>1. use early_param to get the physical start address and size of
test_region, or you can just ignore this step and hard code to 510M and 2M
for test purpose only.
>2. use ioremap_nocache() to map this region to a virtual region. note that
this funtion may fail if you are asking a very large vitual memroy region.
I did the following things,
1) Reserved 3MB memory through ATAGS
2) Wrote small driver to ioremap that memory in following way,
void *tcpm_base = ioremap_nocache(0x03B00000, SZ_3MB);
27 if(tcpm_base!=NULL)
28 {
29 printk("Jiffies %x %ld\n\n\n\n", jiffies, jiffies);
30 for(i=0;i<SZ_4KB;i++)
31 src = readl(tcpm_base+i);
32 printk("Jiffies %x %ld\n\n\n\n", jiffies, jiffies);
33 }
34 else
35 printk("unable to map 3MB\n");
3) I am getting the following error,
[ 1.876647] Unable to handle kernel paging request at virtual address
ea82c000
[ 1.880950] pgd = c0004000
[ 1.883636] [ea82c000] *pgd=49818811, *pte=00000000, *ppte=00000000
[ 1.889892] Internal error: Oops: 7 [#1] PREEMPT
[ 1.894500] Modules linked in:
[ 1.897521] CPU: 0 Not tainted (3.0.31-g1080f34-dirty #106)
[ 1.903442] PC is at sand_misc_init+0x4c/0xac
[ 1.907775] LR is at sand_misc_init+0x3c/0xac
[ 1.912109] pc : [<c0022ee0>] lr : [<c0022ed0>] psr: 80000013
[ 1.912139] sp : e982bf98 ip : 00000000 fp : 00000000
[ 1.923553] r10: 00000000 r9 : 00000000 r8 : 00000000
[ 1.928771] r7 : 00000000 r6 : c00461b4 r5 : ea828000 r4 : 00000000
[ 1.935272] r3 : 00003fff r2 : 00003ffd r1 : c07ea2cf r0 : 00000063
[ 1.941802] Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment
kernel
[ 1.949096] Control: 10c57c7d Table: 00404059 DAC: 00000015
[ 1.954803]
[ 1.954833] PC: 0xc0022e60:
[ 1.959075] 2e60 c09105f0 c0366554 c07ea27e c07ea296 e3a01000 e92d4010
e1a02001 eb0a9acd
[ 1.967224] 2e80 e59f3008 e5830008 e3a00001 e8bd8010 c0dd8380 e92d4037
e3a04000 e3a0063b
[ 1.975402] 2ea0 e3a01901 e1a02004 e5cd4007 e5cd4006 eb00b9aa e2505000
0a000019 e59f3070
[ 1.983551] 2ec0 e59f0070 e5931000 e5932000 eb18a072 e58d4000 e3033fff
ea000007 e59d2000
[ 1.991699] 2ee0 e7952002 f57ff04f e6ef2072 e5cd2007 e59d2000 e2822001
e58d2000 e59d2000
[ 1.999877] 2f00 e1520003 dafffff4 e59f3024 e59f0024 e5931000 e5932000
e28dd00c e8bd4030
[ 2.008026] 2f20 ea18a05d e59f0010 e28dd00c e8bd4030 ea18a059 c08ea600
c07ea2cf c07ea2e2
[ 2.016174] 2f40 e59f3040 e3a01000 e92d4010 e59f0038 e5932000 eb0a845a
e59f3030 e3500000
[ 2.024353]
[ 2.024353] LR: 0xc0022e50:
[ 2.028594] 2e50 e3e00015 e8bd81fc c0dd8380 c07ea279 c09105f0 c0366554
c07ea27e c07ea296
[ 2.036773] 2e70 e3a01000 e92d4010 e1a02001 eb0a9acd e59f3008 e5830008
e3a00001 e8bd8010
[ 2.044921] 2e90 c0dd8380 e92d4037 e3a04000 e3a0063b e3a01901 e1a02004
e5cd4007 e5cd4006
[ 2.053070] 2eb0 eb00b9aa e2505000 0a000019 e59f3070 e59f0070 e5931000
e5932000 eb18a072
