Hi, Jiaxun,
On Mon, Jul 20, 2020 at 3:44 PM Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> wrote:
>
> Previously, we're hardcoding resserved ISA I/O Space in code, now
> we're processing reverved I/O via DeviceTree directly. Using the ranges
> property to determine the size and address of reserved I/O space.
Maybe it is better to reserve a default legacy io range if there is no
"isa" node in the .dts file?
Huacai
>
> Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
> ---
> arch/mips/loongson64/init.c | 85 ++++++++++++++++++++++++++-----------
> 1 file changed, 60 insertions(+), 25 deletions(-)
>
> diff --git a/arch/mips/loongson64/init.c b/arch/mips/loongson64/init.c
> index 59ddadace83f..028d7b324ec2 100644
> --- a/arch/mips/loongson64/init.c
> +++ b/arch/mips/loongson64/init.c
> @@ -7,6 +7,8 @@
> #include <linux/irqchip.h>
> #include <linux/logic_pio.h>
> #include <linux/memblock.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> #include <asm/bootinfo.h>
> #include <asm/traps.h>
> #include <asm/smp-ops.h>
> @@ -63,41 +65,74 @@ void __init prom_free_prom_memory(void)
> {
> }
>
> -static __init void reserve_pio_range(void)
> +static int __init add_legacy_isa_io(struct fwnode_handle *fwnode, phys_addr_t addr,
> + resource_size_t size)
> {
> + int ret = 0;
> struct logic_pio_hwaddr *range;
> + unsigned long vaddr;
>
> range = kzalloc(sizeof(*range), GFP_ATOMIC);
> if (!range)
> - return;
> + return -ENOMEM;
>
> - range->fwnode = &of_root->fwnode;
> - range->size = MMIO_LOWER_RESERVED;
> - range->hw_start = LOONGSON_PCIIO_BASE;
> + range->fwnode = fwnode;
> + range->size = size;
> + range->hw_start = addr;
> 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;
> + ret = logic_pio_register_range(range);
> + if (ret) {
> + kfree(range);
> + return ret;
> + }
> +
> + /* Legacy ISA must placed at the start of PCI_IOBASE */
> + if (range->io_start != 0) {
> + logic_pio_unregister_range(range);
> + kfree(range);
> + return -EINVAL;
> }
>
> - 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);
> + vaddr = PCI_IOBASE + range->io_start;
> +
> + ioremap_page_range(vaddr, vaddr + size, addr, pgprot_device(PAGE_KERNEL));
> +
> + return 0;
> +}
> +
> +static __init void reserve_pio_range(void)
> +{
> + struct device_node *np;
> +
> + for_each_node_by_name(np, "isa") {
> + struct of_pci_range range;
> + struct of_pci_range_parser parser;
> +
> + pr_info("ISA Bridge: %pOF\n", np);
> +
> + if (of_pci_range_parser_init(&parser, np)) {
> + pr_info("Failed to parse resources.\n");
> + break;
> + }
> +
> + for_each_of_pci_range(&parser, &range) {
> + switch (range.flags & IORESOURCE_TYPE_BITS) {
> + case IORESOURCE_IO:
> + pr_info(" IO 0x%016llx..0x%016llx\n",
> + range.cpu_addr,
> + range.cpu_addr + range.size - 1);
> + if (add_legacy_isa_io(&np->fwnode, range.cpu_addr, range.size))
> + pr_warn("Failed to reserve legacy IO in Logic PIO\n");
> + break;
> + case IORESOURCE_MEM:
> + pr_info(" MEM 0x%016llx..0x%016llx\n",
> + range.cpu_addr,
> + range.cpu_addr + range.size - 1);
> + break;
> + }
> + }
> + }
> }
>
> void __init arch_init_irq(void)
> --
> 2.28.0.rc1
>
