/*
* This function takes a contiguous pfn range that needs to be identity mapped
* and:
*
* 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn.
* 2) Calls the do_ function to actually do the mapping/remapping work.
*
* The goal is to not allocate additional memory but to remap the existing
* pages. In the case of an error the underlying memory is simply released back
* to Xen and not remapped.
*/
static unsigned long __init xen_set_identity_and_remap_chunk(
unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
unsigned long remap_pfn)
{
unsigned long pfn;
unsigned long i = 0;
unsigned long n = end_pfn - start_pfn;
if (remap_pfn == 0)
remap_pfn = nr_pages;
while (i < n) {
unsigned long cur_pfn = start_pfn + i;
unsigned long left = n - i;
unsigned long size = left;
unsigned long remap_range_size;
/* Do not remap pages beyond the current allocation */
if (cur_pfn >= nr_pages) {
/* Identity map remaining pages */
set_phys_range_identity(cur_pfn, cur_pfn + size);
break;
}
if (cur_pfn + size > nr_pages)
size = nr_pages - cur_pfn;
remap_range_size = xen_find_pfn_range(&remap_pfn);
if (!remap_range_size) {
pr_warning("Unable to find available pfn range, not remapping identity pages\n");
xen_set_identity_and_release_chunk(cur_pfn,
cur_pfn + left, nr_pages);
break;
}
/* Adjust size to fit in current e820 RAM region */
if (size > remap_range_size)
size = remap_range_size;
xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
/* Update variables to reflect new mappings. */
i += size;
remap_pfn += size;
}
/*
* If the PFNs are currently mapped, the VA mapping also needs
* to be updated to be 1:1.
*/
for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
(void)HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
mfn_pte(pfn, PAGE_KERNEL_IO), 0);
return remap_pfn;
}
static unsigned long __init xen_set_identity(const struct e820entry *list,
ssize_t map_size)
{
phys_addr_t last = xen_initial_domain() ? 0 : ISA_END_ADDRESS;
phys_addr_t start_pci = last;
const struct e820entry *entry;
unsigned long identity = 0;
int i;
for (i = 0, entry = list; i < map_size; i++, entry++) {
phys_addr_t start = entry->addr;
phys_addr_t end = start + entry->size;
if (start < last)
start = last;
if (end <= start)
continue;
/* Skip over the 1MB region. */
if (last > end)
continue;
if ((entry->type == E820_RAM) || (entry->type == E820_UNUSABLE)) {
if (start > start_pci)
identity += set_phys_range_identity(
PFN_UP(start_pci), PFN_DOWN(start));
/* Without saving 'last' we would gooble RAM too
* at the end of the loop. */
last = end;
start_pci = end;
continue;
}
start_pci = min(start, start_pci);
last = end;
}
if (last > start_pci)
identity += set_phys_range_identity(
PFN_UP(start_pci), PFN_DOWN(last));
return identity;
}
static int __init xen_free_mfn(unsigned long mfn)
{
struct xen_memory_reservation reservation = {
.address_bits = 0,
.extent_order = 0,
.domid = DOMID_SELF
};
set_xen_guest_handle(reservation.extent_start, &mfn);
reservation.nr_extents = 1;
return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
}
/*
* This releases a chunk of memory and then does the identity map. It's used
* as a fallback if the remapping fails.
