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[4/4] ARM: add 32bit support to GICv3

Message ID 1418307788-17977-5-git-send-email-jean-philippe.brucker@arm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jean-Philippe Brucker Dec. 11, 2014, 2:23 p.m. UTC
Implement the system and memory-mapped register accesses in
asm/arch_gicv3.h for 32bit architectures.

This patch is a straightforward translation of the arm64 header. 64bit
accesses are done in two times and don't need atomicity: TYPER is
read-only, and the upper-word of IROUTER is always zero on 32bit
architectures.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
---
 arch/arm/include/asm/arch_gicv3.h | 182 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 182 insertions(+)
 create mode 100644 arch/arm/include/asm/arch_gicv3.h

Comments

Russell King - ARM Linux Dec. 11, 2014, 2:32 p.m. UTC | #1
On Thu, Dec 11, 2014 at 02:23:08PM +0000, Jean-Philippe Brucker wrote:
> +#ifndef __ASM_ARCH_GICV3_H
> +#define __ASM_ARCH_GICV3_H
> +
> +#ifndef __ASSEMBLY__
> +
> +#include <asm/io.h>

This should be linux/io.h

> +/* Low-level accessors */
> +
> +static inline void __maybe_unused gic_write_eoir(u32 irq)

No need for __maybe_unused with static inline.
Marc Zyngier Dec. 11, 2014, 3:40 p.m. UTC | #2
On 11/12/14 14:32, Russell King - ARM Linux wrote:
> On Thu, Dec 11, 2014 at 02:23:08PM +0000, Jean-Philippe Brucker wrote:
>> +#ifndef __ASM_ARCH_GICV3_H
>> +#define __ASM_ARCH_GICV3_H
>> +
>> +#ifndef __ASSEMBLY__
>> +
>> +#include <asm/io.h>
> 
> This should be linux/io.h

Also, you should probably move the #ifndef down to the level of the
inline functions. The #defines are perfectly usable in assembly context.

Thanks,

	M.
Jean-Philippe Brucker Dec. 11, 2014, 4:57 p.m. UTC | #3
On Thu, Dec 11, 2014 at 03:40:31PM +0000, Marc Zyngier wrote:
> On 11/12/14 14:32, Russell King - ARM Linux wrote:
> > On Thu, Dec 11, 2014 at 02:23:08PM +0000, Jean-Philippe Brucker wrote:
> >> +#ifndef __ASM_ARCH_GICV3_H
> >> +#define __ASM_ARCH_GICV3_H
> >> +
> >> +#ifndef __ASSEMBLY__
> >> +
> >> +#include <asm/io.h>
> > 
> > This should be linux/io.h
> 
> Also, you should probably move the #ifndef down to the level of the
> inline functions. The #defines are perfectly usable in assembly context.
> 

This would require a change in the definition of __ACCESS_CP15, in order
to distinguish between inlined parameter '%0' and explicit registers.
I don't see any pleasant ways to do this, apart from adding a 'reg'
argument to all those #defines.
Furthermore, all other cp15 accesses from assembly on the arm/ side seem
to use raw opcodes, instead of macro names.

Thanks,
Jean
Marc Zyngier Dec. 11, 2014, 5:23 p.m. UTC | #4
On 11/12/14 16:57, Jean-Philippe Brucker wrote:
> On Thu, Dec 11, 2014 at 03:40:31PM +0000, Marc Zyngier wrote:
>> On 11/12/14 14:32, Russell King - ARM Linux wrote:
>>> On Thu, Dec 11, 2014 at 02:23:08PM +0000, Jean-Philippe Brucker wrote:
>>>> +#ifndef __ASM_ARCH_GICV3_H
>>>> +#define __ASM_ARCH_GICV3_H
>>>> +
>>>> +#ifndef __ASSEMBLY__
>>>> +
>>>> +#include <asm/io.h>
>>>
>>> This should be linux/io.h
>>
>> Also, you should probably move the #ifndef down to the level of the
>> inline functions. The #defines are perfectly usable in assembly context.
>>
> 
> This would require a change in the definition of __ACCESS_CP15, in order
> to distinguish between inlined parameter '%0' and explicit registers.
> I don't see any pleasant ways to do this, apart from adding a 'reg'
> argument to all those #defines.
> Furthermore, all other cp15 accesses from assembly on the arm/ side seem
> to use raw opcodes, instead of macro names.

