-/* See COPYRIGHT for copyright information. */
-
-/** @file
- * This file is responsible for managing physical pages as they
- * are mapped into the page tables of a particular virtual address
- * space. The functions defined in this file operate on these
- * page tables to insert and remove physical pages from them at
- * particular virtual addresses.
+/* Copyright (c) 2009,13 The Regents of the University of California
+ * Barret Rhoden <brho@cs.berkeley.edu>
+ * See LICENSE for details.
*
- * @author Kevin Klues <klueska@cs.berkeley.edu>
- * @author Barret Rhoden <brho@cs.berkeley.edu>
- */
-
-#ifdef __SHARC__
-#pragma nosharc
-#endif
+ * Arch independent physical memory and page table management.
+ *
+ * For page allocation, check out the family of page_alloc files. */
#include <arch/arch.h>
#include <arch/mmu.h>
-#include <ros/error.h>
+#include <error.h>
#include <kmalloc.h>
#include <atomic.h>
#include <string.h>
#include <assert.h>
#include <pmap.h>
-#include <kclock.h>
#include <process.h>
#include <stdio.h>
+#include <mm.h>
+#include <multiboot.h>
+#include <arena.h>
+#include <init.h>
-/**
- * @brief Global variable used to store erroneous virtual addresses as the
- * result of a failed user_mem_check().
- */
-static void *DANGEROUS user_mem_check_addr;
+physaddr_t max_pmem = 0; /* Total amount of physical memory (bytes) */
+physaddr_t max_paddr = 0; /* Maximum addressable physical address */
+size_t max_nr_pages = 0; /* Number of addressable physical memory pages */
+struct page *pages = 0;
+struct multiboot_info *multiboot_kaddr = 0;
+uintptr_t boot_freemem = 0;
+uintptr_t boot_freelimit = 0;
+
+static size_t sizeof_mboot_mmentry(struct multiboot_mmap_entry *entry)
+{
+ /* Careful - len is a uint64 (need to cast down for 32 bit) */
+ return (size_t)(entry->len);
+}
+
+static void adjust_max_pmem(struct multiboot_mmap_entry *entry, void *data)
+{
+ if (entry->type != MULTIBOOT_MEMORY_AVAILABLE)
+ return;
+ /* Careful - addr + len is a uint64 (need to cast down for 32 bit) */
+ max_pmem = MAX(max_pmem, (size_t)(entry->addr + entry->len));
+}
-volatile uint32_t vpt_lock = 0;
-volatile uint32_t vpd_lock = 0;
+static void kpages_arena_init(void)
+{
+ void *kpages_pg;
+
+ kpages_pg = arena_alloc(base_arena, PGSIZE, MEM_WAIT);
+ kpages_arena = arena_builder(kpages_pg, "kpages", PGSIZE, arena_alloc,
+ arena_free, base_arena, 8 * PGSIZE);
+}
/**
- * @brief Initialize the array of physical pages and memory free list.
+ * @brief Initializes physical memory. Determines the pmem layout, sets up the
+ * base and kpages arenas, and turns on virtual memory/page tables.
*
- * The 'pages' array has one 'page_t' entry per physical page.
- * Pages are reference counted, and free pages are kept on a linked list.
- */
-void page_init(void)
+ * Regarding max_pmem vs max_paddr and max_nr_pages: max_pmem is the largest
+ * physical address that is in a FREE region. It includes RESERVED regions that
+ * are below this point. max_paddr is the largest physical address, <=
+ * max_pmem, that the KERNBASE mapping can map. It too may include reserved
+ * ranges. The 'pages' array will track all physical pages up to max_paddr.
+ * There are max_nr_pages of them. On 64 bit systems, max_pmem == max_paddr. */
+void pmem_init(struct multiboot_info *mbi)
{
- /*
- * First, make 'pages' point to an array of size 'npages' of
- * type 'page_t'.
- * The kernel uses this structure to keep track of physical pages;
- * 'npages' equals the number of physical pages in memory.
- * round up to the nearest page
- */
- pages = (page_t*)boot_alloc(npages*sizeof(page_t), PGSIZE);
- memset(pages, 0, npages*sizeof(page_t));
+ mboot_detect_memory(mbi);
+ mboot_print_mmap(mbi);
+ /* adjust the max memory based on the mmaps, since the old detection doesn't
+ * help much on 64 bit systems */
+ mboot_foreach_mmap(mbi, adjust_max_pmem, 0);
+ /* KERN_VMAP_TOP - KERNBASE is the max amount of virtual addresses we can
+ * use for the physical memory mapping (aka - the KERNBASE mapping).
