| From 353725d455cc27aa2008456c2711e7fae2b8a631 Mon Sep 17 00:00:00 2001 |
| From: Bharat Bhushan <Bharat.Bhushan@nxp.com> |
| Date: Wed, 7 Mar 2018 21:35:37 +0530 |
| Subject: [PATCH] soc: fsl: dpio: aligned access of qbman cacheable region |
| |
| Alignment requirement on ARM is lenient (In Linux) for regions |
| mapped as "Memory Type" but have very strict policy for regions |
| mapped as "Device Type". Unaligned access to regions mapped |
| as "Device Type" will always result to unaligned fault. |
| |
| DPIO driver have un-aligned access to QBman cacheable region |
| and the Linux driver maps the region as "Memory Type". On Host |
| Linux this works because MMU Stage-1 configured by driver allows |
| unaligned access. In Virtual Machine cases, final region mapping type |
| is governed by combination of Stage-1 and Stage-2 MMU mapping. |
| |
| Linux driver in VM controls maps the region as "Memory Type" in |
| Stage-1 MMU while Stage-2 is controlled by KVM. And current KVM |
| implementation does not allow device region to be mapped as |
| "Memory Type". Till we have a working/upstream-able solution |
| for Virtual Machine, we need to change un-aligned access in DPIO |
| driver to be aligned |
| |
| While we reached to this point as we observed below alignment |
| exception in Virtual Machine when accessing qbman cacheable region. |
| |
| kvm [2347]: Unsupported FSC: EC=0x24 xFSC=0x21 |
| ESR_EL2=0x92000061 |
| error: kvm run failed Bad address |
| PC=ffff000008398e78 SP=ffff800009bcb540 |
| X00=ffff000008041000 X01=ffff800009bcb580 X02=ffff800009bcb650 |
| X03=0000000000000180 |
| X04=ffff000008041001 X05=ffff800009bcb581 X06=0200000000000000 |
| X07=0000000000000000 |
| X08=0000000000000000 X09=ffff000008041000 X10=0000000000000001 |
| X11=0000000000de6cb0 |
| X12=00000000fa83b2da X13=0000000000000001 X14=000000007f605ec8 |
| X15=00000000e26f5d5e |
| X16=000000008521af1e X17=000000001076277e X18=ffff800009bcb5c0 |
| X19=ffff800079da2b00 |
| X20=ffff800009bcb650 X21=0000000000000002 X22=0000000000000000 |
| X23=0000000000000000 |
| X24=0000000000000000 X25=ffff8000099e7440 X26=ffff000008da6000 |
| X27=ffff000008e7f000 |
| X28=00000000499e7440 X29=ffff800009bcb540 X30=ffff00000839a160 |
| PSTATE=20000145 --C- EL1h |
| |
| Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com> |
| --- |
| drivers/soc/fsl/dpio/qbman-portal.c | 12 +++++++++++- |
| 1 file changed, 11 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/soc/fsl/dpio/qbman-portal.c |
| +++ b/drivers/soc/fsl/dpio/qbman-portal.c |
| @@ -515,7 +515,17 @@ int qbman_swp_enqueue(struct qbman_swp * |
| return -EBUSY; |
| |
| p = qbman_get_cmd(s, QBMAN_CENA_SWP_EQCR(EQAR_IDX(eqar))); |
| - memcpy(&p->dca, &d->dca, 31); |
| + /* This is mapped as DEVICE type memory, writes are |
| + * with address alignment: |
| + * desc.dca address alignment = 1 |
| + * desc.seqnum address alignment = 2 |
| + * desc.orpid address alignment = 4 |
| + * desc.tgtid address alignment = 8 |
| + */ |
| + p->dca = d->dca; |
| + p->seqnum = d->seqnum; |
| + p->orpid = d->orpid; |
| + memcpy(&p->tgtid, &d->tgtid, 24); |
| memcpy(&p->fd, fd, sizeof(*fd)); |
| |
| if ((s->desc->qman_version & QMAN_REV_MASK) < QMAN_REV_5000) { |