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 71CB4C433EF for ; Tue, 30 Nov 2021 18:46:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245592AbhK3Stu (ORCPT ); Tue, 30 Nov 2021 13:49:50 -0500 Received: from gloria.sntech.de ([185.11.138.130]:50328 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245552AbhK3Sti (ORCPT ); Tue, 30 Nov 2021 13:49:38 -0500 Received: from ip5f5b2004.dynamic.kabel-deutschland.de ([95.91.32.4] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ms88q-0006cW-9u; Tue, 30 Nov 2021 19:46:12 +0100 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: anup.patel@wdc.com, atishp04@gmail.com, palmer@dabbelt.com, guoren@kernel.org, christoph.muellner@vrull.eu, philipp.tomsich@vrull.eu, hch@lst.de, liush@allwinnertech.com, wefu@redhat.com, lazyparser@gmail.com, drew@beagleboard.org, linux-riscv@lists.infradead.org Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, taiten.peng@canonical.com, aniket.ponkshe@canonical.com, heinrich.schuchardt@canonical.com, gordan.markus@canonical.com, guoren@linux.alibaba.com, arnd@arndb.de, wens@csie.org, maxime@cerno.tech, dlustig@nvidia.com, gfavor@ventanamicro.com, andrea.mondelli@huawei.com, behrensj@mit.edu, xinhaoqu@huawei.com, huffman@cadence.com, mick@ics.forth.gr, allen.baum@esperantotech.com, jscheid@ventanamicro.com, rtrauben@gmail.com, Palmer Dabbelt , Atish Patra , wefu@redhat.com Subject: Re: [PATCH V4 2/2] riscv: add RISC-V Svpbmt extension supports Date: Tue, 30 Nov 2021 19:46:10 +0100 Message-ID: <4669908.7LBx6Dm1N1@diego> In-Reply-To: <20211129014007.286478-3-wefu@redhat.com> References: <20211129014007.286478-1-wefu@redhat.com> <20211129014007.286478-3-wefu@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Montag, 29. November 2021, 02:40:07 CET schrieb wefu@redhat.com: > From: Wei Fu > > This patch follows the standard pure RISC-V Svpbmt extension in > privilege spec to solve the non-coherent SOC dma synchronization > issues. > > Here is the svpbmt PTE format: > | 63 | 62-61 | 60-8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 > N MT RSW D A G U X W R V > ^ > > Of the Reserved bits [63:54] in a leaf PTE, the high bit is already > allocated (as the N bit), so bits [62:61] are used as the MT (aka > MemType) field. This field specifies one of three memory types that > are close equivalents (or equivalent in effect) to the three main x86 > and ARMv8 memory types - as shown in the following table. > > RISC-V > Encoding & > MemType RISC-V Description > ---------- ------------------------------------------------ > 00 - PMA Normal Cacheable, No change to implied PMA memory type > 01 - NC Non-cacheable, idempotent, weakly-ordered Main Memory > 10 - IO Non-cacheable, non-idempotent, strongly-ordered I/O memory > 11 - Rsvd Reserved for future standard use > > The standard protection_map[] needn't be modified because the "PMA" > type keeps the highest bits zero. And the whole modification is > limited in the arch/riscv/* and using a global variable > (__svpbmt) as _PAGE_MASK/IO/NOCACHE for pgprot_noncached > (&writecombine) in pgtable.h. We also