| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright 2015 Google, Inc. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; version 2 of the License. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc. |
| */ |
| |
| #include <assert.h> |
| #include <cbmem.h> |
| #include <console/console.h> |
| #include <imd.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| /* For more details on implementation and usage please see the imd.h header. */ |
| |
| static const uint32_t IMD_ROOT_PTR_MAGIC = 0xc0389481; |
| static const uint32_t IMD_ENTRY_MAGIC = ~0xc0389481; |
| static const uint32_t SMALL_REGION_ID = CBMEM_ID_IMD_SMALL; |
| static const size_t LIMIT_ALIGN = 4096; |
| |
| /* In-memory data structures. */ |
| struct imd_root_pointer { |
| uint32_t magic; |
| /* Relative to upper limit/offset. */ |
| int32_t root_offset; |
| } __attribute__((packed)); |
| |
| struct imd_entry { |
| uint32_t magic; |
| /* start is located relative to imd_root */ |
| int32_t start_offset; |
| uint32_t size; |
| uint32_t id; |
| } __attribute__((packed)); |
| |
| struct imd_root { |
| uint32_t max_entries; |
| uint32_t num_entries; |
| uint32_t flags; |
| uint32_t entry_align; |
| /* Used for fixing the size of an imd. Relative to the root. */ |
| int32_t max_offset; |
| struct imd_entry entries[0]; |
| } __attribute__((packed)); |
| |
| #define IMD_FLAG_LOCKED 1 |
| |
| static void *relative_pointer(void *base, ssize_t offset) |
| { |
| intptr_t b = (intptr_t)base; |
| b += offset; |
| return (void *)b; |
| } |
| |
| static bool imd_root_pointer_valid(const struct imd_root_pointer *rp) |
| { |
| return !!(rp->magic == IMD_ROOT_PTR_MAGIC); |
| } |
| |
| static struct imd_root *imdr_root(const struct imdr *imdr) |
| { |
| return imdr->r; |
| } |
| |
| /* |
| * The root pointer is relative to the upper limit of the imd. i.e. It sits |
| * just below the upper limit. |
| */ |
| static struct imd_root_pointer *imdr_get_root_pointer(const struct imdr *imdr) |
| { |
| struct imd_root_pointer *rp; |
| |
| rp = relative_pointer((void *)imdr->limit, -sizeof(*rp)); |
| |
| return rp; |
| } |
| |
| static void imd_link_root(struct imd_root_pointer *rp, struct imd_root *r) |
| { |
| rp->magic = IMD_ROOT_PTR_MAGIC; |
| rp->root_offset = (int32_t)((intptr_t)r - (intptr_t)rp); |
| } |
| |
| static struct imd_entry *root_last_entry(struct imd_root *r) |
| { |
| return &r->entries[r->num_entries - 1]; |
| } |
| |
| static size_t root_num_entries(size_t root_size) |
| { |
| size_t entries_size; |
| |
| entries_size = root_size; |
| entries_size -= sizeof(struct imd_root_pointer); |
| entries_size -= sizeof(struct imd_root); |
| |
| return entries_size / sizeof(struct imd_entry); |
| } |
| |
| static size_t imd_root_data_left(struct imd_root *r) |
| { |
| struct imd_entry *last_entry; |
| |
| last_entry = root_last_entry(r); |
| |
| if (r->max_offset != 0) |
| return last_entry->start_offset - r->max_offset; |
| |
| return ~(size_t)0; |
| } |
| |
| static bool root_is_locked(const struct imd_root *r) |
| { |
| return !!(r->flags & IMD_FLAG_LOCKED); |
| } |
| |
| static void imd_entry_assign(struct imd_entry *e, uint32_t id, |
| ssize_t offset, size_t size) |
| { |
| e->magic = IMD_ENTRY_MAGIC; |
| e->start_offset = offset; |
| e->size = size; |
| e->id = id; |
| } |
| |
| static void imdr_init(struct imdr *ir, void *upper_limit) |
| { |
