cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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reboot_fixups_32.c (2609B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * This is a good place to put board specific reboot fixups.
      4 *
      5 * List of supported fixups:
      6 * geode-gx1/cs5530a - Jaya Kumar <jayalk@intworks.biz>
      7 * geode-gx/lx/cs5536 - Andres Salomon <dilinger@debian.org>
      8 *
      9 */
     10
     11#include <asm/delay.h>
     12#include <linux/pci.h>
     13#include <linux/interrupt.h>
     14#include <asm/reboot_fixups.h>
     15#include <asm/msr.h>
     16#include <linux/cs5535.h>
     17
     18static void cs5530a_warm_reset(struct pci_dev *dev)
     19{
     20	/* writing 1 to the reset control register, 0x44 causes the
     21	cs5530a to perform a system warm reset */
     22	pci_write_config_byte(dev, 0x44, 0x1);
     23	udelay(50); /* shouldn't get here but be safe and spin-a-while */
     24	return;
     25}
     26
     27static void cs5536_warm_reset(struct pci_dev *dev)
     28{
     29	/* writing 1 to the LSB of this MSR causes a hard reset */
     30	wrmsrl(MSR_DIVIL_SOFT_RESET, 1ULL);
     31	udelay(50); /* shouldn't get here but be safe and spin a while */
     32}
     33
     34static void rdc321x_reset(struct pci_dev *dev)
     35{
     36	unsigned i;
     37	/* Voluntary reset the watchdog timer */
     38	outl(0x80003840, 0xCF8);
     39	/* Generate a CPU reset on next tick */
     40	i = inl(0xCFC);
     41	/* Use the minimum timer resolution */
     42	i |= 0x1600;
     43	outl(i, 0xCFC);
     44	outb(1, 0x92);
     45}
     46
     47static void ce4100_reset(struct pci_dev *dev)
     48{
     49	int i;
     50
     51	for (i = 0; i < 10; i++) {
     52		outb(0x2, 0xcf9);
     53		udelay(50);
     54	}
     55}
     56
     57struct device_fixup {
     58	unsigned int vendor;
     59	unsigned int device;
     60	void (*reboot_fixup)(struct pci_dev *);
     61};
     62
     63/*
     64 * PCI ids solely used for fixups_table go here
     65 */
     66#define PCI_DEVICE_ID_INTEL_CE4100	0x0708
     67
     68static const struct device_fixup fixups_table[] = {
     69{ PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY, cs5530a_warm_reset },
     70{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA, cs5536_warm_reset },
     71{ PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE, cs5530a_warm_reset },
     72{ PCI_VENDOR_ID_RDC, PCI_DEVICE_ID_RDC_R6030, rdc321x_reset },
     73{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CE4100, ce4100_reset },
     74};
     75
     76/*
     77 * we see if any fixup is available for our current hardware. if there
     78 * is a fixup, we call it and we expect to never return from it. if we
     79 * do return, we keep looking and then eventually fall back to the
     80 * standard mach_reboot on return.
     81 */
     82void mach_reboot_fixups(void)
     83{
     84	const struct device_fixup *cur;
     85	struct pci_dev *dev;
     86	int i;
     87
     88	/* we can be called from sysrq-B code. In such a case it is
     89	 * prohibited to dig PCI */
     90	if (in_interrupt())
     91		return;
     92
     93	for (i=0; i < ARRAY_SIZE(fixups_table); i++) {
     94		cur = &(fixups_table[i]);
     95		dev = pci_get_device(cur->vendor, cur->device, NULL);
     96		if (!dev)
     97			continue;
     98
     99		cur->reboot_fixup(dev);
    100		pci_dev_put(dev);
    101	}
    102}
    103