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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH V3 40/41] xen/arm: WORKAROUND Support kick cpus and switch to hypervisor for the exynos5
Use machine ID to know what is the current board. This value is only given
to the first CPU by the bootloader.
When the exynos 5 starts, there is only one CPU up. Xen needs to start the
secondary cpu. The latter boots in secure mode.
Theses modifications aim to be removed as soon as possible. It should
be moved either in a platform specific boot-wrapper (which will be start
before Xen), or in the bootloader (assuming U-Boot/Grub will support SMP).
Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Changes in v2:
- Add WORKAROUND keyword in the title
- Add fall-through comment when it's needed
- Setup the spis with a while loop instead of a do-while loop
---
xen/arch/arm/arm32/head.S | 19 +++++++-
xen/arch/arm/arm32/mode_switch.S | 75 +++++++++++++++++++++++-------
xen/include/asm-arm/platforms/vexpress.h | 11 +++++
3 files changed, 86 insertions(+), 19 deletions(-)
diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S
index d452b59..ec7f640 100644
--- a/xen/arch/arm/arm32/head.S
+++ b/xen/arch/arm/arm32/head.S
@@ -76,7 +76,7 @@ past_zImage:
cpsid aif /* Disable all interrupts */
/* Save the bootloader arguments in less-clobberable registers */
- /* No need to save r1 == Unused ARM-linux machine type */
+ mov r5, r1 /* r5: ARM-linux machine type */
mov r8, r2 /* r8 := DTB base address */
/* Find out where we are */
@@ -119,11 +119,25 @@ boot_cpu:
bl putn
PRINT(" booting -\r\n")
#endif
+ /* Secondary CPUs doesn't have machine ID
+ * - Store machine ID on boot CPU
+ * - Load machine ID on secondary CPUs
+ * Machine ID is needed in kick_cpus and enter_hyp_mode */
+ ldr r0, =machine_id /* VA of machine_id */
+ add r0, r0, r10 /* PA of machine_id */
+ teq r12, #0
+ streq r5, [r0] /* On boot CPU save machine ID */
+ ldrne r5, [r0] /* If non boot cpu r5 := machine ID */
/* Wake up secondary cpus */
teq r12, #0
bleq kick_cpus
+ PRINT("- Machine ID ")
+ mov r0, r5
+ bl putn
+ PRINT(" -\r\n")
+
/* Check that this CPU has Hyp mode */
mrc CP32(r0, ID_PFR1)
and r0, r0, #0xf000 /* Bits 12-15 define virt extensions */
@@ -403,6 +417,9 @@ putn: mov pc, lr
#endif /* !EARLY_PRINTK */
+/* Place holder for machine ID */
+machine_id: .word 0x0
+
/*
* Local variables:
* mode: ASM
diff --git a/xen/arch/arm/arm32/mode_switch.S b/xen/arch/arm/arm32/mode_switch.S
index d6741d0..c92a1cf 100644
--- a/xen/arch/arm/arm32/mode_switch.S
+++ b/xen/arch/arm/arm32/mode_switch.S
@@ -20,14 +20,21 @@
#include <asm/config.h>
#include <asm/page.h>
#include <asm/platforms/vexpress.h>
+#include <asm/platforms/exynos5.h>
#include <asm/asm_defns.h>
#include <asm/gic.h>
-
-/* XXX: Versatile Express specific code */
-/* wake up secondary cpus */
+/* Wake up secondary cpus
+ * This code relies on Machine ID and only works for Vexpress and the Arndale
+ * TODO: Move this code either later (via platform specific desc) or in a
bootwrapper
+ * r5: Machine ID
+ * Clobber r0 r2 */
.globl kick_cpus
kick_cpus:
+ ldr r0, =MACH_TYPE_SMDK5250
+ teq r5, r0 /* Are we running on the
arndale? */
+ beq kick_cpus_arndale
+ /* otherwise versatile express */
/* write start paddr to v2m sysreg FLAGSSET register */
ldr r0, =(V2M_SYS_MMIO_BASE) /* base V2M sysreg MMIO address
*/
dsb
@@ -38,8 +45,20 @@ kick_cpus:
add r2, r2, r10
str r2, [r0, #(V2M_SYS_FLAGSSET)]
dsb
+ ldr r2, =V2M_GIC_BASE_ADDRESS /* r2 := VE gic base address */
+ b kick_cpus_sgi
+kick_cpus_arndale:
+ /* write start paddr to CPU 1 sysreg register */
+ ldr r0, =(S5P_PA_SYSRAM)
+ ldr r2, =start
+ add r2, r2, r10
+ str r2, [r0]
+ dsb
+ ldr r2, =EXYNOS5_GIC_BASE_ADDRESS /* r2 := Exynos5 gic base
address */
+kick_cpus_sgi:
/* send an interrupt */
- ldr r0, =(GIC_BASE_ADDRESS + GIC_DR_OFFSET) /* base GICD MMIO
address */
+ ldr r0, =GIC_DR_OFFSET /* GIC distributor offset */
+ add r0, r2 /* r0 := r0 + gic base address */
mov r2, #0x1
str r2, [r0, #(GICD_CTLR * 4)] /* enable distributor */
mov r2, #0xfe0000
@@ -51,13 +70,15 @@ kick_cpus:
/* Get up a CPU into Hyp mode. Clobbers r0-r3.