+ * Should't be an issue on 64b, but is usually for 32 bit. */
+ max_paddr = MIN(max_pmem, KERN_VMAP_TOP - KERNBASE);
+ /* Note not all of this memory is free. */
+ max_nr_pages = max_paddr / PGSIZE;
+ printk("Max physical RAM (appx, bytes): %lu\n", max_pmem);
+ printk("Max addressable physical RAM (appx): %lu\n", max_paddr);
+ printk("Highest page number (including reserved): %lu\n", max_nr_pages);
+ /* We should init the page structs, but zeroing happens to work, except for
+ * the sems. Those are init'd by the page cache before they are used. */
+ pages = (struct page*)boot_zalloc(max_nr_pages * sizeof(struct page),
+ PGSIZE);
+ base_arena_init(mbi);
+ /* kpages will use some of the basic slab caches. kmem_cache_init needs to
+ * not do memory allocations (which it doesn't, and it can base_alloc()). */
+ kmem_cache_init();
+ kpages_arena_init();
+ printk("Base arena total mem: %lu\n", arena_amt_total(base_arena));
+ vm_init();
- /*
- * Then initilaize everything so pages can start to be alloced and freed
- * from the memory free list
- */
- page_alloc_init();
+ static_assert(PROCINFO_NUM_PAGES*PGSIZE <= PTSIZE);
+ static_assert(PROCDATA_NUM_PAGES*PGSIZE <= PTSIZE);
}
-/**
+static void set_largest_freezone(struct multiboot_mmap_entry *entry, void *data)
+{
+ struct multiboot_mmap_entry **boot_zone =
+ (struct multiboot_mmap_entry**)data;
+
+ if (entry->type != MULTIBOOT_MEMORY_AVAILABLE)
+ return;
+ if (!*boot_zone || (sizeof_mboot_mmentry(entry) >
+ sizeof_mboot_mmentry(*boot_zone)))
+ *boot_zone = entry;
+}
+
+/* Initialize boot freemem and its limit.
+ *
+ * "end" is a symbol marking the end of the kernel. This covers anything linked
+ * in with the kernel (KFS, etc). However, 'end' is a kernel load address,
+ * which differs from kernbase addrs in 64 bit. We need to use the kernbase
+ * mapping for anything dynamic (because it could go beyond 1 GB).
+ *
+ * Ideally, we'll use the largest mmap zone, as reported by multiboot. If we
+ * don't have one (riscv), we'll just use the memory after the kernel.
+ *
+ * If we do have a zone, there is a chance we've already used some of it (for
+ * the kernel, etc). We'll use the lowest address in the zone that is
+ * greater than "end" (and adjust the limit accordingly). */
+static void boot_alloc_init(void)
+{
+ extern char end[];
+ uintptr_t boot_zone_start, boot_zone_end;
+ uintptr_t end_kva = (uintptr_t)KBASEADDR(end);
+ struct multiboot_mmap_entry *boot_zone = 0;
+
+ /* Find our largest mmap_entry; that will set bootzone */
+ mboot_foreach_mmap(multiboot_kaddr, set_largest_freezone, &boot_zone);
+ if (boot_zone) {
+ boot_zone_start = (uintptr_t)KADDR(boot_zone->addr);
+ /* one issue for 32b is that the boot_zone_end could be beyond max_paddr
+ * and even wrap-around. Do the min check as a uint64_t. The result
+ * should be a safe, unwrapped 32/64b when cast to physaddr_t. */
+ boot_zone_end = (uintptr_t)KADDR(MIN(boot_zone->addr + boot_zone->len,
+ (uint64_t)max_paddr));
+ /* using KERNBASE (kva, btw) which covers the kernel and anything before
+ * it (like the stuff below EXTPHYSMEM on x86) */
+ if (regions_collide_unsafe(KERNBASE, end_kva,
+ boot_zone_start, boot_zone_end))
+ boot_freemem = end_kva;
+ else
+ boot_freemem = boot_zone_start;
+ boot_freelimit = boot_zone_end;
+ } else {
+ boot_freemem = end_kva;
+ boot_freelimit = max_paddr + KERNBASE;
+ }
+ printd("boot_zone: %p, paddr base: 0x%llx, paddr len: 0x%llx\n", boot_zone,
+ boot_zone ? boot_zone->addr : 0,
+ boot_zone ? boot_zone->len : 0);
+ printd("boot_freemem: %p, boot_freelimit %p\n", boot_freemem,
+ boot_freelimit);
+}
+
+/* Low-level allocator, used before page_alloc is on. Returns size bytes,
+ * aligned to align (should be a power of 2). Retval is a kernbase addr. Will
