2020-05-27 15:53:07

by Jiaxun Yang

Subject: [PATCH] MIPS: Loongson64: Define PCI_IOBASE

PCI_IOBASE is used to create VM maps for PCI I/O ports, it is
required by generic PCI drivers to make memory mapped I/O range
work.

To deal with legacy drivers that have fixed I/O ports range we
reserved 0x10000 in PCI_IOBASE, should be enough for i8259 i8042
stuff.

Signed-off-by: Jiaxun Yang <[email protected]>
---
.../mips/include/asm/mach-loongson64/spaces.h | 8 ++++
arch/mips/loongson64/init.c | 42 ++++++++++++++++++-
2 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/mach-loongson64/spaces.h b/arch/mips/include/asm/mach-loongson64/spaces.h
index e85bc1d9c4f2..3de0ac9d8829 100644
--- a/arch/mips/include/asm/mach-loongson64/spaces.h
+++ b/arch/mips/include/asm/mach-loongson64/spaces.h
@@ -6,5 +6,13 @@
#define CAC_BASE _AC(0x9800000000000000, UL)
#endif /* CONFIG_64BIT */

+/* Skip 128k to trap NULL pointer dereferences */
+#define PCI_IOBASE _AC(0xc000000000000000 + SZ_128K, UL)
+#define PCI_IOSIZE SZ_16M
+#define MAP_BASE (PCI_IOBASE + PCI_IOSIZE)
+
+/* Reserved at the start of PCI_IOBASE for legacy drivers */
+#define MMIO_LOWER_RESERVED 0x10000
+
#include <asm/mach-generic/spaces.h>
#endif
diff --git a/arch/mips/loongson64/init.c b/arch/mips/loongson64/init.c
index 23eeb85b1abf..59ddadace83f 100644
--- a/arch/mips/loongson64/init.c
+++ b/arch/mips/loongson64/init.c
@@ -5,6 +5,7 @@
*/

#include <linux/irqchip.h>
+#include <linux/logic_pio.h>
#include <linux/memblock.h>
#include <asm/bootinfo.h>
#include <asm/traps.h>
@@ -45,8 +46,7 @@ void __init prom_init(void)
prom_init_env();

/* init base address of io space */
- set_io_port_base((unsigned long)
- ioremap(LOONGSON_PCIIO_BASE, LOONGSON_PCIIO_SIZE));
+ set_io_port_base(PCI_IOBASE);

loongson_sysconf.early_config();

@@ -63,7 +63,45 @@ void __init prom_free_prom_memory(void)
{
}

+static __init void reserve_pio_range(void)
+{
+ struct logic_pio_hwaddr *range;
+
+ range = kzalloc(sizeof(*range), GFP_ATOMIC);
+ if (!range)
+ return;
+
+ range->fwnode = &of_root->fwnode;
+ range->size = MMIO_LOWER_RESERVED;
+ range->hw_start = LOONGSON_PCIIO_BASE;
+ range->flags = LOGIC_PIO_CPU_MMIO;
+
+ if (logic_pio_register_range(range)) {
+ pr_err("Failed to reserve PIO range for legacy ISA\n");
+ goto free_range;
+ }
+
+ if (WARN(range->io_start != 0,
+ "Reserved PIO range does not start from 0\n"))
+ goto unregister;
+
+ /*
+ * i8259 would access I/O space, so mapping must be done here.
+ * Please remove it when all drivers can be managed by logic_pio.
+ */
+ ioremap_page_range(PCI_IOBASE, PCI_IOBASE + MMIO_LOWER_RESERVED,
+ LOONGSON_PCIIO_BASE,
+ pgprot_device(PAGE_KERNEL));
+
+ return;
+unregister:
+ logic_pio_unregister_range(range);
+free_range:
+ kfree(range);
+}
+
void __init arch_init_irq(void)
{
+ reserve_pio_range();
irqchip_init();
}
--
2.27.0.rc0

2020-05-28 07:48:59

by Thomas Bogendoerfer

Subject: Re: [PATCH] MIPS: Loongson64: Define PCI_IOBASE

On Wed, May 27, 2020 at 09:17:21PM +0800, Jiaxun Yang wrote:
> PCI_IOBASE is used to create VM maps for PCI I/O ports, it is
> required by generic PCI drivers to make memory mapped I/O range
> work.
>
> To deal with legacy drivers that have fixed I/O ports range we
> reserved 0x10000 in PCI_IOBASE, should be enough for i8259 i8042
> stuff.
>
> Signed-off-by: Jiaxun Yang <[email protected]>
> ---
> .../mips/include/asm/mach-loongson64/spaces.h | 8 ++++
> arch/mips/loongson64/init.c | 42 ++++++++++++++++++-
> 2 files changed, 48 insertions(+), 2 deletions(-)

that looks so much nicer, thank you for doing this. Applied to mips-next.

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]