linux-stable/arch/parisc/kernel/hpmc.S
Sven Schnelle c70919bd9d parisc: Fix IVT checksum calculation wrt HPMC
On my C8000 a HPMC was triggered, but the HPMC handler wasn't called.
I got the following chassis codes:

<Cpu2> e800009802e00000  0000000000000000  CC_ERR_CHECK_HPMC
<Cpu3> e800009803e00000  00000000001b28a3  CC_ERR_CHECK_HPMC
<Cpu2> 37000f7302e00000  8400000000800000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu3> 37000f7303e00000  8400000000800000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu2> f600105e02e00000  fffffff0f0c00000  CC_MC_HPMC_MONARCH_SELECTED
<Cpu3> 5600100b03e00000  00000000000001a0  CC_MC_OS_HPMC_LEN_ERR
<Cpu2> 140003b202e00000  000000000000000b  CC_ERR_HPMC_STATE_ENTRY
<Cpu3> 5600106403e00000  fffffff0f043ad20  CC_MC_BR_TO_OS_HPMC_FAILED
<Cpu3> 160012cf03e00000  030001001e000007  CC_MPS_CPU_WAITING
<Cpu2> 5600100b02e00000  00000000000001a0  CC_MC_OS_HPMC_LEN_ERR
<Cpu2> 5600106402e00000  fffffff0f0438e70  CC_MC_BR_TO_OS_HPMC_FAILED
<Cpu2> e800009802e00000  0000000000000000  CC_ERR_CHECK_HPMC
<Cpu2> 37000f7302e00000  8400000000800000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu2> 4000109f02e00000  0000000000000000  CC_MC_HPMC_INITIATED
<Cpu2> 4000101902e00000  0000000000000000  CC_MC_MULTIPLE_HPMCS
<Cpu2> 030010d502e00000  0000000000000000  CC_CPU_STOP

C8000 PDC is complaining about our HPMC handler length, which is 1a0 (second
part of the chassis code). Changing that to 0 makes the error go away:

<Cpu0> e800009800e00000  0000000000000000  CC_ERR_CHECK_HPMC
<Cpu3> e800009803e00000  0000000000000000  CC_ERR_CHECK_HPMC
<Cpu1> e800009801e00000  0000000000000000  CC_ERR_CHECK_HPMC
<Cpu2> e800009802e00000  0000000000000000  CC_ERR_CHECK_HPMC
<Cpu0> 37000f7300e00000  8060004000000000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu3> 37000f7303e00000  8060004000000000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu1> 37000f7301e00000  8060004000000000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu2> 37000f7302e00000  8060004000000000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu0> f600105e00e00000  fffffff0f0c00000  CC_MC_HPMC_MONARCH_SELECTED
<Cpu3> 5600109b03e00000  00000000001eb024  CC_MC_BR_TO_OS_HPMC
<Cpu1> 5600109b01e00000  00000000001eb024  CC_MC_BR_TO_OS_HPMC
<Cpu2> 5600109b02e00000  00000000001eb024  CC_MC_BR_TO_OS_HPMC
<Cpu0> 140003b200e00000  000000000000000b  CC_ERR_HPMC_STATE_ENTRY
<Cpu3> 0000000003000000  0000000000000000
<Cpu1> 0000000001000000  0000000000000000
<Cpu2> 0000000002000000  0000000000000000
<Cpu0> 5600109b00e00000  00000000001eb024  CC_MC_BR_TO_OS_HPMC
<Cpu0> 0000000000000000  0000000000000000

So at least the HPMC handler is now called, but it hangs. Which isn't really
suprising, as the code has at least one comment saying it can't handle multiple
CPUs, and here the handler is called on all CPUs. And i'm not sure whether it
can handle 64 Bit.

