[PATCH v3 2/2] asm-generic: Add new pci.h and use it

Stafford Horne
2022-07-18T00:41:50Z

The asm/pci.h used for many newer architectures share similar
definitions. Move the common parts to asm-generic/pci.h to allow for
sharing code.

Two things to note are:

- isa_dma_bridge_buggy, traditionally this is defined in asm/dma.h but
these architectures avoid creating that file and add the definition
to asm/pci.h.
- ARCH_GENERIC_PCI_MMAP_RESOURCE, csky does not define this so we
undefine it after including asm-generic/pci.h. Why doesn't csky
define it?
- pci_get_legacy_ide_irq, This function is only used on architectures
that support PNP. It is only maintained for arm64, in other
architectures it is removed.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/lkml/CAK8P3a0JmPeczfmMBE__vn=Jbvf=nkbpVaZCycyv40pZNCJJXQ@mail.gmail.com/
Signed-off-by: Stafford Horne <shorne@gmail.com>
---
Second note on isa_dma_bridge_buggy, this is set on x86 but it it also set in
pci/quirks.c. We discussed limiting it only to x86 though as its a general
quick triggered by pci ids I think it will be more tricky than we thought so I
will leave as is. It might be nice to move it out of asm/dma.h and into
asm/pci.h though.

Since v2:
- Nothing
Since v1:
- Remove definition of pci_get_legacy_ide_irq

arch/arm64/include/asm/pci.h | 12 +++---------
arch/csky/include/asm/pci.h | 24 ++++--------------------
arch/riscv/include/asm/pci.h | 25 +++----------------------
arch/um/include/asm/pci.h | 24 ++----------------------
include/asm-generic/pci.h | 36 ++++++++++++++++++++++++++++++++++++
5 files changed, 48 insertions(+), 73 deletions(-)
create mode 100644 include/asm-generic/pci.h

diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h
index b33ca260e3c9..1180e83712f5 100644
--- a/arch/arm64/include/asm/pci.h
+++ b/arch/arm64/include/asm/pci.h
@@ -9,7 +9,6 @@
#include <asm/io.h>

#define PCIBIOS_MIN_IO 0x1000
-#define PCIBIOS_MIN_MEM 0

/*
* Set to 1 if the kernel should re-assign all PCI bus numbers
@@ -18,9 +17,6 @@
(pci_has_flag(PCI_REASSIGN_ALL_BUS))

#define arch_can_pci_mmap_wc() 1
-#define ARCH_GENERIC_PCI_MMAP_RESOURCE 1
-
-extern int isa_dma_bridge_buggy;

#ifdef CONFIG_PCI
static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
@@ -28,11 +24,9 @@ static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
/* no legacy IRQ on arm64 */
return -ENODEV;
}
-
-static inline int pci_proc_domain(struct pci_bus *bus)
-{
- return 1;
-}
#endif /* CONFIG_PCI */

+/* Generic PCI */
+#include <asm-generic/pci.h>
+
#endif /* __ASM_PCI_H */
diff --git a/arch/csky/include/asm/pci.h b/arch/csky/include/asm/pci.h
index ebc765b1f78b..44866c1ad461 100644
--- a/arch/csky/include/asm/pci.h
+++ b/arch/csky/include/asm/pci.h
@@ -9,26 +9,10 @@

#include <asm/io.h>

-#define PCIBIOS_MIN_IO 0
-#define PCIBIOS_MIN_MEM 0
+/* Generic PCI */
+#include <asm-generic/pci.h>

-/* C-SKY shim does not initialize PCI bus */
-#define pcibios_assign_all_busses() 1
-
-extern int isa_dma_bridge_buggy;
-
-#ifdef CONFIG_PCI
-static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
-{
- /* no legacy IRQ on csky */
- return -ENODEV;
-}
-
-static inline int pci_proc_domain(struct pci_bus *bus)
-{
- /* always show the domain in /proc */
- return 1;
-}
-#endif /* CONFIG_PCI */
+/* csky doesn't use generic pci resource mapping */
+#undef ARCH_GENERIC_PCI_MMAP_RESOURCE