Ah, fair enough. I guess we can rework that part, should we ever support
KVM on 32bit ARMv8 CPUs...

Thanks,

	M.
diff mbox

Patch

diff --git a/arch/arm/include/asm/arch_gicv3.h b/arch/arm/include/asm/arch_gicv3.h
new file mode 100644
index 0000000..de285aa
--- /dev/null
+++ b/arch/arm/include/asm/arch_gicv3.h
@@ -0,0 +1,182 @@ 
+/*
+ * arch/arm/include/asm/arch_gicv3.h
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_ARCH_GICV3_H
+#define __ASM_ARCH_GICV3_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/io.h>
+
+#define __ACCESS_CP15(CRn, Op1, CRm, Op2)	p15, Op1, %0, CRn, CRm, Op2
+#define __ACCESS_CP15_64(Op1, CRm)		p15, Op1, %Q0, %R0, CRm
+
+#define ICC_EOIR1			__ACCESS_CP15(c12, 0, c12, 1)
+#define ICC_IAR1			__ACCESS_CP15(c12, 0, c12, 0)
+#define ICC_SGI1R			__ACCESS_CP15_64(0, c12)
+#define ICC_PMR				__ACCESS_CP15(c4, 0, c6, 0)
+#define ICC_CTLR			__ACCESS_CP15(c12, 0, c12, 4)
+#define ICC_SRE				__ACCESS_CP15(c12, 0, c12, 5)
+#define ICC_IGRPEN1			__ACCESS_CP15(c12, 0, c12, 7)
+
+#define ICC_HSRE			__ACCESS_CP15(c12, 4, c9, 5)
+
+#define ICH_VSEIR			__ACCESS_CP15(c12, 4, c9, 4)
+#define ICH_HCR				__ACCESS_CP15(c12, 4, c11, 0)
+#define ICH_VTR				__ACCESS_CP15(c12, 4, c11, 1)
+#define ICH_MISR			__ACCESS_CP15(c12, 4, c11, 2)
+#define ICH_EISR			__ACCESS_CP15(c12, 4, c11, 3)
+#define ICH_ELSR			__ACCESS_CP15(c12, 4, c11, 5)
+#define ICH_VMCR			__ACCESS_CP15(c12, 4, c11, 7)
+
+#define __LR0(x)			__ACCESS_CP15(c12, 4, c12, x)
+#define __LR8(x)			__ACCESS_CP15(c12, 4, c13, x)
+
+#define ICH_LR0				__LR0(0)
+#define ICH_LR1				__LR0(1)
+#define ICH_LR2				__LR0(2)
+#define ICH_LR3				__LR0(3)
+#define ICH_LR4				__LR0(4)
+#define ICH_LR5				__LR0(5)
+#define ICH_LR6				__LR0(6)
+#define ICH_LR7				__LR0(7)
+#define ICH_LR8				__LR8(0)
+#define ICH_LR9				__LR8(1)
+#define ICH_LR10			__LR8(2)
+#define ICH_LR11			__LR8(3)
+#define ICH_LR12			__LR8(4)
+#define ICH_LR13			__LR8(5)
+#define ICH_LR14			__LR8(6)
+#define ICH_LR15			__LR8(7)
+
+/* LR top half */
+#define __LRC0(x)			__ACCESS_CP15(c12, 4, c14, x)
+#define __LRC8(x)			__ACCESS_CP15(c12, 4, c15, x)
+
+#define ICH_LRC0			__LRC0(0)
+#define ICH_LRC1			__LRC0(1)
+#define ICH_LRC2			__LRC0(2)
+#define ICH_LRC3			__LRC0(3)
+#define ICH_LRC4			__LRC0(4)
+#define ICH_LRC5			__LRC0(5)
+#define ICH_LRC6			__LRC0(6)
+#define ICH_LRC7			__LRC0(7)
+#define ICH_LRC8			__LRC8(0)
+#define ICH_LRC9			__LRC8(1)
+#define ICH_LRC10			__LRC8(2)
+#define ICH_LRC11			__LRC8(3)
+#define ICH_LRC12			__LRC8(4)
+#define ICH_LRC13			__LRC8(5)
+#define ICH_LRC14			__LRC8(6)
+#define ICH_LRC15			__LRC8(7)
+
