From e891becdccaa9048b1ab91c08ad5722edd571806 Mon Sep 17 00:00:00 2001
From: Niklas Cassel <cassel@kernel.org>
Date: Wed, 7 Feb 2024 22:39:14 +0100
Subject: PCI: endpoint: Refactor pci_epf_alloc_space() API

Refactor pci_epf_alloc_space() API to accept "epc_features" as a parameter.
This is a preparatory work to make the API more robust.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Link: https://lore.kernel.org/r/20240207213922.1796533-2-cassel@kernel.org
[mani: reworded commit message]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 include/linux/pci-epf.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'include')

diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 77b146e0f672..adee6a1b35db 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -15,6 +15,7 @@
 #include <linux/pci.h>
 
 struct pci_epf;
+struct pci_epc_features;
 enum pci_epc_interface_type;
 
 enum pci_barno {
@@ -216,7 +217,8 @@ int __pci_epf_register_driver(struct pci_epf_driver *driver,
 			      struct module *owner);
 void pci_epf_unregister_driver(struct pci_epf_driver *driver);
 void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
-			  size_t align, enum pci_epc_interface_type type);
+			  const struct pci_epc_features *epc_features,
+			  enum pci_epc_interface_type type);
 void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar,
 			enum pci_epc_interface_type type);
 int pci_epf_bind(struct pci_epf *epf);
-- 
cgit v1.2.3


From e01c9797c0ebb307c9bb196c677f6e571335773e Mon Sep 17 00:00:00 2001
From: Niklas Cassel <cassel@kernel.org>
Date: Fri, 16 Feb 2024 14:45:14 +0100
Subject: PCI: endpoint: Clean up hardware description for BARs

The hardware description for BARs is scattered in many different variables
in pci_epc_features. Some of these things are mutually exclusive, so it
can create confusion over which variable that has precedence over another.

Improve the situation by creating a struct pci_epc_bar_desc, and a new
enum pci_epc_bar_type, and convert the endpoint controller drivers to use
this more well defined format.

Additionally, some endpoint controller drivers mark the BAR succeeding a
"64-bit only BAR" as reserved, while some do not. By definition, a 64-bit
BAR uses the succeeding BAR for the upper 32-bits, so an EPF driver cannot
use a BAR succeeding a 64-bit BAR. Ensure that all endpoint controller
drivers are uniform, and actually describe a reserved BAR as reserved.

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>
Link: https://lore.kernel.org/r/20240216134524.1142149-2-cassel@kernel.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/controller/dwc/pci-imx6.c          |  3 ++-
 drivers/pci/controller/dwc/pci-keystone.c      | 12 ++++-----
 drivers/pci/controller/dwc/pci-layerscape-ep.c |  5 +++-
 drivers/pci/controller/dwc/pcie-keembay.c      |  8 ++++--
 drivers/pci/controller/dwc/pcie-rcar-gen4.c    |  4 ++-
 drivers/pci/controller/dwc/pcie-tegra194.c     | 10 +++++---
 drivers/pci/controller/dwc/pcie-uniphier-ep.c  | 15 +++++++++---
 drivers/pci/controller/pcie-rcar-ep.c          | 14 +++++++----
 drivers/pci/endpoint/functions/pci-epf-ntb.c   |  4 +--
 drivers/pci/endpoint/functions/pci-epf-test.c  |  8 +++---
 drivers/pci/endpoint/functions/pci-epf-vntb.c  |  2 +-
 drivers/pci/endpoint/pci-epc-core.c            | 32 ++++++++++++------------
 drivers/pci/endpoint/pci-epf-core.c            | 15 ++++++------
 include/linux/pci-epc.h                        | 34 +++++++++++++++++++++-----
 14 files changed, 108 insertions(+), 58 deletions(-)

(limited to 'include')

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index dc2c036ab28c..47a9a96484ed 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1081,7 +1081,8 @@ static const struct pci_epc_features imx8m_pcie_epc_features = {
 	.linkup_notifier = false,
 	.msi_capable = true,
 	.msix_capable = false,
-	.reserved_bar = 1 << BAR_1 | 1 << BAR_3,
+	.bar[BAR_1] = { .type = BAR_RESERVED, },
+	.bar[BAR_3] = { .type = BAR_RESERVED, },
 	.align = SZ_64K,
 };
 
diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index c0c62533a3f1..b2b93b4fa82d 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -924,12 +924,12 @@ static const struct pci_epc_features ks_pcie_am654_epc_features = {
 	.linkup_notifier = false,
 	.msi_capable = true,
 	.msix_capable = true,
-	.reserved_bar = 1 << BAR_0 | 1 << BAR_1,
-	.bar_fixed_64bit = 1 << BAR_0,
-	.bar_fixed_size[2] = SZ_1M,
-	.bar_fixed_size[3] = SZ_64K,
-	.bar_fixed_size[4] = 256,
-	.bar_fixed_size[5] = SZ_1M,
+	.bar[BAR_0] = { .type = BAR_RESERVED, .only_64bit = true, },
+	.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, },
+	.bar[BAR_4] = { .type = BAR_FIXED, .fixed_size = 256, },
+	.bar[BAR_5] = { .type = BAR_FIXED, .fixed_size = SZ_1M, },
 	.align = SZ_1M,
 };
 
diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c b/drivers/pci/controller/dwc/pci-layerscape-ep.c
index 2e398494e7c0..1f6ee1460ec2 100644
--- a/drivers/pci/controller/dwc/pci-layerscape-ep.c
+++ b/drivers/pci/controller/dwc/pci-layerscape-ep.c
@@ -250,7 +250,10 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev)
 	pci->dev = dev;
 	pci->ops = pcie->drvdata->dw_pcie_ops;
 
