mirror of https://gitee.com/openkylin/linux.git
Pull ar-k0-usage into release branch
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commit
0ace57a96b
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@ -244,28 +244,31 @@ find_initrd (void)
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static void __init
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io_port_init (void)
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{
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extern unsigned long ia64_iobase;
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unsigned long phys_iobase;
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/*
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* Set `iobase' to the appropriate address in region 6 (uncached access range).
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* Set `iobase' based on the EFI memory map or, failing that, the
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* value firmware left in ar.k0.
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*
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* The EFI memory map is the "preferred" location to get the I/O port space base,
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* rather the relying on AR.KR0. This should become more clear in future SAL
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* specs. We'll fall back to getting it out of AR.KR0 if no appropriate entry is
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* found in the memory map.
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* Note that in ia32 mode, IN/OUT instructions use ar.k0 to compute
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* the port's virtual address, so ia32_load_state() loads it with a
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* user virtual address. But in ia64 mode, glibc uses the
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* *physical* address in ar.k0 to mmap the appropriate area from
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* /dev/mem, and the inX()/outX() interfaces use MMIO. In both
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* cases, user-mode can only use the legacy 0-64K I/O port space.
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*
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* ar.k0 is not involved in kernel I/O port accesses, which can use
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* any of the I/O port spaces and are done via MMIO using the
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* virtual mmio_base from the appropriate io_space[].
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*/
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phys_iobase = efi_get_iobase();
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if (phys_iobase)
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/* set AR.KR0 since this is all we use it for anyway */
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ia64_set_kr(IA64_KR_IO_BASE, phys_iobase);
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else {
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if (!phys_iobase) {
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phys_iobase = ia64_get_kr(IA64_KR_IO_BASE);
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printk(KERN_INFO "No I/O port range found in EFI memory map, falling back "
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"to AR.KR0\n");
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printk(KERN_INFO "I/O port base = 0x%lx\n", phys_iobase);
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printk(KERN_INFO "No I/O port range found in EFI memory map, "
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"falling back to AR.KR0 (0x%lx)\n", phys_iobase);
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}
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ia64_iobase = (unsigned long) ioremap(phys_iobase, 0);
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ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
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/* setup legacy IO port space */
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io_space[0].mmio_base = ia64_iobase;
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