refactor(mpam): enable FEAT_MPAM for FEAT_STATE_CHECKED
At the moment we only support FEAT_MPAM to be either unconditionally
compiled in, or to be not supported at all.
Add support for runtime detection (ENABLE_MPAM_FOR_LOWER_ELS=2), by
splitting get_mpam_version() into an ID register reading
function and a second function to report the support status. That
function considers both build time settings and runtime information (if
needed), and is used before we access MPAM related registers.
Also move the context saving code from assembly to C, and use the new
is_feat_mpam_supported() function to guard its execution.
ENABLE_MPAM_FOR_LOWER_ELS defaults to 0, so add a stub enable function
to cover builds with compiler optimisations turned off. The unused
mpam_enable() function call will normally be optimised away (because it
would never be called), but with -O0 the compiler will leave the symbol
in the object file.
Change-Id: I531d87cb855a7c43471f861f625b5a6d4bc61313
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/lib/el3_runtime/aarch64/context.S b/lib/el3_runtime/aarch64/context.S
index b058334..7bb0f99 100644
--- a/lib/el3_runtime/aarch64/context.S
+++ b/lib/el3_runtime/aarch64/context.S
@@ -17,10 +17,6 @@
.global el2_sysregs_context_save_mte
.global el2_sysregs_context_restore_mte
#endif /* CTX_INCLUDE_MTE_REGS */
-#if ENABLE_MPAM_FOR_LOWER_ELS
- .global el2_sysregs_context_save_mpam
- .global el2_sysregs_context_restore_mpam
-#endif /* ENABLE_MPAM_FOR_LOWER_ELS */
#if ENABLE_FEAT_ECV
.global el2_sysregs_context_save_ecv
.global el2_sysregs_context_restore_ecv
@@ -230,208 +226,6 @@
endfunc el2_sysregs_context_restore_mte
#endif /* CTX_INCLUDE_MTE_REGS */
-#if ENABLE_MPAM_FOR_LOWER_ELS
-func el2_sysregs_context_save_mpam
- mrs x10, MPAM2_EL2
- str x10, [x0, #CTX_MPAM2_EL2]
-
- mrs x10, MPAMIDR_EL1
-
- /*
- * The context registers that we intend to save would be part of the
- * PE's system register frame only if MPAMIDR_EL1.HAS_HCR == 1.
- */
- tbz w10, #MPAMIDR_EL1_HAS_HCR_SHIFT, 3f
-
- /*
- * MPAMHCR_EL2, MPAMVPMV_EL2 and MPAMVPM0_EL2 would be present in the
- * system register frame if MPAMIDR_EL1.HAS_HCR == 1. Proceed to save
- * the context of these registers.
- */
- mrs x11, MPAMHCR_EL2
- mrs x12, MPAMVPM0_EL2
- stp x11, x12, [x0, #CTX_MPAMHCR_EL2]
-
- mrs x13, MPAMVPMV_EL2
- str x13, [x0, #CTX_MPAMVPMV_EL2]
-
- /*
- * MPAMIDR_EL1.VPMR_MAX has to be probed to obtain the maximum supported
- * VPMR value. Proceed to save the context of registers from
- * MPAMVPM1_EL2 to MPAMVPM<x>_EL2 where x is VPMR_MAX. From MPAM spec,
- * VPMR_MAX should not be zero if HAS_HCR == 1.
- */
- ubfx x10, x10, #MPAMIDR_EL1_VPMR_MAX_SHIFT, \
- #MPAMIDR_EL1_VPMR_MAX_WIDTH
-
- /*
- * Once VPMR_MAX has been identified, calculate the offset relative to
- * PC to jump to so that relevant context can be saved. The offset is
- * calculated as (VPMR_POSSIBLE_MAX - VPMR_MAX) * (instruction size for
- * saving one VPM register) + (absolute address of label "1").
- */
- mov w11, #MPAMIDR_EL1_VPMR_MAX_POSSIBLE
- sub w10, w11, w10
-
- /* Calculate the size of one block of MPAMVPM*_EL2 save */
- adr x11, 1f
- adr x12, 2f
- sub x12, x12, x11
-
- madd x10, x10, x12, x11
- br x10
-
- /*
- * The branch above would land properly on one of the blocks following
- * label "1". Make sure that the order of save is retained.
