Commit 7559d3d2 authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Michael Ellerman
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powerpc/pseries: Allow not having ibm, hypertas-functions::hcall-multi-tce for DDW 



By default a pseries guest supports a H_PUT_TCE hypercall which maps
a single IOMMU page in a DMA window. Additionally the hypervisor may
support H_PUT_TCE_INDIRECT/H_STUFF_TCE which update multiple TCEs at once;
this is advertised via the device tree /rtas/ibm,hypertas-functions
property which Linux converts to FW_FEATURE_MULTITCE.

FW_FEATURE_MULTITCE is checked when dma_iommu_ops is used; however
the code managing the huge DMA window (DDW) ignores it and calls
H_PUT_TCE_INDIRECT even if it is explicitly disabled via
the "multitce=off" kernel command line parameter.

This adds FW_FEATURE_MULTITCE checking to the DDW code path.

This changes tce_build_pSeriesLP to take liobn and page size as
the huge window does not have iommu_table descriptor which usually
the place to store these numbers.

Fixes: 4e8b0cf4 ("powerpc/pseries: Add support for dynamic dma windows")
Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: default avatarThiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: default avatarThiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191216041924.42318-3-aik@ozlabs.ru
parent d862b441

arch/powerpc/platforms/pseries/iommu.c

+29 −14
Original line number Diff line number Diff line
@@ -132,10 +132,10 @@ static unsigned long tce_get_pseries(struct iommu_table *tbl, long index) 
	return be64_to_cpu(*tcep);

}



static void tce_free_pSeriesLP(struct iommu_table*, long, long);

static void tce_free_pSeriesLP(unsigned long liobn, long, long);

static void tce_freemulti_pSeriesLP(struct iommu_table*, long, long);



static int tce_build_pSeriesLP(struct iommu_table *tbl, long tcenum,

static int tce_build_pSeriesLP(unsigned long liobn, long tcenum, long tceshift,

				long npages, unsigned long uaddr,

				enum dma_data_direction direction,

				unsigned long attrs)
@@ -146,25 +146,25 @@ static int tce_build_pSeriesLP(struct iommu_table *tbl, long tcenum, 
	int ret = 0;

	long tcenum_start = tcenum, npages_start = npages;



	rpn = __pa(uaddr) >> TCE_SHIFT;

	rpn = __pa(uaddr) >> tceshift;

	proto_tce = TCE_PCI_READ;

	if (direction != DMA_TO_DEVICE)

		proto_tce |= TCE_PCI_WRITE;



	while (npages--) {

		tce = proto_tce | (rpn & TCE_RPN_MASK) << TCE_RPN_SHIFT;

		rc = plpar_tce_put((u64)tbl->it_index, (u64)tcenum << 12, tce);

		tce = proto_tce | (rpn & TCE_RPN_MASK) << tceshift;

		rc = plpar_tce_put((u64)liobn, (u64)tcenum << tceshift, tce);



		if (unlikely(rc == H_NOT_ENOUGH_RESOURCES)) {

			ret = (int)rc;

			tce_free_pSeriesLP(tbl, tcenum_start,

			tce_free_pSeriesLP(liobn, tcenum_start,

			                   (npages_start - (npages + 1)));

			break;

		}



		if (rc && printk_ratelimit()) {

			printk("tce_build_pSeriesLP: plpar_tce_put failed. rc=%lld\n", rc);

			printk("\tindex   = 0x%llx\n", (u64)tbl->it_index);

			printk("\tindex   = 0x%llx\n", (u64)liobn);

			printk("\ttcenum  = 0x%llx\n", (u64)tcenum);

			printk("\ttce val = 0x%llx\n", tce );

			dump_stack();
@@ -193,7 +193,8 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum, 
	unsigned long flags;



	if ((npages == 1) || !firmware_has_feature(FW_FEATURE_MULTITCE)) {

		return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,

		return tce_build_pSeriesLP(tbl->it_index, tcenum,

					   tbl->it_page_shift, npages, uaddr,

		                           direction, attrs);

	}
@@ -209,8 +210,9 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum, 
		/* If allocation fails, fall back to the loop implementation */

		if (!tcep) {

			local_irq_restore(flags);

			return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,

					    direction, attrs);

			return tce_build_pSeriesLP(tbl->it_index, tcenum,

					tbl->it_page_shift,

					npages, uaddr, direction, attrs);

		}

		__this_cpu_write(tce_page, tcep);

	}
@@ -261,16 +263,16 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum, 
	return ret;

}



static void tce_free_pSeriesLP(struct iommu_table *tbl, long tcenum, long npages)

static void tce_free_pSeriesLP(unsigned long liobn, long tcenum, long npages)

{

	u64 rc;



	while (npages--) {

		rc = plpar_tce_put((u64)tbl->it_index, (u64)tcenum << 12, 0);

		rc = plpar_tce_put((u64)liobn, (u64)tcenum << 12, 0);



		if (rc && printk_ratelimit()) {

			printk("tce_free_pSeriesLP: plpar_tce_put failed. rc=%lld\n", rc);

			printk("\tindex   = 0x%llx\n", (u64)tbl->it_index);

			printk("\tindex   = 0x%llx\n", (u64)liobn);

			printk("\ttcenum  = 0x%llx\n", (u64)tcenum);

			dump_stack();

		}
@@ -285,7 +287,7 @@ static void tce_freemulti_pSeriesLP(struct iommu_table *tbl, long tcenum, long n 
	u64 rc;



	if (!firmware_has_feature(FW_FEATURE_MULTITCE))

		return tce_free_pSeriesLP(tbl, tcenum, npages);

		return tce_free_pSeriesLP(tbl->it_index, tcenum, npages);



	rc = plpar_tce_stuff((u64)tbl->it_index, (u64)tcenum << 12, 0, npages);
@@ -400,6 +402,19 @@ static int tce_setrange_multi_pSeriesLP(unsigned long start_pfn, 
	u64 rc = 0;

	long l, limit;



	if (!firmware_has_feature(FW_FEATURE_MULTITCE)) {

		unsigned long tceshift = be32_to_cpu(maprange->tce_shift);

		unsigned long dmastart = (start_pfn << PAGE_SHIFT) +

				be64_to_cpu(maprange->dma_base);

		unsigned long tcenum = dmastart >> tceshift;

		unsigned long npages = num_pfn << PAGE_SHIFT >> tceshift;

		void *uaddr = __va(start_pfn << PAGE_SHIFT);



		return tce_build_pSeriesLP(be32_to_cpu(maprange->liobn),

				tcenum, tceshift, npages, (unsigned long) uaddr,

				DMA_BIDIRECTIONAL, 0);

	}



	local_irq_disable();	/* to protect tcep and the page behind it */

	tcep = __this_cpu_read(tce_page);