xref: /linux/arch/x86/kernel/reboot_fixups_32.c (revision 98366c20a275e957416e9516db5dcb7195b4e101)
1 /*
2  * This is a good place to put board specific reboot fixups.
3  *
4  * List of supported fixups:
5  * geode-gx1/cs5530a - Jaya Kumar <jayalk@intworks.biz>
6  * geode-gx/lx/cs5536 - Andres Salomon <dilinger@debian.org>
7  *
8  */
9 
10 #include <asm/delay.h>
11 #include <linux/pci.h>
12 #include <linux/interrupt.h>
13 #include <asm/reboot_fixups.h>
14 #include <asm/msr.h>
15 #include <asm/geode.h>
16 
17 static void cs5530a_warm_reset(struct pci_dev *dev)
18 {
19 	/* writing 1 to the reset control register, 0x44 causes the
20 	cs5530a to perform a system warm reset */
21 	pci_write_config_byte(dev, 0x44, 0x1);
22 	udelay(50); /* shouldn't get here but be safe and spin-a-while */
23 	return;
24 }
25 
26 static void cs5536_warm_reset(struct pci_dev *dev)
27 {
28 	/* writing 1 to the LSB of this MSR causes a hard reset */
29 	wrmsrl(MSR_DIVIL_SOFT_RESET, 1ULL);
30 	udelay(50); /* shouldn't get here but be safe and spin a while */
31 }
32 
33 struct device_fixup {
34 	unsigned int vendor;
35 	unsigned int device;
36 	void (*reboot_fixup)(struct pci_dev *);
37 };
38 
39 static struct device_fixup fixups_table[] = {
40 { PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY, cs5530a_warm_reset },
41 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA, cs5536_warm_reset },
42 };
43 
44 /*
45  * we see if any fixup is available for our current hardware. if there
46  * is a fixup, we call it and we expect to never return from it. if we
47  * do return, we keep looking and then eventually fall back to the
48  * standard mach_reboot on return.
49  */
50 void mach_reboot_fixups(void)
51 {
52 	struct device_fixup *cur;
53 	struct pci_dev *dev;
54 	int i;
55 
56 	/* we can be called from sysrq-B code. In such a case it is
57 	 * prohibited to dig PCI */
58 	if (in_interrupt())
59 		return;
60 
61 	for (i=0; i < ARRAY_SIZE(fixups_table); i++) {
62 		cur = &(fixups_table[i]);
63 		dev = pci_get_device(cur->vendor, cur->device, NULL);
64 		if (!dev)
65 			continue;
66 
67 		cur->reboot_fixup(dev);
68 	}
69 }
70 
71