So despite what the PDC spec says, C8000 and RP34xx/RP44xx don't want the
OS_HPMC length in the vector set, which is odd. I disassembled the firmware and
it actually looks like a Bug in PDC.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
2021-02-12 16:31:42 +01:00

291 lines
7 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* HPMC (High Priority Machine Check) handler.
*
* Copyright (C) 1999 Philipp Rumpf <prumpf@tux.org>
* Copyright (C) 1999 Hewlett-Packard (Frank Rowand)
* Copyright (C) 2000 Hewlett-Packard (John Marvin)
*/
/*
* This HPMC handler retrieves the HPMC pim data, resets IO and
* returns to the default trap handler with code set to 1 (HPMC).
* The default trap handler calls handle interruption, which
* does a stack and register dump. This at least allows kernel
* developers to get back to C code in virtual mode, where they
* have the option to examine and print values from memory that
* would help in debugging an HPMC caused by a software bug.
*
* There is more to do here:
*
* 1) On MP systems we need to synchronize processors
* before calling pdc/iodc.
* 2) We should be checking the system state and not
* returning to the fault handler if things are really
* bad.
*
*/
.level 1.1
#include <asm/assembly.h>
#include <asm/pdc.h>
#include <asm/psw.h>
#include <linux/linkage.h>
#include <linux/init.h>
/*
* stack for os_hpmc, the HPMC handler.
* buffer for IODC procedures (for the HPMC handler).
*
* IODC requires 7K byte stack. That leaves 1K byte for os_hpmc.
*/
__PAGE_ALIGNED_BSS
.align 4096
hpmc_stack:
.block 16384
#define HPMC_IODC_BUF_SIZE 0x8000
__PAGE_ALIGNED_BSS
.align 4096
hpmc_iodc_buf:
.block HPMC_IODC_BUF_SIZE
.section .bss
.align 8
hpmc_raddr:
.block 128
#define HPMC_PIM_DATA_SIZE 896 /* Enough to hold all architected 2.0 state */
.section .bss
.align 8
ENTRY(hpmc_pim_data)
.block HPMC_PIM_DATA_SIZE
END(hpmc_pim_data)
.text
.import intr_save, code
.align 16
ENTRY(os_hpmc)
.os_hpmc:
/*
* registers modified:
*
* Using callee saves registers without saving them. The
* original values are in the pim dump if we need them.
*
* r2 (rp) return pointer
* r3 address of PDCE_PROC
* r4 scratch
* r5 scratch
* r23 (arg3) procedure arg
* r24 (arg2) procedure arg
* r25 (arg1) procedure arg
* r26 (arg0) procedure arg
* r30 (sp) stack pointer
*
* registers read:
*
* r26 contains address of PDCE_PROC on entry
* r28 (ret0) return value from procedure
*/
copy arg0, %r3 /* save address of PDCE_PROC */
/*
* disable nested HPMCs
*
* Increment os_hpmc checksum to invalidate it.
* Do this before turning the PSW M bit off.
*/
mfctl %cr14, %r4
ldw 52(%r4),%r5
addi 1,%r5,%r5
stw %r5,52(%r4)
/* MP_FIXME: synchronize all processors. */
/* Setup stack pointer. */
load32 PA(hpmc_stack),sp
ldo 128(sp),sp /* leave room for arguments */
/*
* Most PDC routines require that the M bit be off.
* So turn on the Q bit and turn off the M bit.
*/
ldi PSW_SM_Q,%r4 /* PSW Q on, PSW M off */
mtctl %r4,ipsw
mtctl %r0,pcsq
mtctl %r0,pcsq
load32 PA(os_hpmc_1),%r4
mtctl %r4,pcoq
ldo 4(%r4),%r4
mtctl %r4,pcoq
rfi
nop
os_hpmc_1:
/* Call PDC_PIM to get HPMC pim info */
/*
* Note that on some newer boxes, PDC_PIM must be called
* before PDC_IO if you want IO to be reset. PDC_PIM sets