*/
static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
unsigned long end_pfn, unsigned long nr_pages)
{
unsigned long pfn, end;
int ret;
WARN_ON(start_pfn > end_pfn);
/* Release pages first. */
end = min(end_pfn, nr_pages);
for (pfn = start_pfn; pfn < end; pfn++) {
unsigned long mfn = pfn_to_mfn(pfn);
/* Make sure pfn exists to start with */
if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
continue;
ret = xen_free_mfn(mfn);
WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
if (ret == 1) {
xen_released_pages++;
if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
break;
} else
break;
}
set_phys_range_identity(start_pfn, end_pfn);
}
static unsigned long __init xen_do_chunk(unsigned long start,
unsigned long end, bool release)
{
struct xen_memory_reservation reservation = {
.address_bits = 0,
.extent_order = 0,
.domid = DOMID_SELF
};
unsigned long len = 0;
unsigned long pfn;
int ret;
for (pfn = start; pfn < end; pfn++) {
unsigned long frame;
unsigned long mfn = pfn_to_mfn(pfn);
if (release) {
/* Make sure pfn exists to start with */
if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
continue;
frame = mfn;
} else {
if (mfn != INVALID_P2M_ENTRY)
continue;
frame = pfn;
}
set_xen_guest_handle(reservation.extent_start, &frame);
reservation.nr_extents = 1;
ret = HYPERVISOR_memory_op(release ? XENMEM_decrease_reservation : XENMEM_populate_physmap,
&reservation);
WARN(ret != 1, "Failed to %s pfn %lx err=%d\n",
release ? "release" : "populate", pfn, ret);
if (ret == 1) {
if (!early_set_phys_to_machine(pfn, release ? INVALID_P2M_ENTRY : frame)) {
if (release)
break;
set_xen_guest_handle(reservation.extent_start, &frame);
reservation.nr_extents = 1;
ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
&reservation);
break;
}
len++;
} else
break;
}
if (len)
printk(KERN_INFO "%s %lx-%lx pfn range: %lu pages %s\n",
release ? "Freeing" : "Populating",
start, end, len,
release ? "freed" : "added");
return len;
}
static unsigned long __init xen_release_chunk(unsigned long start,
unsigned long end)
{
return xen_do_chunk(start, end, true);
}
static unsigned long __init xen_populate_chunk(
const struct e820entry *list, size_t map_size,
unsigned long max_pfn, unsigned long *last_pfn,
unsigned long credits_left)
{
const struct e820entry *entry;
unsigned int i;
unsigned long done = 0;
unsigned long dest_pfn;
for (i = 0, entry = list; i < map_size; i++, entry++) {
unsigned long s_pfn;
unsigned long e_pfn;
unsigned long pfns;
long capacity;
if (credits_left <= 0)
break;
if (entry->type != E820_RAM)
continue;
e_pfn = PFN_DOWN(entry->addr + entry->size);
/* We only care about E820 after the xen_start_info->nr_pages */
if (e_pfn <= max_pfn)
continue;
s_pfn = PFN_UP(entry->addr);
/* If the E820 falls within the nr_pages, we want to start
* at the nr_pages PFN.
* If that would mean going past the E820 entry, skip it
*/
if (s_pfn <= max_pfn) {
capacity = e_pfn - max_pfn;
dest_pfn = max_pfn;
} else {
capacity = e_pfn - s_pfn;
dest_pfn = s_pfn;
}
if (credits_left < capacity)
capacity = credits_left;
pfns = xen_do_chunk(dest_pfn, dest_pfn + capacity, false);
done += pfns;
*last_pfn = (dest_pfn + pfns);
if (pfns < capacity)
break;
credits_left -= pfns;
}
return done;
}
static void __init xen_set_identity_and_release_chunk(
unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
unsigned long *released, unsigned long *identity)
{
unsigned long pfn;
/*
* If the PFNs are currently mapped, the VA mapping also needs
* to be updated to be 1:1.
