mm: properly implement page locking

This commit is contained in:
Matheus
2026-07-08 01:37:12 -03:00
parent af30088c0d
commit 1512b2f3c6
14 changed files with 123 additions and 45 deletions
+5 -5
View File
@@ -308,12 +308,12 @@ static int cmd_identify(ahci_t *ahci, int port, identify_t *results_phys) {
static void release_prdt(command_table_t *command_table, uint16_t prdtl) {
for (int i = 0; i < prdtl; ++i) {
void *address = (void *)((uint64_t)command_table->prdt[i].base_low | ((uint64_t)command_table->prdt[i].base_high << 32));
mm_release_page(address);
mm_unlock_and_release_page(address);
}
}
#define PRDTL_LIMIT ((PAGE_SIZE - sizeof(command_table_t)) / sizeof(prdt_t))
static int setup_prdt(iovec_iterator_t *iterator, command_table_t *command_table, uint16_t *prdtl, size_t *requested_size) {
static int setup_prdt(iovec_iterator_t *iterator, command_table_t *command_table, uint16_t *prdtl, size_t *requested_size, bool write) {
int err;
size_t block_done = 0;
size_t prdt_done = 0;
@@ -321,14 +321,14 @@ static int setup_prdt(iovec_iterator_t *iterator, command_table_t *command_table
while (block_done < *requested_size && prdt_done < PRDTL_LIMIT) {
void *page;
size_t page_offset, page_remaining;
err = iovec_iterator_next_page(iterator, &page_offset, &page_remaining, &page);
err = iovec_iterator_next_page(iterator, &page_offset, &page_remaining, &page, !write);
if (err)
goto cleanup;
__assert(page);
// not block aligned
if (page_remaining % 512) {
mm_release_page(page);
mm_unlock_and_release_page(page);
err = EINVAL;
goto cleanup;
}
@@ -386,7 +386,7 @@ static int rw(port_data_t *port_data, iovec_iterator_t *iterator, uintmax_t lba,
while (done != count) {
size_t do_count = count - done;
uint16_t prdtl_tmp;
error = setup_prdt(iterator, command_table, &prdtl_tmp, &do_count);
error = setup_prdt(iterator, command_table, &prdtl_tmp, &do_count, write);
if (error)
break;
+17 -14
View File
@@ -510,26 +510,29 @@ static int iowrite(nvmenamespace_t *namespace, uint64_t prp[2], uint64_t lba, ui
#define PAGES_IN_PRP_PAGE (PAGE_SIZE / sizeof(uint64_t))
static void free_prps(uint64_t prp[2], bool has_list) {
mm_release_page((void *)ROUND_DOWN(prp[0], PAGE_SIZE));
if (has_list) {
uint64_t *prp_list = MAKE_HHDM((uint64_t *)prp[1]);
for (int i = 0; prp_list[i] && i < PAGES_IN_PRP_PAGE; ++i)
mm_release_page((void *)prp_list[i]);
}
void *prp1 = (void *)prp[1];
if (prp[1])
mm_release_page((void *)prp[1]);
mm_unlock_and_release_page((void *)ROUND_DOWN(prp[0], PAGE_SIZE));
if (has_list) {
uint64_t *prp_list = MAKE_HHDM(prp1);
for (int i = 0; i < PAGES_IN_PRP_PAGE && prp_list[i]; ++i)
mm_unlock_and_release_page((void *)prp_list[i]);
mm_release_page(prp1);
} else if (prp1) {
mm_unlock_and_release_page(prp1);
}
}
// sets up prps based on an iovec iterator.
// takes in the wanted block count and outputs an io_count for the i/o operation (for example, if it did not fit entirely on the prp)
static int setup_prps(nvmenamespace_t *namespace, iovec_iterator_t *iovec_iterator, uint64_t prp[2], size_t count, size_t *io_count, bool *has_list) {
static int setup_prps(nvmenamespace_t *namespace, iovec_iterator_t *iovec_iterator, uint64_t prp[2], size_t count, size_t *io_count, bool *has_list, bool write) {
count = min(count, namespace->max_transfer_size_blocks);
// first page
void *page;
size_t page_offset, page_remaining;
int error = iovec_iterator_next_page(iovec_iterator, &page_offset, &page_remaining, &page);
int error = iovec_iterator_next_page(iovec_iterator, &page_offset, &page_remaining, &page, !write);
if (error)
return error;
__assert(page);
@@ -553,7 +556,7 @@ static int setup_prps(nvmenamespace_t *namespace, iovec_iterator_t *iovec_iterat
}
// second page
error = iovec_iterator_next_page(iovec_iterator, &page_offset, &page_remaining, &page);
error = iovec_iterator_next_page(iovec_iterator, &page_offset, &page_remaining, &page, !write);
if (error) {
free_prps(prp, false);
return error;
@@ -591,7 +594,7 @@ static int setup_prps(nvmenamespace_t *namespace, iovec_iterator_t *iovec_iterat
// loop over the pages
for (int i = 1; i < PAGES_IN_PRP_PAGE; ++i) {
error = iovec_iterator_next_page(iovec_iterator, &page_offset, &page_remaining, &page);
error = iovec_iterator_next_page(iovec_iterator, &page_offset, &page_remaining, &page, !write);
if (error) {
prp_list[i] = 0;
free_prps(prp, true);
@@ -603,7 +606,7 @@ static int setup_prps(nvmenamespace_t *namespace, iovec_iterator_t *iovec_iterat
if (page_offset || page_remaining % namespace->blocksize) {
prp_list[i] = 0;
free_prps(prp, true);
mm_release_page(page);
mm_unlock_and_release_page(page);
return EINVAL;
}
@@ -641,7 +644,7 @@ static int rwblocks(nvmenamespace_t *namespace, iovec_iterator_t *iovec_iterator
for (;;) {
size_t io_count;
bool has_list;
error = setup_prps(namespace, iovec_iterator, prp, count, &io_count, &has_list);
error = setup_prps(namespace, iovec_iterator, prp, count, &io_count, &has_list, write);
if (error)
return error;
+2 -2
View File
@@ -116,7 +116,7 @@ static int vioblk_rw(vioblkdev_t *blkdev, iovec_iterator_t *iovec_iterator, uint
while (done < count) {
void *page;
size_t page_offset, page_remaining;
err = iovec_iterator_next_page(iovec_iterator, &page_offset, &page_remaining, &page);
err = iovec_iterator_next_page(iovec_iterator, &page_offset, &page_remaining, &page, !write);
if (err)
break;
@@ -133,7 +133,7 @@ static int vioblk_rw(vioblkdev_t *blkdev, iovec_iterator_t *iovec_iterator, uint
vioblk_enqueue(blkdev, header, (void *)((uintptr_t)page + page_offset), PAGE_SIZE, status, write);
mm_release_page(page);
mm_unlock_and_release_page(page);
// if we didnt use the whole space in the page, set the iterator back a bit
size_t diff_between_available_and_used = page_remaining - docount * 512;