* a flag that PDC_IO examines.
*/
ldo PDC_PIM(%r0), arg0
ldo PDC_PIM_HPMC(%r0),arg1 /* Transfer HPMC data */
load32 PA(hpmc_raddr),arg2
load32 PA(hpmc_pim_data),arg3
load32 HPMC_PIM_DATA_SIZE,%r4
stw %r4,-52(sp)
ldil L%PA(os_hpmc_2), rp
bv (r3) /* call pdce_proc */
ldo R%PA(os_hpmc_2)(rp), rp
os_hpmc_2:
comib,<> 0,ret0, os_hpmc_fail
/* Reset IO by calling the hversion dependent PDC_IO routine */
ldo PDC_IO(%r0),arg0
ldo 0(%r0),arg1 /* log IO errors */
ldo 0(%r0),arg2 /* reserved */
ldo 0(%r0),arg3 /* reserved */
stw %r0,-52(sp) /* reserved */
ldil L%PA(os_hpmc_3),rp
bv (%r3) /* call pdce_proc */
ldo R%PA(os_hpmc_3)(rp),rp
os_hpmc_3:
/* FIXME? Check for errors from PDC_IO (-1 might be OK) */
/*
* Initialize the IODC console device (HPA,SPA, path etc.
* are stored on page 0.
*/
/*
* Load IODC into hpmc_iodc_buf by calling PDC_IODC.
* Note that PDC_IODC handles flushing the appropriate
* data and instruction cache lines.
*/
ldo PDC_IODC(%r0),arg0
ldo PDC_IODC_READ(%r0),arg1
load32 PA(hpmc_raddr),arg2
ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg3 /* console hpa */
ldo PDC_IODC_RI_INIT(%r0),%r4
stw %r4,-52(sp)
load32 PA(hpmc_iodc_buf),%r4
stw %r4,-56(sp)
load32 HPMC_IODC_BUF_SIZE,%r4
stw %r4,-60(sp)
ldil L%PA(os_hpmc_4),rp
bv (%r3) /* call pdce_proc */
ldo R%PA(os_hpmc_4)(rp),rp
os_hpmc_4:
comib,<> 0,ret0,os_hpmc_fail
/* Call the entry init (just loaded by PDC_IODC) */
ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg0 /* console hpa */
ldo ENTRY_INIT_MOD_DEV(%r0), arg1
ldw BOOT_CONSOLE_SPA_OFFSET(%r0),arg2 /* console spa */
depi 0,31,11,arg2 /* clear bits 21-31 */
ldo BOOT_CONSOLE_PATH_OFFSET(%r0),arg3 /* console path */
load32 PA(hpmc_raddr),%r4
stw %r4, -52(sp)
stw %r0, -56(sp) /* HV */
stw %r0, -60(sp) /* HV */
stw %r0, -64(sp) /* HV */
stw %r0, -68(sp) /* lang, must be zero */
load32 PA(hpmc_iodc_buf),%r5
ldil L%PA(os_hpmc_5),rp
bv (%r5)
ldo R%PA(os_hpmc_5)(rp),rp
os_hpmc_5:
comib,<> 0,ret0,os_hpmc_fail
/* Prepare to call intr_save */
/*
* Load kernel page directory (load into user also, since
* we don't intend to ever return to user land anyway)
*/
load32 PA(swapper_pg_dir),%r4
mtctl %r4,%cr24 /* Initialize kernel root pointer */
mtctl %r4,%cr25 /* Initialize user root pointer */
/* Clear sr4-sr7 */
mtsp %r0, %sr4
mtsp %r0, %sr5
mtsp %r0, %sr6
mtsp %r0, %sr7
tovirt_r1 %r30 /* make sp virtual */
rsm PSW_SM_Q,%r0 /* Clear Q bit */
ldi 1,%r8 /* Set trap code to "1" for HPMC */
load32 PA(intr_save),%r1
be 0(%sr7,%r1)
nop
os_hpmc_fail:
/*
* Reset the system
*
* Some systems may lockup from a broadcast reset, so try the
* hversion PDC_BROADCAST_RESET() first.
* MP_FIXME: reset all processors if more than one central bus.
*/
/* PDC_BROADCAST_RESET() */
ldo PDC_BROADCAST_RESET(%r0),arg0
ldo 0(%r0),arg1 /* do reset */
ldil L%PA(os_hpmc_6),rp
bv (%r3) /* call pdce_proc */
ldo R%PA(os_hpmc_6)(rp),rp
os_hpmc_6:
/*
* possible return values:
* -1 non-existent procedure
* -2 non-existent option
* -16 unaligned stack
*
* If call returned, do a broadcast reset.
*/
ldil L%0xfffc0000,%r4 /* IO_BROADCAST */
ldo 5(%r0),%r5
stw %r5,48(%r4) /* CMD_RESET to IO_COMMAND offset */
b .
nop
.align 16 /* make function length multiple of 16 bytes */