[PATCH AUTOSEL 6.14 30/44] PCI: Add Rockchip Vendor ID

[PATCH AUTOSEL 6.14 30/44] PCI: Add Rockchip Vendor ID

[Sasha Levin]

From: Shawn Lin <shawn.lin@rock-chips.com>

[ Upstream commit 20bbb083bbc9d3f8db390f2e35e168f1b23dae8a ]

Move PCI_VENDOR_ID_ROCKCHIP from pci_endpoint_test.c to pci_ids.h and
reuse it in pcie-rockchip-host.c.

Link: https://lore.kernel.org/r/20250218092120.2322784-2-cassel@kernel.org
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/misc/pci_endpoint_test.c            | 1 -
 drivers/pci/controller/pcie-rockchip-host.c | 2 +-
 drivers/pci/controller/pcie-rockchip.h      | 1 -
 include/linux/pci_ids.h                     | 2 ++
 4 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
index d5ac71a493865..b002740acf8d5 100644
--- a/drivers/misc/pci_endpoint_test.c
+++ b/drivers/misc/pci_endpoint_test.c
@@ -88,7 +88,6 @@
 #define PCI_DEVICE_ID_RENESAS_R8A774E1		0x0025
 #define PCI_DEVICE_ID_RENESAS_R8A779F0		0x0031
 
-#define PCI_VENDOR_ID_ROCKCHIP			0x1d87
 #define PCI_DEVICE_ID_ROCKCHIP_RK3588		0x3588
 
 static DEFINE_IDA(pci_endpoint_test_ida);
diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c
index 5adac6adc046f..6a46be17aa91b 100644
--- a/drivers/pci/controller/pcie-rockchip-host.c
+++ b/drivers/pci/controller/pcie-rockchip-host.c
@@ -367,7 +367,7 @@ static int rockchip_pcie_host_init_port(struct rockchip_pcie *rockchip)
 		}
 	}
 
-	rockchip_pcie_write(rockchip, ROCKCHIP_VENDOR_ID,
+	rockchip_pcie_write(rockchip, PCI_VENDOR_ID_ROCKCHIP,
 			    PCIE_CORE_CONFIG_VENDOR);
 	rockchip_pcie_write(rockchip,
 			    PCI_CLASS_BRIDGE_PCI_NORMAL << 8,
diff --git a/drivers/pci/controller/pcie-rockchip.h b/drivers/pci/controller/pcie-rockchip.h
index 11def598534b2..14954f43e5e9a 100644
--- a/drivers/pci/controller/pcie-rockchip.h
+++ b/drivers/pci/controller/pcie-rockchip.h
@@ -200,7 +200,6 @@
 #define AXI_WRAPPER_NOR_MSG			0xc
 
 #define PCIE_RC_SEND_PME_OFF			0x11960
-#define ROCKCHIP_VENDOR_ID			0x1d87
 #define PCIE_LINK_IS_L2(x) \
 	(((x) & PCIE_CLIENT_DEBUG_LTSSM_MASK) == PCIE_CLIENT_DEBUG_LTSSM_L2)
 #define PCIE_LINK_TRAINING_DONE(x) \
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 1a2594a38199f..2a9ca3dbaa0e9 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -2609,6 +2609,8 @@
 
 #define PCI_VENDOR_ID_ZHAOXIN		0x1d17
 
+#define PCI_VENDOR_ID_ROCKCHIP		0x1d87
+
 #define PCI_VENDOR_ID_HYGON		0x1d94
 
 #define PCI_VENDOR_ID_META		0x1d9b
-- 
2.39.5

[PATCH AUTOSEL 6.14 33/44] PCI: Enable Configuration RRS SV early

[Sasha Levin]

From: Bjorn Helgaas <bhelgaas@google.com>

[ Upstream commit 3f8c4959fc18e477801386a625e726c59f52a2c4 ]

Following a reset, a Function may respond to Config Requests with Request
Retry Status (RRS) Completion Status to indicate that it is temporarily
unable to process the Request, but will be able to process the Request in
the future (PCIe r6.0, sec 2.3.1).

