From a3eba19470c09f42272dac5ca1a34bd8a5cbe834 Mon Sep 17 00:00:00 2001 From: Zheng Da Date: Tue, 17 Nov 2009 10:26:25 +0100 Subject: The original version of DDEKit. --- libddekit/pgtab.c | 219 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 219 insertions(+) create mode 100644 libddekit/pgtab.c (limited to 'libddekit/pgtab.c') diff --git a/libddekit/pgtab.c b/libddekit/pgtab.c new file mode 100644 index 00000000..3c39f54f --- /dev/null +++ b/libddekit/pgtab.c @@ -0,0 +1,219 @@ +/* + * \brief Virtual page-table facility + * \author Thomas Friebel + * \author Christian Helmuth + * \date 2006-11-01 + * + * This implementation uses l4rm (especially the AVL tree and userptr) to + * manage virt->phys mappings. Each mapping region is represented by one + * pgtab_object that is kept in the l4rm region userptr. + * + * For this to work, dataspaces must be attached to l4rm regions! + */ + +#include +#include +#include + +#include +#include +#include + +#include "config.h" + + +/** + * "Page-table" object + */ +struct pgtab_object +{ + l4_addr_t va; /* virtual start address */ + l4_addr_t pa; /* physical start address */ + + /* FIXME reconsider the following members */ + l4_size_t size; + unsigned type; /* pgtab region type */ + + struct pgtab_object * next; + struct pgtab_object * prev; +}; + +/** + * pa_list_head of page-table object list (for get_virtaddr()) + */ +static struct pgtab_object pa_list_head = + { + .va = 0, + .pa = 0, + .size = 0, + .next = &pa_list_head, + .prev = &pa_list_head + }; + +static l4lock_t pa_list_lock = L4LOCK_UNLOCKED; + +/***************************** + ** Page-table facility API ** + *****************************/ + +/** + * Get physical address for virtual address + * + * \param virtual virtual address + * \return physical address or 0 + */ +ddekit_addr_t ddekit_pgtab_get_physaddr(const void *virtual) +{ + /* find pgtab object */ + struct pgtab_object *p = l4rm_get_userptr(virtual); + if (!p) { + /* XXX this is verbose */ + LOG_Error("no virt->phys mapping for virtual address %p", virtual); + return 0; + } + + /* return virt->phys mapping */ + l4_size_t offset = (l4_addr_t) virtual - p->va; + + return p->pa + offset; +} + +/** + * Get virtual address for physical address + * + * \param physical physical address + * \return virtual address or 0 + */ +ddekit_addr_t ddekit_pgtab_get_virtaddr(const ddekit_addr_t physical) +{ + /* find pgtab object */ + struct pgtab_object *p; + ddekit_addr_t retval = 0; + + /* find phys->virt mapping */ + l4lock_lock(&pa_list_lock); + for (p = pa_list_head.next ; p != &pa_list_head ; p = p->next) { + if (p->pa <= (l4_addr_t)physical && + (l4_addr_t)physical < p->pa + p->size) { + l4_size_t offset = (l4_addr_t) physical - p->pa; + retval = p->va + offset; + break; + } + } + l4lock_unlock(&pa_list_lock); + + if (!retval) + LOG_Error("no phys->virt mapping for physical address %p", (void*)physical); + + return retval; +} + + + +int ddekit_pgtab_get_type(const void *virtual) +{ + /* find pgtab object */ + struct pgtab_object *p = l4rm_get_userptr(virtual); + if (!p) { + /* XXX this is verbose */ + LOG_Error("no virt->phys mapping for %p", virtual); + return -1; + } + + return p->type; +} + + +int ddekit_pgtab_get_size(const void *virtual) +{ + /* find pgtab object */ + struct pgtab_object *p = l4rm_get_userptr(virtual); + if (!p) { + /* XXX this is verbose */ + LOG_Error("no virt->phys mapping for %p", virtual); + return -1; + } + + return p->size; +} + + +/** + * Clear virtual->physical mapping for VM region + * + * \param virtual virtual start address for region + * \param type pgtab type for region + */ +void ddekit_pgtab_clear_region(void *virtual, int type) +{ + struct pgtab_object *p; + + /* find pgtab object */ + p = (struct pgtab_object *)l4rm_get_userptr(virtual); + if (!p) { + /* XXX this is verbose */ + LOG_Error("no virt->phys mapping for %p", virtual); + return; + } + + /* reset userptr in region map */ + /* XXX no error handling here */ + l4rm_set_userptr(virtual, 0); + + /* remove pgtab object from list */ + l4lock_lock(&pa_list_lock); + p->next->prev= p->prev; + p->prev->next= p->next; + l4lock_unlock(&pa_list_lock); + + /* free pgtab object */ + ddekit_simple_free(p); +} + + +/** + * Set virtual->physical mapping for VM region + * + * \param virtual virtual start address for region + * \param physical physical start address for region + * \param pages number of pages in region + * \param type pgtab type for region + */ +void ddekit_pgtab_set_region(void *virtual, ddekit_addr_t physical, int pages, int type) +{ + /* allocate pgtab object */ + struct pgtab_object *p = ddekit_simple_malloc(sizeof(*p)); + if (!p) { + LOG_Error("ddekit heap exhausted"); + return; + } + + /* initialize pgtab object */ + p->va = l4_trunc_page(virtual); + p->pa = l4_trunc_page(physical); + p->size = pages * L4_PAGESIZE; + p->type = type; + + l4lock_lock(&pa_list_lock); + p->next=pa_list_head.next; + p->prev=&pa_list_head; + pa_list_head.next->prev=p; + pa_list_head.next=p; + l4lock_unlock(&pa_list_lock); + + /* set userptr in region map to pgtab object */ + int err = l4rm_set_userptr((void *)p->va, p); + if (err) { + LOG_Error("l4rm_set_userptr returned %d", err); + ddekit_panic("l4rm_set_userptr"); + ddekit_simple_free(p); + } +} + +void ddekit_pgtab_set_region_with_size(void *virt, ddekit_addr_t phys, int size, int type) +{ + int p = l4_round_page(size); + p >>= L4_PAGESHIFT; + ddekit_pgtab_set_region(virt, phys, p, type); +} + -- cgit v1.2.3