Commit 8abd259f authored by Russell King's avatar Russell King
Browse files

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: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent c0fe18ba

arch/arm/include/asm/outercache.h

+4 −1
Original line number Diff line number Diff line
@@ -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;

arch/arm/mm/cache-l2x0.c

+30 −12
Original line number Diff line number Diff line
@@ -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)

{

	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

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