If the Configuration RRS Software Visibility feature is enabled and a Root
Complex receives RRS for a config read of the Vendor ID, the Root Complex
completes the Request to the host by returning PCI_VENDOR_ID_PCI_SIG,
0x0001 (sec 2.3.2).

The Config RRS SV feature applies only to Root Ports and is not directly
related to pci_scan_bridge_extend().  Move the RRS SV enable to
set_pcie_port_type() where we handle other PCIe-specific configuration.

Link: https://lore.kernel.org/r/20250303210217.199504-1-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/probe.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 246744d8d268a..1ca47ef892c6c 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1374,8 +1374,6 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
 	pci_write_config_word(dev, PCI_BRIDGE_CONTROL,
 			      bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT);
 
-	pci_enable_rrs_sv(dev);
-
 	if ((secondary || subordinate) && !pcibios_assign_all_busses() &&
 	    !is_cardbus && !broken) {
 		unsigned int cmax, buses;
@@ -1616,6 +1614,11 @@ void set_pcie_port_type(struct pci_dev *pdev)
 	pdev->pcie_cap = pos;
 	pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
 	pdev->pcie_flags_reg = reg16;
+
+	type = pci_pcie_type(pdev);
+	if (type == PCI_EXP_TYPE_ROOT_PORT)
+		pci_enable_rrs_sv(pdev);
+
 	pci_read_config_dword(pdev, pos + PCI_EXP_DEVCAP, &pdev->devcap);
 	pdev->pcie_mpss = FIELD_GET(PCI_EXP_DEVCAP_PAYLOAD, pdev->devcap);
 
@@ -1632,7 +1635,6 @@ void set_pcie_port_type(struct pci_dev *pdev)
 	 * correctly so detect impossible configurations here and correct
 	 * the port type accordingly.
 	 */
-	type = pci_pcie_type(pdev);
 	if (type == PCI_EXP_TYPE_DOWNSTREAM) {
 		/*
 		 * If pdev claims to be downstream port but the parent
-- 
2.39.5

[PATCH AUTOSEL 6.14 35/44] PCI: Check BAR index for validity

[Sasha Levin]

From: Philipp Stanner <phasta@kernel.org>

[ Upstream commit b1a7f99967fc0c052db8e65b449c7b32b1e9177f ]

Many functions in PCI use accessor macros such as pci_resource_len(),
which take a BAR index. That index, however, is never checked for
validity, potentially resulting in undefined behavior by overflowing the
array pci_dev.resource in the macro pci_resource_n().

Since many users of those macros directly assign the accessed value to
an unsigned integer, the macros cannot be changed easily anymore to
return -EINVAL for invalid indexes. Consequently, the problem has to be
mitigated in higher layers.

Add pci_bar_index_valid(). Use it where appropriate.

Link: https://lore.kernel.org/r/20250312080634.13731-4-phasta@kernel.org
Closes: https://lore.kernel.org/all/adb53b1f-29e1-3d14-0e61-351fd2d3ff0d@linux.intel.com/
Reported-by: Bingbu Cao <bingbu.cao@linux.intel.com>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
[kwilczynski: correct if-statement condition the pci_bar_index_is_valid()
helper function uses, tidy up code comments]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: fix typo]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/devres.c | 16 ++++++++++++++--
 drivers/pci/iomap.c  | 29 +++++++++++++++++++++--------
 drivers/pci/pci.c    |  6 ++++++
 drivers/pci/pci.h    | 16 ++++++++++++++++
 4 files changed, 57 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
index 3431a7df3e0d9..d2c09589c537e 100644
--- a/drivers/pci/devres.c
+++ b/drivers/pci/devres.c
@@ -577,7 +577,7 @@ static int pcim_add_mapping_to_legacy_table(struct pci_dev *pdev,
 {
 	void __iomem **legacy_iomap_table;
 
-	if (bar >= PCI_STD_NUM_BARS)
+	if (!pci_bar_index_is_valid(bar))
 		return -EINVAL;
 
 	legacy_iomap_table = (void __iomem **)pcim_iomap_table(pdev);
@@ -622,7 +622,7 @@ static void pcim_remove_bar_from_legacy_table(struct pci_dev *pdev, int bar)
 {
 	void __iomem **legacy_iomap_table;
 