-	ls_epc->bar_fixed_64bit = (1 << BAR_2) | (1 << BAR_4);
+	ls_epc->bar[BAR_2].only_64bit = true;
+	ls_epc->bar[BAR_3].type = BAR_RESERVED;
+	ls_epc->bar[BAR_4].only_64bit = true;
+	ls_epc->bar[BAR_5].type = BAR_RESERVED;
 	ls_epc->linkup_notifier = true;
 
 	pcie->pci = pci;
diff --git a/drivers/pci/controller/dwc/pcie-keembay.c b/drivers/pci/controller/dwc/pcie-keembay.c
index 208d3b0ba196..5e8e54f597dd 100644
--- a/drivers/pci/controller/dwc/pcie-keembay.c
+++ b/drivers/pci/controller/dwc/pcie-keembay.c
@@ -312,8 +312,12 @@ static const struct pci_epc_features keembay_pcie_epc_features = {
 	.linkup_notifier	= false,
 	.msi_capable		= true,
 	.msix_capable		= true,
-	.reserved_bar		= BIT(BAR_1) | BIT(BAR_3) | BIT(BAR_5),
-	.bar_fixed_64bit	= BIT(BAR_0) | BIT(BAR_2) | BIT(BAR_4),
+	.bar[BAR_0]		= { .only_64bit = true, },
+	.bar[BAR_1]		= { .type = BAR_RESERVED, },
+	.bar[BAR_2]		= { .only_64bit = true, },
+	.bar[BAR_3]		= { .type = BAR_RESERVED, },
+	.bar[BAR_4]		= { .only_64bit = true, },
+	.bar[BAR_5]		= { .type = BAR_RESERVED, },
 	.align			= SZ_16K,
 };
 
diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index e9166619b1f9..0be760ed420b 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -383,7 +383,9 @@ static const struct pci_epc_features rcar_gen4_pcie_epc_features = {
 	.linkup_notifier = false,
 	.msi_capable = true,
 	.msix_capable = false,
-	.reserved_bar = 1 << BAR_1 | 1 << BAR_3 | 1 << BAR_5,
+	.bar[BAR_1] = { .type = BAR_RESERVED, },
+	.bar[BAR_3] = { .type = BAR_RESERVED, },
+	.bar[BAR_5] = { .type = BAR_RESERVED, },
 	.align = SZ_1M,
 };
 
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 7afa9e9aabe2..1f7b662cb8e1 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -2007,9 +2007,13 @@ static const struct pci_epc_features tegra_pcie_epc_features = {
 	.core_init_notifier = true,
 	.msi_capable = false,
 	.msix_capable = false,
-	.reserved_bar = 1 << BAR_2 | 1 << BAR_3 | 1 << BAR_4 | 1 << BAR_5,
-	.bar_fixed_64bit = 1 << BAR_0,
-	.bar_fixed_size[0] = SZ_1M,
+	.bar[BAR_0] = { .type = BAR_FIXED, .fixed_size = SZ_1M,
+			.only_64bit = true, },
+	.bar[BAR_1] = { .type = BAR_RESERVED, },
+	.bar[BAR_2] = { .type = BAR_RESERVED, },
+	.bar[BAR_3] = { .type = BAR_RESERVED, },
+	.bar[BAR_4] = { .type = BAR_RESERVED, },
+	.bar[BAR_5] = { .type = BAR_RESERVED, },
 };
 
 static const struct pci_epc_features*
diff --git a/drivers/pci/controller/dwc/pcie-uniphier-ep.c b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
index 3fced0d3e851..265f65fc673f 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier-ep.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
@@ -411,8 +411,12 @@ static const struct uniphier_pcie_ep_soc_data uniphier_pro5_data = {
 		.msi_capable = true,
 		.msix_capable = false,
 		.align = 1 << 16,
-		.bar_fixed_64bit = BIT(BAR_0) | BIT(BAR_2) | BIT(BAR_4),
-		.reserved_bar =  BIT(BAR_4),
+		.bar[BAR_0] = { .only_64bit = true, },
+		.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_5] = { .type = BAR_RESERVED, },
 	},
 };
 
