[PATCH v2 2/2] PCI: endpoint: Drop only_64bit on reserved BARs

From: Niklas Cassel <cassel@kernel.org>
To: "Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Rob Herring" <robh@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Kunihiko Hayashi" <hayashi.kunihiko@socionext.com>,
	"Masami Hiramatsu" <mhiramat@kernel.org>,
	"Manivannan Sadhasivam" <manivannan.sadhasivam@linaro.org>,
	"Kishon Vijay Abraham I" <kishon@kernel.org>
Cc: Damien Le Moal <dlemoal@kernel.org>, Frank Li <Frank.Li@nxp.com>,
	Niklas Cassel <cassel@kernel.org>,
	linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 2/2] PCI: endpoint: Drop only_64bit on reserved BARs
Date: Fri, 16 Feb 2024 14:45:15 +0100	[thread overview]
Message-ID: <20240216134524.1142149-3-cassel@kernel.org> (raw)
In-Reply-To: <20240216134524.1142149-1-cassel@kernel.org>

The definition of a reserved BAR is that EPF drivers should not touch
them.

The definition of only_64bit is that the EPF driver must configure this
BAR as 64-bit. (An EPF driver is not allowed to choose if this BAR should
be configured as 32-bit or 64-bit.)

Thus, it does not make sense to put only_64bit of a BAR that EPF drivers
are not allow to touch.

Drop the only_64bit property from hardware descriptions that are of type
reserved BAR.

Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/controller/dwc/pci-keystone.c     | 2 +-
 drivers/pci/controller/dwc/pcie-uniphier-ep.c | 2 +-
 drivers/pci/endpoint/pci-epc-core.c           | 7 -------
 include/linux/pci-epc.h                       | 5 +++++
 4 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index b2b93b4fa82d..844de4418724 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -924,7 +924,7 @@ static const struct pci_epc_features ks_pcie_am654_epc_features = {
 	.linkup_notifier = false,
 	.msi_capable = true,
 	.msix_capable = true,
-	.bar[BAR_0] = { .type = BAR_RESERVED, .only_64bit = true, },
+	.bar[BAR_0] = { .type = BAR_RESERVED, },
 	.bar[BAR_1] = { .type = BAR_RESERVED, },
 	.bar[BAR_2] = { .type = BAR_FIXED, .fixed_size = SZ_1M, },
 	.bar[BAR_3] = { .type = BAR_FIXED, .fixed_size = SZ_64K, },
diff --git a/drivers/pci/controller/dwc/pcie-uniphier-ep.c b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
index 265f65fc673f..639bc2e12476 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier-ep.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
@@ -415,7 +415,7 @@ static const struct uniphier_pcie_ep_soc_data uniphier_pro5_data = {
 		.bar[BAR_1] = { .type = BAR_RESERVED, },
 		.bar[BAR_2] = { .only_64bit = true, },
 		.bar[BAR_3] = { .type = BAR_RESERVED, },
-		.bar[BAR_4] = { .type = BAR_RESERVED, .only_64bit = true, },
+		.bar[BAR_4] = { .type = BAR_RESERVED, },
 		.bar[BAR_5] = { .type = BAR_RESERVED, },
 	},
 };
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 7fe8f4336765..da3fc0795b0b 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -120,13 +120,6 @@ enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
 		/* If the BAR is not reserved, return it. */
 		if (epc_features->bar[i].type != BAR_RESERVED)
 			return i;
-
-		/*
-		 * If the BAR is reserved, and marked as 64-bit only, then the
-		 * succeeding BAR is also reserved.
-		 */
-		if (epc_features->bar[i].only_64bit)
-			i++;
 	}
 
 	return NO_BAR;
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 4ccb4f4f3883..cc2f70d061c8 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -164,6 +164,11 @@ enum pci_epc_bar_type {
  *		should be configured as 32-bit or 64-bit, the EPF driver must
  *		configure this BAR as 64-bit. Additionally, the BAR succeeding
  *		this BAR must be set to type BAR_RESERVED.
+ *
+ *		only_64bit should not be set on a BAR of type BAR_RESERVED.
+ *		(If BARx is a 64-bit BAR that an EPF driver is not allowed to
+ *		touch, then both BARx and BARx+1 must be set to type
+ *		BAR_RESERVED.)
  */
 struct pci_epc_bar_desc {
 	enum pci_epc_bar_type type;
-- 
2.43.1


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