-	if (bar >= PCI_STD_NUM_BARS)
+	if (!pci_bar_index_is_valid(bar))
 		return;
 
 	legacy_iomap_table = (void __iomem **)pcim_iomap_table(pdev);
@@ -655,6 +655,9 @@ void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen)
 	void __iomem *mapping;
 	struct pcim_addr_devres *res;
 
+	if (!pci_bar_index_is_valid(bar))
+		return NULL;
+
 	res = pcim_addr_devres_alloc(pdev);
 	if (!res)
 		return NULL;
@@ -722,6 +725,9 @@ void __iomem *pcim_iomap_region(struct pci_dev *pdev, int bar,
 	int ret;
 	struct pcim_addr_devres *res;
 
+	if (!pci_bar_index_is_valid(bar))
+		return IOMEM_ERR_PTR(-EINVAL);
+
 	res = pcim_addr_devres_alloc(pdev);
 	if (!res)
 		return IOMEM_ERR_PTR(-ENOMEM);
@@ -823,6 +829,9 @@ static int _pcim_request_region(struct pci_dev *pdev, int bar, const char *name,
 	int ret;
 	struct pcim_addr_devres *res;
 
+	if (!pci_bar_index_is_valid(bar))
+		return -EINVAL;
+
 	res = pcim_addr_devres_alloc(pdev);
 	if (!res)
 		return -ENOMEM;
@@ -991,6 +1000,9 @@ void __iomem *pcim_iomap_range(struct pci_dev *pdev, int bar,
 	void __iomem *mapping;
 	struct pcim_addr_devres *res;
 
+	if (!pci_bar_index_is_valid(bar))
+		return IOMEM_ERR_PTR(-EINVAL);
+
 	res = pcim_addr_devres_alloc(pdev);
 	if (!res)
 		return IOMEM_ERR_PTR(-ENOMEM);
diff --git a/drivers/pci/iomap.c b/drivers/pci/iomap.c
index 9fb7cacc15cde..fe706ed946dfd 100644
--- a/drivers/pci/iomap.c
+++ b/drivers/pci/iomap.c
@@ -9,6 +9,8 @@
 
 #include <linux/export.h>
 
+#include "pci.h" /* for pci_bar_index_is_valid() */
+
 /**
  * pci_iomap_range - create a virtual mapping cookie for a PCI BAR
  * @dev: PCI device that owns the BAR
@@ -33,12 +35,19 @@ void __iomem *pci_iomap_range(struct pci_dev *dev,
 			      unsigned long offset,
 			      unsigned long maxlen)
 {
-	resource_size_t start = pci_resource_start(dev, bar);
-	resource_size_t len = pci_resource_len(dev, bar);
-	unsigned long flags = pci_resource_flags(dev, bar);
+	resource_size_t start, len;
+	unsigned long flags;
+
+	if (!pci_bar_index_is_valid(bar))
+		return NULL;
+
+	start = pci_resource_start(dev, bar);
+	len = pci_resource_len(dev, bar);
+	flags = pci_resource_flags(dev, bar);
 
 	if (len <= offset || !start)
 		return NULL;
+
 	len -= offset;
 	start += offset;
 	if (maxlen && len > maxlen)
@@ -77,16 +86,20 @@ void __iomem *pci_iomap_wc_range(struct pci_dev *dev,
 				 unsigned long offset,
 				 unsigned long maxlen)
 {
-	resource_size_t start = pci_resource_start(dev, bar);
-	resource_size_t len = pci_resource_len(dev, bar);
-	unsigned long flags = pci_resource_flags(dev, bar);
+	resource_size_t start, len;
+	unsigned long flags;
 
-
-	if (flags & IORESOURCE_IO)
+	if (!pci_bar_index_is_valid(bar))
 		return NULL;
 
