提交 da2372c4 编写于 作者: J Julien Thierry 提交者: Xie XiuQi

irqchip/gic-v3: Factor group0 detection into functions

hulk inclusion
category: feature
bugzilla: 9291
CVE: NA

ported from https://lore.kernel.org/patchwork/patch/1037475/

--------------------------------

The code to detect whether Linux has access to group0 interrupts can
prove useful in other parts of the driver.

Provide a separate function to do this.
Signed-off-by: NJulien Thierry <julien.thierry@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NWei Li <liwei391@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
上级 e63f7221
......@@ -394,6 +394,39 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs
}
}
static u32 gic_get_pribits(void)
{
u32 pribits;
pribits = gic_read_ctlr();
pribits &= ICC_CTLR_EL1_PRI_BITS_MASK;
pribits >>= ICC_CTLR_EL1_PRI_BITS_SHIFT;
pribits++;
return pribits;
}
static bool gic_has_group0(void)
{
u32 val;
/*
* Let's find out if Group0 is under control of EL3 or not by
* setting the highest possible, non-zero priority in PMR.
*
* If SCR_EL3.FIQ is set, the priority gets shifted down in
* order for the CPU interface to set bit 7, and keep the
* actual priority in the non-secure range. In the process, it
* looses the least significant bit and the actual priority
* becomes 0x80. Reading it back returns 0, indicating that
* we're don't have access to Group0.
*/
gic_write_pmr(BIT(8 - gic_get_pribits()));
val = gic_read_pmr();
return val != 0;
}
static void __init gic_dist_init(void)
{
unsigned int i;
......@@ -535,7 +568,7 @@ static void gic_cpu_sys_reg_init(void)
u64 mpidr = cpu_logical_map(cpu);
u64 need_rss = MPIDR_RS(mpidr);
bool group0;
u32 val, pribits;
u32 pribits;
/*
* Need to check that the SRE bit has actually been set. If
......@@ -547,25 +580,9 @@ static void gic_cpu_sys_reg_init(void)
if (!gic_enable_sre())
pr_err("GIC: unable to set SRE (disabled at EL2), panic ahead\n");
pribits = gic_read_ctlr();
pribits &= ICC_CTLR_EL1_PRI_BITS_MASK;
pribits >>= ICC_CTLR_EL1_PRI_BITS_SHIFT;
pribits++;
pribits = gic_get_pribits();
/*
* Let's find out if Group0 is under control of EL3 or not by
* setting the highest possible, non-zero priority in PMR.
*
* If SCR_EL3.FIQ is set, the priority gets shifted down in
* order for the CPU interface to set bit 7, and keep the
* actual priority in the non-secure range. In the process, it
* looses the least significant bit and the actual priority
* becomes 0x80. Reading it back returns 0, indicating that
* we're don't have access to Group0.
*/
write_gicreg(BIT(8 - pribits), ICC_PMR_EL1);
val = read_gicreg(ICC_PMR_EL1);
group0 = val != 0;
group0 = gic_has_group0();
/* Set priority mask register */
write_gicreg(DEFAULT_PMR_VALUE, ICC_PMR_EL1);
......
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