Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH] powerpc/mm: dump block address translation on book3s/32
To:     Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>, npiggin@gmail.com,
        rashmicy@gmail.com
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
References: <26cc609706833f78e3195e3d35c0372b2f40cae3.1542181167.git.christophe.leroy@c-s.fr>
 <878t1uva0q.fsf@concordia.ellerman.id.au>
From:   Christophe LEROY <christophe.leroy@c-s.fr>
Message-ID: <9cb14c1f-02ce-a2a5-94e6-95afb4d3e168@c-s.fr>
Date:   Thu, 15 Nov 2018 12:57:30 +0100
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101
 Thunderbird/60.3.0
MIME-Version: 1.0
In-Reply-To: <878t1uva0q.fsf@concordia.ellerman.id.au>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: fr
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


Le 15/11/2018 à 12:46, Michael Ellerman a écrit :
> Christophe Leroy <christophe.leroy@c-s.fr> writes:
> 
>> This patch adds a debugfs file to dump block address translation:
>>
>> ~# cat /sys/kernel/debug/block_address_translation
> 
> My instinct is it should be in /sys/kernel/debug/powerpc. But I guess
> the other page table dump files are not.

Lol.

Looks like we have the same instinct ...

But you rejected my patch https://patchwork.ozlabs.org/patch/750426/ :)


> 
>> Instruction Block Address Translations:
>> 0:         -
>> 1:         -
>> 2: 0xc0000000-0xcfffffff 0x00000000 Kernel EXEC coherent
>> 3: 0xd0000000-0xdfffffff 0x10000000 Kernel EXEC coherent
>> 4:         -
>> 5:         -
>> 6:         -
>> 7:         -
>>
>> Data Block Address Translations:
>> 0:         -
>> 1:         -
>> 2: 0xc0000000-0xcfffffff 0x00000000 Kernel RW coherent
>> 3: 0xd0000000-0xdfffffff 0x10000000 Kernel RW coherent
>> 4:         -
>> 5:         -
>> 6:         -
>> 7:         -
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>> ---
>>   Tested on mpc8321 aka 603
>>   Please review/test the 601 part
>>
>>   arch/powerpc/mm/Makefile    |   2 +-
>>   arch/powerpc/mm/dump_bats.c | 176 ++++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 177 insertions(+), 1 deletion(-)
>>   create mode 100644 arch/powerpc/mm/dump_bats.c
>>
>> diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
>> index ca96e7be4d0e..2adad10b5856 100644
>> --- a/arch/powerpc/mm/Makefile
>> +++ b/arch/powerpc/mm/Makefile
>> @@ -47,7 +47,7 @@ ifdef CONFIG_PPC_PTDUMP
>>   obj-$(CONFIG_4xx)		+= dump_linuxpagetables-generic.o
>>   obj-$(CONFIG_PPC_8xx)		+= dump_linuxpagetables-8xx.o
>>   obj-$(CONFIG_PPC_BOOK3E_MMU)	+= dump_linuxpagetables-generic.o
>> -obj-$(CONFIG_PPC_BOOK3S_32)	+= dump_linuxpagetables-generic.o
>> +obj-$(CONFIG_PPC_BOOK3S_32)	+= dump_linuxpagetables-generic.o dump_bats.o
> 
> BOOK3S_32 covers quite a lot of CPUs.
> 
> But below the only check is that you're on 601 or 603.
> 
> So is the 603 code going to work on all other BOOK3S_32 CPUs?

If I understand function setbat() correctly, it should.

See 
https://elixir.bootlin.com/linux/v4.20-rc1/source/arch/powerpc/mm/ppc_mmu_32.c#L115 
Tell me if you see something I missed.

