arch/alpha/kernel/console.c

root/arch/alpha/kernel/console.c
// SPDX-License-Identifier: GPL-2.0
/*
 *      linux/arch/alpha/kernel/console.c
 *
 * Architecture-specific specific support for VGA device on 
 * non-0 I/O hose
 */

#include <linux/pci.h>
#include <linux/init.h>
#include <linux/tty.h>
#include <linux/console.h>
#include <linux/vt.h>
#include <asm/vga.h>
#include <asm/machvec.h>

#include "pci_impl.h"
#include "proto.h"

#ifdef CONFIG_VGA_HOSE

struct pci_controller *pci_vga_hose;
static struct resource alpha_vga = {
        .name   = "alpha-vga+",
        .flags  = IORESOURCE_IO,
        .start  = 0x3C0,
        .end    = 0x3DF
};

static struct pci_controller * __init 
default_vga_hose_select(struct pci_controller *h1, struct pci_controller *h2)
{
        if (h2->index < h1->index)
                return h2;

        return h1;
}

void __init 
locate_and_init_vga(void *(*sel_func)(void *, void *))
{
        struct pci_controller *hose = NULL;
        struct pci_dev *dev = NULL;

        /* Default the select function */
        if (!sel_func) sel_func = (void *)default_vga_hose_select;

        /* Find the console VGA device */
        for(dev=NULL; (dev=pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, dev));) {
                if (!hose)
                        hose = dev->sysdata;
                else
                        hose = sel_func(hose, dev->sysdata);
        }

        /* Did we already initialize the correct one? Is there one? */
        if (!hose || (conswitchp == &vga_con && pci_vga_hose == hose))
                return;

        /* Create a new VGA ioport resource WRT the hose it is on. */
        alpha_vga.start += hose->io_space->start;
        alpha_vga.end += hose->io_space->start;
        request_resource(hose->io_space, &alpha_vga);

        /* Set the VGA hose and init the new console. */
        pci_vga_hose = hose;
        console_lock();
        do_take_over_console(&vga_con, 0, MAX_NR_CONSOLES-1, 1);
        console_unlock();
}

void __init
find_console_vga_hose(void)
{
        u64 *pu64 = (u64 *)((u64)hwrpb + hwrpb->ctbt_offset);

        if (pu64[7] == 3) {     /* TERM_TYPE == graphics */
                struct pci_controller *hose;
                int h = (pu64[30] >> 24) & 0xff;        /* console hose # */

                /*
                 * Our hose numbering DOES match the console's, so find
                 * the right one...
                 */
                for (hose = hose_head; hose; hose = hose->next) {
                        if (hose->index == h) break;
                }

                if (hose) {
                        printk("Console graphics on hose %d\n", h);
                        pci_vga_hose = hose;
                }
        }
}

#endif
Linux
