ARM32 find_pte can only look up a page and returns NULL when
encountering a section. The ARM64 find_pte, on the other hand, returns
the PTE at any level and stores the found level into a pointer supplied
by the caller.
Let's have the ARM32 version behave as the ARM64 version does to allow
reuse of code between them and to simplify maintenance.
Signed-off-by: Ahmad Fatoum <a.fat...@pengutronix.de>
---
arch/arm/cpu/mmu_32.c | 48 ++++++++++++++++++++++++++++++-------------
1 file changed, 34 insertions(+), 14 deletions(-)
diff --git a/arch/arm/cpu/mmu_32.c b/arch/arm/cpu/mmu_32.c
index e43d9d0d4606..521e5f3a5769 100644
--- a/arch/arm/cpu/mmu_32.c
+++ b/arch/arm/cpu/mmu_32.c
@@ -94,16 +94,38 @@ static uint32_t *alloc_pte(void)
}
#endif
-static u32 *find_pte(unsigned long adr)
+/**
+ * find_pte - Find page table entry
+ * @ttb: Translation Table Base
+ * @addr: Virtual address to lookup
+ * @level: used to store the level at which the page table walk ended.
+ * if NULL, asserts that the smallest page was found
+ *
+ * This function walks the page table from the top down and finds the page
+ * table entry associated with the supplied virtual address.
+ * The level at which a page was found is saved into *level.
+ * if the level is NULL, a last level page must be found or the function
+ * panics.
+ *
+ * Returns a pointer to the page table entry
+ */
+static u32 *find_pte(uint32_t *ttb, uint32_t adr, unsigned *level)
{
+ u32 *pgd = &ttb[pgd_index(adr)];
u32 *table;
- uint32_t *ttb = get_ttb();
- if (!pgd_type_table(ttb[pgd_index(adr)]))
- return NULL;
+ if (!pgd_type_table(*pgd)) {
+ if (!level)
+ panic("Got level 1 page table entry, where level 2
expected\n");
+ *level = 1;
+ return pgd;
+ }
+
+ if (level)
+ *level = 2;
/* find the coarse page table base address */
- table = (u32 *)(ttb[pgd_index(adr)] & ~0x3ff);
+ table = (u32 *)(*pgd & ~0x3ff);
/* find second level descriptor */
return &table[(adr >> PAGE_SHIFT) & 0xff];
@@ -308,7 +330,7 @@ static void __arch_remap_range(void *_virt_addr,
phys_addr_t phys_addr, size_t s
} else {
unsigned int num_ptes;
u32 *table = NULL;
- unsigned int i;
+ unsigned int i, level;
u32 *pte;
/*
* We only want to cover pages up until next
@@ -328,17 +350,15 @@ static void __arch_remap_range(void *_virt_addr,
phys_addr_t phys_addr, size_t s
chunk = min(chunk, size);
num_ptes = chunk / PAGE_SIZE;
- pte = find_pte(virt_addr);
- if (!pte) {
+ pte = find_pte(ttb, virt_addr, &level);
+ if (level == 1) {
/*
- * If PTE is not found it means that
- * we needs to split this section and
- * create a new page table for it
+ * No PTE at level 2, so we needs to split this
section
+ * and create a new page table for it
*/
table = arm_create_pte(virt_addr, phys_addr,
pmd_flags_to_pte(*pgd));
- pte = find_pte(virt_addr);
- BUG_ON(!pte);
+ pte = find_pte(ttb, virt_addr, NULL);
}
for (i = 0; i < num_ptes; i++) {
@@ -452,7 +472,7 @@ static void create_vector_table(unsigned long adr)
pr_debug("Creating vector table, virt = 0x%p, phys = 0x%08lx\n",
vectors, adr);
arm_create_pte(adr, adr, get_pte_flags(MAP_UNCACHED));
- pte = find_pte(adr);
+ pte = find_pte(get_ttb(), adr, NULL);
// TODO break-before-make missing
set_pte(pte, (u32)vectors | PTE_TYPE_SMALL |
get_pte_flags(MAP_CACHED));
--
2.39.5