Christophe

> 
> cheers
> 
>> diff --git a/arch/powerpc/mm/dump_bats.c b/arch/powerpc/mm/dump_bats.c
>> new file mode 100644
>> index 000000000000..824a94ee9051
>> --- /dev/null
>> +++ b/arch/powerpc/mm/dump_bats.c
>> @@ -0,0 +1,176 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Copyright 2018, Christophe Leroy CS S.I.
>> + * <christophe.leroy@c-s.fr>
>> + *
>> + * This dumps the content of BATS
>> + */
>> +
>> +#include <linux/debugfs.h>
>> +#include <linux/fs.h>
>> +#include <linux/hugetlb.h>
>> +#include <linux/io.h>
>> +#include <linux/mm.h>
>> +#include <linux/sched.h>
>> +#include <linux/seq_file.h>
>> +#include <asm/fixmap.h>
>> +#include <asm/pgtable.h>
>> +#include <linux/const.h>
>> +#include <asm/page.h>
>> +#include <asm/pgalloc.h>
>> +
>> +#include <asm/book3s/32/mmu-hash.h>
>> +
>> +static char *pp_601(int k, int pp)
>> +{
>> +	if (pp == 0)
>> +		return k ? "NA" : "RWX";
>> +	if (pp == 1)
>> +		return k ? "ROX" : "RWX";
>> +	if (pp == 2)
>> +		return k ? "RWX" : "RWX";
>> +	return k ? "ROX" : "ROX";
>> +}
>> +
>> +static void bat_show_601(struct seq_file *m, int idx, u32 lower, u32 upper)
>> +{
>> +	u32 blpi = upper & 0xfffe0000;
>> +	u32 k = (upper >> 2) & 3;
>> +	u32 pp = upper & 3;
>> +	u32 pbn = lower & 0xfffe0000;
>> +	u32 bsm = lower & 0x3ff;
>> +	u32 size = (bsm + 1) << 17;
>> +
>> +	seq_printf(m, "%d: ", idx);
>> +	if (!(lower & 0x40)) {
>> +		seq_puts(m, "        -\n");
>> +		return;
>> +	}
>> +
>> +	seq_printf(m, "0x%08x-0x%08x ", blpi, blpi + size - 1);
>> +	seq_printf(m, "0x%08x ", pbn);
>> +
>> +	seq_printf(m, "Kernel %s User %s", pp_601(k & 2, pp), pp_601(k & 1, pp));
>> +
>> +	if (lower & _PAGE_WRITETHRU)
>> +		seq_puts(m, "write through ");
>> +	if (lower & _PAGE_NO_CACHE)
>> +		seq_puts(m, "no cache ");
>> +	if (lower & _PAGE_COHERENT)
>> +		seq_puts(m, "coherent ");
>> +	seq_puts(m, "\n");
>> +}
>> +
>> +#define BAT_SHOW_601(_m, _n, _l, _u) bat_show_601(_m, _n, mfspr(_l), mfspr(_u))
>> +
>> +static int bats_show_601(struct seq_file *m, void *v)
>> +{
>> +	seq_puts(m, "Block Address Translation:\n");
>> +
>> +	BAT_SHOW_601(m, 0, SPRN_IBAT0L, SPRN_IBAT0U);
>> +	BAT_SHOW_601(m, 1, SPRN_IBAT1L, SPRN_IBAT1U);
>> +	BAT_SHOW_601(m, 2, SPRN_IBAT2L, SPRN_IBAT2U);
>> +	BAT_SHOW_601(m, 3, SPRN_IBAT3L, SPRN_IBAT3U);
>> +
>> +	return 0;
>> +}
>> +
>> +static void bat_show_603(struct seq_file *m, int idx, u32 lower, u32 upper, bool is_d)
>> +{
>> +	u32 bepi = upper & 0xfffe0000;
>> +	u32 bl = (upper >> 2) & 0x7ff;
>> +	u32 k = upper & 3;
>> +	u32 brpn = lower & 0xfffe0000;
>> +	u32 size = (bl + 1) << 17;
>> +
>> +	seq_printf(m, "%d: ", idx);
>> +	if (k == 0) {
>> +		seq_puts(m, "        -\n");
>> +		return;
>> +	}
>> +
>> +	seq_printf(m, "0x%08x-0x%08x ", bepi, bepi + size - 1);
