From patchwork Thu Oct 3 09:49:16 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leif Lindholm X-Patchwork-Id: 2981861 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 52D309F288 for ; Thu, 3 Oct 2013 09:52:48 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 421BF20272 for ; Thu, 3 Oct 2013 09:52:43 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 73C98201F4 for ; Thu, 3 Oct 2013 09:52:41 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VRfZW-0004UF-PR; Thu, 03 Oct 2013 09:51:51 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VRfZK-0005Oa-Rh; Thu, 03 Oct 2013 09:51:38 +0000 Received: from mail-wi0-f178.google.com ([209.85.212.178]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VRfZ5-0005LG-61 for linux-arm-kernel@lists.infradead.org; Thu, 03 Oct 2013 09:51:26 +0000 Received: by mail-wi0-f178.google.com with SMTP id hn9so2266298wib.11 for ; Thu, 03 Oct 2013 02:51:01 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=oOF9ANPoH+HkJIUIv31EToWDkZfpeWMYHikrNufnv9A=; b=Oz4mqEWy7ak9G3Sib7YuOKMO2QbIDnsri4hFTbsp9N0rzXyKZVCgg+/X1+Vla8oepI 5TvQT+0LCOlEYivA5cMFktxG1aX1eIUOzsKNcYCkfvoSdoaQtGRUTe0aXn+QzbOw7jMK e22mGkUxJCNnkPYxwTlb2amqcaHqTPG6WmQbz13f40dII1LLnIMWr5kAuMUcqcOo3VAX lOBlsy6N/ty/PIkAxEpedkPA9AKuCsKzvq5MSVlU85jNSK5pH6W4vn/cv7VfVkDDxFPu pq5QccKsGWmdiLwlx0u3zfx4Umc9dSuQENIYRzv1Fc2XleTTME+Ir/DSNB2Hlj00ZYao CsQA== X-Gm-Message-State: ALoCoQkn+imIO7wA8XSAyCDNHymiwkHJl/sPhl9E+30aXZ+DM0i2dNPciZoY+L26YzE+ANwVtFib X-Received: by 10.180.20.77 with SMTP id l13mr1675112wie.40.1380793861221; Thu, 03 Oct 2013 02:51:01 -0700 (PDT) Received: from mohikan.mushroom.smurfnet.nu (cpc4-cmbg17-2-0-cust71.5-4.cable.virginmedia.com. [86.14.224.72]) by mx.google.com with ESMTPSA id fb9sm12112888wid.7.1969.12.31.16.00.00 (version=TLSv1.2 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 03 Oct 2013 02:51:00 -0700 (PDT) From: Leif Lindholm To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 2/2] arm: add early_ioremap support Date: Thu, 3 Oct 2013 10:49:16 +0100 Message-Id: <1380793756-2562-3-git-send-email-leif.lindholm@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1380793756-2562-1-git-send-email-leif.lindholm@linaro.org> References: <1380793756-2562-1-git-send-email-leif.lindholm@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131003_055123_569703_4785FE7D X-CRM114-Status: GOOD ( 29.72 ) X-Spam-Score: -2.6 (--) Cc: Catalin Marinas , linux-kernel@vger.kernel.org, Leif Lindholm , Nicolas Pitre X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds support for early_ioremap, based on the existing mechanism in x86. Up to 7 regions of up to 128KB each can be temporarily mapped in before paging_init, regardless of later highmem status. Cc: Nicolas Pitre Cc: Arnd Bergman Cc: Catalin Marinas Signed-off-by: Leif Lindholm --- arch/arm/Kconfig | 9 ++ arch/arm/include/asm/fixmap.h | 29 ++++- arch/arm/include/asm/io.h | 23 ++++ arch/arm/kernel/setup.c | 3 + arch/arm/mm/Makefile | 1 + arch/arm/mm/early_ioremap.c | 271 +++++++++++++++++++++++++++++++++++++++++ arch/arm/mm/mmu.c | 2 + 7 files changed, 337 insertions(+), 1 deletion(-) create mode 100644 arch/arm/mm/early_ioremap.c diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 1ad6fb6..5916a90 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1846,6 +1846,15 @@ config UACCESS_WITH_MEMCPY However, if the CPU data cache is using a write-allocate mode, this option is unlikely to provide any performance gain. +config EARLY_IOREMAP + bool "Provide