From:   Rob Herring <robh@kernel.org>
To:     Toan Le <toan@os.amperecomputing.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Andrew Murray <amurray@thegoodpenguin.co.uk>
Cc:     =?UTF-8?q?St=C3=A9phane=20Graber?= <stgraber@ubuntu.com>,
        stable@vger.kernel.org, linux-pci@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] PCI: xgene: Fix IB window setup
Date:   Mon, 29 Nov 2021 11:36:37 -0600
Message-Id: <20211129173637.303201-1-robh@kernel.org>
MIME-Version: 1.0
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Precedence: bulk

Commit 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup")
broke PCI support on XGene. The cause is the IB resources are now sorted
in address order instead of being in DT dma-ranges order. The result is
which inbound registers are used for each region are swapped. I don't
know the details about this h/w, but it appears that IB region 0
registers can't handle a size greater than 4GB. In any case, limiting
the size for region 0 is enough to get back to the original assignment
of dma-ranges to regions.

Reported-by: Stéphane Graber <stgraber@ubuntu.com>
Fixes: 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup")
Link: https://lore.kernel.org/all/CA+enf=v9rY_xnZML01oEgKLmvY1NGBUUhnSJaETmXtDtXfaczA@mail.gmail.com/
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Rob Herring <robh@kernel.org>
---
 drivers/pci/controller/pci-xgene.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pci-xgene.c b/drivers/pci/controller/pci-xgene.c
index 56d0d50338c8..d83dbd977418 100644
--- a/drivers/pci/controller/pci-xgene.c
+++ b/drivers/pci/controller/pci-xgene.c
@@ -465,7 +465,7 @@ static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size)
 		return 1;
 	}
 
-	if ((size > SZ_1K) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 0))) {
+	if ((size > SZ_1K) && (size < SZ_4G) && !(*ib_reg_mask & (1 << 0))) {
 		*ib_reg_mask |= (1 << 0);
 		return 0;
 	}
-- 
2.32.0