Each EL2 MPU protection region could be configured using PRBAR<n>_EL2 and
PRLAR<n>_EL2.
This commit introduces a new helper access_protection_region() to access
EL2 MPU protection region, including both read/write operations.
As explained in section G1.3.18 of the reference manual for AArch64v8R,
a set of system register PRBAR<n>_EL2 and PRLAR<n>_EL2 provide access to
the EL2 MPU region which is determined by the value of 'n' and
PRSELR_EL2.REGION as PRSELR_EL2.REGION<7:4>:n.(n = 0, 1, 2, ... , 15)
For example to access regions from 16 to 31:
- Set PRSELR_EL2 to 0b1xxxx
- Region 16 configuration is accessible through PRBAR0_EL2 and PRLAR0_EL2
- Region 17 configuration is accessible through PRBAR1_EL2 and PRLAR1_EL2
- Region 18 configuration is accessible through PRBAR2_EL2 and PRLAR2_EL2
- ...
- Region 31 configuration is accessible through PRBAR15_EL2 and PRLAR15_EL2
Signed-off-by: Penny Zheng <penny.zh...@arm.com>
Signed-off-by: Wei Chen <wei.c...@arm.com>
---
xen/arch/arm/mm_mpu.c | 151 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 151 insertions(+)
diff --git a/xen/arch/arm/mm_mpu.c b/xen/arch/arm/mm_mpu.c
index c9e17ab6da..f2b494449c 100644
--- a/xen/arch/arm/mm_mpu.c
+++ b/xen/arch/arm/mm_mpu.c
@@ -46,6 +46,157 @@ uint64_t __ro_after_init next_transient_region_idx;
/* Maximum number of supported MPU memory regions by the EL2 MPU. */
uint64_t __ro_after_init max_xen_mpumap;
+/* Write a MPU protection region */
+#define WRITE_PROTECTION_REGION(sel, pr, prbar_el2, prlar_el2) ({ \
+ uint64_t _sel = sel; \
+ const pr_t *_pr = pr; \
+ asm volatile( \
+ "msr "__stringify(PRSELR_EL2)", %0;" /* Selects the region */ \
+ "dsb sy;" \
+ "msr "__stringify(prbar_el2)", %1;" /* Write PRBAR<n>_EL2 */ \
+ "msr "__stringify(prlar_el2)", %2;" /* Write PRLAR<n>_EL2 */ \
+ "dsb sy;" \
+ : : "r" (_sel), "r" (_pr->prbar.bits), "r" (_pr->prlar.bits)); \
+})
+
+/* Read a MPU protection region */
+#define READ_PROTECTION_REGION(sel, prbar_el2, prlar_el2) ({ \
+ uint64_t _sel = sel; \
+ pr_t _pr; \
+ asm volatile( \
+ "msr "__stringify(PRSELR_EL2)", %2;" /* Selects the region */ \
+ "dsb sy;" \
+ "mrs %0, "__stringify(prbar_el2)";" /* Read PRBAR<n>_EL2 */ \
+ "mrs %1, "__stringify(prlar_el2)";" /* Read PRLAR<n>_EL2 */ \
+ "dsb sy;" \
+ : "=r" (_pr.prbar.bits), "=r" (_pr.prlar.bits) : "r" (_sel)); \
+ _pr; \
+})
+
+/*
+ * Access MPU protection region, including both read/write operations.
+ * Armv8-R AArch64 at most supports 255 MPU protection regions.
+ * See section G1.3.18 of the reference manual for Armv8-R AArch64,
+ * PRBAR<n>_EL2 and PRLAR<n>_EL2 provide access to the EL2 MPU region
+ * determined by the value of 'n' and PRSELR_EL2.REGION as
+ * PRSELR_EL2.REGION<7:4>:n(n = 0, 1, 2, ... , 15)
+ * For example to access regions from 16 to 31 (0b10000 to 0b11111):
+ * - Set PRSELR_EL2 to 0b1xxxx
+ * - Region 16 configuration is accessible through PRBAR0_ELx and PRLAR0_ELx
+ * - Region 17 configuration is accessible through PRBAR1_ELx and PRLAR1_ELx
+ * - Region 18 configuration is accessible through PRBAR2_ELx and PRLAR2_ELx
+ * - ...
+ * - Region 31 configuration is accessible through PRBAR15_ELx and PRLAR15_ELx
+ *
+ * @read: if it is read operation.
+ * @pr_read: mpu protection region returned by read op.
+ * @pr_write: const mpu protection region passed through write op.
+ * @sel: mpu protection region selector
+ */
+static void access_protection_region(bool read, pr_t *pr_read,
+ const pr_t *pr_write, uint64_t sel)
+{
+ switch ( sel & 0xf )
+ {
+ case 0:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR0_EL2, PRLAR0_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR0_EL2, PRLAR0_EL2);
+ break;
+ case 1:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR1_EL2, PRLAR1_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR1_EL2, PRLAR1_EL2);
+ break;
+ case 2:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR2_EL2, PRLAR2_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR2_EL2, PRLAR2_EL2);
+ break;
+ case 3:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR3_EL2, PRLAR3_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR3_EL2, PRLAR3_EL2);
+ break;
+ case 4:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR4_EL2, PRLAR4_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR4_EL2, PRLAR4_EL2);
+ break;
+ case 5:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR5_EL2, PRLAR5_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR5_EL2, PRLAR5_EL2);
+ break;
+ case 6:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR6_EL2, PRLAR6_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR6_EL2, PRLAR6_EL2);
+ break;
+ case 7:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR7_EL2, PRLAR7_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR7_EL2, PRLAR7_EL2);
+ break;
+ case 8:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR8_EL2, PRLAR8_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR8_EL2, PRLAR8_EL2);
+ break;
+ case 9:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR9_EL2, PRLAR9_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR9_EL2, PRLAR9_EL2);
+ break;
+ case 10:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR10_EL2, PRLAR10_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR10_EL2, PRLAR10_EL2);
+ break;
+ case 11:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR11_EL2, PRLAR11_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR11_EL2, PRLAR11_EL2);
+ break;
+ case 12:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR12_EL2, PRLAR12_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR12_EL2, PRLAR12_EL2);
+ break;
+ case 13:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR13_EL2, PRLAR13_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR13_EL2, PRLAR13_EL2);
+ break;
+ case 14:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR14_EL2, PRLAR14_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR14_EL2, PRLAR14_EL2);
+ break;
+ case 15:
+ if ( read )
+ *pr_read = READ_PROTECTION_REGION(sel, PRBAR15_EL2, PRLAR15_EL2);
+ else
+ WRITE_PROTECTION_REGION(sel, pr_write, PRBAR15_EL2, PRLAR15_EL2);
+ break;
+ }
+}
+
/* TODO: Implementation on the first usage */
void dump_hyp_walk(vaddr_t addr)
{
--
2.25.1