*/
for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
(void)HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
mfn_pte(pfn, PAGE_KERNEL_IO), 0);
if (start_pfn < nr_pages)
*released += xen_release_chunk(
start_pfn, min(end_pfn, nr_pages));
*identity += set_phys_range_identity(start_pfn, end_pfn);
}
static unsigned long __init xen_release_chunk(unsigned long start,
unsigned long end)
{
struct xen_memory_reservation reservation = {
.address_bits = 0,
.extent_order = 0,
.domid = DOMID_SELF
};
unsigned long len = 0;
unsigned long pfn;
int ret;
for(pfn = start; pfn < end; pfn++) {
unsigned long mfn = pfn_to_mfn(pfn);
/* Make sure pfn exists to start with */
if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
continue;
set_xen_guest_handle(reservation.extent_start, &mfn);
reservation.nr_extents = 1;
ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
&reservation);
WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
if (ret == 1) {
__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
len++;
}
}
printk(KERN_INFO "Freeing %lx-%lx pfn range: %lu pages freed\n",
start, end, len);
return len;
}
static unsigned long __init xen_set_identity_and_release(
const struct e820entry *list, size_t map_size, unsigned long nr_pages)
{
phys_addr_t start = 0;
unsigned long released = 0;
unsigned long identity = 0;
const struct e820entry *entry;
int i;
/*
* Combine non-RAM regions and gaps until a RAM region (or the
* end of the map) is reached, then set the 1:1 map and
* release the pages (if available) in those non-RAM regions.
*
* The combined non-RAM regions are rounded to a whole number
* of pages so any partial pages are accessible via the 1:1
* mapping. This is needed for some BIOSes that put (for
* example) the DMI tables in a reserved region that begins on
* a non-page boundary.
*/
for (i = 0, entry = list; i < map_size; i++, entry++) {
phys_addr_t end = entry->addr + entry->size;
if (entry->type == E820_RAM || i == map_size - 1) {
unsigned long start_pfn = PFN_DOWN(start);
unsigned long end_pfn = PFN_UP(end);
if (entry->type == E820_RAM)
end_pfn = PFN_UP(entry->addr);
if (start_pfn < end_pfn) {
if (start_pfn < nr_pages)
released += xen_release_chunk(
start_pfn, min(end_pfn, nr_pages));
identity += set_phys_range_identity(
start_pfn, end_pfn);
}
start = end;
}
}
printk(KERN_INFO "Released %lu pages of unused memory\n", released);
printk(KERN_INFO "Set %ld page(s) to 1-1 mapping\n", identity);
return released;
}
static unsigned long __init xen_release_chunk(unsigned long start,
unsigned long end)
{
struct xen_memory_reservation reservation = {
.address_bits = 0,
.extent_order = 0,
.domid = DOMID_SELF
};
unsigned long len = 0;
unsigned long pfn;
int ret;
for(pfn = start; pfn < end; pfn++) {
unsigned long mfn = pfn_to_mfn(pfn);
/* */
if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
continue;
set_xen_guest_handle(reservation.extent_start, &mfn);
reservation.nr_extents = 1;
ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
&reservation);
WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
if (ret == 1) {
__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
len++;
}
}
printk(KERN_INFO "Freeing %lx-%lx pfn range: %lu pages freed\n",
start, end, len);
return len;
}
static unsigned long __init xen_set_identity_and_release(
const struct e820entry *list, size_t map_size, unsigned long nr_pages)
{
phys_addr_t start = 0;
unsigned long released = 0;
unsigned long identity = 0;
const struct e820entry *entry;
int i;
/*
*/
for (i = 0, entry = list; i < map_size; i++, entry++) {
phys_addr_t end = entry->addr + entry->size;
if (entry->type == E820_RAM || i == map_size - 1) {
unsigned long start_pfn = PFN_DOWN(start);
unsigned long end_pfn = PFN_UP(end);
if (entry->type == E820_RAM)
end_pfn = PFN_UP(entry->addr);
if (start_pfn < end_pfn) {
if (start_pfn < nr_pages)
released += xen_release_chunk(
start_pfn, min(end_pfn, nr_pages));
identity += set_phys_range_identity(
start_pfn, end_pfn);
}
start = end;
}
}
printk(KERN_INFO "Released %lu pages of unused memory\n", released);
printk(KERN_INFO "Set %ld page(s) to 1-1 mapping\n", identity);
return released;
}
/**
* machine_specific_memory_setup - Hook for machine specific memory setup.
