arm64: mmu: Support userspace memory mapping

carlocaione · carlescufi · commit 4d7d784d1e8c · 2022-06-10T09:48:23.000+02:00
arch_mem_map() on ARM64 is currently not supporting the K_MEM_PERM_USER
parameter so we cannot allocate userspace accessible memory using the
memory helpers. Fix this.

Signed-off-by: Carlo Caione &lt;ccaione@baylibre.com&gt;
diff --git a/arch/arm64/core/mmu.c b/arch/arm64/core/mmu.c
@@ -862,7 +862,7 @@ static void sync_domains(uintptr_t virt, size_t size)
 static int __arch_mem_map(void *virt, uintptr_t phys, size_t size, uint32_t flags)
 {
 	struct arm_mmu_ptables *ptables;
-	uint32_t entry_flags = MT_SECURE | MT_P_RX_U_NA;
+	uint32_t entry_flags = MT_DEFAULT_SECURE_STATE | MT_P_RX_U_NA;
 
 	/* Always map in the kernel page tables */
 	ptables = &kernel_ptables;
@@ -911,7 +911,7 @@ static int __arch_mem_map(void *virt, uintptr_t phys, size_t size, uint32_t flag
 	}
 
 	if ((flags & K_MEM_PERM_USER) != 0U) {
-		return -ENOTSUP;
+		entry_flags |= MT_RW_AP_ELx;
 	}
 
 	return add_map(ptables, "generic", phys, (uintptr_t)virt, size, entry_flags);

Original file line number	Diff line number	Diff line change
`@@ -862,7 +862,7 @@ static void sync_domains(uintptr_t virt, size_t size)`
`862`	`862`	`static int __arch_mem_map(void *virt, uintptr_t phys, size_t size, uint32_t flags)`
`863`	`863`	`{`
`864`	`864`	`struct arm_mmu_ptables *ptables;`
`865`		`- uint32_t entry_flags = MT_SECURE \| MT_P_RX_U_NA;`
	`865`	`+ uint32_t entry_flags = MT_DEFAULT_SECURE_STATE \| MT_P_RX_U_NA;`
`866`	`866`
`867`	`867`	`/* Always map in the kernel page tables */`
`868`	`868`	`ptables = &kernel_ptables;`
`@@ -911,7 +911,7 @@ static int __arch_mem_map(void *virt, uintptr_t phys, size_t size, uint32_t flag`
`911`	`911`	`}`
`912`	`912`
`913`	`913`	`if ((flags & K_MEM_PERM_USER) != 0U) {`
`914`		`- return -ENOTSUP;`
	`914`	`+ entry_flags \|= MT_RW_AP_ELx;`
`915`	`915`	`}`
`916`	`916`
`917`	`917`	`return add_map(ptables, "generic", phys, (uintptr_t)virt, size, entry_flags);`