+ * panic on failure. */
+void *boot_alloc(size_t amt, size_t align)
+{
+ uintptr_t retval;
+
+ if (!boot_freemem)
+ boot_alloc_init();
+ boot_freemem = ROUNDUP(boot_freemem, align);
+ retval = boot_freemem;
+ if (boot_freemem + amt > boot_freelimit){
+ printk("boot_alloc: boot_freemem is 0x%x\n", boot_freemem);
+ printk("boot_alloc: amt is %d\n", amt);
+ printk("boot_freelimit is 0x%x\n", boot_freelimit);
+ printk("boot_freemem + amt is > boot_freelimit\n");
+ panic("Out of memory in boot alloc, you fool!\n");
+ }
+ boot_freemem += amt;
+ printd("boot alloc from %p to %p\n", retval, boot_freemem);
+ /* multiboot info probably won't ever conflict with our boot alloc */
+ if (mboot_region_collides(multiboot_kaddr, retval, boot_freemem))
+ panic("boot allocation could clobber multiboot info! Get help!");
+ return (void*)retval;
+}
+
+void *boot_zalloc(size_t amt, size_t align)
+{
+ /* boot_alloc panics on failure */
+ void *v = boot_alloc(amt, align);
+ memset(v, 0, amt);
+ return v;
+}
+
+/**
* @brief Map the physical page 'pp' into the virtual address 'va' in page
* directory 'pgdir'
*
* Map the physical page 'pp' at virtual address 'va'.
* The permissions (the low 12 bits) of the page table
* entry should be set to 'perm|PTE_P'.
- *
+ *
* Details:
* - If there is already a page mapped at 'va', it is page_remove()d.
- * - If necessary, on demand, allocates a page table and inserts it into
+ * - If necessary, on demand, allocates a page table and inserts it into
* 'pgdir'.
- * - page_incref() should be called if the insertion succeeds.
+ * - This saves your refcnt in the pgdir (refcnts going away soon).
* - The TLB must be invalidated if a page was formerly present at 'va'.
* (this is handled in page_remove)
*
* No support for jumbos here. We will need to be careful when trying to
* insert regular pages into something that was already jumbo. We will
- * also need to be careful with our overloading of the PTE_PS and
+ * also need to be careful with our overloading of the PTE_PS and
* PTE_PAT flags...
*
* @param[in] pgdir the page directory to insert the page into
* physical page that should be inserted.
* @param[in] va the virtual address where the page should be
* inserted.
- * @param[in] perm the permition bits with which to set up the
+ * @param[in] perm the permition bits with which to set up the
* virtual mapping.
*
* @return ESUCCESS on success
* into which the page should be inserted
*
*/
-int page_insert(pde_t *pgdir, page_t *pp, void *va, int perm)
+int page_insert(pgdir_t pgdir, struct page *page, void *va, int perm)
{
- pte_t* pte = pgdir_walk(pgdir, va, 1);
- if (!pte)
+ pte_t pte = pgdir_walk(pgdir, va, 1);
+ if (!pte_walk_okay(pte))
return -ENOMEM;
- // need to up the ref count in case pp is already mapped at va
- // and we don't want to page_remove (which could free pp) and then
- // continue as if pp wasn't freed. moral = up the ref asap
- page_incref(pp);
- if (*pte & PTE_P) {
- page_remove(pgdir, va);
- }
- *pte = PTE(page2ppn(pp), PTE_P | perm);
+ /* Leftover from older times, but we no longer suppor this: */
+ assert(!pte_is_mapped(pte));
+ pte_write(pte, page2pa(page), perm);
return 0;
}
/**
- * @brief Map the physical page 'pp' at the first virtual address that is free
- * in the range 'vab' to 'vae' in page directory 'pgdir'.
- *
- * The permissions (the low 12 bits) of the page table entry get set to
- * 'perm|PTE_P'.
- *
- * Details:
- * - If there is no free entry in the range 'vab' to 'vae' this
- * function returns NULL.
- * - If necessary, on demand, this function will allocate a page table
- * and inserts it into 'pgdir'.
- * - page_incref() will be called if the insertion succeeds.