**/
char * __init xen_memory_setup(void)
{
unsigned long max_pfn, pfn_s, n_pfns;
phys_addr_t mem_end, addr, size, chunk_size;
u32 type;
int rc;
struct xen_memory_map memmap;
unsigned long max_pages;
unsigned long extra_pages = 0;
int i;
int op;
xen_parse_512gb();
max_pfn = xen_get_pages_limit();
max_pfn = min(max_pfn, xen_start_info->nr_pages);
mem_end = PFN_PHYS(max_pfn);
memmap.nr_entries = E820MAX;
set_xen_guest_handle(memmap.buffer, xen_e820_map);
op = xen_initial_domain() ?
XENMEM_machine_memory_map :
XENMEM_memory_map;
rc = HYPERVISOR_memory_op(op, &memmap);
if (rc == -ENOSYS) {
BUG_ON(xen_initial_domain());
memmap.nr_entries = 1;
xen_e820_map[0].addr = 0ULL;
xen_e820_map[0].size = mem_end;
/* 8MB slack (to balance backend allocations). */
xen_e820_map[0].size += 8ULL << 20;
xen_e820_map[0].type = E820_RAM;
rc = 0;
}
BUG_ON(rc);
BUG_ON(memmap.nr_entries == 0);
xen_e820_map_entries = memmap.nr_entries;
/*
* Xen won't allow a 1:1 mapping to be created to UNUSABLE
* regions, so if we're using the machine memory map leave the
* region as RAM as it is in the pseudo-physical map.
*
* UNUSABLE regions in domUs are not handled and will need
* a patch in the future.
*/
if (xen_initial_domain())
xen_ignore_unusable();
/* Make sure the Xen-supplied memory map is well-ordered. */
sanitize_e820_map(xen_e820_map, ARRAY_SIZE(xen_e820_map),
&xen_e820_map_entries);
max_pages = xen_get_max_pages();
/* How many extra pages do we need due to remapping? */
max_pages += xen_count_remap_pages(max_pfn);
if (max_pages > max_pfn)
extra_pages += max_pages - max_pfn;
/*
* Clamp the amount of extra memory to a EXTRA_MEM_RATIO
* factor the base size. On non-highmem systems, the base
* size is the full initial memory allocation; on highmem it
* is limited to the max size of lowmem, so that it doesn't
* get completely filled.
*
* Make sure we have no memory above max_pages, as this area
* isn't handled by the p2m management.
*
* In principle there could be a problem in lowmem systems if
* the initial memory is also very large with respect to
* lowmem, but we won't try to deal with that here.
*/
extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
extra_pages, max_pages - max_pfn);
i = 0;
addr = xen_e820_map[0].addr;
size = xen_e820_map[0].size;
while (i < xen_e820_map_entries) {
bool discard = false;
chunk_size = size;
type = xen_e820_map[i].type;
if (type == E820_RAM) {
if (addr < mem_end) {
chunk_size = min(size, mem_end - addr);
} else if (extra_pages) {
chunk_size = min(size, PFN_PHYS(extra_pages));
pfn_s = PFN_UP(addr);
n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
extra_pages -= n_pfns;
xen_add_extra_mem(pfn_s, n_pfns);
xen_max_p2m_pfn = pfn_s + n_pfns;
} else
discard = true;
}
if (!discard)
xen_align_and_add_e820_region(addr, chunk_size, type);
addr += chunk_size;
size -= chunk_size;
if (size == 0) {
i++;
if (i < xen_e820_map_entries) {
addr = xen_e820_map[i].addr;
size = xen_e820_map[i].size;
}
}
}
/*
* Set the rest as identity mapped, in case PCI BARs are
* located here.
*/
set_phys_range_identity(addr / PAGE_SIZE, ~0ul);
/*
* In domU, the ISA region is normal, usable memory, but we
* reserve ISA memory anyway because too many things poke
* about in there.
*/
e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
E820_RESERVED);
sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
/*
* Check whether the kernel itself conflicts with the target E820 map.
