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Commit a697e21d authored by Vikram Mulukutla's avatar Vikram Mulukutla
Browse files

msm: scm-pas: Provide a strongly ordered buffer to the secure world 



The secure world requires that the metadata-containing buffer
be strongly ordered. Use the dma_alloc_attrs API to obtain a
strongly ordered region for this purpose.

CRs-Fixed: 525863
Change-Id: I0fdfb9957aa0eb66279afa362edec075c3dff131
Signed-off-by: default avatarVikram Mulukutla <markivx@codeaurora.org>
parent 6e5f62e7

arch/arm/mach-msm/scm-pas.c

+13 −10
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/slab.h>

#include <linux/string.h>

#include <linux/clk.h>

#include <linux/dma-mapping.h>



#include <asm/cacheflush.h>
@@ -138,28 +139,30 @@ int pas_init_image(enum pas_id id, const u8 *metadata, size_t size) 
	} request;

	u32 scm_ret = 0;

	void *mdata_buf;

	dma_addr_t mdata_phys;

	DEFINE_DMA_ATTRS(attrs);



	ret = scm_pas_enable_bw();

	if (ret)

		return ret;



	/* Make memory physically contiguous */

	mdata_buf = kmemdup(metadata, size, GFP_KERNEL);



	if (!mdata_buf)

	dma_set_attr(DMA_ATTR_STRONGLY_ORDERED, &attrs);

	mdata_buf = dma_alloc_attrs(NULL, size, &mdata_phys, GFP_KERNEL,

					&attrs);

	if (!mdata_buf) {

		pr_err("Allocation for metadata failed.\n");

		return -ENOMEM;

	}



	request.proc = id;

	request.image_addr = virt_to_phys(mdata_buf);

	memcpy(mdata_buf, metadata, size);



	/* Flush metadata to ensure secure world doesn't read stale data */

	__cpuc_flush_dcache_area(mdata_buf, size);

	outer_flush_range(request.image_addr, request.image_addr + size);

	request.proc = id;

	request.image_addr = mdata_phys;



	ret = scm_call(SCM_SVC_PIL, PAS_INIT_IMAGE_CMD, &request,

			sizeof(request), &scm_ret, sizeof(scm_ret));



	kfree(mdata_buf);

	dma_free_attrs(NULL, size, mdata_buf, mdata_phys, &attrs);

	scm_pas_disable_bw();



	if (ret)