| Message ID | 20190107161047.10516-6-anup@brainfault.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fixmap support and MM cleanups | expand |
On Mon, Jan 07, 2019 at 09:40:47PM +0530, Anup Patel wrote: > From: Anup Patel <anup.patel@wdc.com> > > This patch implements compile-time virtual to physical > mappings. These compile-time fixed mappings can be used > by earlycon, ACPI, and early ioremap for creating fixed > mappings when FIX_EARLYCON_MEM=y. > > To start with, we have enabled compile-time fixed > mappings for earlycon. > > Signed-off-by: Anup Patel <anup.patel@wdc.com> > --- > arch/riscv/Kconfig | 3 ++ > arch/riscv/include/asm/fixmap.h | 52 +++++++++++++++++++++++++++++++++ > arch/riscv/mm/init.c | 32 ++++++++++++++++++++ > 3 files changed, 87 insertions(+) > create mode 100644 arch/riscv/include/asm/fixmap.h > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index e0d7d61779a6..66094aba9a59 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -86,6 +86,9 @@ config GENERIC_CSUM > config GENERIC_HWEIGHT > def_bool y > > +config FIX_EARLYCON_MEM > + def_bool y > + Can you please throw in a prep patch to move FIX_EARLYCON_MEM to drivers/tty/serial/Kconfig and only select it from the architectures that use it? > + * fixmap.h: compile-time virtual memory allocation No need to mention the header name. > + */ > + > +#ifndef _ASM_RISCV_FIXMAP_H > +#define _ASM_RISCV_FIXMAP_H > + > +#ifndef __ASSEMBLY__ As far as I can tell we never include this header from assembly files, so this ifdef should not be needed. > +/* > + * Here we define all the compile-time 'special' virtual > + * addresses. The point is to have a constant address at > + * compile time, but to set the physical address only > + * in the boot process. > + * > + * These 'compile-time allocated' memory buffers are > + * page-sized. Use set_fixmap(idx,phys) to associate > + * physical memory with fixmap indices. > + */ Please use up the available 80 chars per line for comments.
On Tue, Jan 15, 2019 at 7:17 PM Christoph Hellwig <hch@infradead.org> wrote: > > On Mon, Jan 07, 2019 at 09:40:47PM +0530, Anup Patel wrote: > > From: Anup Patel <anup.patel@wdc.com> > > > > This patch implements compile-time virtual to physical > > mappings. These compile-time fixed mappings can be used > > by earlycon, ACPI, and early ioremap for creating fixed > > mappings when FIX_EARLYCON_MEM=y. > > > > To start with, we have enabled compile-time fixed > > mappings for earlycon. > > > > Signed-off-by: Anup Patel <anup.patel@wdc.com> > > --- > > arch/riscv/Kconfig | 3 ++ > > arch/riscv/include/asm/fixmap.h | 52 +++++++++++++++++++++++++++++++++ > > arch/riscv/mm/init.c | 32 ++++++++++++++++++++ > > 3 files changed, 87 insertions(+) > > create mode 100644 arch/riscv/include/asm/fixmap.h > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > index e0d7d61779a6..66094aba9a59 100644 > > --- a/arch/riscv/Kconfig > > +++ b/arch/riscv/Kconfig > > @@ -86,6 +86,9 @@ config GENERIC_CSUM > > config GENERIC_HWEIGHT > > def_bool y > > > > +config FIX_EARLYCON_MEM > > + def_bool y > > + > > Can you please throw in a prep patch to move FIX_EARLYCON_MEM to > drivers/tty/serial/Kconfig and only select it from the architectures > that use it? > > > + * fixmap.h: compile-time virtual memory allocation > > No need to mention the header name. > > > + */ > > + > > +#ifndef _ASM_RISCV_FIXMAP_H > > +#define _ASM_RISCV_FIXMAP_H > > + > > +#ifndef __ASSEMBLY__ > > As far as I can tell we never include this header from assembly files, > so this ifdef should not be needed. Okay, will drop #ifndef > > > +/* > > + * Here we define all the compile-time 'special' virtual > > + * addresses. The point is to have a constant address at > > + * compile time, but to set the physical address only > > + * in the boot process. > > + * > > + * These 'compile-time allocated' memory buffers are > > + * page-sized. Use set_fixmap(idx,phys) to associate > > + * physical memory with fixmap indices. > > + */ > > Please use up the available 80 chars per line for comments. Sure, will do. Regards, Anup
On Tue, Jan 15, 2019 at 7:17 PM Christoph Hellwig <hch@infradead.org> wrote: > > On Mon, Jan 07, 2019 at 09:40:47PM +0530, Anup Patel wrote: > > From: Anup Patel <anup.patel@wdc.com> > > > > This patch implements compile-time virtual to physical > > mappings. These compile-time fixed mappings can be used > > by earlycon, ACPI, and early ioremap for creating fixed > > mappings when FIX_EARLYCON_MEM=y. > > > > To start with, we have enabled compile-time fixed > > mappings for earlycon. > > > > Signed-off-by: Anup Patel <anup.patel@wdc.com> > > --- > > arch/riscv/Kconfig | 3 ++ > > arch/riscv/include/asm/fixmap.h | 52 +++++++++++++++++++++++++++++++++ > > arch/riscv/mm/init.c | 32 ++++++++++++++++++++ > > 3 files changed, 87 insertions(+) > > create mode 100644 arch/riscv/include/asm/fixmap.h > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > index e0d7d61779a6..66094aba9a59 100644 > > --- a/arch/riscv/Kconfig > > +++ b/arch/riscv/Kconfig > > @@ -86,6 +86,9 @@ config GENERIC_CSUM > > config GENERIC_HWEIGHT > > def_bool y > > > > +config FIX_EARLYCON_MEM > > + def_bool y > > + > > Can you please throw in a prep patch to move FIX_EARLYCON_MEM to > drivers/tty/serial/Kconfig