| uintptr_t limit = (uintptr_t)upper_limit; |
| /* Upper limit is aligned down to 4KiB */ |
| ir->limit = ALIGN_DOWN(limit, LIMIT_ALIGN); |
| ir->r = NULL; |
| } |
| |
| static int imdr_create_empty(struct imdr *imdr, size_t root_size, |
| size_t entry_align) |
| { |
| struct imd_root_pointer *rp; |
| struct imd_root *r; |
| struct imd_entry *e; |
| ssize_t root_offset; |
| |
| if (!imdr->limit) |
| return -1; |
| |
| /* root_size and entry_align should be a power of 2. */ |
| assert(IS_POWER_OF_2(root_size)); |
| assert(IS_POWER_OF_2(entry_align)); |
| |
| if (!imdr->limit) |
| return -1; |
| |
| /* |
| * root_size needs to be large enough to accomodate root pointer and |
| * root book keeping structure. The caller needs to ensure there's |
| * enough room for tracking individual allocations. |
| */ |
| if (root_size < (sizeof(*rp) + sizeof(*r))) |
| return -1; |
| |
| /* For simplicity don't allow sizes or alignments to exceed LIMIT_ALIGN. */ |
| if (root_size > LIMIT_ALIGN || entry_align > LIMIT_ALIGN) |
| return -1; |
| |
| /* Additionally, don't handle an entry alignment > root_size. */ |
| if (entry_align > root_size) |
| return -1; |
| |
| rp = imdr_get_root_pointer(imdr); |
| |
| root_offset = -(ssize_t)root_size; |
| /* Set root pointer. */ |
| imdr->r = relative_pointer((void *)imdr->limit, root_offset); |
| r = imdr_root(imdr); |
| imd_link_root(rp, r); |
| |
| memset(r, 0, sizeof(*r)); |
| r->entry_align = entry_align; |
| |
| /* Calculate size left for entries. */ |
| r->max_entries = root_num_entries(root_size); |
| |
| /* Fill in first entry covering the root region. */ |
| r->num_entries = 1; |
| e = &r->entries[0]; |
| imd_entry_assign(e, CBMEM_ID_IMD_ROOT, 0, root_size); |
| |
| printk(BIOS_DEBUG, "IMD: root @ %p %u entries.\n", r, r->max_entries); |
| |
| return 0; |
| } |
| |
| static int imdr_recover(struct imdr *imdr) |
| { |
| struct imd_root_pointer *rp; |
| struct imd_root *r; |
| uintptr_t low_limit; |
| size_t i; |
| |
| if (!imdr->limit) |
| return -1; |
| |
| rp = imdr_get_root_pointer(imdr); |
| |
| if (!imd_root_pointer_valid(rp)) |
| return -1; |
| |
| r = relative_pointer(rp, rp->root_offset); |
| |
| /* Confirm the root and root pointer are just under the limit. */ |
| if (ALIGN_UP((uintptr_t)&r->entries[r->max_entries], LIMIT_ALIGN) != |
| imdr->limit) |
| return -1; |
| |
| if (r->num_entries > r->max_entries) |
| return -1; |
| |
| /* Entry alignment should be power of 2. */ |
| if (!IS_POWER_OF_2(r->entry_align)) |
| return -1; |
| |
| low_limit = (uintptr_t)relative_pointer(r, r->max_offset); |
| |
| /* If no max_offset then lowest limit is 0. */ |
| if (low_limit == (uintptr_t)r) |
| low_limit = 0; |
| |
| for (i = 0; i < r->num_entries; i++) { |
| uintptr_t start_addr; |
| const struct imd_entry *e = &r->entries[i]; |
| |
| if (e->magic != IMD_ENTRY_MAGIC) |
| return -1; |
| |
| start_addr = (uintptr_t)relative_pointer(r, e->start_offset); |
| if (start_addr < low_limit) |
| return -1; |
| if (start_addr >= imdr->limit || |
| (start_addr + e->size) > imdr->limit) |
| return -1; |
| } |
| |
| /* Set root pointer. */ |
| imdr->r = r; |
| |
| return 0; |
| } |
| |
| static const struct imd_entry *imdr_entry_find(const struct imdr *imdr, |
| uint32_t id) |
| { |
| struct imd_root *r; |
| struct imd_entry *e; |
| size_t i; |
| |
| r = imdr_root(imdr); |
| |
| if (r == NULL) |
| return NULL; |
| |
