[PATCH v3 RESEND 11/17] ARM: LPAE: use 64-bit accessors for TTBR registers

From: Cyril Chemparathy <cyril@ti.com>
To: <linux@arm.linux.org.uk>
Cc: <linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <arnd@arndb.de>,
	<catalin.marinas@arm.com>, <davidb@codeaurora.org>,
	<frank.rowand@am.sony.com>, <hsweeten@visionengravers.com>,
	<linus.walleij@linaro.org>, <marc.zyngier@arm.com>,
	<nico@linaro.org>, <paul.gortmaker@windriver.com>,
	<plagnioj@jcrosoft.com>, <rabin@rab.in>, <rmallon@gmail.com>,
	<rob.herring@calxeda.com>, <sboyd@codeaurora.org>,
	<sjg@chromium.org>, <tglx@linutronix.de>, <tj@kernel.org>,
	<vincent.guittot@linaro.org>, <vitalya@ti.com>,
	<will.deacon@arm.com>, <grant.likely@secretlab.ca>,
	Cyril Chemparathy <cyril@ti.com>
Subject: [PATCH v3 RESEND 11/17] ARM: LPAE: use 64-bit accessors for TTBR registers
Date: Fri, 21 Sep 2012 11:56:09 -0400	[thread overview]
Message-ID: <1348242975-19184-12-git-send-email-cyril@ti.com> (raw)
In-Reply-To: <1348242975-19184-1-git-send-email-cyril@ti.com>

This patch adds TTBR accessor macros, and modifies cpu_get_pgd() and
the LPAE version of cpu_set_reserved_ttbr0() to use these instead.

In the process, we also fix these functions to correctly handle cases
where the physical address lies beyond the 4G limit of 32-bit addressing.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
---
 arch/arm/include/asm/proc-fns.h |   24 +++++++++++++++++++-----
 arch/arm/mm/context.c           |    9 ++-------
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/arch/arm/include/asm/proc-fns.h b/arch/arm/include/asm/proc-fns.h
index 75b5f14..2d270b8 100644
--- a/arch/arm/include/asm/proc-fns.h
+++ b/arch/arm/include/asm/proc-fns.h
@@ -116,13 +116,27 @@ extern void cpu_resume(void);
 #define cpu_switch_mm(pgd,mm) cpu_do_switch_mm(virt_to_phys(pgd),mm)
 
 #ifdef CONFIG_ARM_LPAE
+
+#define cpu_get_ttbr(nr)					\
+	({							\
+		u64 ttbr;					\
+		__asm__("mrrc	p15, " #nr ", %Q0, %R0, c2"	\
+			: "=r" (ttbr)				\
+			: : );					\
+		ttbr;						\
+	})
+
+#define cpu_set_ttbr(nr, val)					\
+	do {							\
+		u64 ttbr = val;					\
+		__asm__("mcrr	p15, " #nr ", %Q0, %R0, c2"	\
+			: : "r" (ttbr)				\
+			: "cc");				\
+	} while (0)
+
 #define cpu_get_pgd()	\
 	({						\
-		unsigned long pg, pg2;			\
-		__asm__("mrrc	p15, 0, %0, %1, c2"	\
-			: "=r" (pg), "=r" (pg2)		\
-			:				\
-			: "cc");			\
+		u64 pg = cpu_get_ttbr(0);		\
 		pg &= ~(PTRS_PER_PGD*sizeof(pgd_t)-1);	\
 		(pgd_t *)phys_to_virt(pg);		\
 	})
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index 4e07eec..f03437e 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -16,6 +16,7 @@
 #include <asm/mmu_context.h>
 #include <asm/thread_notify.h>
 #include <asm/tlbflush.h>
+#include <asm/proc-fns.h>
 
 static DEFINE_RAW_SPINLOCK(cpu_asid_lock);
 unsigned int cpu_last_asid = ASID_FIRST_VERSION;
@@ -23,17 +24,11 @@ unsigned int cpu_last_asid = ASID_FIRST_VERSION;
 #ifdef CONFIG_ARM_LPAE
 void cpu_set_reserved_ttbr0(void)
 {
-	unsigned long ttbl = __pa(swapper_pg_dir);
-	unsigned long ttbh = 0;
-
 	/*
 	 * Set TTBR0 to swapper_pg_dir which contains only global entries. The
 	 * ASID is set to 0.
 	 */
-	asm volatile(
-	"	mcrr	p15, 0, %0, %1, c2		@ set TTBR0\n"
-	:
-	: "r" (ttbl), "r" (ttbh));
+	cpu_set_ttbr(0, __pa(swapper_pg_dir));
 	isb();
 }
 #else
-- 
1.7.9.5

