| Message ID | 1270412343-19334-4-git-send-email-sebastian@breakpoint.cc (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Kumar Gala |
| Headers | show |
On Apr 4, 2010, at 3:19 PM, Sebastian Andrzej Siewior wrote: > From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > > 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. > > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > --- > arch/powerpc/Kconfig | 2 +- > arch/powerpc/include/asm/kexec.h | 13 +++++++++ > arch/powerpc/kernel/fsl_booke_entry_mapping.S | 37 +++++++++++++++++++++++++ > arch/powerpc/kernel/head_fsl_booke.S | 2 + > arch/powerpc/kernel/misc_32.S | 17 +++++++++++ > 5 files changed, 70 insertions(+), 1 deletions(-) Can you explain this a bit more. Mostly would like to have a brief description of the sequence of events as part of the commit message. Something like: * Running kernel calls machine_kexec() * machine_kexec_32() * jump to relocate code * relocate clears out TLBs and sets up 2g mapping ... what I have above might not be quite right. - k
* Kumar Gala | 2010-05-07 01:50:29 [-0500]: >Can you explain this a bit more. Mostly would like to have a brief description of the sequence of events as part of the commit message. > >Something like: > >* Running kernel calls machine_kexec() >* machine_kexec_32() >* jump to relocate code >* relocate clears out TLBs and sets up 2g mapping >... > >what I have above might not be quite right. That is correct: - kexec -l loads the kernel, dtb, ... in userland. It sets up the kimage struct including buffers with the new kernel and a copy list which looks like src, dst, bytes. KEXEC_*_MEMORY_LIMIT is limiting the memory which it might allocate. - kexec -e start the kexec, that is * syscall reboot - kernel/sys.c * kernel_kexec() kernel/kexec.c * machine_kexec() arch/powerpc/kernel/machine_kexec.c * default_machine_kexec() arch/powerpc/kernel/machine_kexec_32.c - copy relocate_new_kernel() into a buffer which was allocated during kexec -l. That buffer is somewhere between 0..2GiB and will not be overwritten. - jump there. Here we clear the tlbs and setup a 1:1 mapping. Then we copy the data from somewhere in 0..2GiB to its final position according to the list. Data means new kernel, device tree and purgatory code. - After that, the code ends in mtlr r5 blrl r5 has the address of purgatory_start(), purgatory/arch/ppc/v2wrap.S in kexec userland [0]. - here we setup stack, jump to purgatory(). We have no console and still the 2GiB 1:1 mapping - the code performs a sha256 check to make sure the kernel is correct. - then we get back from purgatory(), load r3 - r9 and the blr at the bottom shoots us finally to new kernel. - now we boot the kernel. >- k [0] git://git.kernel.org/pub/scm/linux/kernel/git/horms/kexec-tools.git Sebastian
Most booke powerpc are based on SMP, I am looking forward someone to implement this. hiahia
On Fri, May 07, 2010 at 07:35:34PM +0800, wilbur.chan wrote: >Most booke powerpc are based on SMP, I am looking forward someone to >implement this. hiahia Erm, actually most Book-E powerpc CPUs are not SMP. SMP Book-E cores are only a fairly recent development, and if I recall correctly you need an e500mc core to really have it work properly. josh
On May 7, 2010, at 7:16 AM, Josh Boyer wrote: > On Fri, May 07, 2010 at 07:35:34PM +0800, wilbur.chan wrote: >> Most booke powerpc are based on SMP, I am looking forward someone to >> implement this. hiahia > > Erm, actually most Book-E powerpc CPUs are not SMP. SMP Book-E cores are only > a fairly recent development, and if I recall correctly you need an e500mc core > to really have it work properly. e500v2 also does SMP. MPC8572, P2020, P102x are all e500v2 SMP :) - k
On Apr 4, 2010, at 3:19 PM, Sebastian Andrzej Siewior wrote: > From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > > 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. > > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > --- > arch/powerpc/Kconfig | 2 +- > arch/powerpc/include/asm/kexec.h | 13 +++++++++ > arch/powerpc/kernel/fsl_booke_entry_mapping.S | 37 +++++++++++++++++++++++++ > arch/powerpc/kernel/head_fsl_booke.S | 2 + > arch/powerpc/kernel/misc_32.S | 17 +++++++++++ > 5 files changed, 70 insertions(+), 1 deletions(-) applied to next - k
