nvme-apple: serialize the controller-global command tag space on t8015#2
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On t8015 (A11), the admin queue uses command tag 0 and the IO tagset is given no reserved tags, so the admin and IO queues can have tag 0 outstanding at the same time. When that happens the controller reports a duplicate-tag error for tag 0. We have no documentation for ANS2's tag handling on this generation, but the failure strongly suggests it treats the command tag as a single controller-wide resource rather than a per-queue one: making the tag unique across both queues makes the error go away. Enforce that with a controller-wide bitmap of active tags and: - reserve the tag before hardware submission; - if it is already active, return BLK_STS_RESOURCE so blk-mq retries rather than busy-waiting; - release it only after the CQ head has been acknowledged to ANS; - clear stale tag state on controller reset. Signed-off-by: Yuriy Havrylyuk <yhavry@gmail.com> Signed-off-by: yhavry <34289148+yhavry@users.noreply.github.com>
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| return BLK_STS_OK; | ||
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| out_release_tag: | ||
| apple_nvme_t8015_release_cid(anv, cmnd->common.command_id); |
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No need for a separate label here since there was only one goto out_free_cmd, so just put this line after out_free_cmd:
| "NVMMU TCB invalidation failed\n"); | ||
| } | ||
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| static bool apple_nvme_t8015_reserve_tag(struct apple_nvme *anv, |
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For consistency with existing function put _t8015 at the end of the function name instead of in the middle.
| { | ||
| u16 tag; | ||
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| if (anv->hw->has_lsq_nvmmu) |
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Do not check for anv->hw->has_lsq_nvmmu in functions marked as t8015. Instead check at the call site.
| return !test_and_set_bit(tag, &anv->t8015_active_tags); | ||
| } | ||
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| static void apple_nvme_t8015_release_cid(struct apple_nvme *anv, |
| { | ||
| u16 tag; | ||
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| if (anv->hw->has_lsq_nvmmu) |
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| if (!anv->hw->has_lsq_nvmmu) { | ||
| writel(q->cq_head, q->cq_db); | ||
| readl(q->cq_db); |
| } | ||
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| if (found) | ||
| if (found && anv->hw->has_lsq_nvmmu) |
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This function apple_nvme_poll_cq() may complete multiple commands in one invocation, is it possible to set a bitfield in the apple_nvme_cqe_pending() while loop, and only release tags and write doorbell according to the bitfield after the loop is completed?
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On A11, ANS2 apparently treats the firmware-visible command tag as
controller-global rather than queue-local. The admin queue uses tag 0
and the IO queue is not given reserved tags, so both can submit tag 0
concurrently, which the controller reports as a duplicate-tag error.
Track active t8015 tags in a controller-wide bitmap:
rather than busy-waiting;
Signed-off-by: Yuriy Havrylyuk yhavry@gmail.com