| e = NULL; |
| /* Skip first entry covering the root. */ |
| for (i = 1; i < r->num_entries; i++) { |
| if (id != r->entries[i].id) |
| continue; |
| e = &r->entries[i]; |
| break; |
| } |
| |
| return e; |
| } |
| |
| static int imdr_limit_size(struct imdr *imdr, size_t max_size) |
| { |
| struct imd_root *r; |
| ssize_t smax_size; |
| size_t root_size; |
| |
| r = imdr_root(imdr); |
| if (r == NULL) |
| return -1; |
| |
| root_size = imdr->limit - (uintptr_t)r; |
| |
| if (max_size < root_size) |
| return -1; |
| |
| /* Take into account the root size. */ |
| smax_size = max_size - root_size; |
| smax_size = -smax_size; |
| |
| r->max_offset = smax_size; |
| |
| return 0; |
| } |
| |
| static size_t imdr_entry_size(const struct imdr *imdr, |
| const struct imd_entry *e) |
| { |
| return e->size; |
| } |
| |
| static void *imdr_entry_at(const struct imdr *imdr, const struct imd_entry *e) |
| { |
| return relative_pointer(imdr_root(imdr), e->start_offset); |
| } |
| |
| static struct imd_entry *imd_entry_add_to_root(struct imd_root *r, uint32_t id, |
| size_t size) |
| { |
| struct imd_entry *entry; |
| struct imd_entry *last_entry; |
| ssize_t e_offset; |
| size_t used_size; |
| |
| if (r->num_entries == r->max_entries) |
| return NULL; |
| |
| /* Determine total size taken up by entry. */ |
| used_size = ALIGN_UP(size, r->entry_align); |
| |
| /* See if size overflows imd total size. */ |
| if (used_size > imd_root_data_left(r)) |
| return NULL; |
| |
| /* |
| * Determine if offset field overflows. All offsets should be lower |
| * than the previous one. |
| */ |
| last_entry = root_last_entry(r); |
| e_offset = last_entry->start_offset; |
| e_offset -= (ssize_t)used_size; |
| if (e_offset > last_entry->start_offset) |
| return NULL; |
| |
| entry = root_last_entry(r) + 1; |
| r->num_entries++; |
| |
| imd_entry_assign(entry, id, e_offset, size); |
| |
| return entry; |
| } |
| |
| static const struct imd_entry *imdr_entry_add(const struct imdr *imdr, |
| uint32_t id, size_t size) |
| { |
| struct imd_root *r; |
| |
| r = imdr_root(imdr); |
| |
| if (r == NULL) |
| return NULL; |
| |
| if (root_is_locked(r)) |
| return NULL; |
| |
| return imd_entry_add_to_root(r, id, size); |
| } |
| |
| static bool imdr_has_entry(const struct imdr *imdr, const struct imd_entry *e) |
| { |
| struct imd_root *r; |
| size_t idx; |
| |
| r = imdr_root(imdr); |
| if (r == NULL) |
| return false; |
| |
| /* Determine if the entry is within this root structure. */ |
| idx = e - &r->entries[0]; |
| if (idx >= r->num_entries) |
| return false; |
| |
| return true; |
| } |
| |
| static const struct imdr *imd_entry_to_imdr(const struct imd *imd, |
| const struct imd_entry *entry) |
| { |
| if (imdr_has_entry(&imd->lg, entry)) |
| return &imd->lg; |
| |
| if (imdr_has_entry(&imd->sm, entry)) |
| return &imd->sm; |
| |
| return NULL; |
| } |
| |
| /* Initialize imd handle. */ |
| void imd_handle_init(struct imd *imd, void *upper_limit) |
| { |
| imdr_init(&imd->lg, upper_limit); |
| imdr_init(&imd->sm, NULL); |
| } |
| |
| void imd_handle_init_partial_recovery(struct imd *imd) |
| { |
| const struct imd_entry *e; |
| struct imd_root_pointer *rp; |
| struct imdr *imdr; |
| |
| if (imd->lg.limit == 0) |
| return; |
| |
| imd_handle_init(imd, (void *)imd->lg.limit); |
| |
| /* Initialize root pointer for the large regions. */ |
| imdr = &imd->lg; |