early_ioremap() support for kernel initialization." + depends on MMU + help + Provides a mechanism for kernel initialisation code to temporarily + map, in a highmem-agnostic way, memory pages in before paging_init(). + It generates its map entries in kmap region (0xfff00000) before kmap + is initialized. + config SECCOMP bool prompt "Enable seccomp to safely compute untrusted bytecode" diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index bbae919..8b2507e 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -1,6 +1,8 @@ #ifndef _ASM_FIXMAP_H #define _ASM_FIXMAP_H +#include + /* * Nothing too fancy for now. * @@ -20,13 +22,38 @@ #define FIX_KMAP_BEGIN 0 #define FIX_KMAP_END (FIXADDR_SIZE >> PAGE_SHIFT) +/* + * 224 temporary boot-time mappings, used by early_ioremap(), + * before ioremap() is functional. + * + * (P)re-using the FIXADDR region, which is used for highmem + * later on, and statically aligned to 1MB. + */ +#define NR_FIX_BTMAPS 32 +#define FIX_BTMAPS_SLOTS 7 +#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) +#define FIX_BTMAP_BEGIN FIX_KMAP_BEGIN +#define FIX_BTMAP_END (FIX_KMAP_END - 1) + +#define clear_fixmap(idx) \ + __set_fixmap(idx, 0, __pgprot(0)) + #define __fix_to_virt(x) (FIXADDR_START + ((x) << PAGE_SHIFT)) #define __virt_to_fix(x) (((x) - FIXADDR_START) >> PAGE_SHIFT) extern void __this_fixmap_does_not_exist(void); -static inline unsigned long fix_to_virt(const unsigned int idx) +static __always_inline unsigned long fix_to_virt(const unsigned int idx) { + /* + * this branch gets completely eliminated after inlining, + * except when someone tries to use fixaddr indices in an + * illegal way. (such as mixing up address types or using + * out-of-range indices). + * + * If it doesn't get removed, the linker will complain + * loudly with a reasonably clear error message.. + */ if (idx >= FIX_KMAP_END) __this_fixmap_does_not_exist(); return __fix_to_virt(idx); diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h index d070741..826cd88 100644 --- a/arch/arm/include/asm/io.h +++ b/arch/arm/include/asm/io.h @@ -26,6 +26,7 @@ #include #include #include +#include #include /* @@ -397,5 +398,27 @@ extern int devmem_is_allowed(unsigned long pfn); extern void register_isa_ports(unsigned int mmio, unsigned int io, unsigned int io_shift); +/* + * early_ioremap(), early_memremap() and early_iounmap() are for + * temporary early boot-time mappings, before the real ioremap() + * is functional. + * A boot-time mapping is currently limited to at most 16 pages. + * + * This is all squashed by paging_init(). + */ +#ifdef CONFIG_EARLY_IOREMAP +extern void early_ioremap_init(void); +extern void early_ioremap_reset(void); +extern void __iomem *early_remap(resource_size_t phys_addr, + unsigned long size, u32 prot); +#define early_ioremap(x, y) early_remap(x, y, L_PTE_MT_DEV_NONSHARED) +#define early_memremap(x, y) early_remap(x, y, L_PTE_MT_WRITEALLOC) + +extern void early_iounmap(void __iomem *addr, unsigned long size); +#else +#define early_ioremap_init() +#define early_ioremap_reset() +#endif + #endif /* __KERNEL__ */ #endif /* __ASM_ARM_IO_H */ diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 0e1e2b3..b0b2360 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include #include @@ -877,6 +878,8 @@ void __init setup_arch(char **cmdline_p) parse_early_param(); + early_ioremap_init(); + sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL); sanity_check_meminfo(); arm_memblock_init(&meminfo, mdesc); diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile index ecfe6e5..fea855e 100644 --- a/arch/arm/mm/Makefile +++ b/arch/arm/mm/Makefile @@ -15,6 +15,7 @@ endif obj-$(CONFIG_MODULES) += proc-syms.o obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o +obj-$(CONFIG_EARLY_IOREMAP) += early_ioremap.o obj-$(CONFIG_HIGHMEM) += highmem.