@@ -425,7 +429,12 @@ static const struct uniphier_pcie_ep_soc_data uniphier_nx1_data = {
 		.msi_capable = true,
 		.msix_capable = false,
 		.align = 1 << 12,
-		.bar_fixed_64bit = BIT(BAR_0) | BIT(BAR_2) | BIT(BAR_4),
+		.bar[BAR_0] = { .only_64bit = true, },
+		.bar[BAR_1] = { .type = BAR_RESERVED, },
+		.bar[BAR_2] = { .only_64bit = true, },
+		.bar[BAR_3] = { .type = BAR_RESERVED, },
+		.bar[BAR_4] = { .only_64bit = true, },
+		.bar[BAR_5] = { .type = BAR_RESERVED, },
 	},
 };
 
diff --git a/drivers/pci/controller/pcie-rcar-ep.c b/drivers/pci/controller/pcie-rcar-ep.c
index e6909271def7..05967c6c0b42 100644
--- a/drivers/pci/controller/pcie-rcar-ep.c
+++ b/drivers/pci/controller/pcie-rcar-ep.c
@@ -440,11 +440,15 @@ static const struct pci_epc_features rcar_pcie_epc_features = {
 	.msi_capable = true,
 	.msix_capable = false,
 	/* use 64-bit BARs so mark BAR[1,3,5] as reserved */
-	.reserved_bar = 1 << BAR_1 | 1 << BAR_3 | 1 << BAR_5,
-	.bar_fixed_64bit = 1 << BAR_0 | 1 << BAR_2 | 1 << BAR_4,
-	.bar_fixed_size[0] = 128,
-	.bar_fixed_size[2] = 256,
-	.bar_fixed_size[4] = 256,
+	.bar[BAR_0] = { .type = BAR_FIXED, .fixed_size = 128,
+			.only_64bit = true, },
+	.bar[BAR_1] = { .type = BAR_RESERVED, },
+	.bar[BAR_2] = { .type = BAR_FIXED, .fixed_size = 256,
+			.only_64bit = true, },
+	.bar[BAR_3] = { .type = BAR_RESERVED, },
+	.bar[BAR_4] = { .type = BAR_FIXED, .fixed_size = 256,
+			.only_64bit = true, },
+	.bar[BAR_5] = { .type = BAR_RESERVED, },
 };
 
 static const struct pci_epc_features*
diff --git a/drivers/pci/endpoint/functions/pci-epf-ntb.c b/drivers/pci/endpoint/functions/pci-epf-ntb.c
index 43cd309ce22f..e01a98e74d21 100644
--- a/drivers/pci/endpoint/functions/pci-epf-ntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-ntb.c
@@ -1012,13 +1012,13 @@ static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb,
 
 	epc_features = ntb_epc->epc_features;
 	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
-	size = epc_features->bar_fixed_size[barno];
+	size = epc_features->bar[barno].fixed_size;
 	align = epc_features->align;
 
 	peer_ntb_epc = ntb->epc[!type];
 	peer_epc_features = peer_ntb_epc->epc_features;
 	peer_barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
-	peer_size = peer_epc_features->bar_fixed_size[peer_barno];
+	peer_size = peer_epc_features->bar[peer_barno].fixed_size;
 
 	/* Check if epc_features is populated incorrectly */
 	if ((!IS_ALIGNED(size, align)))
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 981894e40681..cd4ffb39dcdc 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -729,7 +729,7 @@ static int pci_epf_test_set_bar(struct pci_epf *epf)
 		 */
 		add = (epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64) ? 2 : 1;
 
-		if (!!(epc_features->reserved_bar & (1 << bar)))
+		if (epc_features->bar[bar].type == BAR_RESERVED)
 			continue;
 
 		ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no,
@@ -856,7 +856,7 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
 		if (bar == test_reg_bar)
 			continue;
 
-		if (!!(epc_features->reserved_bar & (1 << bar)))
+		if (epc_features->bar[bar].type == BAR_RESERVED)
 			continue;
 
 		base = pci_epf_alloc_space(epf, bar_size[bar], bar,
@@ -874,13 +874,11 @@ static void pci_epf_configure_bar(struct pci_epf *epf,
 				  const struct pci_epc_features *epc_features)
 {
 	struct pci_epf_bar *epf_bar;
-	bool bar_fixed_64bit;
 	int i;
 
 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 		epf_bar = &epf->bar[i];
-		bar_fixed_64bit = !!(epc_features->bar_fixed_64bit & (1 << i));
-		if (bar_fixed_64bit)
+		if (epc_features->bar[i].only_64bit)
 			epf_bar->flags |= PCI_BASE_ADDRESS_MEM_TYPE_64;
 	}
 }
diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
index 0675929fc529..8e779eecd62d 100644
--- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
@@ -422,7 +422,7 @@ static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb)
 								epf->func_no,
 								epf->vfunc_no);
 	barno = ntb->epf_ntb_bar[BAR_CONFIG];
-	size = epc_features->bar_fixed_size[barno];
+	size = epc_features->bar[barno].fixed_size;
 	align = epc_features->align;
 
 	if ((!IS_ALIGNED(size, align)))
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index dcd4e66430c1..7fe8f4336765 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -87,7 +87,7 @@ EXPORT_SYMBOL_GPL(pci_epc_get);
  * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
  *
  * Invoke to get the first unreserved BAR that can be used by the endpoint
- * function. For any incorrect value in reserved_bar return '0'.
+ * function.
  */
 enum pci_barno
 pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features)
@@ -102,32 +102,34 @@ EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
  * @bar: the starting BAR number from where unreserved BAR should be searched
  *
  * Invoke to get the next unreserved BAR starting from @bar that can be used
- * for endpoint function. For any incorrect value in reserved_bar return '0'.
+ * for endpoint function.
  */
 enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
 					 *epc_features, enum pci_barno bar)
 {
-	unsigned long free_bar;
+	int i;
 
 	if (!epc_features)
 		return BAR_0;
 