*
- * Expects r12 == CPU number
+ * r5: Machine ID
+ * r12: CPU number
*
- * This code is specific to the VE model, and not intended to be used
+ * This code is specific to the VE model/Arndale, and not intended to be used
* on production systems. As such it's a bit hackier than the main
* boot code in head.S. In future it will be replaced by better
* integration with the bootloader/firmware so that Xen always starts
- * in Hyp mode. */
+ * in Hyp mode.
+ * Clobber r0 - r4 */
.globl enter_hyp_mode
enter_hyp_mode:
@@ -68,33 +89,51 @@ enter_hyp_mode:
orr r0, r0, #0xb1 /* Set SCD, AW, FW and NS */
bic r0, r0, #0xe /* Clear EA, FIQ and IRQ */
mcr CP32(r0, SCR)
+
+ ldr r2, =MACH_TYPE_SMDK5250 /* r4 := Arndale machine ID */
+ /* By default load Arndale defaults values */
+ ldr r0, =EXYNOS5_TIMER_FREQUENCY /* r0 := timer's frequency */
+ ldr r1, =EXYNOS5_GIC_BASE_ADDRESS /* r1 := GIC base address */
+ /* If it's not the Arndale machine ID, load VE values */
+ teq r5, r2
+ ldrne r0, =V2M_TIMER_FREQUENCY
+ ldrne r1, =V2M_GIC_BASE_ADDRESS
+
/* Ugly: the system timer's frequency register is only
* programmable in Secure state. Since we don't know where its
* memory-mapped control registers live, we can't find out the
- * right frequency. Use the VE model's default frequency here. */
- ldr r0, =0x5f5e100 /* 100 MHz */
+ * right frequency. */
mcr CP32(r0, CNTFRQ)
ldr r0, =0x40c00 /* SMP, c11, c10 in non-secure mode */
mcr CP32(r0, NSACR)
- mov r0, #GIC_BASE_ADDRESS
- add r0, r0, #GIC_DR_OFFSET
+
+ add r0, r1, #GIC_DR_OFFSET
/* Disable the GIC distributor, on the boot CPU only */
- mov r1, #0
+ mov r4, #0
teq r12, #0 /* Is this the boot CPU? */
- streq r1, [r0]
+ streq r4, [r0]
/* Continuing ugliness: Set up the GIC so NS state owns interrupts,
* The first 32 interrupts (SGIs & PPIs) must be configured on all
* CPUs while the remainder are SPIs and only need to be done one, on
* the boot CPU. */
add r0, r0, #0x80 /* GICD_IGROUP0 */
mov r2, #0xffffffff /* All interrupts to group 1 */
- teq r12, #0 /* Boot CPU? */
str r2, [r0] /* Interrupts 0-31 (SGI & PPI) */
- streq r2, [r0, #4] /* Interrupts 32-63 (SPI) */
- streq r2, [r0, #8] /* Interrupts 64-95 (SPI) */
+ teq r12, #0 /* Boot CPU? */
+ bne skip_spis /* Don't route SPIs on secondary CPUs */
+
+ add r4, r1, #GIC_DR_OFFSET
+ ldr r4, [r4, #4] /* r4 := Interrupt Controller Type Reg */
+ and r4, r4, #GICD_TYPE_LINES /* r4 := number of SPIs */
+1: teq r4, #0
+ beq skip_spis
+ add r0, r0, #4 /* Go to the new group */
+ str r2, [r0] /* Update the group */
+ sub r4, r4, #1
+ b 1b
+skip_spis:
/* Disable the GIC CPU interface on all processors */
- mov r0, #GIC_BASE_ADDRESS
- add r0, r0, #GIC_CR_OFFSET
+ add r0, r1, #GIC_CR_OFFSET
mov r1, #0
str r1, [r0]
/* Must drop priority mask below 0x80 before entering NS state */
diff --git a/xen/include/asm-arm/platforms/vexpress.h
b/xen/include/asm-arm/platforms/vexpress.h
index 5cf3aba..982a293 100644
--- a/xen/include/asm-arm/platforms/vexpress.h
+++ b/xen/include/asm-arm/platforms/vexpress.h
@@ -32,6 +32,17 @@
int vexpress_syscfg(int write, int function, int device, uint32_t *data);
#endif
+/* Constants below is only used in assembly because the DTS is not yet parsed
*/
+#ifdef __ASSEMBLY__
+
+/* GIC base address */
+#define V2M_GIC_BASE_ADDRESS 0x2c000000
+
+/* Timer's frequency */
+#define V2M_TIMER_FREQUENCY 0x5f5e100 /* 100 Mhz */
+
+#endif /* __ASSEMBLY__ */
+
#endif /* __ASM_ARM_PLATFORMS_VEXPRESS_H */
/*
* Local variables:
--
1.7.10.4
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