- */
-1:
-#if ENABLE_BTI
- bti j
-#endif
- mrs x10, MPAMVPM7_EL2
- str x10, [x0, #CTX_MPAMVPM7_EL2]
-2:
-#if ENABLE_BTI
- bti j
-#endif
- mrs x11, MPAMVPM6_EL2
- str x11, [x0, #CTX_MPAMVPM6_EL2]
-
-#if ENABLE_BTI
- bti j
-#endif
- mrs x12, MPAMVPM5_EL2
- str x12, [x0, #CTX_MPAMVPM5_EL2]
-
-#if ENABLE_BTI
- bti j
-#endif
- mrs x13, MPAMVPM4_EL2
- str x13, [x0, #CTX_MPAMVPM4_EL2]
-
-#if ENABLE_BTI
- bti j
-#endif
- mrs x14, MPAMVPM3_EL2
- str x14, [x0, #CTX_MPAMVPM3_EL2]
-
-#if ENABLE_BTI
- bti j
-#endif
- mrs x15, MPAMVPM2_EL2
- str x15, [x0, #CTX_MPAMVPM2_EL2]
-
-#if ENABLE_BTI
- bti j
-#endif
- mrs x16, MPAMVPM1_EL2
- str x16, [x0, #CTX_MPAMVPM1_EL2]
-
-3: ret
-endfunc el2_sysregs_context_save_mpam
-
-func el2_sysregs_context_restore_mpam
- ldr x10, [x0, #CTX_MPAM2_EL2]
- msr MPAM2_EL2, x10
-
- mrs x10, MPAMIDR_EL1
- /*
- * The context registers that we intend to restore would be part of the
- * PE's system register frame only if MPAMIDR_EL1.HAS_HCR == 1.
- */
- tbz w10, #MPAMIDR_EL1_HAS_HCR_SHIFT, 3f
-
- /*
- * MPAMHCR_EL2, MPAMVPMV_EL2 and MPAMVPM0_EL2 would be present in the
- * system register frame if MPAMIDR_EL1.HAS_HCR == 1. Proceed to restore
- * the context of these registers
- */
- ldp x11, x12, [x0, #CTX_MPAMHCR_EL2]
- msr MPAMHCR_EL2, x11
- msr MPAMVPM0_EL2, x12
-
- ldr x13, [x0, #CTX_MPAMVPMV_EL2]
- msr MPAMVPMV_EL2, x13
-
- /*
- * MPAMIDR_EL1.VPMR_MAX has to be probed to obtain the maximum supported
- * VPMR value. Proceed to restore the context of registers from
- * MPAMVPM1_EL2 to MPAMVPM<x>_EL2 where x is VPMR_MAX. from MPAM spec,
- * VPMR_MAX should not be zero if HAS_HCR == 1.
- */
- ubfx x10, x10, #MPAMIDR_EL1_VPMR_MAX_SHIFT, \
- #MPAMIDR_EL1_VPMR_MAX_WIDTH
-
- /*
- * Once VPMR_MAX has been identified, calculate the offset relative to
- * PC to jump to so that relevant context can be restored. The offset is
- * calculated as (VPMR_POSSIBLE_MAX - VPMR_MAX) * (instruction size for
- * restoring one VPM register) + (absolute address of label "1").
- */
- mov w11, #MPAMIDR_EL1_VPMR_MAX_POSSIBLE
- sub w10, w11, w10
-
- /* Calculate the size of one block of MPAMVPM*_EL2 restore */
- adr x11, 1f
- adr x12, 2f
- sub x12, x12, x11
-
- madd x10, x10, x12, x11
- br x10
-
- /*
- * The branch above would land properly on one of the blocks following
- * label "1". Make sure that the order of restore is retained.
