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Commit 9410e018 authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Michael Ellerman
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powerpc/iommu/ddw: Fix endianness 



rtas_call() accepts and returns values in CPU endianness.
The ddw_query_response and ddw_create_response structs members are
defined and treated as BE but as they are passed to rtas_call() as
(u32 *) and they get byteswapped automatically, the data is CPU-endian.
This fixes ddw_query_response and ddw_create_response definitions and use.

of_read_number() is designed to work with device tree cells - it assumes
the input is big-endian and returns data in CPU-endian. However due
to the ddw_create_response struct fix, create.addr_hi/lo are already
CPU-endian so do not byteswap them.

ddw_avail is a pointer to the "ibm,ddw-applicable" property which contains
3 cells which are big-endian as it is a device tree. rtas_call() accepts
a RTAS token in CPU-endian. This makes use of of_property_read_u32_array
to byte swap and avoid the need for a number of be32_to_cpu calls.

Cc: stable@vger.kernel.org # v3.13+
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[aik: folded Anton's patch with of_property_read_u32_array]
Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent a7696b36

arch/powerpc/platforms/pseries/iommu.c

+28 −23
Original line number Diff line number Diff line
@@ -329,16 +329,16 @@ struct direct_window { 


/* Dynamic DMA Window support */

struct ddw_query_response {

	__be32 windows_available;

	__be32 largest_available_block;

	__be32 page_size;

	__be32 migration_capable;

	u32 windows_available;

	u32 largest_available_block;

	u32 page_size;

	u32 migration_capable;

};



struct ddw_create_response {

	__be32 liobn;

	__be32 addr_hi;

	__be32 addr_lo;

	u32 liobn;

	u32 addr_hi;

	u32 addr_lo;

};



static LIST_HEAD(direct_window_list);
@@ -725,16 +725,18 @@ static void remove_ddw(struct device_node *np, bool remove_prop) 
{

	struct dynamic_dma_window_prop *dwp;

	struct property *win64;

	const u32 *ddw_avail;

	u32 ddw_avail[3];

	u64 liobn;

	int len, ret = 0;

	int ret = 0;



	ret = of_property_read_u32_array(np, "ibm,ddw-applicable",

					 &ddw_avail[0], 3);



	ddw_avail = of_get_property(np, "ibm,ddw-applicable", &len);

	win64 = of_find_property(np, DIRECT64_PROPNAME, NULL);

	if (!win64)

		return;



	if (!ddw_avail || len < 3 * sizeof(u32) || win64->length < sizeof(*dwp))

	if (ret || win64->length < sizeof(*dwp))

		goto delprop;



	dwp = win64->value;
@@ -872,8 +874,9 @@ static int create_ddw(struct pci_dev *dev, const u32 *ddw_avail, 


	do {

		/* extra outputs are LIOBN and dma-addr (hi, lo) */

		ret = rtas_call(ddw_avail[1], 5, 4, (u32 *)create, cfg_addr,

				BUID_HI(buid), BUID_LO(buid), page_shift, window_shift);

		ret = rtas_call(ddw_avail[1], 5, 4, (u32 *)create,

				cfg_addr, BUID_HI(buid), BUID_LO(buid),

				page_shift, window_shift);

	} while (rtas_busy_delay(ret));

	dev_info(&dev->dev,

		"ibm,create-pe-dma-window(%x) %x %x %x %x %x returned %d "
@@ -910,7 +913,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn) 
	int page_shift;

	u64 dma_addr, max_addr;

	struct device_node *dn;

	const u32 *uninitialized_var(ddw_avail);

	u32 ddw_avail[3];

	struct direct_window *window;

	struct property *win64;

	struct dynamic_dma_window_prop *ddwprop;
@@ -942,8 +945,9 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn) 
	 * for the given node in that order.

	 * the property is actually in the parent, not the PE

	 */

	ddw_avail = of_get_property(pdn, "ibm,ddw-applicable", &len);

	if (!ddw_avail || len < 3 * sizeof(u32))

	ret = of_property_read_u32_array(pdn, "ibm,ddw-applicable",

					 &ddw_avail[0], 3);

	if (ret)

		goto out_failed;



       /*
@@ -966,11 +970,11 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn) 
		dev_dbg(&dev->dev, "no free dynamic windows");

		goto out_failed;

	}

	if (be32_to_cpu(query.page_size) & 4) {

	if (query.page_size & 4) {

		page_shift = 24; /* 16MB */

	} else if (be32_to_cpu(query.page_size) & 2) {

	} else if (query.page_size & 2) {

		page_shift = 16; /* 64kB */

	} else if (be32_to_cpu(query.page_size) & 1) {

	} else if (query.page_size & 1) {

		page_shift = 12; /* 4kB */

	} else {

		dev_dbg(&dev->dev, "no supported direct page size in mask %x",
@@ -980,7 +984,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn) 
	/* verify the window * number of ptes will map the partition */

	/* check largest block * page size > max memory hotplug addr */

	max_addr = memory_hotplug_max();

	if (be32_to_cpu(query.largest_available_block) < (max_addr >> page_shift)) {

	if (query.largest_available_block < (max_addr >> page_shift)) {

		dev_dbg(&dev->dev, "can't map partiton max 0x%llx with %u "

			  "%llu-sized pages\n", max_addr,  query.largest_available_block,

			  1ULL << page_shift);
@@ -1006,8 +1010,9 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn) 
	if (ret != 0)

		goto out_free_prop;



	ddwprop->liobn = create.liobn;

	ddwprop->dma_base = cpu_to_be64(of_read_number(&create.addr_hi, 2));

	ddwprop->liobn = cpu_to_be32(create.liobn);

	ddwprop->dma_base = cpu_to_be64(((u64)create.addr_hi << 32) |

			create.addr_lo);

	ddwprop->tce_shift = cpu_to_be32(page_shift);

	ddwprop->window_shift = cpu_to_be32(len);
@@ -1039,7 +1044,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn) 
	list_add(&window->list, &direct_window_list);

	spin_unlock(&direct_window_list_lock);



	dma_addr = of_read_number(&create.addr_hi, 2);

	dma_addr = be64_to_cpu(ddwprop->dma_base);

	goto out_unlock;



out_free_window: