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Commit 7a34b607 authored by Olav Haugan's avatar Olav Haugan
Browse files

iommu: msm: Check VBIF state during IOMMU access timeout 



Check whether halting the VBIF XIN when the TLB sync or IOMMU halt
times out clears the issue indicating an issue with the master not clearing
the VBIF FIFO.

Change-Id: I552f72db17e31a174ab2725bbecbf4ad98a9d378
Signed-off-by: default avatarOlav Haugan <ohaugan@codeaurora.org>
parent 6a233e66

drivers/iommu/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -101,6 +101,16 @@ config IOMMU_LPAE 


	  If unsure, say N here.



config MSM_IOMMU_VBIF_CHECK

	bool "Enable support for VBIF check when IOMMU gets stuck"

	depends on MSM_IOMMU

	help

	  Enables an extra check in the IOMMU driver that logs debugging

	  information when TLB sync or iommu halt issue occurs. This helps

	  in debugging such issues.



	  If unsure, say N here.



config IOMMU_NON_SECURE

	bool "Turns on programming of secure SMMU by kernel"

	depends on MSM_IOMMU

drivers/iommu/msm_iommu-v1.c

+124 −3
Original line number Diff line number Diff line
@@ -175,6 +175,127 @@ struct iommu_access_ops iommu_access_ops_v1 = { 
	.iommu_lock_release = _iommu_lock_release,

};



#ifdef CONFIG_MSM_IOMMU_VBIF_CHECK



#define VBIF_XIN_HALT_CTRL0 0x200

#define VBIF_XIN_HALT_CTRL1 0x204

#define VBIF_AXI_HALT_CTRL0 0x208

#define VBIF_AXI_HALT_CTRL1 0x20C



static void __halt_vbif_xin(void __iomem *vbif_base)

{

	pr_err("Halting VBIF_XIN\n");

	writel_relaxed(0xFFFFFFFF, vbif_base + VBIF_XIN_HALT_CTRL0);

}



static void __dump_vbif_state(void __iomem *base, void __iomem *vbif_base)

{

	unsigned int reg_val;



	reg_val = readl_relaxed(base + MICRO_MMU_CTRL);

	pr_err("Value of SMMU_IMPLDEF_MICRO_MMU_CTRL = 0x%x\n", reg_val);



	reg_val = readl_relaxed(vbif_base + VBIF_XIN_HALT_CTRL0);

	pr_err("Value of VBIF_XIN_HALT_CTRL0 = 0x%x\n", reg_val);

	reg_val = readl_relaxed(vbif_base + VBIF_XIN_HALT_CTRL1);

	pr_err("Value of VBIF_XIN_HALT_CTRL1 = 0x%x\n", reg_val);

	reg_val = readl_relaxed(vbif_base + VBIF_AXI_HALT_CTRL0);

	pr_err("Value of VBIF_AXI_HALT_CTRL0 = 0x%x\n", reg_val);

	reg_val = readl_relaxed(vbif_base + VBIF_AXI_HALT_CTRL1);

	pr_err("Value of VBIF_AXI_HALT_CTRL1 = 0x%x\n", reg_val);

}



static int __check_vbif_state(struct msm_iommu_drvdata const *drvdata)

{

	phys_addr_t addr = (phys_addr_t) (drvdata->phys_base

			   - (phys_addr_t) 0x4000);

	void __iomem *base = ioremap(addr, 0x1000);

	int ret = 0;



	if (base) {

		__dump_vbif_state(drvdata->base, base);

		__halt_vbif_xin(drvdata->base);

		__dump_vbif_state(drvdata->base, base);

		iounmap(base);

	} else {

		pr_err("%s: Unable to ioremap\n", __func__);

		ret = -ENOMEM;

	}

	return ret;

}



static void check_halt_state(struct msm_iommu_drvdata const *drvdata)

{

	int res;

	unsigned int val;

	void __iomem *base = drvdata->base;

	char const *name = drvdata->name;



	pr_err("Timed out waiting for IOMMU halt to complete for %s\n", name);

	res = __check_vbif_state(drvdata);

	if (res)

		BUG();



	pr_err("Checking if IOMMU halt completed for %s\n", name);



	res = readl_tight_poll_timeout(

		GLB_REG(MICRO_MMU_CTRL, base), val,

			(val & MMU_CTRL_IDLE) == MMU_CTRL_IDLE, 5000000);



	if (res) {

		pr_err("Timed out (again) waiting for IOMMU halt to complete for %s\n",

			name);

	} else {

		pr_err("IOMMU halt completed. VBIF FIFO most likely not getting drained by master\n");

	}

	BUG();

}



static void check_tlb_sync_state(struct msm_iommu_drvdata const *drvdata,

				int ctx)

{

	int res;

	unsigned int val;

	void __iomem *base = drvdata->base;

	char const *name = drvdata->name;



	pr_err("Timed out waiting for TLB SYNC to complete for %s\n", name);

	res = __check_vbif_state(drvdata);

	if (res)

		BUG();



	pr_err("Checking if TLB sync completed for %s\n", name);



	res = readl_tight_poll_timeout(CTX_REG(CB_TLBSTATUS, base, ctx), val,

				(val & CB_TLBSTATUS_SACTIVE) == 0, 5000000);

	if (res) {

		pr_err("Timed out (again) waiting for TLB SYNC to complete for %s\n",

			name);

	} else {

		pr_err("TLB Sync completed. VBIF FIFO most likely not getting drained by master\n");

	}

	BUG();

}



#else



/*

 * For targets without VBIF or for targets with the VBIF check disabled

 * we directly just crash to capture the issue

 */

static void check_halt_state(struct msm_iommu_drvdata const *drvdata)

{

	BUG();

}



static void check_tlb_sync_state(struct msm_iommu_drvdata const *drvdata,

				int ctx)

{

	BUG();

}



#endif



void iommu_halt(struct msm_iommu_drvdata const *iommu_drvdata)

{

	if (iommu_drvdata->halt_enabled) {
@@ -188,7 +309,7 @@ void iommu_halt(struct msm_iommu_drvdata const *iommu_drvdata) 
			     (val & MMU_CTRL_IDLE) == MMU_CTRL_IDLE, 5000000);



		if (res)

			BUG();

			check_halt_state(iommu_drvdata);

		/* Ensure device is idle before continuing */

		mb();

	}
@@ -219,12 +340,12 @@ static void __sync_tlb(struct msm_iommu_drvdata *iommu_drvdata, int ctx) 
	void __iomem *base = iommu_drvdata->cb_base;



	SET_TLBSYNC(base, ctx, 0);



	/* No barrier needed due to read dependency */



	res = readl_tight_poll_timeout(CTX_REG(CB_TLBSTATUS, base, ctx), val,

				(val & CB_TLBSTATUS_SACTIVE) == 0, 5000000);

	if (res)

		BUG();

		check_tlb_sync_state(iommu_drvdata, ctx);

}



static int __flush_iotlb_va(struct iommu_domain *domain, unsigned int va)