+	start = pci_resource_start(dev, bar);
+	len = pci_resource_len(dev, bar);
+	flags = pci_resource_flags(dev, bar);
+
 	if (len <= offset || !start)
 		return NULL;
+	if (flags & IORESOURCE_IO)
+		return NULL;
 
 	len -= offset;
 	start += offset;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 869d204a70a37..da82d734d09c0 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3921,6 +3921,9 @@ EXPORT_SYMBOL(pci_enable_atomic_ops_to_root);
  */
 void pci_release_region(struct pci_dev *pdev, int bar)
 {
+	if (!pci_bar_index_is_valid(bar))
+		return;
+
 	/*
 	 * This is done for backwards compatibility, because the old PCI devres
 	 * API had a mode in which the function became managed if it had been
@@ -3965,6 +3968,9 @@ EXPORT_SYMBOL(pci_release_region);
 static int __pci_request_region(struct pci_dev *pdev, int bar,
 				const char *name, int exclusive)
 {
+	if (!pci_bar_index_is_valid(bar))
+		return -EINVAL;
+
 	if (pci_is_managed(pdev)) {
 		if (exclusive == IORESOURCE_EXCLUSIVE)
 			return pcim_request_region_exclusive(pdev, bar, name);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 01e51db8d285a..d22755de688b8 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -167,6 +167,22 @@ static inline void pci_wakeup_event(struct pci_dev *dev)
 	pm_wakeup_event(&dev->dev, 100);
 }
 
+/**
+ * pci_bar_index_is_valid - Check whether a BAR index is within valid range
+ * @bar: BAR index
+ *
+ * Protects against overflowing &struct pci_dev.resource array.
+ *
+ * Return: true for valid index, false otherwise.
+ */
+static inline bool pci_bar_index_is_valid(int bar)
+{
+	if (bar >= 0 && bar < PCI_NUM_RESOURCES)
+		return true;
+
+	return false;
+}
+
 static inline bool pci_has_subordinate(struct pci_dev *pci_dev)
 {
 	return !!(pci_dev->subordinate);
-- 
2.39.5

[PATCH AUTOSEL 6.14 36/44] PCI: vmd: Make vmd_dev::cfg_lock a raw_spinlock_t type

[Sasha Levin]

From: Ryo Takakura <ryotkkr98@gmail.com>

[ Upstream commit 18056a48669a040bef491e63b25896561ee14d90 ]

The access to the PCI config space via pci_ops::read and pci_ops::write is
a low-level hardware access. The functions can be accessed with disabled
interrupts even on PREEMPT_RT. The pci_lock is a raw_spinlock_t for this
purpose.

A spinlock_t becomes a sleeping lock on PREEMPT_RT, so it cannot be
acquired with disabled interrupts. The vmd_dev::cfg_lock is accessed in
the same context as the pci_lock.

Make vmd_dev::cfg_lock a raw_spinlock_t type so it can be used with
interrupts disabled.

This was reported as:

  BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
  Call Trace:
   rt_spin_lock+0x4e/0x130
   vmd_pci_read+0x8d/0x100 [vmd]
   pci_user_read_config_byte+0x6f/0xe0
   pci_read_config+0xfe/0x290
   sysfs_kf_bin_read+0x68/0x90

Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Acked-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
[bigeasy: reword commit message]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Link: https://lore.kernel.org/r/20250218080830.ufw3IgyX@linutronix.de
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: add back report info from
https://lore.kernel.org/lkml/20241218115951.83062-1-ryotkkr98@gmail.com/]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/controller/vmd.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 9d9596947350f..94ceec50a2b94 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -125,7 +125,7 @@ struct vmd_irq_list {
 struct vmd_dev {
 	struct pci_dev		*dev;
 
-	spinlock_t		cfg_lock;
+	raw_spinlock_t		cfg_lock;
 	void __iomem		*cfgbar;
 
 	int msix_count;
@@ -391,7 +391,7 @@ static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
 	if (!addr)
 		return -EFAULT;
 
