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bh=ESp2E7pfeoT/Ep8DHoSveXOnYfjxa2ukAzQSH1Y2Mbs=; b=zqiREk2L/k55W1IC0WzdHVBVwlGWm5CtCEzfIcA0QSiFKE2fSIJ8By0BCbup1PUxra J8AvAJbvHC4e/NTCO/hzwA3C1e1VY1C0bihHE1iaJ02aavAuG1p1fht/nC3VFv+5Mpnu ID2jbCXMvQD9rbtUu8YX7sEEruuXIZRzROLmTku/TdpuIsykCVp8ZP6f4pwOTAXvskUL ac0L2wV17JcoMx8QiTkmXJUoC7SkOUDaRP3FmAIn8ZVcoPmv92UhdgrGwys2k/rdje6C +pXEZ7YCRE7EEF/1QG+pWAIBqJVqWpIUfwIURk7AW/Ra5qQ77IRB5vJ/bKOfpTfkPHO1 UC1A== X-Gm-Message-State: AOAM530WiO12WM7sobpctNML/ag0Yrz6aPLwjK6CSZqKq4zQDLm4Uxvy DK7v1gKuoOawtuPzv09aeZTZzu1udrTrUEDmaILO X-Google-Smtp-Source: ABdhPJzv5y7rMTiwliOC7ZtzsES1QyzKHnNjh0FOdc2dd9fKr9gwE4F6V691iqLUDyE1u9OUro8JLlJVhXV5ZHVCw8U= X-Received: by 2002:a25:8b0a:: with SMTP id i10mr10088995ybl.651.1644538386314; Thu, 10 Feb 2022 16:13:06 -0800 (PST) MIME-Version: 1.0 References: <20220209123800.269774-1-heiko@sntech.de> <20220209123800.269774-15-heiko@sntech.de> In-Reply-To: <20220209123800.269774-15-heiko@sntech.de> From: Atish Patra Date: Thu, 10 Feb 2022 16:12:55 -0800 Message-ID: Subject: Re: [PATCH v6 14/14] riscv: add memory-type errata for T-Head To: Heiko Stuebner Cc: Palmer Dabbelt , Paul Walmsley , Albert Ou , linux-riscv , devicetree , "linux-kernel@vger.kernel.org List" , Rob Herring , Wei Fu , liush , Guo Ren , Anup Patel , Drew Fustini , Christoph Hellwig , Arnd Bergmann , Chen-Yu Tsai , Maxime Ripard , Greg Favor , Andrea Mondelli , Jonathan Behrens , Xinhaoqu , Bill Huffman , Nick Kossifidis , Allen Baum , Josh Scheid , Richard Trauben , Samuel Holland , Christoph Muellner , Philipp Tomsich X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220210_161307_814734_03E6A344 X-CRM114-Status: GOOD ( 34.35 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Wed, Feb 9, 2022 at 4:41 AM Heiko Stuebner wrote: > > Some current cpus based on T-Head cores implement memory-types > way different than described in the svpbmt spec even going > so far as using PTE bits marked as reserved. > > Add the T-Head vendor-id and necessary errata code to > replace the affected instructions. > > Signed-off-by: Heiko Stuebner > --- > arch/riscv/Kconfig.erratas | 19 ++++++ > arch/riscv/errata/Makefile | 1 + > arch/riscv/errata/sifive/errata.c | 7 ++- > arch/riscv/errata/thead/Makefile | 1 + > arch/riscv/errata/thead/errata.c | 85 ++++++++++++++++++++++++++ > arch/riscv/include/asm/alternative.h | 5 ++ > arch/riscv/include/asm/errata_list.h | 47 ++++++++++++-- > arch/riscv/include/asm/pgtable-64.h | 18 +++++- > arch/riscv/include/asm/pgtable.h | 18 +++++- > arch/riscv/include/asm/vendorid_list.h | 1 + > arch/riscv/kernel/alternative.c | 14 +++++ > arch/riscv/kernel/cpufeature.c | 2 + > arch/riscv/mm/init.c | 1 + > 13 files changed, 210 insertions(+), 9 deletions(-) > create mode 100644 arch/riscv/errata/thead/Makefile > create mode 100644 arch/riscv/errata/thead/errata.c > > diff --git a/arch/riscv/Kconfig.erratas b/arch/riscv/Kconfig.erratas > index d18be8ff0245..380ec039c3dc 100644 > --- a/arch/riscv/Kconfig.erratas > +++ b/arch/riscv/Kconfig.erratas > @@ -31,4 +31,23 @@ config ERRATA_SIFIVE_CIP_1200 > > If you don't know what to do here, say "Y". > > +config ERRATA_THEAD > + bool "T-HEAD errata" > + help > + All T-HEAD errata Kconfig depend on this Kconfig. Disabling > + this Kconfig will disable all T-HEAD errata. Please say "Y" > + here if your platform uses T-HEAD CPU cores. > + > + If you don't know what to do here, say "Y". > + > +config ERRATA_THEAD_PBMT > + bool "Apply T-Head memory type errata" > + depends on ERRATA_THEAD && 64BIT > + default y > + help > + This will apply the memory type errata to handle the non-standard > + memory type bits in page-table-entries on T-Head SoCs. > + > + If