From: Frederic Barrat <fbarrat@linux.ibm.com>
To: Leonardo Bras <leobras.c@gmail.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Alexey Kardashevskiy <aik@ozlabs.ru>,
David Gibson <david@gibson.dropbear.id.au>,
kernel test robot <lkp@intel.com>,
Nicolin Chen <nicoleotsuka@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 02/11] powerpc/kernel/iommu: Add new iommu_table_in_use() helper
Date: Mon, 19 Jul 2021 15:53:43 +0200 [thread overview]
Message-ID: <29c199f3-63a8-3edb-b29e-de157431d89f@linux.ibm.com> (raw)
In-Reply-To: <20210716082755.428187-3-leobras.c@gmail.com>
On 16/07/2021 10:27, Leonardo Bras wrote:
> @@ -1099,18 +1105,13 @@ int iommu_take_ownership(struct iommu_table *tbl)
> for (i = 0; i < tbl->nr_pools; i++)
> spin_lock_nest_lock(&tbl->pools[i].lock, &tbl->large_pool.lock);
>
> - iommu_table_release_pages(tbl);
> -
> - if (!bitmap_empty(tbl->it_map, tbl->it_size)) {
> + if (iommu_table_in_use(tbl)) {
> pr_err("iommu_tce: it_map is not empty");
> ret = -EBUSY;
> - /* Undo iommu_table_release_pages, i.e. restore bit#0, etc */
> - iommu_table_reserve_pages(tbl, tbl->it_reserved_start,
> - tbl->it_reserved_end);
> - } else {
> - memset(tbl->it_map, 0xff, sz);
> }
>
> + memset(tbl->it_map, 0xff, sz);
> +
So if the table is not empty, we fail (EBUSY) but we now also completely
overwrite the bitmap. It was in an unexpected state, but we're making it
worse. Or am I missing something?
Fred
> for (i = 0; i < tbl->nr_pools; i++)
> spin_unlock(&tbl->pools[i].lock);
> spin_unlock_irqrestore(&tbl->large_pool.lock, flags);
next prev parent reply other threads:[~2021-07-19 13:54 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-16 8:27 [PATCH v5 00/11] DDW + Indirect Mapping Leonardo Bras
2021-07-16 8:27 ` [PATCH v5 01/11] powerpc/pseries/iommu: Replace hard-coded page shift Leonardo Bras
2021-07-19 13:48 ` Frederic Barrat
2021-07-19 18:43 ` Leonardo Brás
2021-07-16 8:27 ` [PATCH v5 02/11] powerpc/kernel/iommu: Add new iommu_table_in_use() helper Leonardo Bras
2021-07-19 13:53 ` Frederic Barrat [this message]
2021-07-20 5:38 ` Leonardo Brás
2021-07-20 9:41 ` Alexey Kardashevskiy
2021-07-16 8:27 ` [PATCH v5 03/11] powerpc/pseries/iommu: Add iommu_pseries_alloc_table() helper Leonardo Bras
2021-07-19 14:04 ` Frederic Barrat
2021-07-19 18:47 ` Leonardo Brás
2021-07-16 8:27 ` [PATCH v5 04/11] powerpc/pseries/iommu: Add ddw_list_new_entry() helper Leonardo Bras
2021-07-19 14:14 ` Frederic Barrat
2021-07-19 18:47 ` Leonardo Brás
2021-07-16 8:27 ` [PATCH v5 05/11] powerpc/pseries/iommu: Allow DDW windows starting at 0x00 Leonardo Bras
2021-07-20 17:44 ` Frederic Barrat
2021-07-16 8:27 ` [PATCH v5 06/11] powerpc/pseries/iommu: Add ddw_property_create() and refactor enable_ddw() Leonardo Bras
2021-07-20 17:49 ` Frederic Barrat
2021-08-17 5:59 ` Leonardo Brás
2021-07-16 8:27 ` [PATCH v5 07/11] powerpc/pseries/iommu: Reorganize iommu_table_setparms*() with new helper Leonardo Bras
2021-07-20 17:50 ` Frederic Barrat
2021-07-16 8:27 ` [PATCH v5 08/11] powerpc/pseries/iommu: Update remove_dma_window() to accept property name Leonardo Bras
2021-07-20 17:51 ` Frederic Barrat
2021-08-17 5:59 ` Leonardo Brás
2021-08-17 6:12 ` Leonardo Brás
2021-08-24 6:31 ` Alexey Kardashevskiy
2021-07-16 8:27 ` [PATCH v5 09/11] powerpc/pseries/iommu: Find existing DDW with given " Leonardo Bras
2021-07-20 17:52 ` Frederic Barrat
2021-07-16 8:27 ` [PATCH v5 10/11] powerpc/pseries/iommu: Make use of DDW for indirect mapping Leonardo Bras
2021-07-20 18:12 ` Frederic Barrat
2021-07-21 3:32 ` Alexey Kardashevskiy
2021-07-21 15:04 ` Frederic Barrat
2021-07-23 5:34 ` Alexey Kardashevskiy
2021-08-17 5:59 ` Leonardo Brás
2021-08-17 5:59 ` Leonardo Brás
2021-07-16 8:27 ` [PATCH v5 11/11] powerpc/pseries/iommu: Rename "direct window" to "dma window" Leonardo Bras
2021-07-20 18:12 ` Frederic Barrat
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=29c199f3-63a8-3edb-b29e-de157431d89f@linux.ibm.com \
--to=fbarrat@linux.ibm.com \
--cc=aik@ozlabs.ru \
--cc=benh@kernel.crashing.org \
--cc=david@gibson.dropbear.id.au \
--cc=leobras.c@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=lkp@intel.com \
--cc=mpe@ellerman.id.au \
--cc=nicoleotsuka@gmail.com \
--cc=paulus@samba.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).