[ 2.061248] 2ed0 e58d4000 e3033fff ea000007 e59d2000 e7952002 f57ff04f
e6ef2072 e5cd2007
[ 2.069396] 2ef0 e59d2000 e2822001 e58d2000 e59d2000 e1520003 dafffff4
e59f3024 e59f0024
[ 2.077575] 2f10 e5931000 e5932000 e28dd00c e8bd4030 ea18a05d e59f0010
e28dd00c e8bd4030
[ 2.085723] 2f30 ea18a059 c08ea600 c07ea2cf c07ea2e2 e59f3040 e3a01000
e92d4010 e59f0038
[ 2.093872]
[ 2.093902] SP: 0xe982bf18:
[ 2.098144] bf18 382e3120 30393536 00205d35 000000d0 00004fff 00003b00
192d8000 ea82bfff
[ 2.106292] bf38 03b00000 ffffffff e982bf84 c00461b4 00000000 c0044dac
00000063 c07ea2cf
[ 2.114440] bf58 00003ffd 00003fff 00000000 ea828000 c00461b4 00000000
00000000 00000000
[ 2.122619] bf78 00000000 00000000 00000000 e982bf98 c0022ed0 c0022ee0
80000013 ffffffff
[ 2.130767] bf98 00003ffd 0000a27e 00000000 c0037b4c c0022e94 c003f3fc
e9814a80 00373231
[ 2.138946] bfb8 00000000 00000000 00000000 00000236 c0037b4c c003818c
c00461b4 00000013
[ 2.147094] bfd8 00000000 00000000 00000000 c0008374 00000000 c0008300
c00461b4 c00461b4
[ 2.155242] bff8 00000000 00000000 00000000 00000001 00000000 e9817940
c08e8ef4 00000000
[ 2.163421]
[ 2.163421] R1: 0xc07ea24f:
[ 2.167663] a24c 65207265 726f7272 6f6c6220 25206b63 000a646c 706f6f6c
26006425 3e2d6f6c
[ 2.175842] a26c 635f6f6c 6d5f6c74 78657475 6f6f6c00 363c0070 6f6f6c3e
6d203a70 6c75646f
[ 2.183990] a28c 6f6c2065 64656461 363c000a 6f6f6c3e 6f203a70 6f207475
656d2066 79726f6d
[ 2.192138] a2ac 6162000a 6e696b63 69665f67 7300656c 6c657a69 74696d69
74756100 656c636f
[ 2.200317] a2cc 4a007261 69666669 25207365 6c252078 0a0a0a64 6e75000a
656c6261 206f7420
[ 2.208465] a2ec 2070616d 0a424d33 656d7000 65725f6d 6e6f6967 333c0073
656d703e 7325286d
[ 2.216613] a30c 736b3a29 635f7465 74616572 6e615f65 64615f64 61662064
000a6c69 703e343c
[ 2.224792] a32c 3a6d656d 6d6f7320 69687465 6920676e 65762073 77207972
676e6f72 6f79202c
[ 2.232940] a34c 72612075 6c632065 6e69736f 20612067 62206d76 696b6361
6120676e 6c61206e
[ 2.241119]
[ 2.241119] R5: 0xea827f80:
[ 2.245361] 7f80 ******** ******** ******** ******** ******** ********
******** ********
[ 2.253509] 7fa0 ******** ******** ******** ******** ******** ********
******** ********
[ 2.261688] 7fc0 ******** ******** ******** ******** ******** ********
******** ********
[ 2.269836] 7fe0 ******** ******** ******** ******** ******** ********
******** ********
[ 2.278015] 8000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000
[ 2.286163] 8020 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000
[ 2.294311] 8040 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000
[ 2.302490] 8060 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000
[ 2.310638]
[ 2.310638] R6: 0xc0046134:
[ 2.314880] 6134 eb038dff eb02a1f9 e1a03007 e1a00005 e1a02006 eb025566
e59f3008 e5834000
[ 2.323059] 6154 e8bd41f0 ea0259b3 c09059d4 c08fbcd4 c064e808 c0791c0d
