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From:   Dmitry Osipenko <digetx@gmail.com>
To:     Joerg Roedel <joro@8bytes.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Thierry Reding <thierry.reding@gmail.com>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Rob Herring <robh+dt@kernel.org>
Cc:     iommu@lists.linux-foundation.org, devicetree@vger.kernel.org,
        linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 10/19] memory: tegra: Read client ID on GART page fault
Date:   Sat, 18 Aug 2018 18:54:21 +0300
Message-Id: <20180818155430.5586-11-digetx@gmail.com>
In-Reply-To: <20180818155430.5586-1-digetx@gmail.com>
References: <20180818155430.5586-1-digetx@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

With the device tree binding changes, now Memory Controller has access to
GART registers. Hence it is now possible to read client ID on GART page
fault to get information about what memory client causes the fault.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/mc.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index 3bf3138769f4..ab383d7a7842 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -38,6 +38,7 @@
 
 #define MC_ERR_ADR 0x0c
 
+#define MC_GART_ERROR_REQ		0x30
 #define MC_DECERR_EMEM_OTHERS_STATUS	0x58
 #define MC_SECURITY_VIOLATION_STATUS	0x74
 
@@ -575,8 +576,15 @@ static __maybe_unused irqreturn_t tegra20_mc_irq(int irq, void *data)
 			break;
 
 		case MC_INT_INVALID_GART_PAGE:
-			dev_err_ratelimited(mc->dev, "%s\n", error);
-			continue;
+			reg = MC_GART_ERROR_REQ;
+			value = mc_readl(mc, reg);
+
+			id = (value >> 1) & mc->soc->client_id_mask;
+			desc = error_names[2];
+
+			if (value & BIT(0))
+				direction = "write";
+			break;
 
 		case MC_INT_SECURITY_VIOLATION:
 			reg = MC_SECURITY_VIOLATION_STATUS;
-- 
2.18.0