- */
-1:
-
-#if ENABLE_BTI
- bti j
-#endif
- ldr x10, [x0, #CTX_MPAMVPM7_EL2]
- msr MPAMVPM7_EL2, x10
-2:
-#if ENABLE_BTI
- bti j
-#endif
- ldr x11, [x0, #CTX_MPAMVPM6_EL2]
- msr MPAMVPM6_EL2, x11
-
-#if ENABLE_BTI
- bti j
-#endif
- ldr x12, [x0, #CTX_MPAMVPM5_EL2]
- msr MPAMVPM5_EL2, x12
-
-#if ENABLE_BTI
- bti j
-#endif
- ldr x13, [x0, #CTX_MPAMVPM4_EL2]
- msr MPAMVPM4_EL2, x13
-
-#if ENABLE_BTI
- bti j
-#endif
- ldr x14, [x0, #CTX_MPAMVPM3_EL2]
- msr MPAMVPM3_EL2, x14
-
-#if ENABLE_BTI
- bti j
-#endif
- ldr x15, [x0, #CTX_MPAMVPM2_EL2]
- msr MPAMVPM2_EL2, x15
-
-#if ENABLE_BTI
- bti j
-#endif
- ldr x16, [x0, #CTX_MPAMVPM1_EL2]
- msr MPAMVPM1_EL2, x16
-
-3: ret
-endfunc el2_sysregs_context_restore_mpam
-#endif /* ENABLE_MPAM_FOR_LOWER_ELS */
-
#if ENABLE_FEAT_ECV
func el2_sysregs_context_save_ecv
mrs x11, CNTPOFF_EL2
diff --git a/lib/el3_runtime/aarch64/context_mgmt.c b/lib/el3_runtime/aarch64/context_mgmt.c
index c5f20ad..eb5d1db 100644
--- a/lib/el3_runtime/aarch64/context_mgmt.c
+++ b/lib/el3_runtime/aarch64/context_mgmt.c
@@ -498,9 +498,9 @@
sve_enable(ctx);
#endif
-#if ENABLE_MPAM_FOR_LOWER_ELS
- mpam_enable(el2_unused);
-#endif
+ if (is_feat_mpam_supported()) {
+ mpam_enable(el2_unused);
+ }
if (is_feat_trbe_supported()) {
trbe_enable();
@@ -834,6 +834,96 @@
write_hfgwtr_el2(read_ctx_reg(ctx, CTX_HFGWTR_EL2));
}
+static void el2_sysregs_context_save_mpam(el2_sysregs_t *ctx)
+{
+ u_register_t mpam_idr = read_mpamidr_el1();
+
+ write_ctx_reg(ctx, CTX_MPAM2_EL2, read_mpam2_el2());
+
+ /*
+ * The context registers that we intend to save would be part of the
+ * PE's system register frame only if MPAMIDR_EL1.HAS_HCR == 1.
+ */
+ if ((mpam_idr & MPAMIDR_HAS_HCR_BIT) == 0U) {
+ return;
+ }
+
+ /*
+ * MPAMHCR_EL2, MPAMVPMV_EL2 and MPAMVPM0_EL2 are always present if
+ * MPAMIDR_HAS_HCR_BIT == 1.
+ */
+ write_ctx_reg(ctx, CTX_MPAMHCR_EL2, read_mpamhcr_el2());
+ write_ctx_reg(ctx, CTX_MPAMVPM0_EL2, read_mpamvpm0_el2());
+ write_ctx_reg(ctx, CTX_MPAMVPMV_EL2, read_mpamvpmv_el2());
+
+ /*
+ * The number of MPAMVPM registers is implementation defined, their
+ * number is stored in the MPAMIDR_EL1 register.
