static void *physmap_common(const char *descr, uintptr_t phys_addr, size_t len, bool readonly, bool autocleanup,
bool round)
{
void *virt_addr;
uintptr_t offset = 0;
if (len == 0) {
msg_pspew("Not mapping %s, zero size at 0x%0*" PRIxPTR ".\n", descr, PRIxPTR_WIDTH, phys_addr);
return ERROR_PTR;
}
if (round)
offset = round_to_page_boundaries(&phys_addr, &len);
if (readonly)
virt_addr = sys_physmap_ro_cached(phys_addr, len);
else
virt_addr = sys_physmap_rw_uncached(phys_addr, len);
if (ERROR_PTR == virt_addr) {
if (NULL == descr)
descr = "memory";
msg_perr("Error accessing %s, 0x%zx bytes at 0x%0*" PRIxPTR "\n",
descr, len, PRIxPTR_WIDTH, phys_addr);
msg_perr(MEM_DEV " mmap failed: %s\n", strerror(errno));
#ifdef __linux__
if (EINVAL == errno) {
msg_perr("In Linux this error can be caused by the CONFIG_NONPROMISC_DEVMEM (<2.6.27),\n");
msg_perr("CONFIG_STRICT_DEVMEM (>=2.6.27) and CONFIG_X86_PAT kernel options.\n");
msg_perr("Please check if either is enabled in your kernel before reporting a failure.\n");
msg_perr("You can override CONFIG_X86_PAT at boot with the nopat kernel parameter but\n");
msg_perr("disabling the other option unfortunately requires a kernel recompile. Sorry!\n");
}
#elif defined (__OpenBSD__)
msg_perr("Please set securelevel=-1 in /etc/rc.securelevel "
"and reboot, or reboot into\n"
"single user mode.\n");
#endif
return ERROR_PTR;
}
if (autocleanup) {
struct undo_physmap_data *d = malloc(sizeof(struct undo_physmap_data));
if (d == NULL) {
msg_perr("%s: Out of memory!\n", __func__);
physunmap(virt_addr, len);
return ERROR_PTR;
}
d->virt_addr = virt_addr;
d->len = len;
if (register_shutdown(undo_physmap, d) != 0) {
msg_perr("%s: Could not register shutdown function!\n", __func__);
physunmap(virt_addr, len);
return ERROR_PTR;
}
}
return virt_addr + offset;
}
void physunmap(void *virt_addr, size_t len)
{
uintptr_t tmp;
/* No need to check for zero size, such mappings would have yielded ERROR_PTR. */
if (virt_addr == ERROR_PTR) {
msg_perr("Trying to unmap a nonexisting mapping!\n"
"Please report a bug at [email protected]\n");
return;
}
tmp = (uintptr_t)virt_addr;
/* We assume that the virtual address of a page-aligned physical address is page-aligned as well. By
* extension, rounding a virtual unaligned address as returned by physmap should yield the same offset
* between rounded and original virtual address as between rounded and original physical address.
*/
round_to_page_boundaries(&tmp, &len);
virt_addr = (void *)tmp;
physunmap_unaligned(virt_addr, len);
}