* Failing now is better than running into weird problems later due
* to relocating (and even reusing) pages with kernel text or data.
*/
if (xen_is_e820_reserved(__pa_symbol(_text),
__pa_symbol(__bss_stop) - __pa_symbol(_text))) {
xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n");
BUG();
}
/*
* Check for a conflict of the hypervisor supplied page tables with
* the target E820 map.
*/
xen_pt_check_e820();
xen_reserve_xen_mfnlist();
/* Check for a conflict of the initrd with the target E820 map. */
if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image,
boot_params.hdr.ramdisk_size)) {
phys_addr_t new_area, start, size;
new_area = xen_find_free_area(boot_params.hdr.ramdisk_size);
if (!new_area) {
xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n");
BUG();
}
start = boot_params.hdr.ramdisk_image;
size = boot_params.hdr.ramdisk_size;
xen_phys_memcpy(new_area, start, size);
pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n",
start, start + size, new_area, new_area + size);
memblock_free(start, size);
boot_params.hdr.ramdisk_image = new_area;
boot_params.ext_ramdisk_image = new_area >> 32;
}
/*
* Helper function to update the p2m and m2p tables and kernel mapping.
*/
static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
{
struct mmu_update update = {
.ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
.val = pfn
};
/* Update p2m */
if (!set_phys_to_machine(pfn, mfn)) {
WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n",
pfn, mfn);
BUG();
}
/* Update m2p */
if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) {
WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n",
mfn, pfn);
BUG();
}
/* Update kernel mapping, but not for highmem. */
if (pfn >= PFN_UP(__pa(high_memory - 1)))
return;
if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
mfn_pte(mfn, PAGE_KERNEL), 0)) {
WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n",
mfn, pfn);
BUG();
}
}
/*
* This function updates the p2m and m2p tables with an identity map from
* start_pfn to start_pfn+size and prepares remapping the underlying RAM of the
* original allocation at remap_pfn. The information needed for remapping is
* saved in the memory itself to avoid the need for allocating buffers. The
* complete remap information is contained in a list of MFNs each containing
* up to REMAP_SIZE MFNs and the start target PFN for doing the remap.
* This enables us to preserve the original mfn sequence while doing the
* remapping at a time when the memory management is capable of allocating
* virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and
* its callers.
*/
static void __init xen_do_set_identity_and_remap_chunk(
unsigned long start_pfn, unsigned long size, unsigned long remap_pfn)
{
unsigned long buf = (unsigned long)&xen_remap_buf;
unsigned long mfn_save, mfn;
unsigned long ident_pfn_iter, remap_pfn_iter;
unsigned long ident_end_pfn = start_pfn + size;
unsigned long left = size;
unsigned int i, chunk;
WARN_ON(size == 0);
BUG_ON(xen_feature(XENFEAT_auto_translated_physmap));
mfn_save = virt_to_mfn(buf);
for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn;
ident_pfn_iter < ident_end_pfn;
ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) {
chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE;
/* Map first pfn to xen_remap_buf */
mfn = pfn_to_mfn(ident_pfn_iter);
set_pte_mfn(buf, mfn, PAGE_KERNEL);
/* Save mapping information in page */
xen_remap_buf.next_area_mfn = xen_remap_mfn;
xen_remap_buf.target_pfn = remap_pfn_iter;
xen_remap_buf.size = chunk;
for (i = 0; i < chunk; i++)
xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i);
/* Put remap buf into list. */
xen_remap_mfn = mfn;
/* Set identity map */
set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
left -= chunk;
}
/* Restore old xen_remap_buf mapping */
