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e24b15d470
Setting the genpd's struct device's name with dev_set_name() is
happening within pm_genpd_init(). If it remains NULL, things can blow up
later, such as when crafting the devfs hierarchy for the power domain:
Unable to handle kernel NULL pointer dereference at virtual address 00000000 when read
...
Call trace:
strlen from start_creating+0x90/0x138
start_creating from debugfs_create_dir+0x20/0x178
debugfs_create_dir from genpd_debug_add.part.0+0x4c/0x144
genpd_debug_add.part.0 from genpd_debug_init+0x74/0x90
genpd_debug_init from do_one_initcall+0x5c/0x244
do_one_initcall from kernel_init_freeable+0x19c/0x1f4
kernel_init_freeable from kernel_init+0x1c/0x12c
kernel_init from ret_from_fork+0x14/0x28
Bisecting tracks this crash back to commit 899f44531fe6 ("pmdomain: core:
Add GENPD_FLAG_DEV_NAME_FW flag"), which exchanges use of genpd->name
with dev_name(&genpd->dev) in genpd_debug_add.part().
Fixes: 899f44531fe6 ("pmdomain: core: Add GENPD_FLAG_DEV_NAME_FW flag")
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Cc: stable@vger.kernel.org # v6.12+
Link: https://lore.kernel.org/r/20241231190336.423172-1-lkundrak@v3.sk
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
116 lines
2.5 KiB
C
116 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* MMP PMU power island support
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*
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* Copyright (C) 2020 Lubomir Rintel <lkundrak@v3.sk>
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*/
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#include <linux/pm_domain.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#include "clk.h"
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#define to_mmp_pm_domain(genpd) container_of(genpd, struct mmp_pm_domain, genpd)
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struct mmp_pm_domain {
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struct generic_pm_domain genpd;
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void __iomem *reg;
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spinlock_t *lock;
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u32 power_on;
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u32 reset;
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u32 clock_enable;
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unsigned int flags;
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};
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static int mmp_pm_domain_power_on(struct generic_pm_domain *genpd)
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{
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struct mmp_pm_domain *pm_domain = to_mmp_pm_domain(genpd);
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unsigned long flags = 0;
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u32 val;
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if (pm_domain->lock)
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spin_lock_irqsave(pm_domain->lock, flags);
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val = readl(pm_domain->reg);
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/* Turn on the power island */
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val |= pm_domain->power_on;
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writel(val, pm_domain->reg);
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/* Disable isolation */
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val |= 0x100;
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writel(val, pm_domain->reg);
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/* Some blocks need to be reset after a power up */
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if (pm_domain->reset || pm_domain->clock_enable) {
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u32 after_power_on = val;
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val &= ~pm_domain->reset;
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writel(val, pm_domain->reg);
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val |= pm_domain->clock_enable;
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writel(val, pm_domain->reg);
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val |= pm_domain->reset;
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writel(val, pm_domain->reg);
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writel(after_power_on, pm_domain->reg);
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}
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if (pm_domain->lock)
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spin_unlock_irqrestore(pm_domain->lock, flags);
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return 0;
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}
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static int mmp_pm_domain_power_off(struct generic_pm_domain *genpd)
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{
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struct mmp_pm_domain *pm_domain = to_mmp_pm_domain(genpd);
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unsigned long flags = 0;
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u32 val;
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if (pm_domain->flags & MMP_PM_DOMAIN_NO_DISABLE)
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return 0;
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if (pm_domain->lock)
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spin_lock_irqsave(pm_domain->lock, flags);
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/* Turn off and isolate the power island. */
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val = readl(pm_domain->reg);
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val &= ~pm_domain->power_on;
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val &= ~0x100;
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writel(val, pm_domain->reg);
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if (pm_domain->lock)
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spin_unlock_irqrestore(pm_domain->lock, flags);
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return 0;
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}
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struct generic_pm_domain *mmp_pm_domain_register(const char *name,
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void __iomem *reg,
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u32 power_on, u32 reset, u32 clock_enable,
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unsigned int flags, spinlock_t *lock)
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{
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struct mmp_pm_domain *pm_domain;
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pm_domain = kzalloc(sizeof(*pm_domain), GFP_KERNEL);
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if (!pm_domain)
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return ERR_PTR(-ENOMEM);
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pm_domain->reg = reg;
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pm_domain->power_on = power_on;
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pm_domain->reset = reset;
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pm_domain->clock_enable = clock_enable;
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pm_domain->flags = flags;
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pm_domain->lock = lock;
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pm_domain->genpd.name = name;
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pm_domain->genpd.power_on = mmp_pm_domain_power_on;
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pm_domain->genpd.power_off = mmp_pm_domain_power_off;
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pm_genpd_init(&pm_domain->genpd, NULL, true);
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return &pm_domain->genpd;
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}
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