pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT; + pmd_num = (va - kernel_virt_addr) >> PGDIR_SHIFT; BUG_ON(pmd_num >= NUM_EARLY_PMDS); return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD]; } @@ -372,14 +379,30 @@ static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing." #endif +static uintptr_t load_pa, load_sz; + +void create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size) +{ + uintptr_t va, end_va; + + end_va = kernel_virt_addr + load_sz; + for (va = kernel_virt_addr; va < end_va; va += map_size) + create_pgd_mapping(pgdir, va, + load_pa + (va - kernel_virt_addr), + map_size, PAGE_KERNEL_EXEC); +} + asmlinkage void __init setup_vm(uintptr_t dtb_pa) { uintptr_t va, 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); + load_pa = (uintptr_t)(&_start); + load_sz = (uintptr_t)(&_end) - load_pa; + va_pa_offset = PAGE_OFFSET - load_pa; + va_kernel_pa_offset = kernel_virt_addr - load_pa; + pfn_base = PFN_DOWN(load_pa); /* @@ -402,26 +425,22 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) create_pmd_mapping(fixmap_pmd, FIXADDR_START, (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE); /* Setup trampoline PGD and PMD */ - create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, + create_pgd_mapping(trampoline_pg_dir, kernel_virt_addr, (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE); - create_pmd_mapping(trampoline_pmd, PAGE_OFFSET, + create_pmd_mapping(trampoline_pmd, kernel_virt_addr, load_pa, PMD_SIZE, PAGE_KERNEL_EXEC); #else /* Setup trampoline PGD */ - create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, + create_pgd_mapping(trampoline_pg_dir, kernel_virt_addr, load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC); #endif /* - * Setup early PGD covering entire kernel which will allows + * Setup early PGD covering entire kernel which will allow * us to reach paging_init(). We map all memory banks later * in setup_vm_final() below. */ - end_va = PAGE_OFFSET + load_sz; - for (va = PAGE_OFFSET; va < end_va; va += map_size) - create_pgd_mapping(early_pg_dir, va, - load_pa + (va - PAGE_OFFSET), - map_size, PAGE_KERNEL_EXEC); + create_kernel_page_table(early_pg_dir, map_size); /* Create fixed mapping for early FDT parsing */ end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE; @@ -441,6 +460,7 @@ static void __init setup_vm_final(void) uintptr_t va, map_size; phys_addr_t pa, start, end; struct memblock_region *reg; + static struct vm_struct vm_kernel = { 0 }; /* Set mmu_enabled flag */ mmu_enabled = true; @@ -467,10 +487,22 @@ static void __init setup_vm_final(void) for (pa = start; pa < end; pa += map_size) { va = (uintptr_t)__va(pa); create_pgd_mapping(swapper_pg_dir, va, pa, - map_size, PAGE_KERNEL_EXEC); + map_size, PAGE_KERNEL); } } + /* Map the kernel */ + create_kernel_page_table(swapper_pg_dir, PMD_SIZE); + + /* Reserve the vmalloc area occupied by the kernel */ + vm_kernel.addr = (void *)kernel_virt_addr; + vm_kernel.phys_addr = load_pa; + vm_kernel.size = (load_sz + PMD_SIZE) & ~(PMD_SIZE - 1); + vm_kernel.flags = VM_MAP | VM_NO_GUARD; + vm_kernel.caller = __builtin_return_address(0); + + vm_area_add_early(&vm_kernel); + /* Clear fixmap PTE and PMD mappings */ clear_fixmap(FIX_PTE); clear_fixmap(FIX_PMD); diff --git a/arch/riscv/mm/physaddr.c b/arch/riscv/mm/physaddr.c index e8e4dcd39fed..35703d5ef5fd 100644 --- a/arch/riscv/mm/physaddr.c +++ b/arch/riscv/mm/physaddr.c @@ -23,7 +23,7 @@ EXPORT_SYMBOL(__virt_to_phys); phys_addr_t __phys_addr_symbol(unsigned long x) { - unsigned long kernel_start = (unsigned long)PAGE_OFFSET; + unsigned long kernel_start = (unsigned long)kernel_virt_addr; unsigned long kernel_end = (unsigned long)_end; /*