c0958220 e59fc020
[ 2.331207] 6174 e92d4007 e59f301c e59cc000 e1a02001 e59f1014 e58dc000
eb055aab e3a00000
[ 2.339385] 6194 e8bd800e c0958220 c0791c27 c0791c1b e121f007 e1a00004
e1a0e006 e1a0f005
[ 2.347534] 61b4 eb02959a e320f000 e59f300c e5932000 e2822001 e5832000
e12fff1e c0958224
[ 2.355682] 61d4 e59f300c e5932000 e2422001 e5832000 e12fff1e c0958224
e12fff1e e12fff1e
[ 2.363861] 61f4 e12fff1e e12fff1e eafffffe e59f3014 e92d4010 e5933004
e3530000 08bd8010
[ 2.372009] 6214 e12fff33 e8bd8010 c0958224 e59f3014 e1a01000 e92d4010
e5d30000 e1a0e00f
[ 2.380187] Process swapper (pid: 1, stack limit = 0xe982a2e8)
[ 2.385986] Stack: (0xe982bf98 to 0xe982c000)
[ 2.390319] bf80:
00003ffd 0000a27e
[ 2.398498] bfa0: 00000000 c0037b4c c0022e94 c003f3fc e9814a80 00373231
00000000 00000000
[ 2.406646] bfc0: 00000000 00000236 c0037b4c c003818c c00461b4 00000013
00000000 00000000
[ 2.414825] bfe0: 00000000 c0008374 00000000 c0008300 c00461b4 c00461b4
00000000 00000000
[ 2.423004] [<c0022ee0>] (sand_misc_init+0x4c/0xac) from [<c003f3fc>]
(do_one_initcall+0xd0/0x1a4)
[ 2.431915] [<c003f3fc>] (do_one_initcall+0xd0/0x1a4) from [<c0008374>]
(kernel_init+0x74/0x118)
[ 2.440673] [<c0008374>] (kernel_init+0x74/0x118) from [<c00461b4>]
(kernel_thread_exit+0x0/0x8)
[ 2.449462] Code: e58d4000 e3033fff ea000007 e59d2000 (e7952002)
[ 2.455566] ---[ end trace f76f3c76dcb9b9ef ]---
[ 2.460144] Kernel panic - not syncing: Attempted to kill init!
[ 2.466064] [<c004ad10>] (unwind_backtrace+0x0/0x12c) from [<c064af70>]
(panic+0x90/0x1bc)
[ 2.474304] [<c064af70>] (panic+0x90/0x1bc) from [<c00eb8dc>]
(do_exit+0xb8/0x734)
[ 2.481842] [<c00eb8dc>] (do_exit+0xb8/0x734) from [<c0048f8c>]
(die+0x208/0x23c)
[ 2.489318] [<c0048f8c>] (die+0x208/0x23c) from [<c004e158>]
(__do_kernel_fault+0x64/0x84)
[ 2.497558] [<c004e158>] (__do_kernel_fault+0x64/0x84) from [<c004e3e0>]
(do_page_fault+0x268/0x288)
[ 2.506683] [<c004e3e0>] (do_page_fault+0x268/0x288) from [<c003f270>]
(do_DataAbort+0x34/0x94)
[ 2.515350] [<c003f270>] (do_DataAbort+0x34/0x94) from [<c0044dac>]
(__dabt_svc+0x4c/0x60)
[ 2.523590] Exception stack(0xe982bf50 to 0xe982bf98)
[ 2.528625] bf40: 00000063 c07ea2cf
00003ffd 00003fff
[ 2.536804] bf60: 00000000 ea828000 c00461b4 00000000 00000000 00000000
00000000 00000000
[ 2.544952] bf80: 00000000 e982bf98 c0022ed0 c0022ee0 80000013 ffffffff
[ 2.551544] [<c0044dac>] (__dabt_svc+0x4c/0x60) from [<c0022ee0>]
(sand_misc_init+0x4c/0xac)
[ 2.559967] [<c0022ee0>] (sand_misc_init+0x4c/0xac) from [<c003f3fc>]
(do_one_initcall+0xd0/0x1a4)
[ 2.568908] [<c003f3fc>] (do_one_initcall+0xd0/0x1a4) from [<c0008374>]
(kernel_init+0x74/0x118)
[ 2.577667] [<c0008374>] (kernel_init+0x74/0x118) from [<c00461b4>]
(kernel_thread_exit+0x0/0x8)
Any idea what went wrong.
