Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8fb0156d authored by Mitchel Humpherys's avatar Mitchel Humpherys
Browse files

iommu/io-pgtable: Add memory stats debugfs file 



It can be useful for debugging to know how much memory is being used for
IOMMU page tables.  Add some dedicated allocation functions and a
debugfs file for this.

Change-Id: Id69b4b1b5df5dcc6c604eec3a12a894b8eab0eb6
Signed-off-by: default avatarMitchel Humpherys <mitchelh@codeaurora.org>
parent 4e1e4ed2

drivers/iommu/io-pgtable-arm.c

+7 −5
Original line number Diff line number Diff line
@@ -249,7 +249,7 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova, 
	/* Grab a pointer to the next level */

	pte = *ptep;

	if (!pte) {

		cptep = alloc_pages_exact(1UL << data->pg_shift,

		cptep = io_pgtable_alloc_pages_exact(1UL << data->pg_shift,

						     GFP_ATOMIC | __GFP_ZERO);

		if (!cptep)

			return -ENOMEM;
@@ -414,7 +414,7 @@ static void __arm_lpae_free_pgtable(struct arm_lpae_io_pgtable *data, int lvl, 
	}



	data->iop.cfg.tlb->unprepare_pgtable(data->iop.cookie, start);

	free_pages_exact(start, table_size);

	io_pgtable_free_pages_exact(start, table_size);

}



static void arm_lpae_free_pgtable(struct io_pgtable *iop)
@@ -733,7 +733,8 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie) 
	cfg->arm_lpae_s1_cfg.mair[1] = 0;



	/* Looking good; allocate a pgd */

	data->pgd = alloc_pages_exact(data->pgd_size, GFP_KERNEL | __GFP_ZERO);

	data->pgd = io_pgtable_alloc_pages_exact(data->pgd_size,

						 GFP_KERNEL | __GFP_ZERO);

	if (!data->pgd)

		goto out_free_data;
@@ -821,7 +822,8 @@ arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie) 
	cfg->arm_lpae_s2_cfg.vtcr = reg;



	/* Allocate pgd pages */

	data->pgd = alloc_pages_exact(data->pgd_size, GFP_KERNEL | __GFP_ZERO);

	data->pgd = io_pgtable_alloc_pages_exact(data->pgd_size,

						 GFP_KERNEL | __GFP_ZERO);

	if (!data->pgd)

		goto out_free_data;

drivers/iommu/io-pgtable.c

+48 −0
Original line number Diff line number Diff line
@@ -18,9 +18,14 @@ 
 * Author: Will Deacon <will.deacon@arm.com>

 */



#define pr_fmt(fmt)	"io-pgtable: " fmt



#include <linux/bug.h>

#include <linux/kernel.h>

#include <linux/types.h>

#include <linux/iommu.h>

#include <linux/debugfs.h>

#include <linux/atomic.h>



#include "io-pgtable.h"
@@ -40,6 +45,8 @@ io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = 
#endif

};



static struct dentry *io_pgtable_top;



struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,

					    struct io_pgtable_cfg *cfg,

					    void *cookie)
@@ -80,3 +87,44 @@ void free_io_pgtable_ops(struct io_pgtable_ops *ops) 
	iop->cfg.tlb->tlb_flush_all(iop->cookie);

	io_pgtable_init_table[iop->fmt]->free(iop);

}



static atomic_t pages_allocated;



void *io_pgtable_alloc_pages_exact(size_t size, gfp_t gfp_mask)

{

	void *ret = alloc_pages_exact(size, gfp_mask);



	if (likely(ret))

		atomic_add(1 << get_order(size), &pages_allocated);

	return ret;

}



void io_pgtable_free_pages_exact(void *virt, size_t size)

{

	free_pages_exact(virt, size);

	atomic_sub(1 << get_order(size), &pages_allocated);

}



static int io_pgtable_init(void)

{

	io_pgtable_top = debugfs_create_dir("io-pgtable", iommu_debugfs_top);



	if (!io_pgtable_top)

		return -ENODEV;



	if (!debugfs_create_atomic_t("pages", 0600,

				     io_pgtable_top, &pages_allocated)) {

		debugfs_remove_recursive(io_pgtable_top);

		return -ENODEV;

	}



	return 0;

}



static void io_pgtable_exit(void)

{

	debugfs_remove_recursive(io_pgtable_top);

}



module_init(io_pgtable_init);

module_exit(io_pgtable_exit);

drivers/iommu/io-pgtable.h

+20 −0
Original line number Diff line number Diff line
@@ -148,4 +148,24 @@ struct io_pgtable_init_fns { 
	void (*free)(struct io_pgtable *iop);

};



/**

 * io_pgtable_alloc_pages_exact - allocate an exact number physically-contiguous pages.

 * @size: the number of bytes to allocate

 * @gfp_mask: GFP flags for the allocation

 *

 * Like alloc_pages_exact(), but with some additional accounting for debug

 * purposes.

 */

void *io_pgtable_alloc_pages_exact(size_t size, gfp_t gfp_mask);



/**

 * io_pgtable_free_pages_exact - release memory allocated via io_pgtable_alloc_pages_exact()

 * @virt: the value returned by alloc_pages_exact.

 * @size: size of allocation, same value as passed to alloc_pages_exact().

 *

 * Like free_pages_exact(), but with some additional accounting for debug

 * purposes.

 */

void io_pgtable_free_pages_exact(void *virt, size_t size);



#endif /* __IO_PGTABLE_H */