[PATCH v3] powerpc/iommu/ddw: Fix endianness
Alexey Kardashevskiy
aik at ozlabs.ru
Thu Sep 25 16:39:18 EST 2014
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 at vger.kernel.org # v3.13
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Reviewed-by: Anton Blanchard <anton at samba.org>
[aik: folded Anton's patch with of_property_read_u32_array]
Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
Changes:
v3:
* of_property_read_u32_array() is used for ddw_avail[]
v2:
* updated commit log
* fixed definition of ddw_query_response and ddw_create_response
---
arch/powerpc/platforms/pseries/iommu.c | 51 +++++++++++++++++++---------------
1 file changed, 28 insertions(+), 23 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 4642d6a..de1ec54 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -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:
--
2.0.0
More information about the Linuxppc-dev
mailing list