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linux/arch/alpha/kernel/sys_mikasa.c
Lorenzo Pieralisi 814eae5982 alpha/PCI: Move pci_map_irq()/pci_swizzle() out of initdata 
The introduction of {map/swizzle}_irq() hooks in the struct pci_host_bridge
allowed to replace the pci_fixup_irqs() PCI IRQ allocation in alpha arch
PCI code with per-bridge map/swizzle functions with commit 0e4c2eeb75
("alpha/PCI: Replace pci_fixup_irqs() call with host bridge IRQ mapping
hooks").

As a side effect of converting PCI IRQ allocation to the struct
pci_host_bridge {map/swizzle}_irq() hooks mechanism, the actual PCI IRQ
allocation function (ie pci_assign_irq()) is carried out per-device in
pci_device_probe() that is called when a PCI device driver is about to be
probed.

This means that, for drivers compiled as loadable modules, the actual PCI
device IRQ allocation can now happen after the system has booted so the
struct pci_host_bridge {map/swizzle}_irq() hooks pci_assign_irq() relies on
must stay valid after the system has booted so that PCI core can carry out
PCI IRQ allocation correctly.

Most of the alpha board structures pci_map_irq() and pci_swizzle() hooks
(that are used to initialize their struct pci_host_bridge equivalent
through the alpha_mv global variable - that represents the struct
alpha_machine_vector of the running kernel) are marked as
__init/__initdata; this causes freed memory dereferences when PCI IRQ
allocation is carried out after the kernel has booted (ie when loading PCI
drivers as loadable module) because when the kernel tries to bind the PCI
device to its (module) driver, the function pci_assign_irq() is called,
that in turn retrieves the struct pci_host_bridge {map/swizzle}_irq() hooks
to carry out PCI IRQ allocation; if those hooks are marked as __init
code/__initdata they point at freed/invalid memory.

Fix the issue by removing the __init/__initdata markers from all subarch
struct alpha_machine_vector.pci_map_irq()/pci_swizzle() functions (and
data).

Fixes: 0e4c2eeb75 ("alpha/PCI: Replace pci_fixup_irqs() call with host bridge IRQ mapping hooks")
Link: http://lkml.kernel.org/r/alpine.LRH.2.21.1710251043170.7098@math.ut.ee
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Meelis Roos <mroos@linux.ee>
Cc: Matt Turner <mattst88@gmail.com>
2017-10-26 11:53:38 -05:00

