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From:   Leonardo Bras <leobras.c@gmail.com>
To:     Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Alexey Kardashevskiy <aik@ozlabs.ru>,
        Leonardo Bras <leobras.c@gmail.com>,
        Thiago Jung Bauermann <bauerman@linux.ibm.com>,
        Ram Pai <linuxram@us.ibm.com>
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/4] powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window
Date:   Fri, 19 Jun 2020 02:06:19 -0300
Message-Id: <20200619050619.266888-4-leobras.c@gmail.com>
In-Reply-To: <20200619050619.266888-1-leobras.c@gmail.com>
References: <20200619050619.266888-1-leobras.c@gmail.com>
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Move the window-removing part of remove_ddw into a new function
(remove_dma_window), so it can be used to remove other DMA windows.

It's useful for removing DMA windows that don't create DIRECT64_PROPNAME
property, like the default DMA window from the device, which uses
"ibm,dma-window".

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
---
 arch/powerpc/platforms/pseries/iommu.c | 53 +++++++++++++++-----------
 1 file changed, 31 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 5e1fbc176a37..de633f6ae093 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -767,25 +767,14 @@ static int __init disable_ddw_setup(char *str)
 
 early_param("disable_ddw", disable_ddw_setup);
 
-static void remove_ddw(struct device_node *np, bool remove_prop)
+static void remove_dma_window(struct device_node *pdn, u32 *ddw_avail,
+			      struct property *win)
 {
 	struct dynamic_dma_window_prop *dwp;
-	struct property *win64;
-	u32 ddw_avail[3];
 	u64 liobn;
-	int ret = 0;
-
-	ret = of_property_read_u32_array(np, "ibm,ddw-applicable",
-					 &ddw_avail[0], 3);
-
-	win64 = of_find_property(np, DIRECT64_PROPNAME, NULL);
-	if (!win64)
-		return;
-
-	if (ret || win64->length < sizeof(*dwp))
-		goto delprop;
+	int ret;
 
-	dwp = win64->value;
+	dwp = win->value;
 	liobn = (u64)be32_to_cpu(dwp->liobn);
 
 	/* clear the whole window, note the arg is in kernel pages */
@@ -793,24 +782,44 @@ static void remove_ddw(struct device_node *np, bool remove_prop)
 		1ULL << (be32_to_cpu(dwp->window_shift) - PAGE_SHIFT), dwp);
 	if (ret)
 		pr_warn("%pOF failed to clear tces in window.\n",
-			np);
+			pdn);
 	else
 		pr_debug("%pOF successfully cleared tces in window.\n",
-			 np);
+			 pdn);
 
 	ret = rtas_call(ddw_avail[2], 1, 1, NULL, liobn);
 	if (ret)
 		pr_warn("%pOF: failed to remove direct window: rtas returned "
 			"%d to ibm,remove-pe-dma-window(%x) %llx\n",
-			np, ret, ddw_avail[2], liobn);
+			pdn, ret, ddw_avail[2], liobn);
 	else
 		pr_debug("%pOF: successfully removed direct window: rtas returned "
 			"%d to ibm,remove-pe-dma-window(%x) %llx\n",
-			np, ret, ddw_avail[2], liobn);
+			pdn, ret, ddw_avail[2], liobn);
+}
+
+static void remove_ddw(struct device_node *np, bool remove_prop)
+{
+	struct property *win;
+	u32 ddw_avail[3];
+	int ret = 0;
+
+	ret = of_property_read_u32_array(np, "ibm,ddw-applicable",
+					 &ddw_avail[0], 3);
+	if (ret)
+		return;
+
+	win = of_find_property(np, DIRECT64_PROPNAME, NULL);
+	if (!win)
+		return;
+
+	if (win->length >= sizeof(struct dynamic_dma_window_prop))
+		remove_dma_window(np, ddw_avail, win);
+
+	if (!remove_prop)
+		return;
 
-delprop:
-	if (remove_prop)
-		ret = of_remove_property(np, win64);
+	ret = of_remove_property(np, win);
 	if (ret)
 		pr_warn("%pOF: failed to remove direct window property: %d\n",
 			np, ret);
-- 
2.25.4