Commit 691602aa authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Michael Ellerman
Browse files

powerpc/iommu/debug: Add debugfs entries for IOMMU tables 



This adds a folder per LIOBN under /sys/kernel/debug/iommu with IOMMU
table parameters.

This is enabled by CONFIG_IOMMU_DEBUGFS.

Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210113102014.124452-1-aik@ozlabs.ru
parent 22f1de2e

arch/powerpc/kernel/iommu.c

+46 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/pci.h>

#include <linux/iommu.h>

#include <linux/sched.h>

#include <linux/debugfs.h>

#include <asm/io.h>

#include <asm/prom.h>

#include <asm/iommu.h>
@@ -38,6 +39,47 @@ 


#define DBG(...)



#ifdef CONFIG_IOMMU_DEBUGFS

static int iommu_debugfs_weight_get(void *data, u64 *val)

{

	struct iommu_table *tbl = data;

	*val = bitmap_weight(tbl->it_map, tbl->it_size);

	return 0;

}

DEFINE_DEBUGFS_ATTRIBUTE(iommu_debugfs_fops_weight, iommu_debugfs_weight_get, NULL, "%llu\n");



static void iommu_debugfs_add(struct iommu_table *tbl)

{

	char name[10];

	struct dentry *liobn_entry;



	sprintf(name, "%08lx", tbl->it_index);

	liobn_entry = debugfs_create_dir(name, iommu_debugfs_dir);



	debugfs_create_file_unsafe("weight", 0400, liobn_entry, tbl, &iommu_debugfs_fops_weight);

	debugfs_create_ulong("it_size", 0400, liobn_entry, &tbl->it_size);

	debugfs_create_ulong("it_page_shift", 0400, liobn_entry, &tbl->it_page_shift);

	debugfs_create_ulong("it_reserved_start", 0400, liobn_entry, &tbl->it_reserved_start);

	debugfs_create_ulong("it_reserved_end", 0400, liobn_entry, &tbl->it_reserved_end);

	debugfs_create_ulong("it_indirect_levels", 0400, liobn_entry, &tbl->it_indirect_levels);

	debugfs_create_ulong("it_level_size", 0400, liobn_entry, &tbl->it_level_size);

}



static void iommu_debugfs_del(struct iommu_table *tbl)

{

	char name[10];

	struct dentry *liobn_entry;



	sprintf(name, "%08lx", tbl->it_index);

	liobn_entry = debugfs_lookup(name, iommu_debugfs_dir);

	if (liobn_entry)

		debugfs_remove(liobn_entry);

}

#else

static void iommu_debugfs_add(struct iommu_table *tbl){}

static void iommu_debugfs_del(struct iommu_table *tbl){}

#endif



static int novmerge;



static void __iommu_free(struct iommu_table *, dma_addr_t, unsigned int);
@@ -725,6 +767,8 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid, 
		welcomed = 1;

	}



	iommu_debugfs_add(tbl);



	return tbl;

}
@@ -744,6 +788,8 @@ static void iommu_table_free(struct kref *kref) 
		return;

	}



	iommu_debugfs_del(tbl);



	iommu_table_release_pages(tbl);



	/* verify that table contains no entries */