Messages in this thread | | | From | John Garry <> | Subject | Re: [PATCH v2 3/3] MIPS: Loongson64: Enable PCI_IO_VMMAP | Date | Tue, 28 Apr 2020 10:25:53 +0100 |
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On 28/04/2020 03:14, Jiaxun Yang wrote: > Finally we are able to elegantly add I/O ports for PCI host bridge > via devicetree with logic_pio. > > 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 <jiaxun.yang@flygoat.com> > --- > arch/mips/Kconfig | 1 + > .../include/asm/mach-loongson64/loongson.h | 2 ++ > arch/mips/loongson64/init.c | 34 ++++++++++++++++--- > arch/mips/loongson64/pci.c | 2 +- > 4 files changed, 34 insertions(+), 5 deletions(-) > > diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig > index 4e5308178649..1669735dacd8 100644 > --- a/arch/mips/Kconfig > +++ b/arch/mips/Kconfig > @@ -479,6 +479,7 @@ config MACH_LOONGSON64 > select I8259 > select IRQ_MIPS_CPU > select NR_CPUS_DEFAULT_64 > + select PCI_IO_VMMAP > select USE_GENERIC_EARLY_PRINTK_8250 > select SYS_HAS_CPU_LOONGSON64 > select SYS_HAS_EARLY_PRINTK > diff --git a/arch/mips/include/asm/mach-loongson64/loongson.h b/arch/mips/include/asm/mach-loongson64/loongson.h > index fde1b75c45ea..94035a47be5b 100644 > --- a/arch/mips/include/asm/mach-loongson64/loongson.h > +++ b/arch/mips/include/asm/mach-loongson64/loongson.h > @@ -86,6 +86,8 @@ extern int mach_i8259_irq(void); > #define LOONGSON_PCIIO_SIZE 0x00100000 /* 1M */ > #define LOONGSON_PCIIO_TOP (LOONGSON_PCIIO_BASE+LOONGSON_PCIIO_SIZE-1) > > +#define MMIO_LOWER_RESERVED 0x10000 > + > /* Loongson Register Bases */ > > #define LOONGSON_PCICONFIGBASE 0x00 > diff --git a/arch/mips/loongson64/init.c b/arch/mips/loongson64/init.c > index da38944471f4..4592eb2f78dd 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> > @@ -29,10 +30,6 @@ void __init prom_init(void) > fw_init_cmdline(); > prom_init_env(); > > - /* init base address of io space */ > - set_io_port_base((unsigned long) > - ioremap(LOONGSON_PCIIO_BASE, LOONGSON_PCIIO_SIZE)); > - > prom_init_numa_memory(); > > /* Hardcode to CPU UART 0 */ > @@ -46,7 +43,36 @@ 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"); > + kfree(range); > + return; > + }
I think that you should also check the range->io_start == 0 is returned here, as your code relies on that.
And I would also like to reiterate that this is somewhat fragile and relies on ordering. But I feel better than modifying common code. And I agree that the right thing to do is take care of the logic pio translations for your drivers now, as you mention, below.
Thanks, John
> + > + /* > + * 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_IO_START, PCI_IO_START + MMIO_LOWER_RESERVED, > + LOONGSON_PCIIO_BASE, > + pgprot_device(PAGE_KERNEL)); > +} > + > void __init arch_init_irq(void) > { > + reserve_pio_range(); > irqchip_init(); > } > diff --git a/arch/mips/loongson64/pci.c b/arch/mips/loongson64/pci.c > index a440a2725a20..7aecb88dd377 100644 > --- a/arch/mips/loongson64/pci.c > +++ b/arch/mips/loongson64/pci.c > @@ -37,7 +37,7 @@ extern int sbx00_acpi_init(void); > static int __init pcibios_init(void) > { > > - loongson_pci_controller.io_map_base = mips_io_port_base; > + loongson_pci_controller.io_map_base = IOPORT_RW_BASE; > loongson_pci_mem_resource.start = loongson_sysconf.pci_mem_start_addr; > loongson_pci_mem_resource.end = loongson_sysconf.pci_mem_end_addr; > >
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