87e956e9 changed the fault handler to return -ENOSYS, which causes the
iommu driver to print out a huge splat.  Which wouldn't be quite so bad
if nothing ever faulted.  But seems like some EXA composite operations
generate quite a lot of (seemingly harmless) faults.  That is probably a
userspace problem, but the huge increase in verbosity from iommu fault
dumps makes things kind of unusable.
We probably should actually log *some* message (not conditional on
drm.debug).  But ratelimit it.
Signed-off-by: Rob Clark <robdclark@gmail.com>
		
	
			
		
			
				
	
	
		
			140 lines
		
	
	
	
		
			3.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			140 lines
		
	
	
	
		
			3.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (C) 2013 Red Hat
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 * Author: Rob Clark <robdclark@gmail.com>
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 *
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 * This program is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 as published by
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 * the Free Software Foundation.
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 *
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 * This program is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
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 * more details.
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 *
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 * You should have received a copy of the GNU General Public License along with
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 * this program.  If not, see <http://www.gnu.org/licenses/>.
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 */
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#include "msm_drv.h"
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#include "msm_mmu.h"
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struct msm_iommu {
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	struct msm_mmu base;
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	struct iommu_domain *domain;
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};
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#define to_msm_iommu(x) container_of(x, struct msm_iommu, base)
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static int msm_fault_handler(struct iommu_domain *iommu, struct device *dev,
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		unsigned long iova, int flags, void *arg)
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{
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	pr_warn_ratelimited("*** fault: iova=%08lx, flags=%d\n", iova, flags);
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	return 0;
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}
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static int msm_iommu_attach(struct msm_mmu *mmu, const char **names, int cnt)
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{
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	struct msm_iommu *iommu = to_msm_iommu(mmu);
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	return iommu_attach_device(iommu->domain, mmu->dev);
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}
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static void msm_iommu_detach(struct msm_mmu *mmu, const char **names, int cnt)
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{
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	struct msm_iommu *iommu = to_msm_iommu(mmu);
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	iommu_detach_device(iommu->domain, mmu->dev);
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}
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static int msm_iommu_map(struct msm_mmu *mmu, uint32_t iova,
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		struct sg_table *sgt, unsigned len, int prot)
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{
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	struct msm_iommu *iommu = to_msm_iommu(mmu);
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	struct iommu_domain *domain = iommu->domain;
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	struct scatterlist *sg;
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	unsigned int da = iova;
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	unsigned int i, j;
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	int ret;
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	if (!domain || !sgt)
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		return -EINVAL;
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	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
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		u32 pa = sg_phys(sg) - sg->offset;
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		size_t bytes = sg->length + sg->offset;
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		VERB("map[%d]: %08x %08x(%x)", i, iova, pa, bytes);
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		ret = iommu_map(domain, da, pa, bytes, prot);
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		if (ret)
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			goto fail;
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		da += bytes;
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	}
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	return 0;
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fail:
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	da = iova;
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	for_each_sg(sgt->sgl, sg, i, j) {
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		size_t bytes = sg->length + sg->offset;
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		iommu_unmap(domain, da, bytes);
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		da += bytes;
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	}
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	return ret;
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}
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static int msm_iommu_unmap(struct msm_mmu *mmu, uint32_t iova,
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		struct sg_table *sgt, unsigned len)
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{
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	struct msm_iommu *iommu = to_msm_iommu(mmu);
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	struct iommu_domain *domain = iommu->domain;
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	struct scatterlist *sg;
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	unsigned int da = iova;
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	int i;
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	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
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		size_t bytes = sg->length + sg->offset;
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		size_t unmapped;
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		unmapped = iommu_unmap(domain, da, bytes);
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		if (unmapped < bytes)
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			return unmapped;
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		VERB("unmap[%d]: %08x(%x)", i, iova, bytes);
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		BUG_ON(!PAGE_ALIGNED(bytes));
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		da += bytes;
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	}
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	return 0;
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}
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static void msm_iommu_destroy(struct msm_mmu *mmu)
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{
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	struct msm_iommu *iommu = to_msm_iommu(mmu);
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	iommu_domain_free(iommu->domain);
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	kfree(iommu);
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}
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static const struct msm_mmu_funcs funcs = {
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		.attach = msm_iommu_attach,
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		.detach = msm_iommu_detach,
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		.map = msm_iommu_map,
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		.unmap = msm_iommu_unmap,
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		.destroy = msm_iommu_destroy,
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};
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struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain)
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{
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	struct msm_iommu *iommu;
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	iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
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	if (!iommu)
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		return ERR_PTR(-ENOMEM);
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	iommu->domain = domain;
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	msm_mmu_init(&iommu->base, dev, &funcs);
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	iommu_set_fault_handler(domain, msm_fault_handler, dev);
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	return &iommu->base;
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}
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