[src/trunk]: src/sys/arch/arm/cortex Change how we detect secure vs non-secur...

[jmcneill <jmcneill%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3ab8ec894c68
branches:  trunk
changeset: 452313:3ab8ec894c68
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Wed Jun 26 23:00:09 2019 +0000

description:
Change how we detect secure vs non-secure access.

Write 0xff to ICC_PMR_EL1 and read back how many bits are implemented,
then do the same with a GICD_IPRIORITYR<n> priority value field.

If the values differ, assume we have a shifted view of IPRIORITYR.

diffstat:

 sys/arch/arm/cortex/gicv3.c |  62 +++++++++++++++++++++++++++-----------------
 1 files changed, 38 insertions(+), 24 deletions(-)

diffs (99 lines):

diff -r d94e49a8ee43 -r 3ab8ec894c68 sys/arch/arm/cortex/gicv3.c
--- a/sys/arch/arm/cortex/gicv3.c       Wed Jun 26 22:58:58 2019 +0000
+++ b/sys/arch/arm/cortex/gicv3.c       Wed Jun 26 23:00:09 2019 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: gicv3.c,v 1.18 2019/06/17 10:15:08 jmcneill Exp $ */
+/* $NetBSD: gicv3.c,v 1.19 2019/06/26 23:00:09 jmcneill Exp $ */
 
 /*-
  * Copyright (c) 2018 Jared McNeill <jmcneill%invisible.ca@localhost>
@@ -31,7 +31,7 @@
 #define        _INTR_PRIVATE
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: gicv3.c,v 1.18 2019/06/17 10:15:08 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: gicv3.c,v 1.19 2019/06/26 23:00:09 jmcneill Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -249,9 +249,7 @@
                ;
 
        /* Enable Affinity routing and G1NS interrupts */
-       gicd_ctrl = GICD_CTRL_EnableGrp1A | GICD_CTRL_Enable | GICD_CTRL_ARE_NS;
-       if (ISSET(sc->sc_flags, GICV3_F_SECURE))
-               gicd_ctrl = (gicd_ctrl & ~GICD_CTRL_EnableGrp1A) << 1;
+       gicd_ctrl = GICD_CTRL_EnableGrp1A | GICD_CTRL_ARE_NS;
        gicd_write_4(sc, GICD_CTRL, gicd_ctrl);
 }
 
@@ -713,6 +711,28 @@
                pic_set_priority(ci, oldipl);
 }
 
+static int
+gicv3_detect_pmr_bits(struct gicv3_softc *sc)
+{
+       const uint32_t opmr = icc_pmr_read();
+       icc_pmr_write(0xff);
+       const uint32_t npmr = icc_pmr_read();
+       icc_pmr_write(opmr);
+
+       return NBBY - (ffs(npmr) - 1);
+}
+
+static int
+gicv3_detect_ipriority_bits(struct gicv3_softc *sc)
+{
+       const uint32_t oipriorityr = gicd_read_4(sc, GICD_IPRIORITYRn(8));
+       gicd_write_4(sc, GICD_IPRIORITYRn(8), oipriorityr | 0xff);
+       const uint32_t nipriorityr = gicd_read_4(sc, GICD_IPRIORITYRn(8));
+       gicd_write_4(sc, GICD_IPRIORITYRn(8), oipriorityr);
+
+       return NBBY - (ffs(nipriorityr & 0xff) - 1);
+}
+
 int
 gicv3_init(struct gicv3_softc *sc)
 {
@@ -728,27 +748,21 @@
                sc->sc_irouter[n] = UINT64_MAX;
 
        sc->sc_priority_shift = 4;
-       const uint32_t oldnsacr = gicd_read_4(sc, GICD_NSACRn(2));
-       gicd_write_4(sc, GICD_NSACRn(2), oldnsacr ^ 0xffffffff);
-       if (gicd_read_4(sc, GICD_NSACRn(2)) != oldnsacr) {
-               gicd_write_4(sc, GICD_NSACRn(2), oldnsacr);
-               sc->sc_priority_shift--;
-               SET(sc->sc_flags, GICV3_F_SECURE);
-       }
-       aprint_verbose_dev(sc->sc_dev, "access is %ssecure\n",
-           ISSET(sc->sc_flags, GICV3_F_SECURE) ? "" : "in");
+       sc->sc_pmr_shift = 4;
+
+       if ((gicd_ctrl & GICD_CTRL_DS) == 0) {
+               const int pmr_bits = gicv3_detect_pmr_bits(sc);
+               const int ipriority_bits = gicv3_detect_ipriority_bits(sc);
 
-       sc->sc_pmr_shift = 4;
-       if ((gicd_ctrl & GICD_CTRL_DS) == 0) {
-               const uint32_t icc_ctlr = icc_ctlr_read();
-               const u_int nbits = __SHIFTOUT(icc_ctlr, ICC_CTLR_EL1_PRIbits) + 1;
-               const u_int oldpmr = icc_pmr_read();
-               icc_pmr_write(0xff);
-               const u_int pmr = icc_pmr_read();
-               icc_pmr_write(oldpmr);
-               if (nbits == 8 - (ffs(pmr) - 1))
-                       sc->sc_pmr_shift--;
+               if (ipriority_bits != pmr_bits)
+                       --sc->sc_priority_shift;
+
+               aprint_verbose_dev(sc->sc_dev, "%d pmr bits, %d ipriority bits\n",
+                   pmr_bits, ipriority_bits);
+       } else {
+               aprint_verbose_dev(sc->sc_dev, "security disabled\n");
        }
+
        aprint_verbose_dev(sc->sc_dev, "priority shift %d, pmr shift %d\n",
            sc->sc_priority_shift, sc->sc_pmr_shift);