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o diff --git a/arch/arm/mm/early_ioremap.c b/arch/arm/mm/early_ioremap.c new file mode 100644 index 0000000..0a012e0 --- /dev/null +++ b/arch/arm/mm/early_ioremap.c @@ -0,0 +1,271 @@ +/* + * early_ioremap() support for ARM + * + * Based on existing support in arch/x86/mm/ioremap.c + * + * Restrictions: currently only functional before paging_init() + */ + +#include +#include + +#include +#include +#include +#include + +#include + +static int early_ioremap_debug __initdata; + +static int __init early_ioremap_debug_setup(char *str) +{ + early_ioremap_debug = 1; + + return 0; +} +early_param("early_ioremap_debug", early_ioremap_debug_setup); + +static pte_t __initdata bm_pte[PTRS_PER_PTE] __aligned(PTRS_PER_PTE * sizeof(pte_t)); +static int after_paging_init __initdata; + +static inline pmd_t * __init early_ioremap_pmd(unsigned long addr) +{ + unsigned int index = pgd_index(addr); + pgd_t *pgd = cpu_get_pgd() + index; + pud_t *pud = pud_offset(pgd, addr); + pmd_t *pmd = pmd_offset(pud, addr); + + return pmd; +} + +static inline pte_t * __init early_ioremap_pte(unsigned long addr) +{ + return &bm_pte[pte_index(addr)]; +} + +static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata; + +void __init early_ioremap_init(void) +{ + pmd_t *pmd; + int i; + u64 desc; + + if (early_ioremap_debug) + pr_info("early_ioremap_init()\n"); + + for (i = 0; i < FIX_BTMAPS_SLOTS; i++) { + slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN + NR_FIX_BTMAPS*i); + if (early_ioremap_debug) + pr_info(" %lu byte slot @ 0x%08x\n", + NR_FIX_BTMAPS * PAGE_SIZE, (u32)slot_virt[i]); + } + + pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)); + desc = *pmd; + memset(bm_pte, 0, sizeof(bm_pte)); + + pmd_populate_kernel(NULL, pmd, bm_pte); + desc = *pmd; + + BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) + != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); + + if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) { + WARN_ON(1); + pr_warn("pmd %p != %p\n", + pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))); + pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", + fix_to_virt(FIX_BTMAP_BEGIN)); + pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n", + fix_to_virt(FIX_BTMAP_END)); + pr_warn("FIX_BTMAP_END: %lu\n", FIX_BTMAP_END); + pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN); + } +} + +void __init early_ioremap_reset(void) +{ + after_paging_init = 1; +} + +static void __init __early_set_fixmap(unsigned long idx, + phys_addr_t phys, pgprot_t flags) +{ + unsigned long addr = __fix_to_virt(idx); + pte_t *pte; + u64 desc; + + if (idx >= FIX_KMAP_END) { + BUG(); + return; + } + pte = early_ioremap_pte(addr); + + if (pgprot_val(flags)) + set_pte_at(NULL, FIXADDR_START, pte, + pfn_pte(phys >> PAGE_SHIFT, flags)); + else + pte_clear(NULL, addr, pte); + flush_tlb_kernel_range(addr, addr + PAGE_SIZE); + desc = *pte; +} + +static inline void __init early_set_fixmap(unsigned long idx, + phys_addr_t phys, pgprot_t prot) +{ + __early_set_fixmap(idx, phys, prot); +} + +static inline void __init early_clear_fixmap(unsigned long idx) +{ + __early_set_fixmap(idx, 0, __pgprot(0)); +} + +static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata; +static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata; + +static void __init __iomem * +__early_remap(resource_size_t phys_addr, unsigned long size, pgprot_t prot) +{ + unsigned long offset; + resource_size_t last_addr; + unsigned int nrpages; + unsigned long idx; + int i, slot; + + slot = -1; + for (i = 0; i < FIX_BTMAPS_SLOTS; i++) { + if (!prev_map[i]) { + slot = i; + break; + } + } + + if (slot < 0) { + pr_info("early_iomap(%08llx, %08lx) not found slot\n", + (u64)phys_addr, size); + WARN_ON(1); + return NULL; + } + + if (early_ioremap_debug) { + pr_info("early_ioremap(%08llx, %08lx) [%d] => ", + (u64)phys_addr, size, slot); + } + + /* Don't allow wraparound or zero size */ + last_addr = phys_addr + size - 1; + if (!size || last_addr < phys_addr) { + WARN_ON(1); + return NULL; + } + + prev_size[slot] = size; + /* + * Mappings have to be page-aligned + */ + offset = phys_addr & ~PAGE_MASK; + phys_addr &= PAGE_MASK; + size = PAGE_ALIGN(last_addr + 1) - phys_addr; + + /* + * Mappings have to fit in the FIX_BTMAP area. + */ + nrpages = size >> PAGE_SHIFT; + if (nrpages > NR_FIX_BTMAPS) { + WARN_ON(1); + return NULL; + } + + /* + * Ok, go for it.. + */ + idx = FIX_BTMAP_BEGIN + slot * NR_FIX_BTMAPS; + while (nrpages > 0) { + early_set_fixmap(idx, phys_addr, prot); + phys_addr += PAGE_SIZE; + idx++; + --nrpages; + } + if (early_ioremap_debug) + pr_cont("%08lx + %08lx\n", offset, slot_virt[slot]); + + prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]); + return prev_map[slot]; +} + +/* Remap an IO device */ +void __init __iomem * +early_remap(resource_size_t phys_addr, unsigned long size, u32 prot) +{ + if (after_paging_init) { + WARN_ON(1); + return NULL; + } + + /* + * PAGE_KERNEL depends on not-yet-initialised variables. + * We don't care about coherency or executability of early_ioremap + * pages anyway. + */ + prot |= L_PTE_YOUNG | L_PTE_PRESENT; + return __early_remap(phys_addr, size, prot); +} + + +void __init early_iounmap(void __iomem *addr, unsigned long size) +{ + unsigned long virt_addr; + unsigned long offset; + unsigned int nrpages; + unsigned long idx; + int i, slot; + + if (after_paging_init) { + WARN_ON(1); + return; + } + + slot = -1; + for (i = 0; i < FIX_BTMAPS_SLOTS; i++) { + if (prev_map[i] == addr) { + slot = i; + break; + } + } + + if (slot < 0) { + pr_info("early_iounmap(%p, %08lx) not found slot\n", + addr, size); + WARN_ON(1); + return; + } + + if (prev_size[slot] != size) { + pr_info("early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n", + addr, size, slot, prev_size[slot]); + WARN_ON(1); + return; + } + + if (early_ioremap_debug) + pr_info("early_iounmap(%p, %08lx) [%d]\n", addr, size, slot); + + virt_addr = (unsigned long)addr; + if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) { + WARN_ON(1); + return; + } + offset = virt_addr & ~PAGE_MASK; + nrpages = PAGE_ALIGN(offset + size) >> PAGE_SHIFT; + + idx = FIX_BTMAP_BEGIN + slot * NR_FIX_BTMAPS; + while (nrpages > 0) { + early_clear_fixmap(idx); + idx++; + --nrpages; + } + prev_map[slot] = NULL; +} diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index b1d17ee..ff71eac 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -1340,4 +1341,5 @@ void __init paging_init(const struct machine_desc *mdesc) empty_zero_page = virt_to_page(zero_page); __flush_dcache_page(NULL, empty_zero_page); + early_ioremap_reset(); }