-	spin_lock_irqsave(&vmd->cfg_lock, flags);
+	raw_spin_lock_irqsave(&vmd->cfg_lock, flags);
 	switch (len) {
 	case 1:
 		*value = readb(addr);
@@ -406,7 +406,7 @@ static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
 		ret = -EINVAL;
 		break;
 	}
-	spin_unlock_irqrestore(&vmd->cfg_lock, flags);
+	raw_spin_unlock_irqrestore(&vmd->cfg_lock, flags);
 	return ret;
 }
 
@@ -426,7 +426,7 @@ static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg,
 	if (!addr)
 		return -EFAULT;
 
-	spin_lock_irqsave(&vmd->cfg_lock, flags);
+	raw_spin_lock_irqsave(&vmd->cfg_lock, flags);
 	switch (len) {
 	case 1:
 		writeb(value, addr);
@@ -444,7 +444,7 @@ static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg,
 		ret = -EINVAL;
 		break;
 	}
-	spin_unlock_irqrestore(&vmd->cfg_lock, flags);
+	raw_spin_unlock_irqrestore(&vmd->cfg_lock, flags);
 	return ret;
 }
 
@@ -1009,7 +1009,7 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	if (features & VMD_FEAT_OFFSET_FIRST_VECTOR)
 		vmd->first_vec = 1;
 
-	spin_lock_init(&vmd->cfg_lock);
+	raw_spin_lock_init(&vmd->cfg_lock);
 	pci_set_drvdata(dev, vmd);
 	err = vmd_enable_domain(vmd, features);
 	if (err)
-- 
2.39.5

[PATCH AUTOSEL 6.14 38/44] s390/pci: Support mmap() of PCI resources except for ISM devices

[Sasha Levin]

From: Niklas Schnelle <schnelle@linux.ibm.com>

[ Upstream commit aa9f168d55dc47c0de564f7dfe0e90467c9fee71 ]

So far s390 does not allow mmap() of PCI resources to user-space via the
usual mechanisms, though it does use it for RDMA. For the PCI sysfs
resource files and /proc/bus/pci it defines neither HAVE_PCI_MMAP nor
ARCH_GENERIC_PCI_MMAP_RESOURCE. For vfio-pci s390 previously relied on
disabled VFIO_PCI_MMAP and now relies on setting pdev->non_mappable_bars
for all devices.

This is partly because access to mapped PCI resources from user-space
requires special PCI load/store memory-I/O (MIO) instructions, or the
special MMIO syscalls when these are not available. Still, such access is
possible and useful not just for RDMA, in fact not being able to mmap() PCI
resources has previously caused extra work when testing devices.

One thing that doesn't work with PCI resources mapped to user-space though
is the s390 specific virtual ISM device. Not only because the BAR size of
256 TiB prevents mapping the whole BAR but also because access requires use
of the legacy PCI instructions which are not accessible to user-space on
systems with the newer MIO PCI instructions.

Now with the pdev->non_mappable_bars flag ISM can be excluded from mapping
its resources while making this functionality available for all other PCI
devices. To this end introduce a minimal implementation of PCI_QUIRKS and
use that to set pdev->non_mappable_bars for ISM devices only. Then also set
ARCH_GENERIC_PCI_MMAP_RESOURCE to take advantage of the generic
implementation of pci_mmap_resource_range() enabling only the newer sysfs
mmap() interface. This follows the recommendation in
Documentation/PCI/sysfs-pci.rst.

Link: https://lore.kernel.org/r/20250226-vfio_pci_mmap-v7-3-c5c0f1d26efd@linux.ibm.com
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/s390/Kconfig           |  4 +---
 arch/s390/include/asm/pci.h |  3 +++
 arch/s390/pci/Makefile      |  2 +-
 arch/s390/pci/pci_fixup.c   | 23 +++++++++++++++++++++++
 drivers/s390/net/ism_drv.c  |  1 -
 include/linux/pci_ids.h     |  1 +
 6 files changed, 29 insertions(+), 5 deletions(-)
 create mode 100644 arch/s390/pci/pci_fixup.c

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 9c9ec08d78c71..e48741e001476 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -41,9 +41,6 @@ config AUDIT_ARCH
 config NO_IOPORT_MAP
 	def_bool y
 