+ */
+ switch ((mpam_idr >> MPAMIDR_EL1_VPMR_MAX_SHIFT) & MPAMIDR_EL1_VPMR_MAX_MASK) {
+ case 7:
+ write_ctx_reg(ctx, CTX_MPAMVPM7_EL2, read_mpamvpm7_el2());
+ __fallthrough;
+ case 6:
+ write_ctx_reg(ctx, CTX_MPAMVPM6_EL2, read_mpamvpm6_el2());
+ __fallthrough;
+ case 5:
+ write_ctx_reg(ctx, CTX_MPAMVPM5_EL2, read_mpamvpm5_el2());
+ __fallthrough;
+ case 4:
+ write_ctx_reg(ctx, CTX_MPAMVPM4_EL2, read_mpamvpm4_el2());
+ __fallthrough;
+ case 3:
+ write_ctx_reg(ctx, CTX_MPAMVPM3_EL2, read_mpamvpm3_el2());
+ __fallthrough;
+ case 2:
+ write_ctx_reg(ctx, CTX_MPAMVPM2_EL2, read_mpamvpm2_el2());
+ __fallthrough;
+ case 1:
+ write_ctx_reg(ctx, CTX_MPAMVPM1_EL2, read_mpamvpm1_el2());
+ break;
+ }
+}
+
+static void el2_sysregs_context_restore_mpam(el2_sysregs_t *ctx)
+{
+ u_register_t mpam_idr = read_mpamidr_el1();
+
+ write_mpam2_el2(read_ctx_reg(ctx, CTX_MPAM2_EL2));
+
+ if ((mpam_idr & MPAMIDR_HAS_HCR_BIT) == 0U) {
+ return;
+ }
+
+ write_mpamhcr_el2(read_ctx_reg(ctx, CTX_MPAMHCR_EL2));
+ write_mpamvpm0_el2(read_ctx_reg(ctx, CTX_MPAMVPM0_EL2));
+ write_mpamvpmv_el2(read_ctx_reg(ctx, CTX_MPAMVPMV_EL2));
+
+ switch ((mpam_idr >> MPAMIDR_EL1_VPMR_MAX_SHIFT) & MPAMIDR_EL1_VPMR_MAX_MASK) {
+ case 7:
+ write_mpamvpm7_el2(read_ctx_reg(ctx, CTX_MPAMVPM7_EL2));
+ __fallthrough;
+ case 6:
+ write_mpamvpm6_el2(read_ctx_reg(ctx, CTX_MPAMVPM6_EL2));
+ __fallthrough;
+ case 5:
+ write_mpamvpm5_el2(read_ctx_reg(ctx, CTX_MPAMVPM5_EL2));
+ __fallthrough;
+ case 4:
+ write_mpamvpm4_el2(read_ctx_reg(ctx, CTX_MPAMVPM4_EL2));
+ __fallthrough;
+ case 3:
+ write_mpamvpm3_el2(read_ctx_reg(ctx, CTX_MPAMVPM3_EL2));
+ __fallthrough;
+ case 2:
+ write_mpamvpm2_el2(read_ctx_reg(ctx, CTX_MPAMVPM2_EL2));
+ __fallthrough;
+ case 1:
+ write_mpamvpm1_el2(read_ctx_reg(ctx, CTX_MPAMVPM1_EL2));
+ break;
+ }
+}
+
/*******************************************************************************
* Save EL2 sysreg context
******************************************************************************/
@@ -859,9 +949,9 @@
#if CTX_INCLUDE_MTE_REGS
el2_sysregs_context_save_mte(el2_sysregs_ctx);
#endif
-#if ENABLE_MPAM_FOR_LOWER_ELS
- el2_sysregs_context_save_mpam(el2_sysregs_ctx);
-#endif
+ if (is_feat_mpam_supported()) {
+ el2_sysregs_context_save_mpam(el2_sysregs_ctx);
+ }
if (is_feat_fgt_supported()) {
el2_sysregs_context_save_fgt(el2_sysregs_ctx);
@@ -919,9 +1009,9 @@
#if CTX_INCLUDE_MTE_REGS
el2_sysregs_context_restore_mte(el2_sysregs_ctx);
#endif
-#if ENABLE_MPAM_FOR_LOWER_ELS
- el2_sysregs_context_restore_mpam(el2_sysregs_ctx);
-#endif
+ if (is_feat_mpam_supported()) {
+ el2_sysregs_context_restore_mpam(el2_sysregs_ctx);
+ }
if (is_feat_fgt_supported()) {
el2_sysregs_context_restore_fgt(el2_sysregs_ctx);