arch: i386: pmem: refactor the physical memory manager

Refactor the physical memory manager to be more efficient and require
fewer function calls from layers above.

Signed-off-by: Danny Holman <dholman@gymli.org>

2 files changed, 30 insertions, 43 deletions

diff --git a/arch/i386/include/kernel/pmem.h b/arch/i386/include/kernel/pmem.h
index da169c7..e6e4f57 100644
--- a/arch/i386/include/kernel/pmem.h
+++ b/arch/i386/include/kernel/pmem.h
@@ -3,8 +3,7 @@
 
 #include <kernel/multiboot.h>
 #include <stdint.h>
-
-#define PFA_ALLOC_ERR   0xFFFFFFFF
+#include <stddef.h>
 
 struct pfa_page {
         struct pfa_page *next;
@@ -12,8 +11,7 @@ struct pfa_page {
 
 void pfa_init(struct mboot_info *header);
 
-uintptr_t pfa_alloc(void);
-void pfa_free(uintptr_t paddr);
-void pfa_free_range(uintptr_t start, uintptr_t end);
+void pfa_free_dma(uintptr_t paddr, size_t num_pages);
+void pfa_free(uintptr_t paddr, size_t num_pages);
 
 #endif
diff --git a/arch/i386/kernel/pmem.c b/arch/i386/kernel/pmem.c
index 0e53507..40e3400 100644
--- a/arch/i386/kernel/pmem.c
+++ b/arch/i386/kernel/pmem.c
@@ -1,56 +1,45 @@
 #include <kernel/pmem.h>
 #include <kernel/asm.h>
+#include <kernel/vmem.h>
 #include <kernel/panic.h>
 #include <kernel/paging.h>
 #include <libk/io.h>
 #include <libk/string.h>
 
-struct pfa_page freelist;
+static struct pfa_page freelist;
 
 void pfa_init(struct mboot_info *header) {
         struct mboot_mmap_entry *mme;
-        struct mboot_mmap_entry *temp_map;
         for (uintptr_t i = 0; i < header->mmap_length; i += sizeof(struct mboot_mmap_entry)) {
                 mme = (struct mboot_mmap_entry*)(header->mmap_addr + i);
-                temp_map = (struct mboot_mmap_entry*)GET_VADDR(mme);
-                map_page(NULL, (uintptr_t)mme, (uintptr_t)temp_map, PD_PRES);
-                if (temp_map->type == MBOOT_MEM_AVAILABLE)
-                        pfa_free_range(temp_map->addr_low, temp_map->addr_low + temp_map->len_low);
-                unmap_page(NULL, (uintptr_t)temp_map);
+                if (mme->type == MBOOT_MEM_AVAILABLE)
+                        pfa_free(mme->addr_low, mme->len_low / PAGE_SIZE);
         }
 }
 
-uintptr_t pfa_alloc(void) {
-        struct pfa_page *ret = freelist.next;
-        if (ret == NULL)
-                return PFA_ALLOC_ERR;
-
-        struct pfa_page *temp_map = (struct pfa_page*)0xD0000000;
-        map_page(NULL, (uintptr_t)ret, (uintptr_t)temp_map, PD_PRES | PD_RW);
-        memset((char*)temp_map, 0, PAGE_SIZE);
-        unmap_page(NULL, (uintptr_t)temp_map);
-        return (uintptr_t)ret;
+uintptr_t pfa_alloc(size_t num_pages) {
+        struct pfa_page *temp = (struct pfa_page*)PAGE_TMP_MAP;
+        map_page(freelist.next, PAGE_TMP_MAP, PD_PRES | PD_RW);
+        uintptr_t ret = freelist.next;
+        freelist.next = temp->next;
+        memset(temp, 0, 32);
+        unmap_page(PAGE_TMP_MAP);
+        return ret;
 }
 
-void pfa_free(uintptr_t paddr) {
-        if (paddr % PAGE_SIZE != 0)
-                panic("Task attempted to free non-aligned memory");
-        if (paddr == 0)
-                return;
-        if (paddr >= KSTART && paddr < KEND)
-                return;
-        if (paddr >= 0x80000 && paddr < 0x100000)
-                return;
-
-        struct pfa_page *temp_map = (struct pfa_page*)0x1000;
-        map_page(NULL, paddr, (uintptr_t)temp_map, PD_PRES | PD_RW);
-        memset(temp_map, 1, 32);
-        temp_map->next = freelist.next;
-        freelist.next = (struct pfa_page*)paddr;
-        unmap_page(NULL, (uintptr_t)temp_map);
-}
-
-void pfa_free_range(uintptr_t start, uintptr_t end) {
-        for (uintptr_t i = start; i < end; i += PAGE_SIZE)
-                pfa_free(i);
+void pfa_free(uintptr_t paddr, size_t num_pages) {
+        uintptr_t addr;
+        struct pfa_page *temp = (struct pfa_page*)PAGE_TMP_MAP;
+        for (size_t i = 0; i < num_pages; i++) {
+                addr = (i * PAGE_SIZE + paddr);
+                if (addr >= KSTART && addr < KEND)
+                        continue;
+                if (addr == 0)
+                        continue;
+                map_page(addr, PAGE_TMP_MAP, PD_PRES | PD_RW);
+                memset(PAGE_TMP_MAP, 1, 32);
+                temp->next = freelist.next;
+                freelist.next = addr;
+                unmap_page(PAGE_TMP_MAP);
+        }
 }