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Diffstat (limited to 'arch/parisc/kernel/hpmc.S')
| -rw-r--r-- | arch/parisc/kernel/hpmc.S | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/arch/parisc/kernel/hpmc.S b/arch/parisc/kernel/hpmc.S new file mode 100644 index 0000000000..eb2e4bd670 --- /dev/null +++ b/arch/parisc/kernel/hpmc.S @@ -0,0 +1,289 @@ +/* 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. + */ + + .import toc_stack,data +#define hpmc_stack toc_stack /* re-use the TOC stack */ + +#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 */ |