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Commit f5ce1f2e authored by Chintan Pandya's avatar Chintan Pandya
Browse files

iommu: msm: fix secure fault handler debug logs 



Present debug log mechanism of secure context bank fault
handler doesn't behave well when it tries to obtain
register dumps from secure environment and fails to get a
sane response.

It is observed that the secure environment doesn't fill up
the register dump structure passed by the kernel correctly.
This leads to secure fault handler constantly dumping
default initialized values for these register making no
sense.

This patch intends to address this issue and fixes
following.

   * initialize dump holding structure and response variable
     to 0
   * return IRQ_NONE and do not proceed if secure
     environment response is 0 length
   * replace incorrect CB register address prints by
     actual context numbers and register offsets.

Change-Id: I07f329fd5dcb4fc56f7bb9a6dc182b73b806005c
Signed-off-by: default avatarChintan Pandya <cpandya@codeaurora.org>
parent 6212b769

drivers/iommu/msm_iommu_sec.c

+14 −7
Original line number Diff line number Diff line
@@ -128,7 +128,7 @@ static int msm_iommu_dump_fault_regs(int smmu_id, int cb_num, 
		uint32_t buff;

		uint32_t len;

	} req_info;

	int resp;

	int resp = 0;



	req_info.id = smmu_id;

	req_info.cb_num = cb_num;
@@ -155,6 +155,9 @@ static int msm_iommu_reg_dump_to_regs( 
	phys_addr_t phys_base = drvdata->phys_base;

	int ctx = ctx_drvdata->num;



	if (!nvals)

		return -EINVAL;



	for (i = 1; it < end; it += 2, i += 2) {

		unsigned int reg_offset;

		uint32_t addr	= *it;
@@ -222,12 +225,10 @@ static int msm_iommu_reg_dump_to_regs( 
	for (i = 0; i < MAX_DUMP_REGS; ++i) {

		if (!ctx_regs[i].valid) {

			if (dump_regs_tbl[i].must_be_present) {

				pr_err("Register missing from dump: %s, 0x%x (0x%lx)\n",

				pr_err("Register missing from dump for ctx %d: %s, 0x%x\n",

					ctx,

					dump_regs_tbl[i].name,

					dump_regs_tbl[i].reg_offset,

					(unsigned long)

					(phys_base +

						dump_regs_tbl[i].reg_offset));

					dump_regs_tbl[i].reg_offset);

				ret = 1;

			}

			ctx_regs[i].val = 0xd00dfeed;
@@ -255,7 +256,7 @@ irqreturn_t msm_iommu_secure_fault_handler_v2(int irq, void *dev_id) 
	ctx_drvdata = dev_get_drvdata(&pdev->dev);

	BUG_ON(!ctx_drvdata);



	regs = kmalloc(sizeof(*regs), GFP_KERNEL);

	regs = kzalloc(sizeof(*regs), GFP_KERNEL);

	if (!regs) {

		pr_err("%s: Couldn't allocate memory\n", __func__);

		goto lock_release;
@@ -287,6 +288,12 @@ irqreturn_t msm_iommu_secure_fault_handler_v2(int irq, void *dev_id) 
		memset(ctx_regs, 0, sizeof(ctx_regs));

		tmp = msm_iommu_reg_dump_to_regs(

			ctx_regs, regs, drvdata, ctx_drvdata);

		if (tmp < 0) {

			ret = IRQ_NONE;

			pr_err("Incorrect response from secure environment\n");

			goto free_regs;

		}



		if (ctx_regs[DUMP_REG_FSR].val) {

			if (tmp)

				pr_err("Incomplete fault register dump. Printout will be incomplete.\n");