set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
}
static unsigned long __init xen_do_chunk(unsigned long start,
unsigned long end, bool release)
{
struct xen_memory_reservation reservation = {
.address_bits = 0,
.extent_order = 0,
.domid = DOMID_SELF
};
unsigned long len = 0;
int xlated_phys = xen_feature(XENFEAT_auto_translated_physmap);
unsigned long pfn;
int ret;
for (pfn = start; pfn < end; pfn++) {
unsigned long frame;
unsigned long mfn = pfn_to_mfn(pfn);
if (release) {
/* Make sure pfn exists to start with */
if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
continue;
frame = mfn;
} else {
if (!xlated_phys && mfn != INVALID_P2M_ENTRY)
continue;
frame = pfn;
}
set_xen_guest_handle(reservation.extent_start, &frame);
reservation.nr_extents = 1;
ret = HYPERVISOR_memory_op(release ? XENMEM_decrease_reservation : XENMEM_populate_physmap,
&reservation);
WARN(ret != 1, "Failed to %s pfn %lx err=%d\n",
release ? "release" : "populate", pfn, ret);
if (ret == 1) {
if (!early_set_phys_to_machine(pfn, release ? INVALID_P2M_ENTRY : frame)) {
if (release)
break;
set_xen_guest_handle(reservation.extent_start, &frame);
reservation.nr_extents = 1;
ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
&reservation);
break;
}
len++;
} else
break;
}
if (len)
printk(KERN_INFO "%s %lx-%lx pfn range: %lu pages %s\n",
release ? "Freeing" : "Populating",
start, end, len,
release ? "freed" : "added");
return len;
}
static unsigned long __init xen_release_chunk(unsigned long start,
unsigned long end)
{
/*
* Xen already ballooned out the E820 non RAM regions for us
* and set them up properly in EPT.
*/
if (xen_feature(XENFEAT_auto_translated_physmap))
return end - start;
return xen_do_chunk(start, end, true);
}
static unsigned long __init xen_populate_chunk(
const struct e820entry *list, size_t map_size,
unsigned long max_pfn, unsigned long *last_pfn,
unsigned long credits_left)
{
const struct e820entry *entry;
unsigned int i;
unsigned long done = 0;
unsigned long dest_pfn;
for (i = 0, entry = list; i < map_size; i++, entry++) {
unsigned long s_pfn;
unsigned long e_pfn;
unsigned long pfns;
long capacity;
if (credits_left <= 0)
break;
if (entry->type != E820_RAM)
continue;
e_pfn = PFN_DOWN(entry->addr + entry->size);
/* We only care about E820 after the xen_start_info->nr_pages */
if (e_pfn <= max_pfn)
continue;
s_pfn = PFN_UP(entry->addr);
/* If the E820 falls within the nr_pages, we want to start
* at the nr_pages PFN.
* If that would mean going past the E820 entry, skip it
*/
if (s_pfn <= max_pfn) {
capacity = e_pfn - max_pfn;
dest_pfn = max_pfn;
} else {
capacity = e_pfn - s_pfn;
dest_pfn = s_pfn;
}
if (credits_left < capacity)
capacity = credits_left;
pfns = xen_do_chunk(dest_pfn, dest_pfn + capacity, false);
done += pfns;
*last_pfn = (dest_pfn + pfns);
if (pfns < capacity)
break;
credits_left -= pfns;
}
return done;
}
static void __init xen_set_identity_and_release_chunk(
unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
unsigned long *released, unsigned long *identity)
{
unsigned long pfn;
/*
* If the PFNs are currently mapped, clear the mappings
* (except for the ISA region which must be 1:1 mapped) to
* release the refcounts (in Xen) on the original frames.
*/
/*
* PVH E820 matches the hypervisor's P2M which means we need to
* account for the proper values of *release and *identity.
*/
for (pfn = start_pfn; !xen_feature(XENFEAT_auto_translated_physmap) &&
pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) {
pte_t pte = __pte_ma(0);
if (pfn < PFN_UP(ISA_END_ADDRESS))
pte = mfn_pte(pfn, PAGE_KERNEL_IO);
(void)HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT), pte, 0);
}
if (start_pfn < nr_pages)
*released += xen_release_chunk(
start_pfn, min(end_pfn, nr_pages));
*identity += set_phys_range_identity(start_pfn, end_pfn);
}