#endif /* __ASM_CSKY_PCI_H */
diff --git a/arch/riscv/include/asm/pci.h b/arch/riscv/include/asm/pci.h
index 7fd52a30e605..12ce8150cfb0 100644
--- a/arch/riscv/include/asm/pci.h
+++ b/arch/riscv/include/asm/pci.h
@@ -12,29 +12,7 @@

#include <asm/io.h>

-#define PCIBIOS_MIN_IO 0
-#define PCIBIOS_MIN_MEM 0
-
-/* RISC-V shim does not initialize PCI bus */
-#define pcibios_assign_all_busses() 1
-
-#define ARCH_GENERIC_PCI_MMAP_RESOURCE 1
-
-extern int isa_dma_bridge_buggy;
-
#ifdef CONFIG_PCI
-static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
-{
- /* no legacy IRQ on risc-v */
- return -ENODEV;
-}
-
-static inline int pci_proc_domain(struct pci_bus *bus)
-{
- /* always show the domain in /proc */
- return 1;
-}
-
#ifdef CONFIG_NUMA

static inline int pcibus_to_node(struct pci_bus *bus)
@@ -50,4 +28,7 @@ static inline int pcibus_to_node(struct pci_bus *bus)

#endif /* CONFIG_PCI */

+/* Generic PCI */
+#include <asm-generic/pci.h>
+
#endif /* _ASM_RISCV_PCI_H */
diff --git a/arch/um/include/asm/pci.h b/arch/um/include/asm/pci.h
index da13fd5519ef..34fe4921b5fa 100644
--- a/arch/um/include/asm/pci.h
+++ b/arch/um/include/asm/pci.h
@@ -4,28 +4,8 @@
#include <linux/types.h>
#include <asm/io.h>

-#define PCIBIOS_MIN_IO 0
-#define PCIBIOS_MIN_MEM 0
-
-#define pcibios_assign_all_busses() 1
-
-extern int isa_dma_bridge_buggy;
-
-#ifdef CONFIG_PCI
-static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
-{
- /* no legacy IRQs */
- return -ENODEV;
-}
-#endif
-
-#ifdef CONFIG_PCI_DOMAINS
-static inline int pci_proc_domain(struct pci_bus *bus)
-{
- /* always show the domain in /proc */
- return 1;
-}
-#endif /* CONFIG_PCI */
+/* Generic PCI */
+#include <asm-generic/pci.h>

#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
/*
diff --git a/include/asm-generic/pci.h b/include/asm-generic/pci.h
new file mode 100644
index 000000000000..fbc25741696a
--- /dev/null
+++ b/include/asm-generic/pci.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_GENERIC_PCI_H
+#define __ASM_GENERIC_PCI_H
+
+#include <linux/types.h>
+
+#ifndef PCIBIOS_MIN_IO
+#define PCIBIOS_MIN_IO 0
+#endif
+
+#ifndef PCIBIOS_MIN_MEM
+#define PCIBIOS_MIN_MEM 0
+#endif
+
+#ifndef pcibios_assign_all_busses
+/* For bootloaders that do not initialize the PCI bus */
+#define pcibios_assign_all_busses() 1
+#endif
+
+extern int isa_dma_bridge_buggy;
+
+/* Enable generic resource mapping code in drivers/pci/ */
+#define ARCH_GENERIC_PCI_MMAP_RESOURCE
+
+#ifdef CONFIG_PCI
+
+static inline int pci_proc_domain(struct pci_bus *bus)
+{
+ /* always show the domain in /proc */
+ return 1;
+}
+
+#endif /* CONFIG_PCI */
+
+#endif /* __ASM_GENERIC_PCI_H */
--
2.36.1