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Commit f01d6e38 authored by Mitchel Humpherys's avatar Mitchel Humpherys Committed by Patrick Daly
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>
Signed-off-by: default avatarPatrick Daly <pdaly@codeaurora.org>
parent c75ae496

drivers/iommu/io-pgtable-arm.c

+3 −3
Original line number Diff line number Diff line
@@ -286,7 +286,7 @@ static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp, 
{

	struct device *dev = cfg->iommu_dev;

	dma_addr_t dma;

	void *pages = alloc_pages_exact(size, gfp | __GFP_ZERO);

	void *pages = io_pgtable_alloc_pages_exact(size, gfp | __GFP_ZERO);



	if (!pages)

		return NULL;
@@ -310,7 +310,7 @@ static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp, 
	dev_err(dev, "Cannot accommodate DMA translation for IOMMU page tables\n");

	dma_unmap_single(dev, dma, size, DMA_TO_DEVICE);

out_free:

	free_pages_exact(pages, size);

	io_pgtable_free_pages_exact(pages, size);

	return NULL;

}
@@ -320,7 +320,7 @@ static void __arm_lpae_free_pages(void *pages, size_t size, 
	if (!selftest_running)

		dma_unmap_single(cfg->iommu_dev, __arm_lpae_dma_addr(pages),

				 size, DMA_TO_DEVICE);

	free_pages_exact(pages, size);

	io_pgtable_free_pages_exact(pages, size);

}



static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, arm_lpae_iopte pte,

drivers/iommu/io-pgtable.c

+49 −0
Original line number Diff line number Diff line
@@ -18,9 +18,15 @@ 
 * 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 <linux/module.h>



#include "io-pgtable.h"
@@ -37,6 +43,8 @@ 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)
@@ -77,3 +85,44 @@ void free_io_pgtable_ops(struct io_pgtable_ops *ops) 
	io_pgtable_tlb_flush_all(iop);

	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

+22 −0
Original line number Diff line number Diff line
@@ -213,4 +213,26 @@ extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns; 
extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;

extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns;



/**

 * io_pgtable_alloc_pages_exact:

 *	allocate an exact number of 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 */