xref: /openbmc/linux/arch/x86/kernel/reboot_fixups_32.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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 
16 static void cs5530a_warm_reset(struct pci_dev *dev)
17 {
18 	/* writing 1 to the reset control register, 0x44 causes the
19 	cs5530a to perform a system warm reset */
20 	pci_write_config_byte(dev, 0x44, 0x1);
21 	udelay(50); /* shouldn't get here but be safe and spin-a-while */
22 	return;
23 }
24 
25 static void cs5536_warm_reset(struct pci_dev *dev)
26 {
27 	/*
28 	 * 6.6.2.12 Soft Reset (DIVIL_SOFT_RESET)
29 	 * writing 1 to the LSB of this MSR causes a hard reset.
30 	 */
31 	wrmsrl(0x51400017, 1ULL);
32 	udelay(50); /* shouldn't get here but be safe and spin a while */
33 }
34 
35 struct device_fixup {
36 	unsigned int vendor;
37 	unsigned int device;
38 	void (*reboot_fixup)(struct pci_dev *);
39 };
40 
41 static struct device_fixup fixups_table[] = {
42 { PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY, cs5530a_warm_reset },
43 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA, cs5536_warm_reset },
44 };
45 
46 /*
47  * we see if any fixup is available for our current hardware. if there
48  * is a fixup, we call it and we expect to never return from it. if we
49  * do return, we keep looking and then eventually fall back to the
50  * standard mach_reboot on return.
51  */
52 void mach_reboot_fixups(void)
53 {
54 	struct device_fixup *cur;
55 	struct pci_dev *dev;
56 	int i;
57 
58 	/* we can be called from sysrq-B code. In such a case it is
59 	 * prohibited to dig PCI */
60 	if (in_interrupt())
61 		return;
62 
63 	for (i=0; i < ARRAY_SIZE(fixups_table); i++) {
64 		cur = &(fixups_table[i]);
65 		dev = pci_get_device(cur->vendor, cur->device, NULL);
66 		if (!dev)
67 			continue;
68 
69 		cur->reboot_fixup(dev);
70 	}
71 }
72 
73