- *
- * @param[in] pgdir the page directory to insert the page into
- * @param[in] pp a pointr to the page struct representing the
- * physical page that should be inserted.
- * @param[in] vab the first virtual address in the range in which the
- * page can be inserted.
- * @param[in] vae the last virtual address in the range in which the
- * page can be inserted.
- * @param[in] perm the permition bits with which to set up the
- * virtual mapping.
- *
- * @return VA the virtual address where pp has been mapped in the
- * range (vab, vae)
- * @return NULL no free va in the range (vab, vae) could be found
- */
-void* page_insert_in_range(pde_t *pgdir, page_t *pp,
- void *vab, void *vae, int perm)
-{
- pte_t* pte = NULL;
- void*SNT new_va;
-
- for(new_va = vab; new_va <= vae; new_va+= PGSIZE) {
- pte = pgdir_walk(pgdir, new_va, 1);
- if(pte != NULL && !(*pte & PTE_P)) break;
- else pte = NULL;
- }
- if (!pte) return NULL;
- *pte = page2pa(pp) | PTE_P | perm;
- return TC(new_va); // trusted because mapping a page is like allocation
-}
-
-/**
- * @brief Return the page mapped at virtual address 'va' in
+ * @brief Return the page mapped at virtual address 'va' in
* page directory 'pgdir'.
*
* If pte_store is not NULL, then we store in it the address
* @param[out] pte_store the address of the page table entry for the returned page
*
* @return PAGE the page mapped at virtual address 'va'
- * @return NULL No mapping exists at virtual address 'va'
+ * @return NULL No mapping exists at virtual address 'va', or it's paged out
*/
-page_t *page_lookup(pde_t *pgdir, void *va, pte_t **pte_store)
+page_t *page_lookup(pgdir_t pgdir, void *va, pte_t *pte_store)
{
- pte_t* pte = pgdir_walk(pgdir, va, 0);
- if (!pte || !(*pte & PTE_P))
+ pte_t pte = pgdir_walk(pgdir, va, 0);
+ if (!pte_walk_okay(pte) || !pte_is_mapped(pte))
return 0;
if (pte_store)
*pte_store = pte;
- return pa2page(PTE_ADDR(*pte));
+ return pa2page(pte_get_paddr(pte));
}
/**
* @brief Unmaps the physical page at virtual address 'va' in page directory
* 'pgdir'.
*
- * If there is no physical page at that address, this function silently
+ * If there is no physical page at that address, this function silently
* does nothing.
*
* Details:
* (if such a PTE exists)
* - The TLB is invalidated if an entry is removes from the pg dir/pg table.
*
- * This may be wonky wrt Jumbo pages and decref.
+ * This may be wonky wrt Jumbo pages and decref.
*
* @param pgdir the page directory from with the page sholuld be removed
- * @param va the virtual address at which the page we are trying to
+ * @param va the virtual address at which the page we are trying to
* remove is mapped
- */
-void page_remove(pde_t *pgdir, void *va)
+ * TODO: consider deprecating this, or at least changing how it works with TLBs.
+ * Might want to have the caller need to manage the TLB. Also note it is used
+ * in env_user_mem_free, minus the walk. */
+void page_remove(pgdir_t pgdir, void *va)
{
- pte_t* pte;
+ pte_t pte;
page_t *page;
- page = page_lookup(pgdir, va, &pte);
- if (!page)
+
+ pte = pgdir_walk(pgdir,va,0);
+ if (!pte_walk_okay(pte) || pte_is_unmapped(pte))
return;
- *pte = 0;
- tlb_invalidate(pgdir, va);
- page_decref(page);
+
+ if (pte_is_mapped(pte)) {
+ /* TODO: (TLB) need to do a shootdown, inval sucks. And might want to
+ * manage the TLB / free pages differently. (like by the caller).
+ * Careful about the proc/memory lock here. */
+ page = pa2page(pte_get_paddr(pte));
+ pte_clear(pte);
+ tlb_invalidate(pgdir, va);
+ page_decref(page);
+ } else if (pte_is_paged_out(pte)) {
+ /* TODO: (SWAP) need to free this from the swap */
+ panic("Swapping not supported!");
+ pte_clear(pte);
+ }
}
/**
* @brief Invalidate a TLB entry, but only if the page tables being
* edited are the ones currently in use by the processor.
