pussuw commented on code in PR #6069: URL: https://github.com/apache/incubator-nuttx/pull/6069#discussion_r859608473
########## arch/risc-v/src/common/riscv_addrenv.c: ########## @@ -0,0 +1,788 @@ +/**************************************************************************** + * arch/risc-v/src/common/riscv_addrenv.c + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance with the + * License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations + * under the License. + * + ****************************************************************************/ + +/**************************************************************************** + * Address Environment Interfaces + * + * Low-level interfaces used in binfmt/ to instantiate tasks with address + * environments. These interfaces all operate on type group_addrenv_t which + * is an abstract representation of a task group's address environment and + * must be defined in arch/arch.h if CONFIG_ARCH_ADDRENV is defined. + * + * up_addrenv_create - Create an address environment + * up_addrenv_destroy - Destroy an address environment. + * up_addrenv_vtext - Returns the virtual base address of the .text + * address environment + * up_addrenv_vdata - Returns the virtual base address of the .bss/.data + * address environment + * up_addrenv_heapsize - Returns the size of the initial heap allocation. + * up_addrenv_select - Instantiate an address environment + * up_addrenv_restore - Restore an address environment + * up_addrenv_clone - Copy an address environment from one location to + * another. + * + * Higher-level interfaces used by the tasking logic. These interfaces are + * used by the functions in sched/ and all operate on the thread which whose + * group been assigned an address environment by up_addrenv_clone(). + * + * up_addrenv_attach - Clone the address environment assigned to one TCB + * to another. This operation is done when a pthread + * is created that share's the same address + * environment. + * up_addrenv_detach - Release the threads reference to an address + * environment when a task/thread exits. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <errno.h> +#include <assert.h> +#include <debug.h> + +#include <nuttx/addrenv.h> +#include <nuttx/arch.h> +#include <nuttx/irq.h> +#include <nuttx/pgalloc.h> + +#include <arch/barriers.h> + +#include "pgalloc.h" +#include "riscv_mmu.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/* Only CONFIG_BUILD_KERNEL is supported (i.e. tested) */ + +#ifndef CONFIG_BUILD_KERNEL +# error "This module is intended to be used with CONFIG_BUILD_KERNEL" +#endif + +/* Entries per PGT */ + +#define ENTRIES_PER_PGT (RV_MMU_PAGE_ENTRIES) + +/* Base address for address environment */ + +#define ADDRENV_VBASE (CONFIG_ARCH_DATA_VBASE) + +/**************************************************************************** + * Public Data + ****************************************************************************/ + +extern uintptr_t g_kernel_mappings; + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: map_spgtables + * + * Description: + * Map vaddr to the static page tables. + * + * Input Parameters: + * addrenv - Describes the address environment + * + ****************************************************************************/ + +static void map_spgtables(group_addrenv_t *addrenv, uintptr_t vaddr) +{ + int i; + uintptr_t prev; + + /* Start from L1, and connect until max level - 1 */ + + prev = riscv_pgvaddr(addrenv->spgtables[0]); + + /* Check if the mapping already exists */ + + if (mmu_ln_getentry(1, prev, vaddr) != 0) + { + return; + } + + /* No mapping yet, create it */ + + for (i = 0; i < (ARCH_SPGTS - 1); i++) + { + uintptr_t next = riscv_pgvaddr(addrenv->spgtables[i + 1]); + mmu_ln_setentry(i + 1, prev, next, vaddr, MMU_UPGT_FLAGS); + prev = next; + } +} + +/**************************************************************************** + * Name: create_spgtables + * + * Description: + * Create the static page tables. Allocate memory for them and connect them + * together. + * + * Input Parameters: + * addrenv - Describes the address environment + * + * Returned value: + * Amount of pages created on success; a negated errno value on failure + * + ****************************************************************************/ + +static int create_spgtables(group_addrenv_t *addrenv) +{ + int i; + uintptr_t paddr; + + for (i = 0; i < ARCH_SPGTS; i++) + { + paddr = mm_pgalloc(1); + if (!paddr) + { + return -ENOMEM; + } + + /* Wipe the memory and assign it */ + + riscv_pgwipe(paddr); + addrenv->spgtables[i] = paddr; + } + + /* Flush the data cache, so the changes are committed to memory */ + + __DMB(); + + return i; +} + +/**************************************************************************** + * Name: copy_kernel_mappings + * + * Description: + * Copy kernel mappings to address environment. Expects that the user page + * table does not contain any mappings yet (as they will be wiped). + * + * Input Parameters: + * addrenv - Describes the address environment. The page tables must exist + * at this point. + * + * Returned value: + * OK on success, ERROR on failure + * + ****************************************************************************/ + +static int copy_kernel_mappings(group_addrenv_t *addrenv) +{ + uintptr_t user_mappings = riscv_pgvaddr(addrenv->spgtables[0]); + + /* Copy the L1 references */ + + if (user_mappings == 0) + { + return -EINVAL; + } + + memcpy((void *)user_mappings, (void *)g_kernel_mappings, RV_MMU_PAGE_SIZE); + + return OK; +} + +/**************************************************************************** + * Name: create_region + * + * Description: + * Map a single region of memory to MMU. Assumes that the static page + * tables exist. Allocates the final level page tables and commits the + * region memory to physical memory. + * + * Input Parameters: + * addrenv - Describes the address environment + * vaddr - Base virtual address for the mapping + * size - Size of the region in bytes + * mmuflags - MMU flags to use + * + * Returned value: + * Amount of pages created on success; a negated errno value on failure + * + ****************************************************************************/ + +static int create_region(group_addrenv_t *addrenv, uintptr_t vaddr, + size_t size, uint32_t mmuflags) +{ + uintptr_t ptlast; + uintptr_t ptprev; + uintptr_t paddr; + uint32_t ptlevel; + int npages; + int nmapped; + int i; + int j; + + nmapped = 0; + npages = MM_NPAGES(size); + ptprev = riscv_pgvaddr(addrenv->spgtables[ARCH_SPGTS - 1]); + ptlevel = ARCH_SPGTS; + + /* Create mappings for the lower level tables */ + + map_spgtables(addrenv, vaddr); + + /* Begin allocating memory for the page tables */ + + for (i = 0; i < npages; i += ENTRIES_PER_PGT) + { + /* Get the current final level entry corresponding to this vaddr */ + + paddr = mmu_pte_to_paddr(mmu_ln_getentry(ptlevel, ptprev, vaddr)); + + if (paddr == 0) + { + /* Nothing yet, allocate one page for final level page table */ + + paddr = mm_pgalloc(1); + if (!paddr) + { + return -ENOMEM; + } + + /* Map the page table to the prior level */ + + mmu_ln_setentry(ptlevel, ptprev, paddr, vaddr, MMU_UPGT_FLAGS); + + /* This is then used to map the final level */ + + riscv_pgwipe(paddr); + } + + ptlast = riscv_pgvaddr(paddr); + + /* Then allocate memory for the region data */ + + for (j = 0; j < ENTRIES_PER_PGT && nmapped < size; j++) + { + paddr = mm_pgalloc(1); + if (!paddr) + { + return -ENOMEM; + } + + /* Wipe the physical page memory */ + + riscv_pgwipe(paddr); + + /* Then map the virtual address to the physical address */ + + mmu_ln_setentry(ptlevel + 1, ptlast, paddr, vaddr, mmuflags); + nmapped += MM_PGSIZE; + vaddr += MM_PGSIZE; Review Comment: Sure -- This is an automated message from the Apache Git Service. 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