From: "Aneesh Kumar K.V" <aneesh.kumar@linux•vnet.ibm.com>
To: benh@kernel•crashing.org
Cc: linuxppc-dev@lists•ozlabs.org,
"Aneesh Kumar K.V" <aneesh.kumar@linux•vnet.ibm.com>
Subject: [PATCH] powerpc/mm: Always invalidate tlb on hpte invalidate and update
Date: Fri, 31 May 2013 16:33:24 +0530 [thread overview]
Message-ID: <1369998204-31490-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> (raw)
From: "Aneesh Kumar K.V" <aneesh.kumar@linux•vnet.ibm.com>
If a hash bucket gets full, we "evict" a more/less random entry from it.
When we do that we don't invalidate the TLB (hpte_remove) because we assume
the old translation is still technically "valid". This implies that when
we are invalidating or updating pte, even if HPTE entry is not valid
we should do a tlb invalidate.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux•vnet.ibm.com>
---
arch/powerpc/mm/hash_native_64.c | 30 ++++++++++++++++++++++--------
1 file changed, 22 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/mm/hash_native_64.c b/arch/powerpc/mm/hash_native_64.c
index 6a2aead..4c122c3 100644
--- a/arch/powerpc/mm/hash_native_64.c
+++ b/arch/powerpc/mm/hash_native_64.c
@@ -336,11 +336,18 @@ static long native_hpte_updatepp(unsigned long slot, unsigned long newpp,
hpte_v = hptep->v;
actual_psize = hpte_actual_psize(hptep, psize);
+ /*
+ * We need to invalidate the TLB always because hpte_remove doesn't do
+ * a tlb invalidate. If a hash bucket gets full, we "evict" a more/less
+ * random entry from it. When we do that we don't invalidate the TLB
+ * (hpte_remove) because we assume the old translation is still
+ * technically "valid".
+ */
if (actual_psize < 0) {
- native_unlock_hpte(hptep);
- return -1;
+ actual_psize = psize;
+ ret = -1;
+ goto err_out;
}
- /* Even if we miss, we need to invalidate the TLB */
if (!HPTE_V_COMPARE(hpte_v, want_v)) {
DBG_LOW(" -> miss\n");
ret = -1;
@@ -350,6 +357,7 @@ static long native_hpte_updatepp(unsigned long slot, unsigned long newpp,
hptep->r = (hptep->r & ~(HPTE_R_PP | HPTE_R_N)) |
(newpp & (HPTE_R_PP | HPTE_R_N | HPTE_R_C));
}
+err_out:
native_unlock_hpte(hptep);
/* Ensure it is out of the tlb too. */
@@ -409,7 +417,7 @@ static void native_hpte_updateboltedpp(unsigned long newpp, unsigned long ea,
hptep = htab_address + slot;
actual_psize = hpte_actual_psize(hptep, psize);
if (actual_psize < 0)
- return;
+ actual_psize = psize;
/* Update the HPTE */
hptep->r = (hptep->r & ~(HPTE_R_PP | HPTE_R_N)) |
@@ -437,21 +445,27 @@ static void native_hpte_invalidate(unsigned long slot, unsigned long vpn,
hpte_v = hptep->v;
actual_psize = hpte_actual_psize(hptep, psize);
+ /*
+ * We need to invalidate the TLB always because hpte_remove doesn't do
+ * a tlb invalidate. If a hash bucket gets full, we "evict" a more/less
+ * random entry from it. When we do that we don't invalidate the TLB
+ * (hpte_remove) because we assume the old translation is still
+ * technically "valid".
+ */
if (actual_psize < 0) {
+ actual_psize = psize;
native_unlock_hpte(hptep);
- local_irq_restore(flags);
- return;
+ goto err_out;
}
- /* Even if we miss, we need to invalidate the TLB */
if (!HPTE_V_COMPARE(hpte_v, want_v))
native_unlock_hpte(hptep);
else
/* Invalidate the hpte. NOTE: this also unlocks it */
hptep->v = 0;
+err_out:
/* Invalidate the TLB */
tlbie(vpn, psize, actual_psize, ssize, local);
-
local_irq_restore(flags);
}
--
1.8.1.2
next reply other threads:[~2013-05-31 11:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-31 11:03 Aneesh Kumar K.V [this message]
2013-06-01 11:19 ` [PATCH] powerpc/mm: Always invalidate tlb on hpte invalidate and update Michael Ellerman
2013-06-01 11:44 ` Benjamin Herrenschmidt
2013-06-02 7:26 ` Aneesh Kumar K.V
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=1369998204-31490-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com \
--to=aneesh.kumar@linux$(echo .)vnet.ibm.com \
--cc=benh@kernel$(echo .)crashing.org \
--cc=linuxppc-dev@lists$(echo .)ozlabs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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