you don't know what to do here, say "Y". > + > endmenu > diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile > index 0ca1c5281a2d..a1055965fbee 100644 > --- a/arch/riscv/errata/Makefile > +++ b/arch/riscv/errata/Makefile > @@ -1 +1,2 @@ > obj-$(CONFIG_ERRATA_SIFIVE) += sifive/ > +obj-$(CONFIG_ERRATA_THEAD) += thead/ > diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c > index 4fe03ac41fd7..f933d6cdf304 100644 > --- a/arch/riscv/errata/sifive/errata.c > +++ b/arch/riscv/errata/sifive/errata.c > @@ -84,10 +84,15 @@ void __init sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry * > unsigned int stage) > { > struct alt_entry *alt; > - u32 cpu_req_errata = sifive_errata_probe(archid, impid); > + u32 cpu_req_errata; > u32 cpu_apply_errata = 0; > u32 tmp; > > + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) > + return; > + > + cpu_req_errata = sifive_errata_probe(archid, impid); > + > for (alt = begin; alt < end; alt++) { > if (alt->vendor_id != SIFIVE_VENDOR_ID) > continue; > diff --git a/arch/riscv/errata/thead/Makefile b/arch/riscv/errata/thead/Makefile > new file mode 100644 > index 000000000000..2d644e19caef > --- /dev/null > +++ b/arch/riscv/errata/thead/Makefile > @@ -0,0 +1 @@ > +obj-y += errata.o > diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c > new file mode 100644 > index 000000000000..fd8e0538a3f0 > --- /dev/null > +++ b/arch/riscv/errata/thead/errata.c > @@ -0,0 +1,85 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (C) 2021 Heiko Stuebner > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +struct errata_info { > + char name[ERRATA_STRING_LENGTH_MAX]; > + bool (*check_func)(unsigned long arch_id, unsigned long impid); > + unsigned int stage; > +}; > + > +static bool errata_mt_check_func(unsigned long arch_id, unsigned long impid) > +{ > + if (arch_id != 0 || impid != 0) > + return false; > + return true; > +} > + > +static const struct errata_info errata_list[ERRATA_THEAD_NUMBER] = { > + { > + .name = "memory-types", > + .stage = RISCV_ALTERNATIVES_EARLY_BOOT, > + .check_func = errata_mt_check_func > + }, > +}; > + > +static u32 thead_errata_probe(unsigned int stage, unsigned long archid, unsigned long impid) > +{ > + const struct errata_info *info; > + u32 cpu_req_errata = 0; > + int idx; > + > + for (idx = 0; idx < ERRATA_THEAD_NUMBER; idx++) { > + info = &errata_list[idx]; > + > + if ((stage == RISCV_ALTERNATIVES_MODULE || > + info->stage == stage) && info->check_func(archid, impid)) > + cpu_req_errata |= (1U << idx); > + } > + > + return cpu_req_errata; > +} > + > +void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, > + unsigned long archid, unsigned long impid, > + unsigned int stage) > +{ > + struct alt_entry *alt; > + u32 cpu_req_errata = thead_errata_probe(stage, archid, impid); > + u32 cpu_apply_errata = 0; > + u32 tmp; > + > + for (alt = begin; alt < end; alt++) { > + if (alt->vendor_id != THEAD_VENDOR_ID) > + continue; > + if (alt->errata_id >= ERRATA_THEAD_NUMBER) > + continue; > + > + tmp = (1U << alt->errata_id); > + if (cpu_req_errata & tmp) { > + /* On vm-alternatives, the mmu isn't running yet */ > + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) > + memcpy((void *)__pa_symbol(alt->old_ptr), > + (void *)__pa_symbol(alt->alt_ptr), alt->alt_len); > + else > + patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); > + > + cpu_apply_errata |= tmp; > + } > + } > + > + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) > + local_flush_icache_all(); > +} > diff --git a/arch/riscv/include/asm/alternative.h b/arch/riscv/include/asm/alternative.h > index cf3b22173834..d1154c91ab03 100644 > --- a/arch/riscv/include/asm/alternative.h > +++ b/arch/riscv/include/asm/alternative.h > @@ -19,8 +19,10 @@ > > #define RISCV_ALTERNATIVES_BOOT 0 /* alternatives applied during regular boot */ > #define RISCV_ALTERNATIVES_MODULE 1 /* alternatives applied during module-init */ > +#define RISCV_ALTERNATIVES_EARLY_BOOT 2 /* alternatives applied before mmu start */ > But this stage invoked is used after RISCV_ALTERNATIVES_BOOT > void __init apply_boot_alternatives(void); > +void __init apply_early_boot_alternatives(void); > void apply_module_alternatives(void *start, size_t length); > > struct alt_entry { > @@ -39,6 +41,9 @@ struct errata_checkfunc_id { > void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, > unsigned long archid, unsigned long impid, > unsigned int stage); > +void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, > + unsigned long archid, unsigned long impid, > + unsigned int stage); > > void riscv_cpufeature_patch_func(struct alt_entry *begin, struct alt_entry *end, > unsigned int stage); > diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h > index a4a9b0842922..4fac46b82c16 100644 > --- a/arch/riscv/include/asm/errata_list.h > +++ b/arch/riscv/include/asm/errata_list.h > @@ -14,6 +14,11 @@ > #define ERRATA_SIFIVE_NUMBER 2 > #endif > > +#ifdef CONFIG_ERRATA_THEAD > +#define ERRATA_THEAD_PBMT 0 > +#define ERRATA_THEAD_NUMBER 1 > +#endif > + > #define CPUFEATURE_SVPBMT 0 > #define CPUFEATURE_NUMBER 1 > > @@ -42,10 +47,44 @@ asm(ALTERNATIVE("sfence.vma %0", "sfence.vma", SIFIVE_VENDOR_ID, \ > * in the default case. > */ > #define ALT_SVPBMT_SHIFT 61 > -#define ALT_SVPBMT(_val, prot) \ > -asm(ALTERNATIVE("li %0, 0\t\nnop", "li %0, %1\t\nslli %0,%0,%2", 0, \ > - CPUFEATURE_SVPBMT, CONFIG_64BIT) \ > - : "=r"(_val) : "I"(prot##_SVPBMT >> ALT_SVPBMT_SHIFT), "I"(ALT_SVPBMT_SHIFT)) > +#define ALT_THEAD_PBMT_SHIFT 59 > +#define ALT_SVPBMT(_val, prot) \ > +asm(ALTERNATIVE_2("li %0, 0\t\nnop", \ > + "li %0, %1\t\nslli %0,%0,%3", 0, CPUFEATURE_SVPBMT, CONFIG_64BIT, \ > + "li %0, %2\t\nslli %0,%0,%4", THEAD_VENDOR_ID, ERRATA_THEAD_PBMT, \ > + CONFIG_ERRATA_THEAD_PBMT) \ > + : "=r"(_val) : "I"(prot##_SVPBMT >> ALT_SVPBMT_SHIFT), \ > + "I"(prot##_THEAD >> ALT_THEAD_PBMT_SHIFT), \ > + "I"(ALT_SVPBMT_SHIFT), "I"(ALT_THEAD_PBMT_SHIFT)) > + > +#ifdef CONFIG_ERRATA_THEAD_PBMT > +/* > + * IO/NOCACHE memory types are handled together with svpbmt, > + * so on T-Head chips, check if no other memory type is set, > + * and set the non-0 PMA type if applicable. > + */ > +#define ALT_THEAD_PMA(_val) \ > +asm volatile(ALTERNATIVE( \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop", \ > + "li t3, %2\n\t" \ > + "slli t3, t3, %4\n\t" \ > + "and t3, %0, t3\n\t" \ > + "bne t3, zero, 2f\n\t" \ > + "li t3, %3\n\t" \ > + "slli t3, t3, %4\n\t" \ > + "or %0, %0, t3\n\t" \ > + "2:", THEAD_VENDOR_ID, ERRATA_THEAD_PBMT, CONFIG_ERRATA_THEAD_PBMT) \ > + : "+r"(_val) : "0"(_val), "I"(_PAGE_MTMASK_THEAD >> ALT_THEAD_PBMT_SHIFT), \ > + "I"(_PAGE_PMA_THEAD >> ALT_THEAD_PBMT_SHIFT), "I"(ALT_THEAD_PBMT_SHIFT)) > +#else > +#define ALT_THEAD_PMA(_val) > +#endif > > #endif /* __ASSEMBLY__ */ > > diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h > index 07ba3416cb19..6d59e4695200 100644 > --- a/arch/riscv/include/asm/pgtable-64.h > +++ b/arch/riscv/include/asm/pgtable-64.h > @@ -69,6 +69,18 @@ typedef struct { > #define _PAGE_IO_SVPBMT (1UL << 62) > #define _PAGE_MTMASK_SVPBMT (_PAGE_NOCACHE_SVPBMT | _PAGE_IO_SVPBMT) > > +/* > + * [63:59] T-Head Memory Type definitions: > + * > + * 00000 - NC Weakly-ordered, Non-cacheable, Non-bufferable, Non-shareable, Non-trustable > + * 01110 - PMA Weakly-ordered, Cacheable, Bufferable, Shareable, Non-trustable > + * 10000 - IO