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305a5551af
Add system_ctl_load() which can be used to load a value to a control register system wide. Refactor system_ctl_set_clear_bit() so it can handle all different request types, and also rename it to system_ctlreg_modify() Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
122 lines
2.6 KiB
C
122 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright IBM Corp. 1999, 2023
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*/
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#include <linux/irqflags.h>
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#include <linux/spinlock.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/smp.h>
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#include <linux/cache.h>
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#include <asm/abs_lowcore.h>
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#include <asm/ctlreg.h>
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/*
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* ctl_lock guards access to global control register contents which
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* are kept in the control register save area within absolute lowcore
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* at physical address zero.
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*/
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static DEFINE_SPINLOCK(system_ctl_lock);
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void system_ctlreg_lock(void)
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__acquires(&system_ctl_lock)
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{
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spin_lock(&system_ctl_lock);
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}
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void system_ctlreg_unlock(void)
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__releases(&system_ctl_lock)
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{
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spin_unlock(&system_ctl_lock);
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}
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static bool system_ctlreg_area_init __ro_after_init;
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void __init system_ctlreg_init_save_area(struct lowcore *lc)
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{
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struct lowcore *abs_lc;
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abs_lc = get_abs_lowcore();
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__local_ctl_store(0, 15, lc->cregs_save_area);
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__local_ctl_store(0, 15, abs_lc->cregs_save_area);
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put_abs_lowcore(abs_lc);
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system_ctlreg_area_init = true;
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}
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struct ctlreg_parms {
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unsigned long andval;
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unsigned long orval;
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unsigned long val;
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int request;
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int cr;
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};
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static void ctlreg_callback(void *info)
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{
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struct ctlreg_parms *pp = info;
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struct ctlreg regs[16];
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__local_ctl_store(0, 15, regs);
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if (pp->request == CTLREG_LOAD) {
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regs[pp->cr].val = pp->val;
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} else {
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regs[pp->cr].val &= pp->andval;
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regs[pp->cr].val |= pp->orval;
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}
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__local_ctl_load(0, 15, regs);
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}
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static void system_ctlreg_update(void *info)
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{
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unsigned long flags;
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if (system_state == SYSTEM_BOOTING) {
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/*
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* For very early calls do not call on_each_cpu()
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* since not everything might be setup.
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*/
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local_irq_save(flags);
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ctlreg_callback(info);
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local_irq_restore(flags);
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} else {
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on_each_cpu(ctlreg_callback, info, 1);
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}
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}
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void system_ctlreg_modify(unsigned int cr, unsigned long data, int request)
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{
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struct ctlreg_parms pp = { .cr = cr, .request = request, };
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struct lowcore *abs_lc;
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switch (request) {
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case CTLREG_SET_BIT:
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pp.orval = 1UL << data;
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pp.andval = -1UL;
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break;
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case CTLREG_CLEAR_BIT:
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pp.orval = 0;
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pp.andval = ~(1UL << data);
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break;
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case CTLREG_LOAD:
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pp.val = data;
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break;
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}
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if (system_ctlreg_area_init) {
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system_ctlreg_lock();
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abs_lc = get_abs_lowcore();
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if (request == CTLREG_LOAD) {
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abs_lc->cregs_save_area[cr].val = pp.val;
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} else {
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abs_lc->cregs_save_area[cr].val &= pp.andval;
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abs_lc->cregs_save_area[cr].val |= pp.orval;
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}
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put_abs_lowcore(abs_lc);
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system_ctlreg_update(&pp);
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system_ctlreg_unlock();
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} else {
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system_ctlreg_update(&pp);
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}
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}
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EXPORT_SYMBOL(system_ctlreg_modify);
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