I am sure about the ioremap() start address, thats what i reserved in ATAGS.
Thanks
Sandeep
On Thu, Feb 28, 2013 at 10:30 AM, sandeep kumar
<coolsandyfor...@gmail.com>wrote:
> >1. use early_param to get the physical start address and size of
> test_region, or you can just ignore this step and hard code to 510M and 2M
> for test purpose only.
>
> >2. use ioremap_nocache() to map this region to a virtual region. note
> that this funtion may fail if you are asking a very large vitual memroy
> region.
>
> Sounds good, i am gonna try this and let you know.. :)
>
>
> On Wed, Feb 27, 2013 at 8:19 PM, buyitian <bu...@live.cn> wrote:
>
>> ----------------------------------------
>> > From: bu...@live.cn
>> > To: coolsandyfor...@gmail.com; kernelnewbies@kernelnewbies.org
>> > Subject: RE: How to measure the RAM read/write performance
>> > Date: Wed, 27 Feb 2013 22:33:15 +0800
>> > CC: dhyla...@gmail.com
>> >
>> > ________________________________
>> > > From: coolsandyfor...@gmail.com
>> > > Date: Tue, 26 Feb 2013 17:01:54 +0530
>> > > Subject: How to measure the RAM read/write performance
>> > > To: kernelnewbies@kernelnewbies.org
>> > > CC: dhyla...@gmail.com
>> > >
>> > > Hi All
>> > > In performance benchmark tools, When we profile read/write timings
>> > > mostly, those read/writes are done to cache only.
>> > >
>> > > I want to measure my DDR(RAM chip) performance.
>> > > So i want to make sure, every read/write should happen to DDR RAM
>> chip only.
>> > >
>> > > How can i achieve this...Any ideas/suggestions...?
>> >
>> > try to reserve a large region from bootloader(L4 in Qualcomm platform),
>> let's say it is 10MB continuous physical memory.
>>
>> sorry, to be accurate, reserve physical memory is done by kernel cmdline,
>> this cmdline parameter can be passed from L4 to kernel, or configed by
>> kernel itself.
>> the cmdline will be like below:
>> mem=510M@0 test_region=2M@510M
>>
>> above example tells kernel you have totally 512MB physical memory, but
>> kernel will only use the first 510MB, the latter 2MB memory is used by you.
>> how to map and use this region depends on you.
>>
>> > in kernel, map this region to an continuous virtual region, note that
>> the pgprot should be uncachable since you want to test without cache.
>>
>> 1. use early_param to get the physical start address and size of
>> test_region, or you can just ignore this step and hard code to 510M and 2M
>> for test purpose only.
>>
>> 2. use ioremap_nocache() to map this region to a virtual region. note
>> that this funtion may fail if you are asking a very large vitual memroy
>> region.
>>
>> > once you configed like this, you can read/write to this vitual region
>> without data cache invovled.
>> >
>> > >
>> > > --
>> > > With regards,
>> > > Sandeep Kumar Anantapalli,
>> > >
>> > > _______________________________________________ Kernelnewbies mailing
>> > > list Kernelnewbies@kernelnewbies.org
>> > > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>> > _______________________________________________
>> > Kernelnewbies mailing list
>> > Kernelnewbies@kernelnewbies.org
>> > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>>
>>
>
>
>
> --
> With regards,
> Sandeep Kumar Anantapalli,
>
--
With regards,
Sandeep Kumar Anantapalli,
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