Strongly-ordered, Non-cacheable, Non-bufferable, Non-shareable, Non-trustable > + */ > +#define _PAGE_PMA_THEAD ((1UL << 62) | (1UL << 61) | (1UL << 60)) > +#define _PAGE_NOCACHE_THEAD 0UL > +#define _PAGE_IO_THEAD (1UL << 63) > +#define _PAGE_MTMASK_THEAD (_PAGE_PMA_THEAD | _PAGE_IO_THEAD | (1UL << 59)) > + > static inline u64 riscv_page_mtmask(void) > { > u64 val; > @@ -167,7 +179,11 @@ static inline bool mm_pud_folded(struct mm_struct *mm) > > static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot) > { > - return __pmd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); > + unsigned long prot_val = pgprot_val(prot); > + > + ALT_THEAD_PMA(prot_val); > + > + return __pmd((pfn << _PAGE_PFN_SHIFT) | prot_val); > } > > static inline unsigned long _pmd_pfn(pmd_t pmd) > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index b8abc75dfe01..3d0c4c144093 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -245,7 +245,11 @@ static inline void pmd_clear(pmd_t *pmdp) > > static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot) > { > - return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); > + unsigned long prot_val = pgprot_val(prot); > + > + ALT_THEAD_PMA(prot_val); > + > + return __pgd((pfn << _PAGE_PFN_SHIFT) | prot_val); > } > > static inline unsigned long _pgd_pfn(pgd_t pgd) > @@ -284,7 +288,11 @@ static inline unsigned long pte_pfn(pte_t pte) > /* Constructs a page table entry */ > static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot) > { > - return __pte((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); > + unsigned long prot_val = pgprot_val(prot); > + > + ALT_THEAD_PMA(prot_val); > + > + return __pte((pfn << _PAGE_PFN_SHIFT) | prot_val); > } > > #define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot) > @@ -393,7 +401,11 @@ static inline int pmd_protnone(pmd_t pmd) > /* Modify page protection bits */ > static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) > { > - return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)); > + unsigned long newprot_val = pgprot_val(newprot); > + > + ALT_THEAD_PMA(newprot_val); > + > + return __pte((pte_val(pte) & _PAGE_CHG_MASK) | newprot_val); > } > > #define pgd_ERROR(e) \ > diff --git a/arch/riscv/include/asm/vendorid_list.h b/arch/riscv/include/asm/vendorid_list.h > index 9d934215b3c8..cb89af3f0704 100644 > --- a/arch/riscv/include/asm/vendorid_list.h > +++ b/arch/riscv/include/asm/vendorid_list.h > @@ -6,5 +6,6 @@ > #define ASM_VENDOR_LIST_H > > #define SIFIVE_VENDOR_ID 0x489 > +#define THEAD_VENDOR_ID 0x5b7 > > #endif > diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c > index e6c9de9f9ba6..3f6ad91f524c 100644 > --- a/arch/riscv/kernel/alternative.c > +++ b/arch/riscv/kernel/alternative.c > @@ -48,6 +48,11 @@ static void __init init_alternative(void) > case SIFIVE_VENDOR_ID: > vendor_patch_func = sifive_errata_patch_func; > break; > +#endif > +#ifdef CONFIG_ERRATA_THEAD > + case THEAD_VENDOR_ID: > + vendor_patch_func = thead_errata_patch_func; > + break; > #endif > default: > vendor_patch_func = NULL; > @@ -85,6 +90,15 @@ void __init apply_boot_alternatives(void) > RISCV_ALTERNATIVES_BOOT); > } > > +void __init apply_early_boot_alternatives(void) > +{ > + init_alternative(); > + > + _apply_alternatives((struct alt_entry *)__alt_start, > + (struct alt_entry *)__alt_end, > + RISCV_ALTERNATIVES_EARLY_BOOT); > +} > + The name is a bit confusing as there is another "apply_boot_alternatives" which was called earlier than "apply_early_boot_alternatives". > #ifdef CONFIG_MODULES > void apply_module_alternatives(void *start, size_t length) > { > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c > index 7bce66ee7ce7..ecc248e5dab7 100644 > --- a/arch/riscv/kernel/cpufeature.c > +++ b/arch/riscv/kernel/cpufeature.c > @@ -224,6 +224,8 @@ static bool cpufeature_svpbmt_check_func(unsigned int stage) > > #if defined(CONFIG_MMU) && defined(CONFIG_64BIT) > switch (stage) { > + case RISCV_ALTERNATIVES_EARLY_BOOT: > + return false; > case RISCV_ALTERNATIVES_BOOT: > return cpufeature_svpbmt_check_fdt(); > default: > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index cf4d018b7d66..7216db5d6a2c 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -819,6 +819,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K); > #endif > > + apply_early_boot_alternatives(); > pt_ops_set_early(); > > /* Setup early PGD for fixmap */ > -- > 2.30.2 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv -- Regards, Atish _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv 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 8C67CC433F5 for ; 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charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 9, 2022 at 4:41 AM Heiko Stuebner wrote: > > Some current cpus based on T-Head cores implement memory-types > way different than described in the svpbmt spec even going > so far as using PTE bits marked as reserved. > > Add the T-Head vendor-id and necessary errata code to > replace the affected instructions. > > Signed-off-by: Heiko Stuebner > --- > arch/riscv/Kconfig.erratas | 19 ++++++ > arch/riscv/errata/Makefile | 1 + > arch/riscv/errata/sifive/errata.c | 7 ++- > arch/riscv/errata/thead/Makefile | 1 + > arch/riscv/errata/thead/errata.c | 85 ++++++++++++++++++++++++++ > arch/riscv/include/asm/alternative.h | 5 ++ > arch/riscv/include/asm/errata_list.h | 47 ++++++++++++-- > arch/riscv/include/asm/pgtable-64.h | 18 +++++- > arch/riscv/include/asm/pgtable.h | 18 +++++- > arch/riscv/include/asm/vendorid_list.h | 1 + > arch/riscv/kernel/alternative.c | 14 +++++ > arch/riscv/kernel/cpufeature.c | 2 + > arch/riscv/mm/init.c | 1 + > 13 files changed, 210 insertions(+), 9 deletions(-) > create mode 100644 arch/riscv/errata/thead/Makefile > create mode 100644 arch/riscv/errata/thead/errata.c > > diff --git a/arch/riscv/Kconfig.erratas b/arch/riscv/Kconfig.erratas > index d18be8ff0245..380ec039c3dc 100644 > --- a/arch/riscv/Kconfig.erratas > +++ b/arch/riscv/Kconfig.erratas > @@ -31,4 +31,23 @@ config ERRATA_SIFIVE_CIP_1200 > > If you don't know what to do here, say "Y". > > +config ERRATA_THEAD > + bool "T-HEAD errata" > + help > + All T-HEAD errata Kconfig depend on this Kconfig. Disabling > + this Kconfig will disable all T-HEAD errata. Please say "Y" > + here if your platform uses T-HEAD CPU cores. > + > + If you don't know what to do here, say "Y". > + > +config ERRATA_THEAD_PBMT > + bool "Apply T-Head memory type errata" > + depends on ERRATA_THEAD && 64BIT > + default y > + help > + This will apply the memory type errata to handle the non-standard > + memory type bits in page-table-entries on T-Head SoCs. > + > + If you don't know what to do here, say "Y". > + > endmenu > diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile > index 0ca1c5281a2d..a1055965fbee 100644 > --- a/arch/riscv/errata/Makefile > +++ b/arch/riscv/errata/Makefile > @@ -1 +1,2 @@ > obj-$(CONFIG_ERRATA_SIFIVE) += sifive/ > +obj-$(CONFIG_ERRATA_THEAD) += thead/ > diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c > index 4fe03ac41fd7..f933d6cdf304 100644 > --- a/arch/riscv/errata/sifive/errata.c > +++ b/arch/riscv/errata/sifive/errata.c > @@ -84,10 +84,15 @@ void __init sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry * > unsigned int stage) > { > struct alt_entry *alt; > - u32 cpu_req_errata = sifive_errata_probe(archid, impid); > + u32 cpu_req_errata; > u32 