-config PCI_QUIRKS
-	def_bool n
-
 config ARCH_SUPPORTS_UPROBES
 	def_bool y
 
@@ -258,6 +255,7 @@ config S390
 	select PCI_DOMAINS		if PCI
 	select PCI_MSI			if PCI
 	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
+	select PCI_QUIRKS		if PCI
 	select SPARSE_IRQ
 	select SWIOTLB
 	select SYSCTL_EXCEPTION_TRACE
diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 474e1f8d1d3c2..d2086af3434c0 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -11,6 +11,9 @@
 #include <asm/pci_insn.h>
 #include <asm/sclp.h>
 
+#define ARCH_GENERIC_PCI_MMAP_RESOURCE	1
+#define arch_can_pci_mmap_wc()		1
+
 #define PCIBIOS_MIN_IO		0x1000
 #define PCIBIOS_MIN_MEM		0x10000000
 
diff --git a/arch/s390/pci/Makefile b/arch/s390/pci/Makefile
index df73c5182990a..1810e0944a4ed 100644
--- a/arch/s390/pci/Makefile
+++ b/arch/s390/pci/Makefile
@@ -5,6 +5,6 @@
 
 obj-$(CONFIG_PCI)	+= pci.o pci_irq.o pci_clp.o \
 			   pci_event.o pci_debug.o pci_insn.o pci_mmio.o \
-			   pci_bus.o pci_kvm_hook.o pci_report.o
+			   pci_bus.o pci_kvm_hook.o pci_report.o pci_fixup.o
 obj-$(CONFIG_PCI_IOV)	+= pci_iov.o
 obj-$(CONFIG_SYSFS)	+= pci_sysfs.o
diff --git a/arch/s390/pci/pci_fixup.c b/arch/s390/pci/pci_fixup.c
new file mode 100644
index 0000000000000..35688b6450983
--- /dev/null
+++ b/arch/s390/pci/pci_fixup.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Exceptions for specific devices,
+ *
+ * Copyright IBM Corp. 2025
+ *
+ * Author(s):
+ *   Niklas Schnelle <schnelle@linux.ibm.com>
+ */
+#include <linux/pci.h>
+
+static void zpci_ism_bar_no_mmap(struct pci_dev *pdev)
+{
+	/*
+	 * ISM's BAR is special. Drivers written for ISM know
+	 * how to handle this but others need to be aware of their
+	 * special nature e.g. to prevent attempts to mmap() it.
+	 */
+	pdev->non_mappable_bars = 1;
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_IBM,
+			PCI_DEVICE_ID_IBM_ISM,
+			zpci_ism_bar_no_mmap);
diff --git a/drivers/s390/net/ism_drv.c b/drivers/s390/net/ism_drv.c
index 2f34761e64135..60ed70a39d2cc 100644
--- a/drivers/s390/net/ism_drv.c
+++ b/drivers/s390/net/ism_drv.c
@@ -20,7 +20,6 @@
 MODULE_DESCRIPTION("ISM driver for s390");
 MODULE_LICENSE("GPL");
 
-#define PCI_DEVICE_ID_IBM_ISM 0x04ED
 #define DRV_NAME "ism"
 
 static const struct pci_device_id ism_device_table[] = {
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 2a9ca3dbaa0e9..5bd122a9afdc6 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -518,6 +518,7 @@
 #define PCI_DEVICE_ID_IBM_ICOM_V2_ONE_PORT_RVX_ONE_PORT_MDM	0x0251
 #define PCI_DEVICE_ID_IBM_ICOM_V2_ONE_PORT_RVX_ONE_PORT_MDM_PCIE 0x0361
 #define PCI_DEVICE_ID_IBM_ICOM_FOUR_PORT_MODEL	0x252
+#define PCI_DEVICE_ID_IBM_ISM		0x04ed
 
 #define PCI_SUBVENDOR_ID_IBM		0x1014
 #define PCI_SUBDEVICE_ID_IBM_SATURN_SERIAL_ONE_PORT	0x03d4
-- 
2.39.5