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ARM: l2c: provide generic hook to intercept writes to secure registers 

When Linux is running in the non-secure world, any write to a secure
L2C register will generate an abort.  Platforms normally have to call
firmware to work around this.  Provide a hook for them to intercept
any L2C secure register write.

l2c_write_sec() avoids writes to secure registers which are already set
to the appropriate value, thus avoiding the overhead of needlessly
calling into the secure monitor.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
hifive-unleashed-5.1
Russell King 2014-03-16 17:38:08 +00:00
parent c0fe18ba30
commit 8abd259f65
2 changed files with 34 additions and 13 deletions
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5
arch/arm/include/asm/outercache.h
View File

@ -32,8 +32,11 @@ struct outer_cache_fns {
#ifdef CONFIG_OUTER_CACHE_SYNC
void (*sync)(void);
#endif
void (*set_debug)(unsigned long);
void (*resume)(void);
/* This is an ARM L2C thing */
void (*set_debug)(unsigned long);
void (*write_sec)(unsigned long, unsigned);
};
extern struct outer_cache_fns outer_cache;

42
arch/arm/mm/cache-l2x0.c
View File

@ -59,6 +59,20 @@ static inline void l2c_wait_mask(void __iomem *reg, unsigned long mask)
cpu_relax();
}
/*
* By default, we write directly to secure registers. Platforms must
* override this if they are running non-secure.
*/
static void l2c_write_sec(unsigned long val, void __iomem *base, unsigned reg)
{
if (val == readl_relaxed(base + reg))
return;
if (outer_cache.write_sec)
outer_cache.write_sec(val, reg);
else
writel_relaxed(val, base + reg);
}
/*
* This should only be called when we have a requirement that the
* register be written due to a work-around, as platforms running
@ -66,7 +80,10 @@ static inline void l2c_wait_mask(void __iomem *reg, unsigned long mask)
*/
static inline void l2c_set_debug(void __iomem *base, unsigned long val)
{
outer_cache.set_debug(val);
if (outer_cache.set_debug)
outer_cache.set_debug(val);
else
l2c_write_sec(val, base, L2X0_DEBUG_CTRL);
}
static void __l2c_op_way(void __iomem *reg)
@ -95,9 +112,7 @@ static void l2c_enable(void __iomem *base, u32 aux, unsigned num_lock)
{
unsigned long flags;
/* Only write the aux register if it needs changing */
if (readl_relaxed(base + L2X0_AUX_CTRL) != aux)
writel_relaxed(aux, base + L2X0_AUX_CTRL);
l2c_write_sec(aux, base, L2X0_AUX_CTRL);
l2c_unlock(base, num_lock);
@ -107,7 +122,7 @@ static void l2c_enable(void __iomem *base, u32 aux, unsigned num_lock)
l2c_wait_mask(base + sync_reg_offset, 1);
local_irq_restore(flags);
writel_relaxed(L2X0_CTRL_EN, base + L2X0_CTRL);
l2c_write_sec(L2X0_CTRL_EN, base, L2X0_CTRL);
}
static void l2c_disable(void)
@ -115,7 +130,7 @@ static void l2c_disable(void)
void __iomem *base = l2x0_base;
outer_cache.flush_all();
writel_relaxed(0, base + L2X0_CTRL);
l2c_write_sec(0, base, L2X0_CTRL);
dsb(st);
}
@ -139,7 +154,7 @@ static inline void cache_sync(void)
#if defined(CONFIG_PL310_ERRATA_588369) || defined(CONFIG_PL310_ERRATA_727915)
static inline void debug_writel(unsigned long val)
{
if (outer_cache.set_debug)
if (outer_cache.set_debug || outer_cache.write_sec)
l2c_set_debug(l2x0_base, val);
}
#else
@ -182,7 +197,7 @@ static void l2x0_disable(void)
raw_spin_lock_irqsave(&l2x0_lock, flags);
__l2x0_flush_all();
writel_relaxed(0, l2x0_base + L2X0_CTRL);
l2c_write_sec(0, l2x0_base, L2X0_CTRL);
dsb(st);
raw_spin_unlock_irqrestore(&l2x0_lock, flags);
}
@ -599,11 +614,11 @@ static void l2c310_resume(void)
L2X0_CACHE_ID_RTL_MASK;
if (revision >= L310_CACHE_ID_RTL_R2P0)
writel_relaxed(l2x0_saved_regs.prefetch_ctrl,
base + L2X0_PREFETCH_CTRL);
l2c_write_sec(l2x0_saved_regs.prefetch_ctrl, base,
L2X0_PREFETCH_CTRL);
if (revision >= L310_CACHE_ID_RTL_R3P0)
writel_relaxed(l2x0_saved_regs.pwr_ctrl,
base + L2X0_POWER_CTRL);
l2c_write_sec(l2x0_saved_regs.pwr_ctrl, base,
L2X0_POWER_CTRL);
l2c_enable(base, l2x0_saved_regs.aux_ctrl, 8);
}
@ -732,8 +747,11 @@ static void __init __l2c_init(const struct l2c_init_data *data,
l2x0_size = ways * (data->way_size_0 << way_size_bits);
fns = data->outer_cache;
fns.write_sec = outer_cache.write_sec;
if (data->fixup)
data->fixup(l2x0_base, cache_id, &fns);
if (fns.write_sec)
fns.set_debug = NULL;
/*
* Check if l2x0 controller is already enabled. If we are booting