248 lines
5.9 KiB
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/*
* linux/arch/alpha/kernel/sys_mikasa.c
*
* Copyright (C) 1995 David A Rusling
* Copyright (C) 1996 Jay A Estabrook
* Copyright (C) 1998, 1999 Richard Henderson
*
* Code supporting the MIKASA (AlphaServer 1000).
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <asm/ptrace.h>
#include <asm/mce.h>
#include <asm/dma.h>
#include <asm/irq.h>
#include <asm/mmu_context.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/core_apecs.h>
#include <asm/core_cia.h>
#include <asm/tlbflush.h>
#include "proto.h"
#include "irq_impl.h"
#include "pci_impl.h"
#include "machvec_impl.h"
/* Note mask bit is true for ENABLED irqs. */
static int cached_irq_mask;
static inline void
mikasa_update_irq_hw(int mask)
{
outw(mask, 0x536);
}
static inline void
mikasa_enable_irq(struct irq_data *d)
{
mikasa_update_irq_hw(cached_irq_mask |= 1 << (d->irq - 16));
}
static void
mikasa_disable_irq(struct irq_data *d)
{
mikasa_update_irq_hw(cached_irq_mask &= ~(1 << (d->irq - 16)));
}
static struct irq_chip mikasa_irq_type = {
.name = "MIKASA",
.irq_unmask = mikasa_enable_irq,
.irq_mask = mikasa_disable_irq,
.irq_mask_ack = mikasa_disable_irq,
};
static void
mikasa_device_interrupt(unsigned long vector)
{
unsigned long pld;
unsigned int i;
/* Read the interrupt summary registers */
pld = (((~inw(0x534) & 0x0000ffffUL) << 16)
| (((unsigned long) inb(0xa0)) << 8)
| inb(0x20));
/*
* Now for every possible bit set, work through them and call
* the appropriate interrupt handler.
*/
while (pld) {
i = ffz(~pld);
pld &= pld - 1; /* clear least bit set */
if (i < 16) {
isa_device_interrupt(vector);
} else {
handle_irq(i);
}
}
}
static void __init
mikasa_init_irq(void)
{
long i;
if (alpha_using_srm)
alpha_mv.device_interrupt = srm_device_interrupt;
mikasa_update_irq_hw(0);
for (i = 16; i < 32; ++i) {
irq_set_chip_and_handler(i, &mikasa_irq_type,
handle_level_irq);
irq_set_status_flags(i, IRQ_LEVEL);
}
init_i8259a_irqs();
common_init_isa_dma();
}
/*
* PCI Fixup configuration.
*
* Summary @ 0x536:
* Bit Meaning
* 0 Interrupt Line A from slot 0
* 1 Interrupt Line B from slot 0
* 2 Interrupt Line C from slot 0
* 3 Interrupt Line D from slot 0
* 4 Interrupt Line A from slot 1
* 5 Interrupt line B from slot 1
* 6 Interrupt Line C from slot 1
* 7 Interrupt Line D from slot 1
* 8 Interrupt Line A from slot 2
* 9 Interrupt Line B from slot 2
*10 Interrupt Line C from slot 2
*11 Interrupt Line D from slot 2
*12 NCR 810 SCSI
*13 Power Supply Fail
*14 Temperature Warn
*15 Reserved
*
* The device to slot mapping looks like:
*
* Slot Device
* 6 NCR SCSI controller
* 7 Intel PCI-EISA bridge chip
* 11 PCI on board slot 0
* 12 PCI on board slot 1
* 13 PCI on board slot 2
*
*
* This two layered interrupt approach means that we allocate IRQ 16 and
* above for PCI interrupts. The IRQ relates to which bit the interrupt
* comes in on. This makes interrupt processing much easier.
*/
static int
mikasa_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
{
static char irq_tab[8][5] = {
/*INT INTA INTB INTC INTD */
{16+12, 16+12, 16+12, 16+12, 16+12}, /* IdSel 17, SCSI */
{ -1, -1, -1, -1, -1}, /* IdSel 18, PCEB */
{ -1, -1, -1, -1, -1}, /* IdSel 19, ???? */
{ -1, -1, -1, -1, -1}, /* IdSel 20, ???? */
{ -1, -1, -1, -1, -1}, /* IdSel 21, ???? */
{ 16+0, 16+0, 16+1, 16+2, 16+3}, /* IdSel 22, slot 0 */
{ 16+4, 16+4, 16+5, 16+6, 16+7}, /* IdSel 23, slot 1 */
{ 16+8, 16+8, 16+9, 16+10, 16+11}, /* IdSel 24, slot 2 */
};
const long min_idsel = 6, max_idsel = 13, irqs_per_slot = 5;
return COMMON_TABLE_LOOKUP;
}
#if defined(CONFIG_ALPHA_GENERIC) || !defined(CONFIG_ALPHA_PRIMO)
static void
mikasa_apecs_machine_check(unsigned long vector, unsigned long la_ptr)
{
#define MCHK_NO_DEVSEL 0x205U
#define MCHK_NO_TABT 0x204U
struct el_common *mchk_header;
unsigned int code;
mchk_header = (struct el_common *)la_ptr;
/* Clear the error before any reporting. */
mb();
mb(); /* magic */
draina();
apecs_pci_clr_err();
wrmces(0x7);
mb();
code = mchk_header->code;
process_mcheck_info(vector, la_ptr, "MIKASA APECS",
(mcheck_expected(0)
&& (code == MCHK_NO_DEVSEL
|| code == MCHK_NO_TABT)));
}
#endif
/*
* The System Vector
*/
#if defined(CONFIG_ALPHA_GENERIC) || !defined(CONFIG_ALPHA_PRIMO)
struct alpha_machine_vector mikasa_mv __initmv = {
.vector_name = "Mikasa",
DO_EV4_MMU,
DO_DEFAULT_RTC,
DO_APECS_IO,
.machine_check = mikasa_apecs_machine_check,
.max_isa_dma_address = ALPHA_MAX_ISA_DMA_ADDRESS,
.min_io_address = DEFAULT_IO_BASE,
.min_mem_address = APECS_AND_LCA_DEFAULT_MEM_BASE,
.nr_irqs = 32,
.device_interrupt = mikasa_device_interrupt,
.init_arch = apecs_init_arch,
.init_irq = mikasa_init_irq,
.init_rtc = common_init_rtc,
.init_pci = common_init_pci,
.pci_map_irq = mikasa_map_irq,
.pci_swizzle = common_swizzle,
};
ALIAS_MV(mikasa)
#endif
#if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_PRIMO)
struct alpha_machine_vector mikasa_primo_mv __initmv = {
.vector_name = "Mikasa-Primo",
DO_EV5_MMU,
DO_DEFAULT_RTC,
DO_CIA_IO,
.machine_check = cia_machine_check,
.max_isa_dma_address = ALPHA_MAX_ISA_DMA_ADDRESS,
.min_io_address = DEFAULT_IO_BASE,
.min_mem_address = CIA_DEFAULT_MEM_BASE,
.nr_irqs = 32,
.device_interrupt = mikasa_device_interrupt,
.init_arch = cia_init_arch,
.init_irq = mikasa_init_irq,
.init_rtc = common_init_rtc,
.init_pci = cia_init_pci,
.kill_arch = cia_kill_arch,
.pci_map_irq = mikasa_map_irq,
.pci_swizzle = common_swizzle,
};
ALIAS_MV(mikasa_primo)
#endif
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