 	/* If 'bar - 1' is a 64-bit BAR, move to the next BAR */
-	if ((epc_features->bar_fixed_64bit << 1) & 1 << bar)
+	if (bar > 0 && epc_features->bar[bar - 1].only_64bit)
 		bar++;
 
-	/* Find if the reserved BAR is also a 64-bit BAR */
-	free_bar = epc_features->reserved_bar & epc_features->bar_fixed_64bit;
-
-	/* Set the adjacent bit if the reserved BAR is also a 64-bit BAR */
-	free_bar <<= 1;
-	free_bar |= epc_features->reserved_bar;
-
-	free_bar = find_next_zero_bit(&free_bar, 6, bar);
-	if (free_bar > 5)
-		return NO_BAR;
+	for (i = bar; i < PCI_STD_NUM_BARS; i++) {
+		/* 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 free_bar;
+	return NO_BAR;
 }
 EXPORT_SYMBOL_GPL(pci_epc_get_next_free_bar);
 
diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
index f2b4d34454c4..0a28a0b0911b 100644
--- a/drivers/pci/endpoint/pci-epf-core.c
+++ b/drivers/pci/endpoint/pci-epf-core.c
@@ -260,7 +260,7 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
 			  const struct pci_epc_features *epc_features,
 			  enum pci_epc_interface_type type)
 {
-	u64 bar_fixed_size = epc_features->bar_fixed_size[bar];
+	u64 bar_fixed_size = epc_features->bar[bar].fixed_size;
 	size_t align = epc_features->align;
 	struct pci_epf_bar *epf_bar;
 	dma_addr_t phys_addr;
@@ -271,13 +271,14 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
 	if (size < 128)
 		size = 128;
 
-	if (bar_fixed_size && size > bar_fixed_size) {
-		dev_err(&epf->dev, "requested BAR size is larger than fixed size\n");
-		return NULL;
-	}
-
-	if (bar_fixed_size)
+	if (epc_features->bar[bar].type == BAR_FIXED && bar_fixed_size) {
+		if (size > bar_fixed_size) {
+			dev_err(&epf->dev,
+				"requested BAR size is larger than fixed size\n");
+			return NULL;
+		}
 		size = bar_fixed_size;
+	}
 
 	if (align)
 		size = ALIGN(size, align);
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 40ea18f5aa02..4ccb4f4f3883 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -145,6 +145,32 @@ struct pci_epc {
 	unsigned long			function_num_map;
 };
 
+/**
+ * @BAR_PROGRAMMABLE: The BAR mask can be configured by the EPC.
+ * @BAR_FIXED: The BAR mask is fixed by the hardware.
+ * @BAR_RESERVED: The BAR should not be touched by an EPF driver.
+ */
+enum pci_epc_bar_type {
+	BAR_PROGRAMMABLE = 0,
+	BAR_FIXED,
+	BAR_RESERVED,
+};
+
+/**
+ * struct pci_epc_bar_desc - hardware description for a BAR
+ * @type: the type of the BAR
+ * @fixed_size: the fixed size, only applicable if type is BAR_FIXED_MASK.
+ * @only_64bit: if true, an EPF driver is not allowed to choose if this BAR
+ *		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.
+ */
+struct pci_epc_bar_desc {
+	enum pci_epc_bar_type type;
+	u64 fixed_size;
+	bool only_64bit;
+};
+
 /**
  * struct pci_epc_features - features supported by a EPC device per function
  * @linkup_notifier: indicate if the EPC device can notify EPF driver on link up
@@ -152,9 +178,7 @@ struct pci_epc {
  *			for initialization
  * @msi_capable: indicate if the endpoint function has MSI capability
  * @msix_capable: indicate if the endpoint function has MSI-X capability
- * @reserved_bar: bitmap to indicate reserved BAR unavailable to function driver
- * @bar_fixed_64bit: bitmap to indicate fixed 64bit BARs
- * @bar_fixed_size: Array specifying the size supported by each BAR
+ * @bar: array specifying the hardware description for each BAR
  * @align: alignment size required for BAR buffer allocation
  */
 struct pci_epc_features {
@@ -162,9 +186,7 @@ struct pci_epc_features {
 	unsigned int	core_init_notifier : 1;
 	unsigned int	msi_capable : 1;
 	unsigned int	msix_capable : 1;
-	u8	reserved_bar;
-	u8	bar_fixed_64bit;
-	u64	bar_fixed_size[PCI_STD_NUM_BARS];
+	struct	pci_epc_bar_desc bar[PCI_STD_NUM_BARS];
 	size_t	align;
 };
 
-- 
cgit v1.2.3


From 9266514689fe6476423209ee40168db53134101d Mon Sep 17 00:00:00 2001
From: Niklas Cassel <cassel@kernel.org>
Date: Fri, 16 Feb 2024 14:45:15 +0100
Subject: PCI: endpoint: Drop only_64bit on reserved BARs

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>
Link: https://lore.kernel.org/r/20240216134524.1142149-3-cassel@kernel.org
Signed-off-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(-)

(limited to 'include')

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;
-- 
cgit v1.2.3


From 0a5a46a6a61be7b63c12c18495d427f91f3662a9 Mon Sep 17 00:00:00 2001
From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Date: Tue, 6 Feb 2024 15:57:15 +0200
Subject: PCI/AER: Generalize TLP Header Log reading
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Both AER and DPC RP PIO provide TLP Header Log registers (PCIe r6.1 secs
7.8.4 & 7.9.14) to convey error diagnostics but the struct is named after
AER as the struct aer_header_log_regs. Also, not all places that handle TLP
Header Log use the struct and the struct members are named individually.

