Commit 38727311 authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Michael Ellerman
Browse files

powerps/pseries/dma: Add support for 2M IOMMU page size 



The upcoming PAPR spec adds a 2M page size, bit 23 right after 16G page
size in the "ibm,query-pe-dma-window" call.

This adds support for the new page size. Since the new page size is out
of sorted order, this changes the loop to not assume that shift[] is
sorted.

This has now been tested and is known to work on a pre-release version
of phyp.

Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: default avatarLeonardo Bras <leobras.c@gmail.com>
Reviewed-by: default avatarFrederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211006044735.1114669-1-aik@ozlabs.ru
parent e4e737bb

arch/powerpc/platforms/pseries/iommu.c

+5 −5
Original line number Diff line number Diff line
@@ -1159,14 +1159,15 @@ static void reset_dma_window(struct pci_dev *dev, struct device_node *par_dn) 
/* Return largest page shift based on "IO Page Sizes" output of ibm,query-pe-dma-window. */

static int iommu_get_page_shift(u32 query_page_size)

{

	/* Supported IO page-sizes according to LoPAR */

	/* Supported IO page-sizes according to LoPAR, note that 2M is out of order */

	const int shift[] = {

		__builtin_ctzll(SZ_4K),   __builtin_ctzll(SZ_64K), __builtin_ctzll(SZ_16M),

		__builtin_ctzll(SZ_32M),  __builtin_ctzll(SZ_64M), __builtin_ctzll(SZ_128M),

		__builtin_ctzll(SZ_256M), __builtin_ctzll(SZ_16G)

		__builtin_ctzll(SZ_256M), __builtin_ctzll(SZ_16G), __builtin_ctzll(SZ_2M)

	};



	int i = ARRAY_SIZE(shift) - 1;

	int ret = 0;



	/*

	 * On LoPAR, ibm,query-pe-dma-window outputs "IO Page Sizes" using a bit field:
@@ -1176,11 +1177,10 @@ static int iommu_get_page_shift(u32 query_page_size) 
	 */

	for (; i >= 0 ; i--) {

		if (query_page_size & (1 << i))

			return shift[i];

			ret = max(ret, shift[i]);

	}



	/* No valid page size found. */

	return 0;

	return ret;

}



static struct property *ddw_property_create(const char *propname, u32 liobn, u64 dma_addr,