| rp = imdr_get_root_pointer(imdr); |
| imdr->r = relative_pointer(rp, rp->root_offset); |
| |
| e = imdr_entry_find(imdr, SMALL_REGION_ID); |
| |
| if (e == NULL) |
| return; |
| |
| imd->sm.limit = (uintptr_t)imdr_entry_at(imdr, e); |
| imd->sm.limit += imdr_entry_size(imdr, e); |
| imdr = &imd->sm; |
| rp = imdr_get_root_pointer(imdr); |
| imdr->r = relative_pointer(rp, rp->root_offset); |
| } |
| |
| int imd_create_empty(struct imd *imd, size_t root_size, size_t entry_align) |
| { |
| return imdr_create_empty(&imd->lg, root_size, entry_align); |
| } |
| |
| int imd_create_tiered_empty(struct imd *imd, |
| size_t lg_root_size, size_t lg_entry_align, |
| size_t sm_root_size, size_t sm_entry_align) |
| { |
| size_t sm_region_size;; |
| const struct imd_entry *e; |
| struct imdr *imdr; |
| |
| imdr = &imd->lg; |
| |
| if (imdr_create_empty(imdr, lg_root_size, lg_entry_align) != 0) |
| return -1; |
| |
| /* Calculate the size of the small region to request. */ |
| sm_region_size = root_num_entries(sm_root_size) * sm_entry_align; |
| sm_region_size += sm_root_size; |
| sm_region_size = ALIGN_UP(sm_region_size, lg_entry_align); |
| |
| /* Add a new entry to the large region to cover the root and entries. */ |
| e = imdr_entry_add(imdr, SMALL_REGION_ID, sm_region_size); |
| |
| if (e == NULL) |
| goto fail; |
| |
| imd->sm.limit = (uintptr_t)imdr_entry_at(imdr, e); |
| imd->sm.limit += sm_region_size; |
| |
| if (imdr_create_empty(&imd->sm, sm_root_size, sm_entry_align) != 0 || |
| imdr_limit_size(&imd->sm, sm_region_size)) |
| goto fail; |
| |
| return 0; |
| fail: |
| imd_handle_init(imd, (void *)imdr->limit); |
| return -1; |
| } |
| |
| int imd_recover(struct imd *imd) |
| { |
| const struct imd_entry *e; |
| uintptr_t small_upper_limit; |
| struct imdr *imdr; |
| |
| imdr = &imd->lg; |
| if (imdr_recover(imdr) != 0) |
| return -1; |
| |
| /* Determine if small region is region is present. */ |
| e = imdr_entry_find(imdr, SMALL_REGION_ID); |
| |
| if (e == NULL) |
| return 0; |
| |
| small_upper_limit = (uintptr_t)imdr_entry_at(imdr, e); |
| small_upper_limit += imdr_entry_size(imdr, e); |
| |
| imd->sm.limit = small_upper_limit; |
| |
| /* Tear down any changes on failure. */ |
| if (imdr_recover(&imd->sm) != 0) { |
| imd_handle_init(imd, (void *)imd->lg.limit); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| int imd_limit_size(struct imd *imd, size_t max_size) |
| { |
| return imdr_limit_size(&imd->lg, max_size); |
| } |
| |
| int imd_lockdown(struct imd *imd) |
| { |
| struct imd_root *r; |
| |
| r = imdr_root(&imd->lg); |
| if (r == NULL) |
| return -1; |
| |
| r->flags |= IMD_FLAG_LOCKED; |
| |
| r = imdr_root(&imd->sm); |
| if (r != NULL) |
| r->flags |= IMD_FLAG_LOCKED; |
| |
| return 0; |
| } |
| |
| int imd_region_used(struct imd *imd, void **base, size_t *size) |
| { |
| struct imd_root *r; |
| struct imd_entry *e; |
| void *low_addr; |
| size_t sz_used; |
| |
| if (!imd->lg.limit) |
| return -1; |
| |
| r = imdr_root(&imd->lg); |
| |
| if (r == NULL) |
| return -1; |
| |
| /* Use last entry to obtain lowest address. */ |
| e = root_last_entry(r); |
| |
| low_addr = relative_pointer(r, e->start_offset); |
| |
| /* Total size used is the last entry's base up to the limit. */ |
| sz_used = imd->lg.limit - (uintptr_t)low_addr; |
| |
| *base = low_addr; |
| *size = sz_used; |
| |
| return 0; |
| } |
| |