Generalize the struct name and members, and use it consistently where TLP
Header Log is being handled so that a pcie_read_tlp_log() helper can be
easily added.

Link: https://lore.kernel.org/r/20240206135717.8565-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: drop ixgbe changes for now, tidy whitespace]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/firmware/efi/cper.c |  4 ++--
 drivers/pci/pci.c           | 28 ++++++++++++++++++++++++++++
 drivers/pci/pci.h           |  2 +-
 drivers/pci/pcie/aer.c      | 14 +++-----------
 drivers/pci/pcie/dpc.c      | 14 ++++----------
 include/linux/aer.h         | 11 +++++------
 include/ras/ras_event.h     | 10 +++++-----
 7 files changed, 48 insertions(+), 35 deletions(-)

(limited to 'include')

diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
index 35c37f667781..d3f98161171e 100644
--- a/drivers/firmware/efi/cper.c
+++ b/drivers/firmware/efi/cper.c
@@ -445,8 +445,8 @@ static void cper_print_pcie(const char *pfx, const struct cper_sec_pcie *pcie,
 		printk("%saer_uncor_severity: 0x%08x\n",
 		       pfx, aer->uncor_severity);
 		printk("%sTLP Header: %08x %08x %08x %08x\n", pfx,
-		       aer->header_log.dw0, aer->header_log.dw1,
-		       aer->header_log.dw2, aer->header_log.dw3);
+		       aer->header_log.dw[0], aer->header_log.dw[1],
+		       aer->header_log.dw[2], aer->header_log.dw[3]);
 	}
 }
 
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d8f11a078924..a0af94cfcf7d 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1067,6 +1067,34 @@ disable_acs_redir:
 	pci_disable_acs_redir(dev);
 }
 
+/**
+ * pcie_read_tlp_log - read TLP Header Log
+ * @dev: PCIe device
+ * @where: PCI Config offset of TLP Header Log
+ * @tlp_log: TLP Log structure to fill
+ *
+ * Fill @tlp_log from TLP Header Log registers, e.g., AER or DPC.
+ *
+ * Return: 0 on success and filled TLP Log structure, <0 on error.
+ */
+int pcie_read_tlp_log(struct pci_dev *dev, int where,
+		      struct pcie_tlp_log *tlp_log)
+{
+	int i, ret;
+
+	memset(tlp_log, 0, sizeof(*tlp_log));
+
+	for (i = 0; i < 4; i++) {
+		ret = pci_read_config_dword(dev, where + i * 4,
+					    &tlp_log->dw[i]);
+		if (ret)
+			return pcibios_err_to_errno(ret);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pcie_read_tlp_log);
+
 /**
  * pci_restore_bars - restore a device's BAR values (e.g. after wake-up)
  * @dev: PCI device to have its BARs restored
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 2336a8d1edab..a59ba6fde2a0 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -409,7 +409,7 @@ struct aer_err_info {
 
 	unsigned int status;		/* COR/UNCOR Error Status */
 	unsigned int mask;		/* COR/UNCOR Error Mask */
-	struct aer_header_log_regs tlp;	/* TLP Header */
+	struct pcie_tlp_log tlp;	/* TLP Header */
 };
 
 int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info);
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index e31e6a9a7773..ac6293c24976 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -664,11 +664,10 @@ static void pci_rootport_aer_stats_incr(struct pci_dev *pdev,
 	}
 }
 
-static void __print_tlp_header(struct pci_dev *dev,
-			       struct aer_header_log_regs *t)
+static void __print_tlp_header(struct pci_dev *dev, struct pcie_tlp_log *t)
 {
 	pci_err(dev, "  TLP Header: %08x %08x %08x %08x\n",
-		t->dw0, t->dw1, t->dw2, t->dw3);
+		t->dw[0], t->dw[1], t->dw[2], t->dw[3]);
 }
 
 static void __aer_print_error(struct pci_dev *dev,
@@ -1246,14 +1245,7 @@ int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
 
 		if (info->status & AER_LOG_TLP_MASKS) {
 			info->tlp_header_valid = 1;
-			pci_read_config_dword(dev,
-				aer + PCI_ERR_HEADER_LOG, &info->tlp.dw0);
-			pci_read_config_dword(dev,
-				aer + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1);
-			pci_read_config_dword(dev,
-				aer + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2);
-			pci_read_config_dword(dev,
-				aer + PCI_ERR_HEADER_LOG + 12, &info->tlp.dw3);
+			pcie_read_tlp_log(dev, aer + PCI_ERR_HEADER_LOG, &info->tlp);
 		}
 	}
 