and only select it from the architectures > that use it? Implementing fixmap is totally optional for architectures so it makes sense to have FIX_EARLYCON_MEM as architecture specific kconfig option. There are many such architecture specific options provided as "def_bool y" in arch/<xyz>/Kconfig. Also, having such "def_bool y" kconfig options in arch/<xyz>/Kconfig gives us idea about optional features implemented by <xyz> arch support. I don't agree with this suggestion. If you still feel this is right way to go then please go ahead and send patch to move FIX_EARLYCON_MEM option in drivers/tty/serial/Kconfig. > > > + * fixmap.h: compile-time virtual memory allocation > > No need to mention the header name. Sure, will remove header name. > > > + */ > > + > > +#ifndef _ASM_RISCV_FIXMAP_H > > +#define _ASM_RISCV_FIXMAP_H > > + > > +#ifndef __ASSEMBLY__ > > As far as I can tell we never include this header from assembly files, > so this ifdef should not be needed. > > > +/* > > + * Here we define all the compile-time 'special' virtual > > + * addresses. The point is to have a constant address at > > + * compile time, but to set the physical address only > > + * in the boot process. > > + * > > + * These 'compile-time allocated' memory buffers are > > + * page-sized. Use set_fixmap(idx,phys) to associate > > + * physical memory with fixmap indices. > > + */ > > Please use up the available 80 chars per line for comments. Regards, Anup
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index e0d7d61779a6..66094aba9a59 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -86,6 +86,9 @@ config GENERIC_CSUM config GENERIC_HWEIGHT def_bool y +config FIX_EARLYCON_MEM + def_bool y + config PGTABLE_LEVELS int default 3 if 64BIT diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h new file mode 100644 index 000000000000..88e99f506ab9 --- /dev/null +++ b/arch/riscv/include/asm/fixmap.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2019 Western Digital Corporation or its affiliates. + * + * fixmap.h: compile-time virtual memory allocation + */ + +#ifndef _ASM_RISCV_FIXMAP_H +#define _ASM_RISCV_FIXMAP_H + +#ifndef __ASSEMBLY__ + +#include <linux/kernel.h> +#include <linux/sizes.h> +#include <asm/page.h> +#include <asm/pgtable.h> + +/* + * Here we define all the compile-time 'special' virtual + * addresses. The point is to have a constant address at + * compile time, but to set the physical address only + * in the boot process. + * + * These 'compile-time allocated' memory buffers are + * page-sized. Use set_fixmap(idx,phys) to associate + * physical memory with fixmap indices. + */ +enum fixed_addresses { + FIX_HOLE, + FIX_EARLYCON_MEM_BASE, + __end_of_fixed_addresses +}; + +#define FIXADDR_SIZE (__end_of_fixed_addresses * PAGE_SIZE) +#define FIXADDR_TOP (PAGE_OFFSET) +#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) + +#define FIXMAP_PAGE_IO PAGE_KERNEL + +#define __early_set_fixmap __set_fixmap + +#define __late_set_fixmap __set_fixmap +#define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR) + +extern void __set_fixmap(enum fixed_addresses idx, + phys_addr_t phys, pgprot_t prot); + +#include <asm-generic/fixmap.h> + +#endif /* !__ASSEMBLY__ */ + +#endif /* _ASM_RISCV_FIXMAP_H */ diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index b487f76d6060..b10f1423c352 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -18,6 +18,7 @@ #include <linux/sizes.h> #include <linux/of_fdt.h> +#include <asm/fixmap.h> #include <asm/tlbflush.h> #include <asm/sections.h> #include <asm/pgtable.h> @@ -110,8 +111,28 @@ pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); #define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT) pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss; pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); +pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss; #endif +pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; + +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) +{ + unsigned long addr = __fix_to_virt(idx); + pte_t *ptep; + + BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); + + ptep = &fixmap_pte[pte_index(addr)]; + + if (pgprot_val(prot)) { + set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot)); + } else { + pte_clear(&init_mm, addr, ptep); + local_flush_tlb_page(addr); + } +} + asmlinkage void __init setup_vm(void) { extern char _start; @@ -141,6 +162,13 @@ asmlinkage void __init setup_vm(void) } for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++) swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot); + + swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] = + pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pmd), + __pgprot(_PAGE_TABLE)); + fixmap_pmd[(FIXADDR_START >> PMD_SHIFT) % PTRS_PER_PMD] = + pfn_pmd(PFN_DOWN((uintptr_t)fixmap_pte), + __pgprot(_PAGE_TABLE)); #else trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] = pfn_pgd(PFN_DOWN(pa), prot); @@ -150,5 +178,9 @@ asmlinkage void __init setup_vm(void) swapper_pg_dir[o] = pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot); } + + swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] = + pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pte), + __pgprot(_PAGE_TABLE)); #endif }