*
- * TODO: Need to sort this for cross core lovin'
+ * TODO: (TLB) Need to sort this for cross core lovin'
*
- * @param pgdir the page directory assocaited with the tlb entry
+ * @param pgdir the page directory assocaited with the tlb entry
* we are trying to invalidate
* @param va the virtual address associated with the tlb entry
* we are trying to invalidate
*/
-void tlb_invalidate(pde_t *pgdir, void *va)
+void tlb_invalidate(pgdir_t pgdir, void *va)
{
// Flush the entry only if we're modifying the current address space.
// For now, there is only one address space, so always invalidate.
invlpg(va);
}
-/**
- * @brief Check that an environment is allowed to access the range of memory
- * [va, va+len) with permissions 'perm | PTE_P'.
- *
- * Normally 'perm' will contain PTE_U at least, but this is not required. The
- * function get_va_perms only checks for PTE_U, PTE_W, and PTE_P. It won't
- * check for things like PTE_PS, PTE_A, etc.
- * 'va' and 'len' need not be page-aligned;
- *
- * A user program can access a virtual address if:
- * -# the address is below ULIM
- * -# the page table gives it permission.
- *
- * If there is an error, 'user_mem_check_addr' is set to the first
- * erroneous virtual address.
- *
- * @param env the environment associated with the user program trying to access
- * the virtual address range
- * @param va the first virtual address in the range
- * @param len the length of the virtual address range
- * @param perm the permissions the user is trying to access the virtual address
- * range with
- *
- * @return VA a pointer of type COUNT(len) to the address range
- * @return NULL trying to access this range of virtual addresses is not allowed
- */
-void* user_mem_check(env_t *env, const void *DANGEROUS va, size_t len, int perm)
+static void __tlb_global(uint32_t srcid, long a0, long a1, long a2)
{
- // TODO - will need to sort this out wrt page faulting / PTE_P
- // also could be issues with sleeping and waking up to find pages
- // are unmapped, though i think the lab ignores this since the
- // kernel is uninterruptible
- void *DANGEROUS start, *DANGEROUS end;
- size_t num_pages, i;
- int page_perms = 0;
-
- perm |= PTE_P;
- start = ROUNDDOWN((void*DANGEROUS)va, PGSIZE);
- end = ROUNDUP((void*DANGEROUS)va + len, PGSIZE);
- if (start >= end) {
- warn("Blimey! Wrap around in VM range calculation!");
- return NULL;
- }
- num_pages = PPN(end - start);
- for (i = 0; i < num_pages; i++, start += PGSIZE) {
- page_perms = get_va_perms(env->env_pgdir, start);
- // ensures the bits we want on are turned on. if not, error out
- if ((page_perms & perm) != perm) {
- if (i == 0)
- user_mem_check_addr = (void*DANGEROUS)va;
- else
- user_mem_check_addr = start;
- return NULL;
- }
- }
- // this should never be needed, since the perms should catch it
- if ((uintptr_t)end > ULIM) {
- warn ("I suck - Bug in user permission mappings!");
- return NULL;
- }
- return (void *COUNT(len))TC(va);
+ tlb_flush_global();
}
-/**
- * @brief Use the kernel to copy a string from a buffer stored in userspace
- * to a buffer stored elsewhere in the address space (potentially in
- * memory only accessible by the kernel)
- *
- * @param env the environment associated with the user program from which
- * the string is being copied
- * @param dst the destination of the buffer into which the string
- * is being copied
- * @param va the start address of the buffer where the string resides
- * @param len the length of the buffer
- * @param perm the permissions with which the user is trying to access
- * elements of the original buffer
- *
- * @return LEN the length of the new buffer copied into 'dst'
- */
-size_t
-user_mem_strlcpy(env_t *env, char *_dst, const char *DANGEROUS va,
- size_t _len, int perm)
+/* Does a global TLB flush on all cores. */
+void tlb_shootdown_global(void)
{
- const char *DANGEROUS src = va;
- size_t len = _len;
- char *NT COUNT(_len-1) dst_in = _dst;
- char *NT BND(_dst,_dst + _len - 1) dst = _dst;
-
- if (len > 0) {
- while (1) {
- char *c;
- // what if len was 1?
- if (--len <= 0) break;
- c = user_mem_check(env, src, 1, perm);
- if (!c) break;
- if (*c == '\0') break;
- // TODO: ivy bitches about this
- *dst++ = *c;
- src++;
- }
- *dst = '\0';
- }
-
- return dst - dst_in;
-}
-
-/**
- * @brief Checks that environment 'env' is allowed to access the range
- * of memory [va, va+len) with permissions 'perm | PTE_U'. Destroy
- * environment 'env' if the assertion fails.