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index 94111e438241..c197bc7f7f2c 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -190,7 +190,8 @@ out:
 static void dpc_process_rp_pio_error(struct pci_dev *pdev)
 {
 	u16 cap = pdev->dpc_cap, dpc_status, first_error;
-	u32 status, mask, sev, syserr, exc, dw0, dw1, dw2, dw3, log, prefix;
+	u32 status, mask, sev, syserr, exc, log, prefix;
+	struct pcie_tlp_log tlp_log;
 	int i;
 
 	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS, &status);
@@ -216,16 +217,9 @@ static void dpc_process_rp_pio_error(struct pci_dev *pdev)
 
 	if (pdev->dpc_rp_log_size < 4)
 		goto clear_status;
-	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG,
-			      &dw0);
-	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 4,
-			      &dw1);
-	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 8,
-			      &dw2);
-	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 12,
-			      &dw3);
+	pcie_read_tlp_log(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG, &tlp_log);
 	pci_err(pdev, "TLP Header: %#010x %#010x %#010x %#010x\n",
-		dw0, dw1, dw2, dw3);
+		tlp_log.dw[0], tlp_log.dw[1], tlp_log.dw[2], tlp_log.dw[3]);
 
 	if (pdev->dpc_rp_log_size < 5)
 		goto clear_status;
diff --git a/include/linux/aer.h b/include/linux/aer.h
index ae0fae70d4bd..4b97f38f3fcf 100644
--- a/include/linux/aer.h
+++ b/include/linux/aer.h
@@ -18,11 +18,8 @@
 
 struct pci_dev;
 
-struct aer_header_log_regs {
-	u32 dw0;
-	u32 dw1;
-	u32 dw2;
-	u32 dw3;
+struct pcie_tlp_log {
+	u32 dw[4];
 };
 
 struct aer_capability_regs {
@@ -33,13 +30,15 @@ struct aer_capability_regs {
 	u32 cor_status;
 	u32 cor_mask;
 	u32 cap_control;
-	struct aer_header_log_regs header_log;
+	struct pcie_tlp_log header_log;
 	u32 root_command;
 	u32 root_status;
 	u16 cor_err_source;
 	u16 uncor_err_source;
 };
 
+int pcie_read_tlp_log(struct pci_dev *dev, int where, struct pcie_tlp_log *log);
+
 #if defined(CONFIG_PCIEAER)
 int pci_aer_clear_nonfatal_status(struct pci_dev *dev);
 int pcie_aer_is_native(struct pci_dev *dev);
diff --git a/include/ras/ras_event.h b/include/ras/ras_event.h
index cbd3ddd7c33d..c011ea236e9b 100644
--- a/include/ras/ras_event.h
+++ b/include/ras/ras_event.h
@@ -300,7 +300,7 @@ TRACE_EVENT(aer_event,
 		 const u32 status,
 		 const u8 severity,
 		 const u8 tlp_header_valid,
-		 struct aer_header_log_regs *tlp),
+		 struct pcie_tlp_log *tlp),
 
 	TP_ARGS(dev_name, status, severity, tlp_header_valid, tlp),
 
@@ -318,10 +318,10 @@ TRACE_EVENT(aer_event,
 		__entry->severity	= severity;
 		__entry->tlp_header_valid = tlp_header_valid;
 		if (tlp_header_valid) {
-			__entry->tlp_header[0] = tlp->dw0;
-			__entry->tlp_header[1] = tlp->dw1;
-			__entry->tlp_header[2] = tlp->dw2;
-			__entry->tlp_header[3] = tlp->dw3;
+			__entry->tlp_header[0] = tlp->dw[0];
+			__entry->tlp_header[1] = tlp->dw[1];
+			__entry->tlp_header[2] = tlp->dw[2];
+			__entry->tlp_header[3] = tlp->dw[3];
 		}
 	),
 
-- 
cgit v1.2.3


From 17423360a27ae58c1850f588bdd8013bbfcd250b Mon Sep 17 00:00:00 2001
From: "David E. Box" <david.e.box@linux.intel.com>
Date: Fri, 23 Feb 2024 14:58:50 -0600
Subject: PCI/ASPM: Save L1 PM Substates Capability for suspend/resume

4ff116d0d5fd ("PCI/ASPM: Save L1 PM Substates Capability for
suspend/resume") restored the L1 PM Substates Capability after resume,
which reduced power consumption by making the ASPM L1.x states work after
resume.

a7152be79b62 ("Revert "PCI/ASPM: Save L1 PM Substates Capability for
suspend/resume"") reverted 4ff116d0d5fd because resume failed on some
systems, so power consumption after resume increased again.

a7152be79b62 mentioned that we restore L1 PM substate configuration even
though ASPM L1 may already be enabled. This is due the fact that the
pci_restore_aspm_l1ss_state() was called before pci_restore_pcie_state().

Save and restore the L1 PM Substates Capability, following PCIe r6.1, sec
5.5.4 more closely by:

  1) Do not restore ASPM configuration in pci_restore_pcie_state() but
     do that after PCIe capability is restored in pci_restore_aspm_state()
     following PCIe r6.1, sec 5.5.4.

  2) If BIOS reenables L1SS, particularly L1.2, we need to clear the
     enables in the right order, downstream before upstream. Defer
     restoring the L1SS config until we are at the downstream component.
     Then update the config for both ends of the link in the prescribed
     order.