>> +	seq_printf(m, "0x%08x ", brpn);
>> +
>> +	if (k == 1)
>> +		seq_puts(m, "User ");
>> +	else if (k == 2)
>> +		seq_puts(m, "Kernel ");
>> +	else
>> +		seq_puts(m, "Kernel/User ");
>> +
>> +	if (lower & BPP_RX)
>> +		seq_puts(m, is_d ? "RO " : "EXEC ");
>> +	else if (lower & BPP_RW)
>> +		seq_puts(m, is_d ? "RW " : "EXEC ");
>> +	else
>> +		seq_puts(m, is_d ? "NA " : "NX   ");
>> +
>> +	if (lower & _PAGE_WRITETHRU)
>> +		seq_puts(m, "write through ");
>> +	if (lower & _PAGE_NO_CACHE)
>> +		seq_puts(m, "no cache ");
>> +	if (lower & _PAGE_COHERENT)
>> +		seq_puts(m, "coherent ");
>> +	if (lower & _PAGE_GUARDED)
>> +		seq_puts(m, "guarded ");
>> +	seq_puts(m, "\n");
>> +}
>> +
>> +#define BAT_SHOW_603(_m, _n, _l, _u, _d) bat_show_603(_m, _n, mfspr(_l), mfspr(_u), _d)
>> +
>> +static int bats_show_603(struct seq_file *m, void *v)
>> +{
>> +	seq_puts(m, "Instruction Block Address Translation:\n");
>> +
>> +	BAT_SHOW_603(m, 0, SPRN_IBAT0L, SPRN_IBAT0U, false);
>> +	BAT_SHOW_603(m, 1, SPRN_IBAT1L, SPRN_IBAT1U, false);
>> +	BAT_SHOW_603(m, 2, SPRN_IBAT2L, SPRN_IBAT2U, false);
>> +	BAT_SHOW_603(m, 3, SPRN_IBAT3L, SPRN_IBAT3U, false);
>> +	if (mmu_has_feature(MMU_FTR_USE_HIGH_BATS)) {
>> +		BAT_SHOW_603(m, 4, SPRN_IBAT4L, SPRN_IBAT4U, false);
>> +		BAT_SHOW_603(m, 5, SPRN_IBAT5L, SPRN_IBAT5U, false);
>> +		BAT_SHOW_603(m, 6, SPRN_IBAT6L, SPRN_IBAT6U, false);
>> +		BAT_SHOW_603(m, 7, SPRN_IBAT7L, SPRN_IBAT7U, false);
>> +	}
>> +
>> +	seq_puts(m, "\nData Block Address Translation:\n");
>> +
>> +	BAT_SHOW_603(m, 0, SPRN_DBAT0L, SPRN_DBAT0U, true);
>> +	BAT_SHOW_603(m, 1, SPRN_DBAT1L, SPRN_DBAT1U, true);
>> +	BAT_SHOW_603(m, 2, SPRN_DBAT2L, SPRN_DBAT2U, true);
>> +	BAT_SHOW_603(m, 3, SPRN_DBAT3L, SPRN_DBAT3U, true);
>> +	if (mmu_has_feature(MMU_FTR_USE_HIGH_BATS)) {
>> +		BAT_SHOW_603(m, 4, SPRN_DBAT4L, SPRN_DBAT4U, true);
>> +		BAT_SHOW_603(m, 5, SPRN_DBAT5L, SPRN_DBAT5U, true);
>> +		BAT_SHOW_603(m, 6, SPRN_DBAT6L, SPRN_DBAT6U, true);
>> +		BAT_SHOW_603(m, 7, SPRN_DBAT7L, SPRN_DBAT7U, true);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int bats_open(struct inode *inode, struct file *file)
>> +{
>> +	if (PVR_VER(mfspr(SPRN_PVR)) == 1)
>> +		return single_open(file, bats_show_601, NULL);
>> +
>> +	return single_open(file, bats_show_603, NULL);
>> +}
>> +
>> +static const struct file_operations bats_fops = {
>> +	.open		= bats_open,
>> +	.read		= seq_read,
>> +	.llseek		= seq_lseek,
>> +	.release	= single_release,
>> +};
>> +
>> +static int bats_init(void)
>> +{
>> +	struct dentry *debugfs_file;
>> +
>> +	debugfs_file = debugfs_create_file("block_address_translation", 0400,
>> +					   NULL, NULL, &bats_fops);
>> +	return debugfs_file ? 0 : -ENOMEM;
>> +}
>> +device_initcall(bats_init);
>> -- 
>> 2.13.3