cpu_apply_errata = 0; > u32 tmp; > > + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) > + return; > + > + cpu_req_errata = sifive_errata_probe(archid, impid); > + > for (alt = begin; alt < end; alt++) { > if (alt->vendor_id != SIFIVE_VENDOR_ID) > continue; > diff --git a/arch/riscv/errata/thead/Makefile b/arch/riscv/errata/thead/Makefile > new file mode 100644 > index 000000000000..2d644e19caef > --- /dev/null > +++ b/arch/riscv/errata/thead/Makefile > @@ -0,0 +1 @@ > +obj-y += errata.o > diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c > new file mode 100644 > index 000000000000..fd8e0538a3f0 > --- /dev/null > +++ b/arch/riscv/errata/thead/errata.c > @@ -0,0 +1,85 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (C) 2021 Heiko Stuebner > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +struct errata_info { > + char name[ERRATA_STRING_LENGTH_MAX]; > + bool (*check_func)(unsigned long arch_id, unsigned long impid); > + unsigned int stage; > +}; > + > +static bool errata_mt_check_func(unsigned long arch_id, unsigned long impid) > +{ > + if (arch_id != 0 || impid != 0) > + return false; > + return true; > +} > + > +static const struct errata_info errata_list[ERRATA_THEAD_NUMBER] = { > + { > + .name = "memory-types", > + .stage = RISCV_ALTERNATIVES_EARLY_BOOT, > + .check_func = errata_mt_check_func > + }, > +}; > + > +static u32 thead_errata_probe(unsigned int stage, unsigned long archid, unsigned long impid) > +{ > + const struct errata_info *info; > + u32 cpu_req_errata = 0; > + int idx; > + > + for (idx = 0; idx < ERRATA_THEAD_NUMBER; idx++) { > + info = &errata_list[idx]; > + > + if ((stage == RISCV_ALTERNATIVES_MODULE || > + info->stage == stage) && info->check_func(archid, impid)) > + cpu_req_errata |= (1U << idx); > + } > + > + return cpu_req_errata; > +} > + > +void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, > + unsigned long archid, unsigned long impid, > + unsigned int stage) > +{ > + struct alt_entry *alt; > + u32 cpu_req_errata = thead_errata_probe(stage, archid, impid); > + u32 cpu_apply_errata = 0; > + u32 tmp; > + > + for (alt = begin; alt < end; alt++) { > + if (alt->vendor_id != THEAD_VENDOR_ID) > + continue; > + if (alt->errata_id >= ERRATA_THEAD_NUMBER) > + continue; > + > + tmp = (1U << alt->errata_id); > + if (cpu_req_errata & tmp) { > + /* On vm-alternatives, the mmu isn't running yet */ > + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) > + memcpy((void *)__pa_symbol(alt->old_ptr), > + (void *)__pa_symbol(alt->alt_ptr), alt->alt_len); > + else > + patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); > + > + cpu_apply_errata |= tmp; > + } > + } > + > + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) > + local_flush_icache_all(); > +} > diff --git a/arch/riscv/include/asm/alternative.h b/arch/riscv/include/asm/alternative.h > index cf3b22173834..d1154c91ab03 100644 > --- a/arch/riscv/include/asm/alternative.h > +++ b/arch/riscv/include/asm/alternative.h > @@ -19,8 +19,10 @@ > > #define RISCV_ALTERNATIVES_BOOT 0 /* alternatives applied during regular boot */ > #define RISCV_ALTERNATIVES_MODULE 1 /* alternatives applied during module-init */ > +#define RISCV_ALTERNATIVES_EARLY_BOOT 2 /* alternatives applied before mmu start */ > But this stage invoked is used after RISCV_ALTERNATIVES_BOOT > void __init apply_boot_alternatives(void); > +void __init apply_early_boot_alternatives(void); > void apply_module_alternatives(void *start, size_t length); > > struct alt_entry { > @@ -39,6 +41,9 @@ struct errata_checkfunc_id { > void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, > unsigned long archid, unsigned long impid, > unsigned int