  3) Program ASPM L1 PM substate configuration before L1 enables.

  4) Program ASPM L1 PM substate enables last, after rest of the fields
     in the capability are programmed.

[bhelgaas: commit log, squash L1SS-related patches, do both LNKCTL restores
in pci_restore_pcie_state()]

Link: https://lore.kernel.org/r/20240128233212.1139663-3-david.e.box@linux.intel.com
Link: https://lore.kernel.org/r/20240128233212.1139663-4-david.e.box@linux.intel.com
Link: https://lore.kernel.org/r/20240223205851.114931-5-helgaas@kernel.org
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217321
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216782
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216877
Co-developed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Co-developed-by: David E. Box <david.e.box@linux.intel.com>
Reported-by: Koba Ko <koba.ko@canonical.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Tasev Nikola <tasev.stefanoska@skynet.be> # Asus UX305FA
Cc: Mark Enriquez <enriquezmark36@gmail.com>
Cc: Thomas Witt <kernel@witt.link>
Cc: Werner Sembach <wse@tuxedocomputers.com>
Cc: Vidya Sagar <vidyas@nvidia.com>
---
 drivers/pci/pci.c       |  17 +++++++-
 drivers/pci/pci.h       |   3 ++
 drivers/pci/pcie/aspm.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++--
 drivers/pci/probe.c     |   1 +
 include/linux/pci.h     |   2 +-
 5 files changed, 119 insertions(+), 6 deletions(-)

(limited to 'include')

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 564e2cf2dde5..ca6673588bc0 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1623,6 +1623,8 @@ static int pci_save_pcie_state(struct pci_dev *dev)
 	pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &cap[i++]);
 	pcie_capability_read_word(dev, PCI_EXP_SLTCTL2, &cap[i++]);
 
+	pci_save_aspm_l1ss_state(dev);
+
 	return 0;
 }
 
@@ -1630,7 +1632,7 @@ static void pci_restore_pcie_state(struct pci_dev *dev)
 {
 	int i = 0;
 	struct pci_cap_saved_state *save_state;
-	u16 *cap;
+	u16 *cap, lnkctl;
 
 	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
 	if (!save_state)
@@ -1645,12 +1647,23 @@ static void pci_restore_pcie_state(struct pci_dev *dev)
 
 	cap = (u16 *)&save_state->cap.data[0];
 	pcie_capability_write_word(dev, PCI_EXP_DEVCTL, cap[i++]);
-	pcie_capability_write_word(dev, PCI_EXP_LNKCTL, cap[i++]);
+
+	/* Restore LNKCTL register with ASPM control field clear */
+	lnkctl = cap[i++];
+	pcie_capability_write_word(dev, PCI_EXP_LNKCTL,
+				   lnkctl & ~PCI_EXP_LNKCTL_ASPMC);
+
 	pcie_capability_write_word(dev, PCI_EXP_SLTCTL, cap[i++]);
 	pcie_capability_write_word(dev, PCI_EXP_RTCTL, cap[i++]);
 	pcie_capability_write_word(dev, PCI_EXP_DEVCTL2, cap[i++]);
 	pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, cap[i++]);
 	pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]);
+
+	pci_restore_aspm_l1ss_state(dev);
+
+	/* Restore ASPM control after restoring L1SS state */
+	pcie_capability_set_word(dev, PCI_EXP_LNKCTL,
+				 lnkctl & PCI_EXP_LNKCTL_ASPMC);
 }
 
 static int pci_save_pcix_state(struct pci_dev *dev)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index ad3add45345c..eca5938deb07 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -571,6 +571,9 @@ int pcie_retrain_link(struct pci_dev *pdev, bool use_lt);
 /* ASPM-related functionality we need even without CONFIG_PCIEASPM */
 void pci_save_ltr_state(struct pci_dev *dev);
 void pci_restore_ltr_state(struct pci_dev *dev);
+void pci_configure_aspm_l1ss(struct pci_dev *dev);
+void pci_save_aspm_l1ss_state(struct pci_dev *dev);
+void pci_restore_aspm_l1ss_state(struct pci_dev *dev);
 
 #ifdef CONFIG_PCIEASPM
 void pcie_aspm_init_link_state(struct pci_dev *pdev);
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 21731b232fb8..977eca893b2a 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -64,6 +64,105 @@ void pci_restore_ltr_state(struct pci_dev *dev)
 	pci_write_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap);
 }
 
