Hi Scott,
Please find my reply in-lined
On Thursday 22 March 2012 01:22 AM, Scott Wood wrote:
On 03/20/2012 11:43 PM, Prabhakar Kushwaha wrote:
Debugging of e500 and e500v1 processer requires debug exception vecter (IVPR + IVOR15) to have valid and fetchable OP code.
While executing in translated space (AS=1), whenever a debug exception is generated, the MSR[DS/IS] gets cleared i.e. AS=0 and the processor tries to fetch an instruction from the debug exception vector (IVPR + IVOR15); since now we are in AS=0, the application needs to ensure the proper TLB configuration to have (IVOR + IVOR15) accessible from AS=0 also.
Create a temporary TLB in AS0 to make sure debug exception verctor is accessible on debug exception.
Signed-off-by: Radu Lazarescuradu.lazarescu@freescale.com Signed-off-by: Marius Grigorasmarius.grigoras@freescale.com Signed-off-by: Prabhakar Kushwahaprabhakar@freescale.com
Can you document the flow of exactly what TLB entries are present at various points of the boot flow, for all the various configurations (NOR boot, NAND SPL, RAMBOOT, IFC versus non-IFC, etc).
Sure. May be separate patch will be send.
diff --git a/arch/powerpc/cpu/mpc85xx/start.S b/arch/powerpc/cpu/mpc85xx/start.S index 597151b..cef00ba 100644 --- a/arch/powerpc/cpu/mpc85xx/start.S +++ b/arch/powerpc/cpu/mpc85xx/start.S @@ -182,6 +182,66 @@ l2_disabled: andi. r1,r3,L1CSR0_DCE@l beq 2b
+#if defined(CONFIG_E500)&& defined(CONFIG_SYS_PPC_E500_DEBUG_TLB) +/*
- TLB for debuggging in AS1
- Create temporary TLB in AS0 to handle debug exception
- As on debug exception MSR is cleared i.e. Address space is changed
- to 0. A TLB (in AS0) is required to handle debug exception generated
- in AS1.
- */
s/TLB/TLB entry/g
Sure, i will update.
- lis r6,FSL_BOOKE_MAS0(1,
CONFIG_SYS_PPC_E500_DEBUG_TLB, 0)@h- ori r6,r6,FSL_BOOKE_MAS0(1,
CONFIG_SYS_PPC_E500_DEBUG_TLB, 0)@l+#if !defined(CONFIG_SYS_RAMBOOT) +/*
- TLB is created for IVPR + IVOR15 to map on valid OP code address
- bacause flash's virtual address maps to 0xff800000 - 0xffffffff.
- and this window is outside of 4K boot window.
- */
- lis r7,FSL_BOOKE_MAS1(1, 1, 0, 0, BOOKE_PAGESZ_4M)@h
- ori r7,r7,FSL_BOOKE_MAS1(1, 1, 0, 0, BOOKE_PAGESZ_4M)@l
- lis r8,FSL_BOOKE_MAS2(CONFIG_SYS_MONITOR_BASE& 0xffc00000,
(MAS2_I|MAS2_G))@h- ori r8,r8,FSL_BOOKE_MAS2(CONFIG_SYS_MONITOR_BASE& 0xffc00000,
(MAS2_I|MAS2_G))@l- /* The 85xx has the default boot window 0xff800000 - 0xffffffff */
- lis r9,FSL_BOOKE_MAS3(0xffc00000, 0, (MAS3_SX|MAS3_SW|MAS3_SR))@h
- ori r9,r9,FSL_BOOKE_MAS3(0xffc00000, 0, (MAS3_SX|MAS3_SW|MAS3_SR))@l
+#else +/*
- TLB is created for IVPR + IVOR15 to map on valid OP code address
- because "nexti" will resize TLB to 4K
- */
- lis r7,FSL_BOOKE_MAS1(1, 1, 0, 0, BOOKE_PAGESZ_256K)@h
- ori r7,r7,FSL_BOOKE_MAS1(1, 1, 0, 0, BOOKE_PAGESZ_256K)@l
- lis r8,FSL_BOOKE_MAS2(CONFIG_SYS_MONITOR_BASE, (MAS2_I|MAS2_G))@h
- ori r8,r8,FSL_BOOKE_MAS2(CONFIG_SYS_MONITOR_BASE,
(MAS2_I|MAS2_G))@l- lis r9,FSL_BOOKE_MAS3(CONFIG_SYS_MONITOR_BASE, 0,
(MAS3_SX|MAS3_SW|MAS3_SR))@h- ori r9,r9,FSL_BOOKE_MAS3(CONFIG_SYS_MONITOR_BASE, 0,
(MAS3_SX|MAS3_SW|MAS3_SR))@l+#endif
In the ramboot case is this really supposed to be I+G?
I am not sure. But same is done under label "create_init_ram_area" for TLB entry 15. what you suggest.
Which path will NAND SPL go through (not the payload, but the SPL itself)? That will be only a 4K window mapped, and guarded doesn't stop speculative instruction fetches, so we don't want to map more than is backed up by something.
NAND SPL go via !defined(CONFIG_SYS_RAMBOOT) path.
i think NAND_SPL does not require temporary TLB as NAND SPL even does not have any interrupt vector.
I will check this point
- lis r10,0xffc00000@h
- ori r10,r10,0xffc00000@l
Don't waste instructions -- this could be in an SPL. That ori is a no-op.
Please refer above response. May be this piece of code is not required for NAND SPL
- mtspr MAS0,r6
- mtspr MAS1,r7
- mtspr MAS2,r8
- mtspr MAS3,r9
- mtspr MAS7,r10
Why are you writing 0xffc00000 into MAS7?
Access to MAS7 needs to be conditional on CONFIG_ENABLE_36BIT_PHYS (misnamed, should be something like CONFIG_SYS_PPC_HAS_MAS7).
i will put this code under #define CONFIG_ENABLE_36BIT_PHYS
For your kind information : in start.S, label label "create_ccsr_new_tlb", "create_ccsr_old_tlb" uses MAS7 without CONFIG_ENABLE_36BIT_PHYS #define. It should be fixed ??
- isync
- msync
- tlbwe
+#endif
Need isync after the tlbwe. I don't think we need the msync before it.
Ok.
diff --git a/arch/powerpc/include/asm/config_mpc85xx.h b/arch/powerpc/include/asm/config_mpc85xx.h index 8654625..268c56e 100644 --- a/arch/powerpc/include/asm/config_mpc85xx.h +++ b/arch/powerpc/include/asm/config_mpc85xx.h @@ -1,5 +1,5 @@ /*
- Copyright 2011 Freescale Semiconductor, Inc.
- Copyright 2011-2012 Freescale Semiconductor, Inc.
- This program is free software; you can redistribute it and/or
- modify it under the terms of the GNU General Public License as
@@ -107,6 +107,7 @@ #define CONFIG_MAX_CPUS 1 #define CONFIG_FSL_SDHC_V2_3 #define CONFIG_SYS_FSL_NUM_LAWS 12 +#define CONFIG_SYS_PPC_E500_DEBUG_TLB 3 #define CONFIG_TSECV2 #define CONFIG_SYS_FSL_SEC_COMPAT 4 #define CONFIG_FSL_SATA_V2
It would be nice if we could have one place where all the fixed TLB entries are assigned.
Am i supposed to send separate patch having TLB entry defined for all e500 v1/v2 SoC ?
--Prabhakar