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 2e19500..f8ce19d 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -350,7 +350,7 @@ config ARCH_ENABLE_MEMORY_HOTREMOVE config KEXEC bool "kexec system call (EXPERIMENTAL)" - depends on PPC_BOOK3S && EXPERIMENTAL + depends on (PPC_BOOK3S || (FSL_BOOKE && !SMP)) && EXPERIMENTAL help kexec is a system call that implements the ability to shutdown your current kernel, and to start another kernel. It is like a reboot diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h index 7e06b43..83f6481 100644 --- a/arch/powerpc/include/asm/kexec.h +++ b/arch/powerpc/include/asm/kexec.h @@ -2,6 +2,18 @@ #define _ASM_POWERPC_KEXEC_H #ifdef __KERNEL__ +#ifdef CONFIG_FSL_BOOKE + +/* + * On FSL-BookE we setup a 1:1 mapping which covers the first 2GiB of memory + * and therefore we can only deal with memory within this range + */ +#define KEXEC_SOURCE_MEMORY_LIMIT (2 * 1024 * 1024 * 1024UL) +#define KEXEC_DESTINATION_MEMORY_LIMIT (2 * 1024 * 1024 * 1024UL) +#define KEXEC_CONTROL_MEMORY_LIMIT (2 * 1024 * 1024 * 1024UL) + +#else + /* * Maximum page that is mapped directly into kernel memory. * XXX: Since we copy virt we can use any page we allocate @@ -21,6 +33,7 @@ /* TASK_SIZE, probably left over from use_mm ?? */ #define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE #endif +#endif #define KEXEC_CONTROL_PAGE_SIZE 4096 diff --git a/arch/powerpc/kernel/fsl_booke_entry_mapping.S b/arch/powerpc/kernel/fsl_booke_entry_mapping.S index cdb1296..beb4d78 100644 --- a/arch/powerpc/kernel/fsl_booke_entry_mapping.S +++ b/arch/powerpc/kernel/fsl_booke_entry_mapping.S @@ -159,6 +159,8 @@ skpinv: addi r6,r6,1 /* Increment */ #define M_IF_SMP 0 #endif +#if defined(ENTRY_MAPPING_BOOT_SETUP) + /* 6. Setup KERNELBASE mapping in TLB1[0] */ lis r6,0x1000 /* Set MAS0(TLBSEL) = TLB1(1), ESEL = 0 */ mtspr SPRN_MAS0,r6 @@ -174,6 +176,41 @@ skpinv: addi r6,r6,1 /* Increment */ /* 7. Jump to KERNELBASE mapping */ lis r6,(KERNELBASE & ~0xfff)@h ori r6,r6,(KERNELBASE & ~0xfff)@l + +#elif defined(ENTRY_MAPPING_KEXEC_SETUP) +/* + * 6. Setup a 1:1 mapping in TLB1. Esel 0 is unsued, 1 or 2 contains the tmp + * mapping so we start at 3. We setup 8 mappings, each 256MiB in size. This + * will cover the first 2GiB of memory. + */ + + lis r10, (MAS1_VALID|MAS1_IPROT)@h + ori r10,r10, (MAS1_TSIZE(BOOK3E_PAGESZ_256M))@l + li r11, 0 + li r0, 8 + mtctr r0 + +next_tlb_setup: + addi r0, r11, 3 + rlwinm r0, r0, 16, 4, 15 // Compute esel + rlwinm r9, r11, 28, 0, 3 // Compute [ER]PN + oris r0, r0, (MAS0_TLBSEL(1))@h + mtspr SPRN_MAS0,r0 + mtspr SPRN_MAS1,r10 + mtspr SPRN_MAS2,r9 + ori r9, r9, (MAS3_SX|MAS3_SW|MAS3_SR) + mtspr SPRN_MAS3,r9 + tlbwe + addi r11, r11, 1 + bdnz+ next_tlb_setup + +/* 7. Jump to our 1:1 mapping */ + li r6, 0 + +#else + #error You need to specify the mapping or not use this at all. +#endif + lis r7,MSR_KERNEL@h ori r7,r7,MSR_KERNEL@l bl 1f /* Find our address */ diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index 3dc7ef7..3620cf5 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -95,7 +95,9 @@ _ENTRY(_start); _ENTRY(__early_start) +#define ENTRY_MAPPING_BOOT_SETUP #include "fsl_booke_entry_mapping.S" +#undef ENTRY_MAPPING_BOOT_SETUP /* Establish the interrupt vector offsets */ SET_IVOR(0, CriticalInput); diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index 8649f53..99bc652 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -706,6 +706,22 @@ relocate_new_kernel: /* r4 = reboot_code_buffer */ /* r5 = start_address */ +#ifdef CONFIG_FSL_BOOKE + + mr r29, r3 + mr r30, r4 + mr r31, r5 + +#define ENTRY_MAPPING_KEXEC_SETUP +#include "fsl_booke_entry_mapping.S" +#undef ENTRY_MAPPING_KEXEC_SETUP + + mr r3, r29 + mr r4, r30 + mr r5, r31 + + li r0, 0 +#else li r0, 0 /* @@ -722,6 +738,7 @@ relocate_new_kernel: rfi 1: +#endif /* from this point address translation is turned off */ /* and interrupts are disabled */