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From:   Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
To:     Michael Ellerman <mpe@ellerman.id.au>
Cc:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        mikey@neuling.org, hbabu@us.ibm.com, nicholas.piggin@gmail.com,
        linuxppc-dev@ozlabs.org, <linux-kernel@vger.kernel.org>
Subject: [PATCH v3 02/18] powerpc/vas: Validate window credits
Date:   Tue,  7 Nov 2017 18:23:42 -0800
In-Reply-To: <1510107838-15181-1-git-send-email-sukadev@linux.vnet.ibm.com>
References: <1510107838-15181-1-git-send-email-sukadev@linux.vnet.ibm.com>
Message-Id: <1510107838-15181-3-git-send-email-sukadev@linux.vnet.ibm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

NX-842, the only user of VAS, sets the window credits to default values
but VAS should check the credits against the possible max values.

The VAS_WCREDS_MIN is not needed and can be dropped.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/powernv/vas-window.c | 6 ++++++
 arch/powerpc/platforms/powernv/vas.h        | 4 ++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index cec7ab7..a2fe120 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -738,6 +738,9 @@ static bool rx_win_args_valid(enum vas_cop_type cop,
 	if (attr->rx_fifo_size > VAS_RX_FIFO_SIZE_MAX)
 		return false;
 
+	if (attr->wcreds_max > VAS_RX_WCREDS_MAX)
+		return false;
+
 	if (attr->nx_win) {
 		/* cannot be fault or user window if it is nx */
 		if (attr->fault_win || attr->user_win)
@@ -927,6 +930,9 @@ static bool tx_win_args_valid(enum vas_cop_type cop,
 	if (cop > VAS_COP_TYPE_MAX)
 		return false;
 
+	if (attr->wcreds_max > VAS_TX_WCREDS_MAX)
+		return false;
+
 	if (attr->user_win &&
 			(cop != VAS_COP_TYPE_FTW || attr->rsvd_txbuf_count))
 		return false;
diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
index 38dee5d..fea0de4 100644
--- a/arch/powerpc/platforms/powernv/vas.h
+++ b/arch/powerpc/platforms/powernv/vas.h
@@ -106,8 +106,8 @@
  *
  * TODO: Needs tuning for per-process credits
  */
-#define VAS_WCREDS_MIN			16
-#define VAS_WCREDS_MAX			((64 << 10) - 1)
+#define VAS_RX_WCREDS_MAX		((64 << 10) - 1)
+#define VAS_TX_WCREDS_MAX		((4 << 10) - 1)
 #define VAS_WCREDS_DEFAULT		(1 << 10)
 
 /*
-- 
2.7.4


From 1583451611408453762@xxx Tue Nov 07 23:25:33 +0000 2017
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