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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/arm/mach-mvebu/coherency_ll.S
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
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+/*
+ * Coherency fabric: low level functions
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * This file implements the assembly function to add a CPU to the
+ * coherency fabric. This function is called by each of the secondary
+ * CPUs during their early boot in an SMP kernel, this why this
+ * function have to callable from assembly. It can also be called by a
+ * primary CPU from C code during its boot.
+ */
+
+#include <linux/linkage.h>
+#define ARMADA_XP_CFB_CTL_REG_OFFSET 0x0
+#define ARMADA_XP_CFB_CFG_REG_OFFSET 0x4
+
+#include <asm/assembler.h>
+#include <asm/cp15.h>
+
+ .text
+/*
+ * Returns the coherency base address in r1 (r0 is untouched), or 0 if
+ * the coherency fabric is not enabled.
+ */
+ENTRY(ll_get_coherency_base)
+ mrc p15, 0, r1, c1, c0, 0
+ tst r1, #CR_M @ Check MMU bit enabled
+ bne 1f
+
+ /*
+ * MMU is disabled, use the physical address of the coherency
+ * base address. However, if the coherency fabric isn't mapped
+ * (i.e its virtual address is zero), it means coherency is
+ * not enabled, so we return 0.
+ */
+ ldr r1, =coherency_base
+ cmp r1, #0
+ beq 2f
+ adr r1, 3f
+ ldr r3, [r1]
+ ldr r1, [r1, r3]
+ b 2f
+1:
+ /*
+ * MMU is enabled, use the virtual address of the coherency
+ * base address.
+ */
+ ldr r1, =coherency_base
+ ldr r1, [r1]
+2:
+ ret lr
+ENDPROC(ll_get_coherency_base)
+
+/*
+ * Returns the coherency CPU mask in r3 (r0 is untouched). This
+ * coherency CPU mask can be used with the coherency fabric
+ * configuration and control registers. Note that the mask is already
+ * endian-swapped as appropriate so that the calling functions do not
+ * have to care about endianness issues while accessing the coherency
+ * fabric registers
+ */
+ENTRY(ll_get_coherency_cpumask)
+ mrc 15, 0, r3, cr0, cr0, 5
+ and r3, r3, #15
+ mov r2, #(1 << 24)
+ lsl r3, r2, r3
+ARM_BE8(rev r3, r3)
+ ret lr
+ENDPROC(ll_get_coherency_cpumask)
+
+/*
+ * ll_add_cpu_to_smp_group(), ll_enable_coherency() and
+ * ll_disable_coherency() use the strex/ldrex instructions while the
+ * MMU can be disabled. The Armada XP SoC has an exclusive monitor
+ * that tracks transactions to Device and/or SO memory and thanks to
+ * that, exclusive transactions are functional even when the MMU is
+ * disabled.
+ */
+
+ENTRY(ll_add_cpu_to_smp_group)
+ /*
+ * As r0 is not modified by ll_get_coherency_base() and
+ * ll_get_coherency_cpumask(), we use it to temporarly save lr
+ * and avoid it being modified by the branch and link
+ * calls. This function is used very early in the secondary
+ * CPU boot, and no stack is available at this point.
+ */
+ mov r0, lr
+ bl ll_get_coherency_base
+ /* Bail out if the coherency is not enabled */
+ cmp r1, #0
+ reteq r0
+ bl ll_get_coherency_cpumask
+ mov lr, r0
+ add r0, r1, #ARMADA_XP_CFB_CFG_REG_OFFSET
+1:
+ ldrex r2, [r0]
+ orr r2, r2, r3
+ strex r1, r2, [r0]
+ cmp r1, #0
+ bne 1b
+ ret lr
+ENDPROC(ll_add_cpu_to_smp_group)
+
+ENTRY(ll_enable_coherency)
+ /*
+ * As r0 is not modified by ll_get_coherency_base() and
+ * ll_get_coherency_cpumask(), we use it to temporarly save lr
+ * and avoid it being modified by the branch and link
+ * calls. This function is used very early in the secondary
+ * CPU boot, and no stack is available at this point.
+ */
+ mov r0, lr
+ bl ll_get_coherency_base
+ /* Bail out if the coherency is not enabled */
+ cmp r1, #0
+ reteq r0
+ bl ll_get_coherency_cpumask
+ mov lr, r0
+ add r0, r1, #ARMADA_XP_CFB_CTL_REG_OFFSET
+1:
+ ldrex r2, [r0]
+ orr r2, r2, r3
+ strex r1, r2, [r0]
+ cmp r1, #0
+ bne 1b
+ dsb
+ mov r0, #0
+ ret lr
+ENDPROC(ll_enable_coherency)
+
+ENTRY(ll_disable_coherency)
+ /*
+ * As r0 is not modified by ll_get_coherency_base() and
+ * ll_get_coherency_cpumask(), we use it to temporarly save lr
+ * and avoid it being modified by the branch and link
+ * calls. This function is used very early in the secondary
+ * CPU boot, and no stack is available at this point.
+ */
+ mov r0, lr
+ bl ll_get_coherency_base
+ /* Bail out if the coherency is not enabled */
+ cmp r1, #0
+ reteq r0
+ bl ll_get_coherency_cpumask
+ mov lr, r0
+ add r0, r1, #ARMADA_XP_CFB_CTL_REG_OFFSET
+1:
+ ldrex r2, [r0]
+ bic r2, r2, r3
+ strex r1, r2, [r0]
+ cmp r1, #0
+ bne 1b
+ dsb
+ ret lr
+ENDPROC(ll_disable_coherency)
+
+ .align 2
+3:
+ .long coherency_phys_base - .