stage); > +void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, > + unsigned long archid, unsigned long impid, > + unsigned int stage); > > void riscv_cpufeature_patch_func(struct alt_entry *begin, struct alt_entry *end, > unsigned int stage); > diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h > index a4a9b0842922..4fac46b82c16 100644 > --- a/arch/riscv/include/asm/errata_list.h > +++ b/arch/riscv/include/asm/errata_list.h > @@ -14,6 +14,11 @@ > #define ERRATA_SIFIVE_NUMBER 2 > #endif > > +#ifdef CONFIG_ERRATA_THEAD > +#define ERRATA_THEAD_PBMT 0 > +#define ERRATA_THEAD_NUMBER 1 > +#endif > + > #define CPUFEATURE_SVPBMT 0 > #define CPUFEATURE_NUMBER 1 > > @@ -42,10 +47,44 @@ asm(ALTERNATIVE("sfence.vma %0", "sfence.vma", SIFIVE_VENDOR_ID, \ > * in the default case. > */ > #define ALT_SVPBMT_SHIFT 61 > -#define ALT_SVPBMT(_val, prot) \ > -asm(ALTERNATIVE("li %0, 0\t\nnop", "li %0, %1\t\nslli %0,%0,%2", 0, \ > - CPUFEATURE_SVPBMT, CONFIG_64BIT) \ > - : "=r"(_val) : "I"(prot##_SVPBMT >> ALT_SVPBMT_SHIFT), "I"(ALT_SVPBMT_SHIFT)) > +#define ALT_THEAD_PBMT_SHIFT 59 > +#define ALT_SVPBMT(_val, prot) \ > +asm(ALTERNATIVE_2("li %0, 0\t\nnop", \ > + "li %0, %1\t\nslli %0,%0,%3", 0, CPUFEATURE_SVPBMT, CONFIG_64BIT, \ > + "li %0, %2\t\nslli %0,%0,%4", THEAD_VENDOR_ID, ERRATA_THEAD_PBMT, \ > + CONFIG_ERRATA_THEAD_PBMT) \ > + : "=r"(_val) : "I"(prot##_SVPBMT >> ALT_SVPBMT_SHIFT), \ > + "I"(prot##_THEAD >> ALT_THEAD_PBMT_SHIFT), \ > + "I"(ALT_SVPBMT_SHIFT), "I"(ALT_THEAD_PBMT_SHIFT)) > + > +#ifdef CONFIG_ERRATA_THEAD_PBMT > +/* > + * IO/NOCACHE memory types are handled together with svpbmt, > + * so on T-Head chips, check if no other memory type is set, > + * and set the non-0 PMA type if applicable. > + */ > +#define ALT_THEAD_PMA(_val) \ > +asm volatile(ALTERNATIVE( \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop", \ > + "li t3, %2\n\t" \ > + "slli t3, t3, %4\n\t" \ > + "and t3, %0, t3\n\t" \ > + "bne t3, zero, 2f\n\t" \ > + "li t3, %3\n\t" \ > + "slli t3, t3, %4\n\t" \ > + "or %0, %0, t3\n\t" \ > + "2:", THEAD_VENDOR_ID, ERRATA_THEAD_PBMT, CONFIG_ERRATA_THEAD_PBMT) \ > + : "+r"(_val) : "0"(_val), "I"(_PAGE_MTMASK_THEAD >> ALT_THEAD_PBMT_SHIFT), \ > + "I"(_PAGE_PMA_THEAD >> ALT_THEAD_PBMT_SHIFT), "I"(ALT_THEAD_PBMT_SHIFT)) > +#else > +#define ALT_THEAD_PMA(_val) > +#endif > > #endif /* __ASSEMBLY__ */ > > diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h > index 07ba3416cb19..6d59e4695200 100644 > --- a/arch/riscv/include/asm/pgtable-64.h > +++ b/arch/riscv/include/asm/pgtable-64.h > @@ -69,6 +69,18 @@ typedef struct { > #define _PAGE_IO_SVPBMT (1UL << 62) > #define _PAGE_MTMASK_SVPBMT (_PAGE_NOCACHE_SVPBMT | _PAGE_IO_SVPBMT) > > +/* > + * [63:59] T-Head Memory Type definitions: > + * > + * 00000 - NC Weakly-ordered, Non-cacheable, Non-bufferable, Non-shareable, Non-trustable > + * 01110 - PMA Weakly-ordered, Cacheable, Bufferable, Shareable, Non-trustable > + * 10000 - IO Strongly-ordered, Non-cacheable, Non-bufferable, Non-shareable, Non-trustable > + */ > +#define _PAGE_PMA_THEAD ((1UL << 62) | (1UL << 61) | (1UL << 60)) > +#define _PAGE_NOCACHE_THEAD 0UL > +#define _PAGE_IO_THEAD (1UL << 63) > +#define _PAGE_MTMASK_THEAD (_PAGE_PMA_THEAD | _PAGE_IO_THEAD | (1UL << 59)) > + > static inline u64 riscv_page_mtmask(void) > { > u64 val; > @@ -167,7 +179,11 @@ static inline bool mm_pud_folded(struct mm_struct *mm) > > static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot) > { > - return __pmd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); > + unsigned long prot_val = pgprot_val(prot); > + > + ALT_THEAD_PMA(prot_val); > + > + return __pmd((pfn << _PAGE_PFN_SHIFT) | prot_val); > } > > static inline unsigned long _pmd_pfn(pmd_t