+#define __AP0Rx(x)			__ACCESS_CP15(c12, 4, c8, x)
+#define ICH_AP0R0			__AP0Rx(0)
+#define ICH_AP0R1			__AP0Rx(1)
+#define ICH_AP0R2			__AP0Rx(2)
+#define ICH_AP0R3			__AP0Rx(3)
+
+#define __AP1Rx(x)			__ACCESS_CP15(c12, 4, c9, x)
+#define ICH_AP1R0			__AP1Rx(0)
+#define ICH_AP1R1			__AP1Rx(1)
+#define ICH_AP1R2			__AP1Rx(2)
+#define ICH_AP1R3			__AP1Rx(3)
+
+/* Low-level accessors */
+
+static inline void __maybe_unused gic_write_eoir(u32 irq)
+{
+	asm volatile("mcr " __stringify(ICC_EOIR1) : : "r" (irq));
+	isb();
+}
+
+static inline u32 __maybe_unused gic_read_iar(void)
+{
+	u32 irqstat;
+
+	asm volatile("mrc " __stringify(ICC_IAR1) : "=r" (irqstat));
+	return irqstat;
+}
+
+static inline void __maybe_unused gic_write_pmr(u32 val)
+{
+	asm volatile("mcr " __stringify(ICC_PMR) : : "r" (val));
+	isb();
+}
+
+static inline void __maybe_unused gic_write_ctlr(u32 val)
+{
+	asm volatile("mcr " __stringify(ICC_CTLR) : : "r" (val));
+	isb();
+}
+
+static inline void __maybe_unused gic_write_grpen1(u32 val)
+{
+	asm volatile("mcr " __stringify(ICC_IGRPEN1) : : "r" (val));
+	isb();
+}
+
+static inline void __maybe_unused gic_write_sgi1r(u64 val)
+{
+	asm volatile("mcrr " __stringify(ICC_SGI1R) : : "r" (val));
+}
+
+static inline u32 __maybe_unused gic_read_sre(void)
+{
+	u32 val;
+
+	asm volatile("mrc " __stringify(ICC_SRE) : "=r" (val));
+	return val;
+}
+
+static inline void __maybe_unused gic_write_sre(u32 val)
+{
+	asm volatile("mcr " __stringify(ICC_SRE) : : "r" (val));
+	isb();
+}
+
+/*
+ * Even in 32bit systems that use LPAE, there is no guarantee that the I/O
+ * interface provides true 64bit atomic accesses, so using strd/ldrd doesn't
+ * make much sense.
+ * Moreover, 64bit I/O emulation is extremely difficult to implement on
+ * AArch32, since the syndrome register doesn't provide any information for
+ * them.
+ * Consequently, the following IO helpers use 32bit accesses.
+ *
+ * There are only two registers that need 64bit accesses in this driver:
+ * - GICD_IROUTERn, contain the affinity values associated to each interrupt.
+ *   The upper-word (aff3) will always be 0, so there is no need for a lock.
+ * - GICR_TYPER is an ID register and doesn't need atomicity.
+ */
+static void gic_write_irouter(u64 val, volatile void __iomem *addr)
+{
+	writel_relaxed((u32)val, addr);
+	writel_relaxed((u32)(val >> 32), addr + 4);
+}
+
+static inline u64 gic_read_typer(const volatile void __iomem *addr)
+{
+	u64 val;
+
+	val = readl_relaxed(addr);
+	val |= (u64)readl_relaxed(addr + 4) << 32;
+	return val;
+}
+
+#endif /* !__ASSEMBLY__ */
+#endif /* !__ASM_ARCH_GICV3_H */