- *
- * This function is identical to user_mem_assert() except that it has a side
- * affect of destroying the environment 'env' if the memory check fails.
- *
- * @param env the environment associated with the user program trying to access
- * the virtual address range
- * @param va the first virtual address in the range
- * @param len the length of the virtual address range
- * @param perm the permissions the user is trying to access the virtual address
- * range with
- *
- * @return VA a pointer of type COUNT(len) to the address range
- * @return NULL trying to access this range of virtual addresses is not allowed
- * environment 'env' is destroyed
- */
-void *
-user_mem_assert(env_t *env, const void *DANGEROUS va, size_t len, int perm)
-{
- void *COUNT(len) res = user_mem_check(env,va,len,perm | PTE_USER_RO);
- if (!res) {
- cprintf("[%08x] user_mem_check assertion failure for "
- "va %08x\n", env->env_id, user_mem_check_addr);
- proc_destroy(env); // may not return
- return NULL;
- }
- return res;
-}
-
-/**
- * @brief Copies data from a user buffer to a kernel buffer.
- *
- * @param env the environment associated with the user program
- * from which the buffer is being copied
- * @param dest the destination address of the kernel buffer
- * @param va the address of the userspace buffer from which we are copying
- * @param len the length of the userspace buffer
- *
- * @return ESUCCESS on success
- * @return -EFAULT the page assocaited with 'va' is not present, the user
- * lacks the proper permissions, or there was an invalid 'va'
- */
-error_t memcpy_from_user(env_t* env, void* COUNT(len) dest,
- const void *DANGEROUS va, size_t len)
-{
- const void *DANGEROUS start, *DANGEROUS end;
- size_t num_pages, i;
- pte_t *pte;
- uintptr_t perm = PTE_P | PTE_USER_RO;
- size_t bytes_copied = 0;
-
- static_assert(ULIM % PGSIZE == 0 && ULIM != 0); // prevent wrap-around
-
- start = ROUNDDOWN(va, PGSIZE);
- end = ROUNDUP(va + len, PGSIZE);
-
- if(start >= (void*SNT)ULIM || end >= (void*SNT)ULIM)
- return -EFAULT;
-
- num_pages = PPN(end - start);
- for(i = 0; i < num_pages; i++)
- {
- pte = pgdir_walk(env->env_pgdir, start+i*PGSIZE, 0);
- if(!pte || (*pte & perm) != perm)
- return -EFAULT;
-
- void*COUNT(PGSIZE) kpage = KADDR(PTE_ADDR(pte));
- void* src_start = i > 0 ? kpage : kpage+(va-start);
- void* dst_start = dest+bytes_copied;
- size_t copy_len = PGSIZE;
- if(i == 0)
- copy_len -= va-start;
- if(i == num_pages-1)
- copy_len -= end-(start+len);
-
- memcpy(dst_start,src_start,copy_len);
- bytes_copied += copy_len;
+ tlb_flush_global();
+ if (booting)
+ return;
+ /* TODO: consider a helper for broadcast messages, though note that we're
+ * doing our flush immediately, which our caller expects from us before it
+ * returns. */
+ for (int i = 0; i < num_cores; i++) {
+ if (i == core_id())
+ continue;
+ send_kernel_message(i, __tlb_global, 0, 0, 0, KMSG_IMMEDIATE);
}
-
- assert(bytes_copied == len);
-
- return ESUCCESS;
}
-/* mmap2() semantics on the offset */
-void *mmap(struct proc *p, uintptr_t addr, size_t len, int prot, int flags, int fd,
- size_t offset)
+/* Helper, returns true if any part of (start1, end1) is within (start2, end2).
+ * Equality of endpoints (like end1 == start2) is okay.
+ * Assumes no wrap-around. */
+bool regions_collide_unsafe(uintptr_t start1, uintptr_t end1,
+ uintptr_t start2, uintptr_t end2)
{
- if (fd || offset) {
- printk("[kernel] mmap() does not support files yet.\n");
- return (void*SAFE)TC(-1);
+ if (start1 <= start2) {
+ if (end1 <= start2)
+ return FALSE;
+ return TRUE;
+ } else {
+ if (end2 <= start1)
+ return FALSE;
+ return TRUE;
}
- void *tmp = get_free_va_range(p->env_pgdir, addr, len);
- printk("tmp = 0x%08x\n", tmp);
- return 0;
}
projects / akaros.git / blobdiff