add _PAGE_CHG_MASK to filter > PFN than before. > > Enable it in devicetree - (Add "riscv,svpbmt" in the mmu of cpu node) > - mmu: > riscv,svpmbt > > Signed-off-by: Wei Fu > Co-developed-by: Liu Shaohua > Signed-off-by: Liu Shaohua > Co-developed-by: Guo Ren > Signed-off-by: Guo Ren > Cc: Palmer Dabbelt > Cc: Christoph Hellwig > Cc: Anup Patel > Cc: Arnd Bergmann > Cc: Atish Patra > Cc: Drew Fustini > Cc: Wei Fu > Cc: Wei Wu > Cc: Chen-Yu Tsai > Cc: Maxime Ripard > Cc: Daniel Lustig > Cc: Greg Favor > Cc: Andrea Mondelli > Cc: Jonathan Behrens > Cc: Xinhaoqu (Freddie) > Cc: Bill Huffman > Cc: Nick Kossifidis > Cc: Allen Baum > Cc: Josh Scheid > Cc: Richard Trauben > --- > arch/riscv/include/asm/fixmap.h | 2 +- > arch/riscv/include/asm/pgtable-64.h | 21 ++++++++++++--- > arch/riscv/include/asm/pgtable-bits.h | 39 +++++++++++++++++++++++++-- > arch/riscv/include/asm/pgtable.h | 39 ++++++++++++++++++++------- > arch/riscv/kernel/cpufeature.c | 35 ++++++++++++++++++++++++ > arch/riscv/mm/init.c | 5 ++++ > 6 files changed, 126 insertions(+), 15 deletions(-) > > diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h > index 54cbf07fb4e9..5acd99d08e74 100644 > --- a/arch/riscv/include/asm/fixmap.h > +++ b/arch/riscv/include/asm/fixmap.h > @@ -43,7 +43,7 @@ enum fixed_addresses { > __end_of_fixed_addresses > }; > > -#define FIXMAP_PAGE_IO PAGE_KERNEL > +#define FIXMAP_PAGE_IO PAGE_IOREMAP > > #define __early_set_fixmap __set_fixmap > > diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h > index 228261aa9628..16d251282b1d 100644 > --- a/arch/riscv/include/asm/pgtable-64.h > +++ b/arch/riscv/include/asm/pgtable-64.h > @@ -59,14 +59,29 @@ static inline void pud_clear(pud_t *pudp) > set_pud(pudp, __pud(0)); > } > > +static inline unsigned long _chg_of_pmd(pmd_t pmd) > +{ > + return (pmd_val(pmd) & _PAGE_CHG_MASK); > +} > + > +static inline unsigned long _chg_of_pud(pud_t pud) > +{ > + return (pud_val(pud) & _PAGE_CHG_MASK); > +} > + > +static inline unsigned long _chg_of_pte(pte_t pte) > +{ > + return (pte_val(pte) & _PAGE_CHG_MASK); > +} > + > static inline pmd_t *pud_pgtable(pud_t pud) > { > - return (pmd_t *)pfn_to_virt(pud_val(pud) >> _PAGE_PFN_SHIFT); > + return (pmd_t *)pfn_to_virt(_chg_of_pud(pud) >> _PAGE_PFN_SHIFT); > } > > static inline struct page *pud_page(pud_t pud) > { > - return pfn_to_page(pud_val(pud) >> _PAGE_PFN_SHIFT); > + return pfn_to_page(_chg_of_pud(pud) >> _PAGE_PFN_SHIFT); > } > > static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot) > @@ -76,7 +91,7 @@ static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot) > > static inline unsigned long _pmd_pfn(pmd_t pmd) > { > - return pmd_val(pmd) >> _PAGE_PFN_SHIFT; > + return _chg_of_pmd(pmd) >> _PAGE_PFN_SHIFT; > } > > #define mk_pmd(page, prot) pfn_pmd(page_to_pfn(page), prot) > diff --git a/arch/riscv/include/asm/pgtable-bits.h b/arch/riscv/include/asm/pgtable-bits.h > index 2ee413912926..e5b0fce4ddc5 100644 > --- a/arch/riscv/include/asm/pgtable-bits.h > +++ b/arch/riscv/include/asm/pgtable-bits.h > @@ -7,7 +7,7 @@ > #define _ASM_RISCV_PGTABLE_BITS_H > > /* > - * PTE format: > + * rv32 PTE format: > * | XLEN-1 10 | 9 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 > * PFN reserved for SW D A G U X W R V > */ > @@ -24,6 +24,40 @@ > #define _PAGE_DIRTY (1 << 7) /* Set by hardware on any write */ > #define _PAGE_SOFT (1 << 8) /* Reserved for software */ > > +#if !defined(__ASSEMBLY__) && defined(CONFIG_64BIT) > +/* > + * rv64 PTE format: > + * | 63 | 62 61 | 60 54 | 53 10 | 9 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 > + * N MT RSV PFN reserved for SW D A G U X W R V > + * [62:61] Memory Type definitions: > + * 00 - PMA Normal Cacheable, No change to implied PMA memory type > + * 01 - NC Non-cacheable, idempotent, weakly-ordered Main Memory > + * 10 - IO Non-cacheable, non-idempotent, strongly-ordered I/O memory > + * 11 - Rsvd Reserved for future standard use > + */ > +#define _SVPBMT_PMA 0UL > +#define _SVPBMT_NC (1UL << 61) > +#define _SVPBMT_IO (1UL << 62) > +#define _SVPBMT_MASK (_SVPBMT_NC | _SVPBMT_IO) > + > +extern struct __svpbmt_struct { > + unsigned long mask; > + unsigned long pma; > + unsigned long nocache; > + unsigned long io; > +} __svpbmt __cacheline_aligned; > + > +#define _PAGE_MASK __svpbmt.mask > +#define _PAGE_PMA __svpbmt.pma > +#define _PAGE_NOCACHE __svpbmt.nocache > +#define _PAGE_IO __svpbmt.io > +#else > +#define _PAGE_MASK 0 > +#define _PAGE_PMA 0 > +#define _PAGE_NOCACHE 0 > +#define _PAGE_IO 0 > +#endif /* !__ASSEMBLY__ && CONFIG_64BIT */ > + > #define _PAGE_SPECIAL _PAGE_SOFT > #define _PAGE_TABLE _PAGE_PRESENT > > @@ -38,7 +72,8 @@ > /* Set of bits to preserve across pte_modify() */ > #define _PAGE_CHG_MASK (~(unsigned long)(_PAGE_PRESENT | _PAGE_READ | \ > _PAGE_WRITE | _PAGE_EXEC | \ > - _PAGE_USER | _PAGE_GLOBAL)) > + _PAGE_USER | _PAGE_GLOBAL | \ > + _PAGE_MASK)) > /* > * when all of R/W/X are zero, the PTE is a pointer to the next level > * of the page table; otherwise, it is a leaf PTE. > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index bf204e7c1f74..0f7a6541015f 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -138,7 +138,8 @@ > | _PAGE_PRESENT \ > | _PAGE_ACCESSED \ > | _PAGE_DIRTY \ > - | _PAGE_GLOBAL) > + | _PAGE_GLOBAL \ > + | _PAGE_PMA) > > #define PAGE_KERNEL __pgprot(_PAGE_KERNEL) > #define PAGE_KERNEL_READ __pgprot(_PAGE_KERNEL & ~_PAGE_WRITE) > @@ -148,11 +149,9 @@ > > #define PAGE_TABLE __pgprot(_PAGE_TABLE) > > -/* > - * The RISC-V ISA doesn't yet specify how to query or modify PMAs, so we can't > - * change the properties of memory regions. > - */ > -#define _PAGE_IOREMAP _PAGE_KERNEL > +#define _PAGE_IOREMAP ((_PAGE_KERNEL & ~_PAGE_MASK) | _PAGE_IO) > + > +#define PAGE_IOREMAP __pgprot(_PAGE_IOREMAP) > > extern pgd_t swapper_pg_dir[]; > > @@ -232,12 +231,12 @@ static inline unsigned long _pgd_pfn(pgd_t pgd) > > static inline struct page *pmd_page(pmd_t pmd) > { > - return pfn_to_page(pmd_val(pmd) >> _PAGE_PFN_SHIFT); > + return pfn_to_page(_chg_of_pmd(pmd) >> _PAGE_PFN_SHIFT); > } > > static inline unsigned long pmd_page_vaddr(pmd_t pmd) > { > - return (unsigned long)pfn_to_virt(pmd_val(pmd) >> _PAGE_PFN_SHIFT); > + return (unsigned long)pfn_to_virt(_chg_of_pmd(pmd) >> _PAGE_PFN_SHIFT); > } > > static inline pte_t pmd_pte(pmd_t pmd) > @@ -253,7 +252,7 @@ static inline pte_t pud_pte(pud_t pud) > /* Yields the page frame number (PFN) of a page table entry */ > static inline unsigned long pte_pfn(pte_t pte) > { > - return (pte_val(pte) >> _PAGE_PFN_SHIFT); > + return (_chg_of_pte(pte) >> _PAGE_PFN_SHIFT); > } > > #define pte_page(x) pfn_to_page(pte_pfn(x)) > @@ -492,6 +491,28 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma, > return ptep_test_and_clear_young(vma, address, ptep); > } > > +#define pgprot_noncached pgprot_noncached > +static inline pgprot_t pgprot_noncached(pgprot_t _prot) > +{ > + unsigned long prot = pgprot_val(_prot); > + > + prot &= ~_PAGE_MASK; > + prot |= _PAGE_IO; > + > + return __pgprot(prot); > +} > + > +#define pgprot_writecombine pgprot_writecombine > +static inline pgprot_t pgprot_writecombine(pgprot_t _prot) > +{ > + unsigned long prot = pgprot_val(_prot); > + > + prot &= ~_PAGE_MASK; > + prot |= _PAGE_NOCACHE; > + > + return __pgprot(prot); > +} > + > /* > * THP functions > */ > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c > index d959d207a40d..fa7480cb8b87 100644 > --- a/arch/riscv/kernel/cpufeature.c > +++ b/arch/riscv/kernel/cpufeature.c > @@ -8,6 +8,7 @@ > > #include > #include > +#include > #include > #include > #include > @@ -59,6 +60,38 @@ bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit) > } > EXPORT_SYMBOL_GPL(__riscv_isa_extension_available); > > +static void __init mmu_supports_svpbmt(void) > +{ > +#if defined(CONFIG_MMU) && defined(CONFIG_64BIT) > + struct device_node *node; > + const char *str; > + > + for_each_of_cpu_node(node) { > + if (of_property_read_string(node, "mmu-type", &str)) > + continue; > + > + if (!strncmp(str + 6, "none", 4)) > + continue; > + > + if (of_property_read_string(node, "mmu", &str)) > + continue; > + > + if (strncmp(str + 6, "svpmbt", 6)) same here ... check for "svpbmt" [m seems to be at the wrong position] > + continue; > + } > + > + __svpbmt.pma = _SVPBMT_PMA; > + __svpbmt.nocache = _SVPBMT_NC; > + __svpbmt.io = _SVPBMT_IO; > + __svpbmt.mask = _SVPBMT_MASK; > +#endif > +} > + > +static void __init mmu_supports(void) > +{ > + mmu_supports_svpbmt(); > +} > + > void __init riscv_fill_hwcap(void) > { > struct device_node *node; > @@ -67,6 +100,8 @@ void __init riscv_fill_hwcap(void) > size_t i, j, isa_len; > static unsigned long isa2hwcap[256] = {0}; > > + mmu_supports(); > + > isa2hwcap['i'] = isa2hwcap['I'] = COMPAT_HWCAP_ISA_I; > isa2hwcap['m'] = isa2hwcap['M'] = COMPAT_HWCAP_ISA_M; > isa2hwcap['a'] = isa2hwcap['A'] = COMPAT_HWCAP_ISA_A; > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index 24b2b8044602..e4e658165ee1 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -854,3 +854,8 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, > return vmemmap_populate_basepages(start, end, node, NULL); > } > #endif > + > +#if defined(CONFIG_64BIT) > +struct __svpbmt_struct __svpbmt __ro_after_init; > +EXPORT_SYMBOL(__svpbmt); > +#endif >