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Sebastian Andrzej Siewiorkumargala
Sebastian Andrzej Siewior
authored and
kumargala
committed
powerpc/kexec: Add support for FSL-BookE
This adds support kexec on FSL-BookE where the MMU can not be simply switched off. The code borrows the initial MMU-setup code to create the identical mapping mapping. The only difference to the original boot code is the size of the mapping(s) and the executeable address. The kexec code maps the first 2 GiB of memory in 256 MiB steps. This should work also on e500v1 boxes. SMP support is still not available. (Kumar: Added minor change to build to ifdef CONFIG_PPC_STD_MMU_64 some code that was PPC64 specific) Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
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‎arch/powerpc/Kconfig

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -351,7 +351,7 @@ config ARCH_ENABLE_MEMORY_HOTREMOVE
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config KEXEC
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bool "kexec system call (EXPERIMENTAL)"
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depends on PPC_BOOK3S && EXPERIMENTAL
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depends on (PPC_BOOK3S || (FSL_BOOKE && !SMP)) && EXPERIMENTAL
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help
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kexec is a system call that implements the ability to shutdown your
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current kernel, and to start another kernel. It is like a reboot

‎arch/powerpc/include/asm/kexec.h

Lines changed: 13 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -2,6 +2,18 @@
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#define _ASM_POWERPC_KEXEC_H
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#ifdef __KERNEL__
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#ifdef CONFIG_FSL_BOOKE
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/*
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* On FSL-BookE we setup a 1:1 mapping which covers the first 2GiB of memory
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* and therefore we can only deal with memory within this range
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*/
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#define KEXEC_SOURCE_MEMORY_LIMIT (2 * 1024 * 1024 * 1024UL)
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#define KEXEC_DESTINATION_MEMORY_LIMIT (2 * 1024 * 1024 * 1024UL)
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#define KEXEC_CONTROL_MEMORY_LIMIT (2 * 1024 * 1024 * 1024UL)
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#else
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/*
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* Maximum page that is mapped directly into kernel memory.
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* XXX: Since we copy virt we can use any page we allocate
@@ -21,6 +33,7 @@
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/* TASK_SIZE, probably left over from use_mm ?? */
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#define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
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#endif
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#endif
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#define KEXEC_CONTROL_PAGE_SIZE 4096
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‎arch/powerpc/kernel/crash.c

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -163,6 +163,7 @@ static void crash_kexec_prepare_cpus(int cpu)
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}
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/* wait for all the CPUs to hit real mode but timeout if they don't come in */
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#ifdef CONFIG_PPC_STD_MMU_64
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static void crash_kexec_wait_realmode(int cpu)
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{
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unsigned int msecs;
@@ -187,6 +188,7 @@ static void crash_kexec_wait_realmode(int cpu)
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}
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mb();
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}
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#endif
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/*
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* This function will be called by secondary cpus or by kexec cpu
@@ -445,7 +447,9 @@ void default_machine_crash_shutdown(struct pt_regs *regs)
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crash_kexec_prepare_cpus(crashing_cpu);
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cpu_set(crashing_cpu, cpus_in_crash);
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crash_kexec_stop_spus();
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#ifdef CONFIG_PPC_STD_MMU_64
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crash_kexec_wait_realmode(crashing_cpu);
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#endif
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if (ppc_md.kexec_cpu_down)
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ppc_md.kexec_cpu_down(1, 0);
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}

‎arch/powerpc/kernel/fsl_booke_entry_mapping.S

Lines changed: 37 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -159,6 +159,8 @@ skpinv: addi r6,r6,1 /* Increment */
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#define M_IF_SMP 0
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#endif
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#if defined(ENTRY_MAPPING_BOOT_SETUP)
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/* 6. Setup KERNELBASE mapping in TLB1[0] */
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lis r6,0x1000 /* Set MAS0(TLBSEL) = TLB1(1), ESEL = 0 */
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mtspr SPRN_MAS0,r6
@@ -174,6 +176,41 @@ skpinv: addi r6,r6,1 /* Increment */
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/* 7. Jump to KERNELBASE mapping */
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lis r6,(KERNELBASE & ~0xfff)@h
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ori r6,r6,(KERNELBASE & ~0xfff)@l
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#elif defined(ENTRY_MAPPING_KEXEC_SETUP)
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/*
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* 6. Setup a 1:1 mapping in TLB1. Esel 0 is unsued, 1 or 2 contains the tmp
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* mapping so we start at 3. We setup 8 mappings, each 256MiB in size. This
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* will cover the first 2GiB of memory.
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*/
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lis r10, (MAS1_VALID|MAS1_IPROT)@h
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ori r10,r10, (MAS1_TSIZE(BOOK3E_PAGESZ_256M))@l
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li r11, 0
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li r0, 8
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mtctr r0
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next_tlb_setup:
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addi r0, r11, 3
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rlwinm r0, r0, 16, 4, 15 // Compute esel
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rlwinm r9, r11, 28, 0, 3 // Compute [ER]PN
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oris r0, r0, (MAS0_TLBSEL(1))@h
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mtspr SPRN_MAS0,r0
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mtspr SPRN_MAS1,r10
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mtspr SPRN_MAS2,r9
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ori r9, r9, (MAS3_SX|MAS3_SW|MAS3_SR)
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mtspr SPRN_MAS3,r9
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tlbwe
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addi r11, r11, 1
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bdnz+ next_tlb_setup
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/* 7. Jump to our 1:1 mapping */
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li r6, 0
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#else
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#error You need to specify the mapping or not use this at all.
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#endif
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lis r7,MSR_KERNEL@h
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ori r7,r7,MSR_KERNEL@l
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bl 1f /* Find our address */

‎arch/powerpc/kernel/head_fsl_booke.S

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -95,7 +95,9 @@ _ENTRY(_start);
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_ENTRY(__early_start)
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#define ENTRY_MAPPING_BOOT_SETUP
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#include "fsl_booke_entry_mapping.S"
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#undef ENTRY_MAPPING_BOOT_SETUP
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/* Establish the interrupt vector offsets */
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SET_IVOR(0, CriticalInput);

‎arch/powerpc/kernel/misc_32.S

Lines changed: 17 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -711,6 +711,22 @@ relocate_new_kernel:
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/* r4 = reboot_code_buffer */
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/* r5 = start_address */
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#ifdef CONFIG_FSL_BOOKE
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mr r29, r3
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mr r30, r4
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mr r31, r5
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#define ENTRY_MAPPING_KEXEC_SETUP
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#include "fsl_booke_entry_mapping.S"
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#undef ENTRY_MAPPING_KEXEC_SETUP
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mr r3, r29
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mr r4, r30
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mr r5, r31
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li r0, 0
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#else
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li r0, 0
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/*
@@ -727,6 +743,7 @@ relocate_new_kernel:
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rfi
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1:
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#endif
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/* from this point address translation is turned off */
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/* and interrupts are disabled */
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