pmd) > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index b8abc75dfe01..3d0c4c144093 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -245,7 +245,11 @@ static inline void pmd_clear(pmd_t *pmdp) > > static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot) > { > - return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); > + unsigned long prot_val = pgprot_val(prot); > + > + ALT_THEAD_PMA(prot_val); > + > + return __pgd((pfn << _PAGE_PFN_SHIFT) | prot_val); > } > > static inline unsigned long _pgd_pfn(pgd_t pgd) > @@ -284,7 +288,11 @@ static inline unsigned long pte_pfn(pte_t pte) > /* Constructs a page table entry */ > static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot) > { > - return __pte((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); > + unsigned long prot_val = pgprot_val(prot); > + > + ALT_THEAD_PMA(prot_val); > + > + return __pte((pfn << _PAGE_PFN_SHIFT) | prot_val); > } > > #define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot) > @@ -393,7 +401,11 @@ static inline int pmd_protnone(pmd_t pmd) > /* Modify page protection bits */ > static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) > { > - return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)); > + unsigned long newprot_val = pgprot_val(newprot); > + > + ALT_THEAD_PMA(newprot_val); > + > + return __pte((pte_val(pte) & _PAGE_CHG_MASK) | newprot_val); > } > > #define pgd_ERROR(e) \ > diff --git a/arch/riscv/include/asm/vendorid_list.h b/arch/riscv/include/asm/vendorid_list.h > index 9d934215b3c8..cb89af3f0704 100644 > --- a/arch/riscv/include/asm/vendorid_list.h > +++ b/arch/riscv/include/asm/vendorid_list.h > @@ -6,5 +6,6 @@ > #define ASM_VENDOR_LIST_H > > #define SIFIVE_VENDOR_ID 0x489 > +#define THEAD_VENDOR_ID 0x5b7 > > #endif > diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c > index e6c9de9f9ba6..3f6ad91f524c 100644 > --- a/arch/riscv/kernel/alternative.c > +++ b/arch/riscv/kernel/alternative.c > @@ -48,6 +48,11 @@ static void __init init_alternative(void) > case SIFIVE_VENDOR_ID: > vendor_patch_func = sifive_errata_patch_func; > break; > +#endif > +#ifdef CONFIG_ERRATA_THEAD > + case THEAD_VENDOR_ID: > + vendor_patch_func = thead_errata_patch_func; > + break; > #endif > default: > vendor_patch_func = NULL; > @@ -85,6 +90,15 @@ void __init apply_boot_alternatives(void) > RISCV_ALTERNATIVES_BOOT); > } > > +void __init apply_early_boot_alternatives(void) > +{ > + init_alternative(); > + > + _apply_alternatives((struct alt_entry *)__alt_start, > + (struct alt_entry *)__alt_end, > + RISCV_ALTERNATIVES_EARLY_BOOT); > +} > + The name is a bit confusing as there is another "apply_boot_alternatives" which was called earlier than "apply_early_boot_alternatives". > #ifdef CONFIG_MODULES > void apply_module_alternatives(void *start, size_t length) > { > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c > index 7bce66ee7ce7..ecc248e5dab7 100644 > --- a/arch/riscv/kernel/cpufeature.c > +++ b/arch/riscv/kernel/cpufeature.c > @@ -224,6 +224,8 @@ static bool cpufeature_svpbmt_check_func(unsigned int stage) > > #if defined(CONFIG_MMU) && defined(CONFIG_64BIT) > switch (stage) { > + case RISCV_ALTERNATIVES_EARLY_BOOT: > + return false; > case RISCV_ALTERNATIVES_BOOT: > return cpufeature_svpbmt_check_fdt(); > default: > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index cf4d018b7d66..7216db5d6a2c 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -819,6 +819,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K); > #endif > > + apply_early_boot_alternatives(); > pt_ops_set_early(); > > /* Setup early PGD for fixmap */ > -- > 2.30.2 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv -- Regards, Atish