| const struct imd_entry *imd_entry_add(const struct imd *imd, uint32_t id, |
| size_t size) |
| { |
| struct imd_root *r; |
| const struct imdr *imdr; |
| const struct imd_entry *e = NULL; |
| |
| /* |
| * Determine if requested size is less than 1/4 of small data |
| * region is left. |
| */ |
| imdr = &imd->sm; |
| r = imdr_root(imdr); |
| |
| /* No small region. Use the large region. */ |
| if (r == NULL) |
| return imdr_entry_add(&imd->lg, id, size); |
| else if (size <= r->entry_align || size <= imd_root_data_left(r) / 4) |
| e = imdr_entry_add(imdr, id, size); |
| |
| /* Fall back on large region allocation. */ |
| if (e == NULL) |
| e = imdr_entry_add(&imd->lg, id, size); |
| |
| return e; |
| } |
| |
| const struct imd_entry *imd_entry_find(const struct imd *imd, uint32_t id) |
| { |
| const struct imd_entry *e; |
| |
| /* Many of the smaller allocations are used a lot. Therefore, try |
| * the small region first. */ |
| e = imdr_entry_find(&imd->sm, id); |
| |
| if (e == NULL) |
| e = imdr_entry_find(&imd->lg, id); |
| |
| return e; |
| } |
| |
| const struct imd_entry *imd_entry_find_or_add(const struct imd *imd, |
| uint32_t id, size_t size) |
| { |
| const struct imd_entry *e; |
| |
| e = imd_entry_find(imd, id); |
| |
| if (e != NULL) |
| return e; |
| |
| return imd_entry_add(imd, id, size); |
| } |
| |
| size_t imd_entry_size(const struct imd *imd, const struct imd_entry *entry) |
| { |
| return imdr_entry_size(NULL, entry); |
| } |
| |
| void *imd_entry_at(const struct imd *imd, const struct imd_entry *entry) |
| { |
| const struct imdr *imdr; |
| |
| imdr = imd_entry_to_imdr(imd, entry); |
| |
| if (imdr == NULL) |
| return NULL; |
| |
| return imdr_entry_at(imdr, entry); |
| } |
| |
| int imd_entry_remove(const struct imd *imd, const struct imd_entry *entry) |
| { |
| struct imd_root *r; |
| const struct imdr *imdr; |
| |
| imdr = imd_entry_to_imdr(imd, entry); |
| |
| if (imdr == NULL) |
| return - 1; |
| |
| r = imdr_root(imdr); |
| |
| if (r == NULL) |
| return -1; |
| |
| if (root_is_locked(r)) |
| return -1; |
| |
| if (entry != root_last_entry(r)) |
| return -1; |
| |
| r->num_entries--; |
| |
| return 0; |
| } |
| |
| static void imdr_print_entries(const struct imdr *imdr, const char *indent, |
| const struct imd_lookup *lookup, size_t size) |
| { |
| struct imd_root *r; |
| size_t i; |
| size_t j; |
| |
| if (imdr == NULL) |
| return; |
| |
| r = imdr_root(imdr); |
| |
| for (i = 0; i < r->num_entries; i++) { |
| const char *name = NULL; |
| const struct imd_entry *e = &r->entries[i]; |
| |
| for (j = 0; j < size; j++) { |
| if (lookup[j].id == e->id) { |
| name = lookup[j].name; |
| break; |
| } |
| } |
| |
| printk(BIOS_DEBUG, "%s", indent); |
| |
| if (name == NULL) |
| printk(BIOS_DEBUG, "%08x ", e->id); |
| else |
| printk(BIOS_DEBUG, "%s", name); |
| printk(BIOS_DEBUG, "%2zu. ", i); |
| printk(BIOS_DEBUG, "%p ", imdr_entry_at(imdr, e)); |
| printk(BIOS_DEBUG, "%08zx\n", imdr_entry_size(imdr, e)); |
| } |
| } |
| |
| int imd_print_entries(const struct imd *imd, const struct imd_lookup *lookup, |
| size_t size) |
| { |
| if (imdr_root(&imd->lg) == NULL) |
| return -1; |
| |
| imdr_print_entries(&imd->lg, "", lookup, size); |
| if (imdr_root(&imd->sm) != NULL) { |
| printk(BIOS_DEBUG, "IMD small region:\n"); |
| imdr_print_entries(&imd->sm, " ", lookup, size); |
| } |
| |
| return 0; |
| } |