pmm: Minor overhaul to try and fix #185

This commit is contained in:
mintsuki 2022-06-26 04:23:13 +02:00
parent b8a3534a41
commit 0836a62fbd
1 changed files with 39 additions and 42 deletions

View File

@ -121,6 +121,8 @@ static bool align_entry(uint64_t *base, uint64_t *length) {
static bool sanitiser_keep_first_page = false;
#define MEMMAP_DROP_LATER ((uint32_t)-1)
static void sanitise_entries(struct e820_entry_t *m, size_t *_count, bool align_entries) {
size_t count = *_count;
@ -141,10 +143,18 @@ static void sanitise_entries(struct e820_entry_t *m, size_t *_count, bool align_
uint64_t res_length = m[j].length;
uint64_t res_top = res_base + res_length;
// TODO actually handle splitting off usable chunks
if ( (res_base >= base && res_base < top)
&& (res_top >= base && res_top < top) ) {
panic(false, "A non-usable e820 entry is inside a usable section.");
// Drop the entry entirely if usable
if (m[j].type == MEMMAP_USABLE) {
m[j].type = MEMMAP_DROP_LATER;
}
if (m[j].type == MEMMAP_DROP_LATER) {
continue;
}
// TODO actually handle splitting off usable chunks
panic(false, "A non-usable memory map entry is inside a usable section.");
}
if (res_base >= base && res_base < top) {
@ -167,6 +177,16 @@ static void sanitise_entries(struct e820_entry_t *m, size_t *_count, bool align_
}
}
// Collect "drop later" entries
for (size_t i = 0; i < count; i++) {
if (m[i].type != MEMMAP_DROP_LATER) {
continue;
}
m[i] = m[count - 1];
count--; i--;
}
// Remove 0 length usable entries and usable entries below 0x1000
for (size_t i = 0; i < count; i++) {
if (m[i].type != MEMMAP_USABLE)
@ -642,7 +662,7 @@ void pmm_free(void *ptr, size_t count) {
count = ALIGN_UP(count, 4096);
if (allocations_disallowed)
panic(false, "Memory allocations disallowed");
memmap_alloc_range((uintptr_t)ptr, count, MEMMAP_USABLE, false, false, false, false);
memmap_alloc_range((uintptr_t)ptr, count, MEMMAP_USABLE, false, false, false, true);
}
void *ext_mem_alloc(size_t count) {
@ -736,9 +756,7 @@ static bool pmm_new_entry(uint64_t base, uint64_t length, uint32_t type) {
// Full overlap
if (base <= entry_base && top >= entry_top) {
// Remove overlapped entry
for (size_t j = i + 1; j < memmap_entries; j++) {
memmap[j - 1] = memmap[j];
}
memmap[i] = memmap[memmap_entries - 1];
memmap_entries--;
i--;
continue;
@ -787,8 +805,6 @@ static bool pmm_new_entry(uint64_t base, uint64_t length, uint32_t type) {
target->base = base;
target->length = length;
sanitise_entries(memmap, &memmap_entries, false);
return true;
}
@ -796,6 +812,10 @@ bool memmap_alloc_range(uint64_t base, uint64_t length, uint32_t type, bool free
if (length == 0)
return true;
if (simulation && new_entry) {
return true;
}
uint64_t top = base + length;
for (size_t i = 0; i < memmap_entries; i++) {
@ -804,52 +824,29 @@ bool memmap_alloc_range(uint64_t base, uint64_t length, uint32_t type, bool free
uint64_t entry_base = memmap[i].base;
uint64_t entry_top = memmap[i].base + memmap[i].length;
uint32_t entry_type = memmap[i].type;
if (base >= entry_base && base < entry_top && top <= entry_top) {
if (simulation)
return true;
struct e820_entry_t *target;
memmap[i].length -= entry_top - base;
if (memmap[i].length == 0) {
target = &memmap[i];
} else {
if (memmap_entries >= memmap_max_entries)
panic(false, "Memory map exhausted.");
target = &memmap[memmap_entries++];
if (pmm_new_entry(base, length, type) == true) {
goto success;
}
target->type = type;
target->base = base;
target->length = length;
if (top < entry_top) {
if (memmap_entries >= memmap_max_entries)
panic(false, "Memory map exhausted.");
target = &memmap[memmap_entries++];
target->type = entry_type;
target->base = top;
target->length = entry_top - top;
}
sanitise_entries(memmap, &memmap_entries, false);
return true;
}
}
if (!new_entry && do_panic)
panic(false, "Memory allocation failure.");
if (new_entry) {
return pmm_new_entry(base, length, type);
if (!new_entry) {
return false;
}
return false;
if (pmm_new_entry(base, length, type) == false) {
return false;
}
success:
sanitise_entries(memmap, &memmap_entries, false);
return true;
}