+void pci_configure_aspm_l1ss(struct pci_dev *pdev)
+{
+	int rc;
+
+	pdev->l1ss = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_L1SS);
+
+	rc = pci_add_ext_cap_save_buffer(pdev, PCI_EXT_CAP_ID_L1SS,
+					 2 * sizeof(u32));
+	if (rc)
+		pci_err(pdev, "unable to allocate ASPM L1SS save buffer (%pe)\n",
+			ERR_PTR(rc));
+}
+
+void pci_save_aspm_l1ss_state(struct pci_dev *pdev)
+{
+	struct pci_cap_saved_state *save_state;
+	u16 l1ss = pdev->l1ss;
+	u32 *cap;
+
+	/*
+	 * Save L1 substate configuration. The ASPM L0s/L1 configuration
+	 * in PCI_EXP_LNKCTL_ASPMC is saved by pci_save_pcie_state().
+	 */
+	if (!l1ss)
+		return;
+
+	save_state = pci_find_saved_ext_cap(pdev, PCI_EXT_CAP_ID_L1SS);
+	if (!save_state)
+		return;
+
+	cap = &save_state->cap.data[0];
+	pci_read_config_dword(pdev, l1ss + PCI_L1SS_CTL2, cap++);
+	pci_read_config_dword(pdev, l1ss + PCI_L1SS_CTL1, cap++);
+}
+
+void pci_restore_aspm_l1ss_state(struct pci_dev *pdev)
+{
+	struct pci_cap_saved_state *pl_save_state, *cl_save_state;
+	struct pci_dev *parent = pdev->bus->self;
+	u32 *cap, pl_ctl1, pl_ctl2, pl_l1_2_enable;
+	u32 cl_ctl1, cl_ctl2, cl_l1_2_enable;
+
+	/*
+	 * In case BIOS enabled L1.2 when resuming, we need to disable it first
+	 * on the downstream component before the upstream. So, don't attempt to
+	 * restore either until we are at the downstream component.
+	 */
+	if (pcie_downstream_port(pdev) || !parent)
+		return;
+
+	if (!pdev->l1ss || !parent->l1ss)
+		return;
+
+	cl_save_state = pci_find_saved_ext_cap(pdev, PCI_EXT_CAP_ID_L1SS);
+	pl_save_state = pci_find_saved_ext_cap(parent, PCI_EXT_CAP_ID_L1SS);
+	if (!cl_save_state || !pl_save_state)
+		return;
+
+	cap = &cl_save_state->cap.data[0];
+	cl_ctl2 = *cap++;
+	cl_ctl1 = *cap;
+	cap = &pl_save_state->cap.data[0];
+	pl_ctl2 = *cap++;
+	pl_ctl1 = *cap;
+
+	/*
+	 * Disable L1.2 on this downstream endpoint device first, followed
+	 * by the upstream
+	 */
+	pci_clear_and_set_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1,
+				       PCI_L1SS_CTL1_L1_2_MASK, 0);
+	pci_clear_and_set_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+				       PCI_L1SS_CTL1_L1_2_MASK, 0);
+
+	/*
+	 * In addition, Common_Mode_Restore_Time and LTR_L1.2_THRESHOLD
+	 * in PCI_L1SS_CTL1 must be programmed *before* setting the L1.2
+	 * enable bits, even though they're all in PCI_L1SS_CTL1.
+	 */
+	pl_l1_2_enable = pl_ctl1 & PCI_L1SS_CTL1_L1_2_MASK;
+	pl_ctl1 &= ~PCI_L1SS_CTL1_L1_2_MASK;
+	cl_l1_2_enable = cl_ctl1 & PCI_L1SS_CTL1_L1_2_MASK;
+	cl_ctl1 &= ~PCI_L1SS_CTL1_L1_2_MASK;
+
+	/* Write back without enables first (above we cleared them in ctl1) */
+	pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, pl_ctl2);
+	pci_write_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL2, cl_ctl2);
+	pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, pl_ctl1);
+	pci_write_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1, cl_ctl1);
+
+	/* Then write back the enables */
+	if (pl_l1_2_enable || cl_l1_2_enable) {
+		pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+				       pl_ctl1 | pl_l1_2_enable);
+		pci_write_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1,
+				       cl_ctl1 | cl_l1_2_enable);
+	}
+}
+
 #ifdef CONFIG_PCIEASPM
 
 #ifdef MODULE_PARAM_PREFIX
@@ -1005,9 +1104,6 @@ void pci_configure_ltr(struct pci_dev *pdev)
 	if (!pci_is_pcie(pdev))
 		return;
 
-	/* Read L1 PM substate capabilities */
-	pdev->l1ss = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_L1SS);
-
 	pcie_capability_read_dword(pdev, PCI_EXP_DEVCAP2, &cap);
 	if (!(cap & PCI_EXP_DEVCAP2_LTR))
 		return;
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b809c0b0e0e5..1434bf495db3 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2259,6 +2259,7 @@ static void pci_configure_device(struct pci_dev *dev)
 	pci_configure_extended_tags(dev, NULL);
 	pci_configure_relaxed_ordering(dev);
 	pci_configure_ltr(dev);
+	pci_configure_aspm_l1ss(dev);
 	pci_configure_eetlp_prefix(dev);
 	pci_configure_serr(dev);
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index add9368e6314..6967ae7b4115 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -390,9 +390,9 @@ struct pci_dev {
 	unsigned int	d3hot_delay;	/* D3hot->D0 transition time in ms */
 	unsigned int	d3cold_delay;	/* D3cold->D0 transition time in ms */
 
+	u16		l1ss;		/* L1SS Capability pointer */
 #ifdef CONFIG_PCIEASPM
 	struct pcie_link_state	*link_state;	/* ASPM link state */
-	u16		l1ss;		/* L1SS Capability pointer */
 	unsigned int	ltr_path:1;	/* Latency Tolerance Reporting
 					   supported from root to here */
 #endif
-- 
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