Commit 6000fc4d authored by Stuart Menefy's avatar Stuart Menefy Committed by Paul Mundt
Browse files

sh: Fixes some write posting issues in the interrupt handling for SH 



It is possible for the CPU to re-enable it's interrupt block bit
before the write to the interrupt controller has actually masked out
the external interupt at the controller. We get around this by
reading back from the interrupt controller which will ensure the
write has happened.

Signed-off-by: default avatarStuart Menefy <stuart.menefy@st.com>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent bd4fb4d4

arch/sh/kernel/cpu/irq/ipr.c

+1 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ static void disable_ipr_irq(unsigned int irq) 
	unsigned long addr = get_ipr_desc(irq)->ipr_offsets[p->ipr_idx];

	/* Set the priority in IPR to 0 */

	__raw_writew(__raw_readw(addr) & (0xffff ^ (0xf << p->shift)), addr);

	(void)__raw_readw(addr);	/* Read back to flush write posting */

}



static void enable_ipr_irq(unsigned int irq)

drivers/sh/intc.c

+7 −1
Original line number Diff line number Diff line
@@ -77,7 +77,7 @@ static unsigned long ack_handle[NR_IRQS]; 
static inline struct intc_desc_int *get_intc_desc(unsigned int irq)

{

	struct irq_chip *chip = get_irq_chip(irq);

	return (void *)((char *)chip - offsetof(struct intc_desc_int, chip));

	return container_of(chip, struct intc_desc_int, chip);

}



static inline unsigned int set_field(unsigned int value,
@@ -95,16 +95,19 @@ static inline unsigned int set_field(unsigned int value, 
static void write_8(unsigned long addr, unsigned long h, unsigned long data)

{

	__raw_writeb(set_field(0, data, h), addr);

	(void)__raw_readb(addr);	/* Defeat write posting */

}



static void write_16(unsigned long addr, unsigned long h, unsigned long data)

{

	__raw_writew(set_field(0, data, h), addr);

	(void)__raw_readw(addr);	/* Defeat write posting */

}



static void write_32(unsigned long addr, unsigned long h, unsigned long data)

{

	__raw_writel(set_field(0, data, h), addr);

	(void)__raw_readl(addr);	/* Defeat write posting */

}



static void modify_8(unsigned long addr, unsigned long h, unsigned long data)
@@ -112,6 +115,7 @@ static void modify_8(unsigned long addr, unsigned long h, unsigned long data) 
	unsigned long flags;

	local_irq_save(flags);

	__raw_writeb(set_field(__raw_readb(addr), data, h), addr);

	(void)__raw_readb(addr);	/* Defeat write posting */

	local_irq_restore(flags);

}
@@ -120,6 +124,7 @@ static void modify_16(unsigned long addr, unsigned long h, unsigned long data) 
	unsigned long flags;

	local_irq_save(flags);

	__raw_writew(set_field(__raw_readw(addr), data, h), addr);

	(void)__raw_readw(addr);	/* Defeat write posting */

	local_irq_restore(flags);

}
@@ -128,6 +133,7 @@ static void modify_32(unsigned long addr, unsigned long h, unsigned long data) 
	unsigned long flags;

	local_irq_save(flags);

	__raw_writel(set_field(__raw_readl(addr), data, h), addr);

	(void)__raw_readl(addr);	/* Defeat write posting */

	local_irq_restore(flags);

}

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