[PATCH v1 08/10] powerpc/pseries/iommu: Add ddw_property_create() and refactor enable_ddw()

Leonardo Bras
2020-08-17T23:41:36Z

Code used to create a ddw property that was previously scattered in
enable_ddw() is now gathered in ddw_property_create(), which deals with
allocation and filling the property, letting it ready for
of_property_add(), which now occurs in sequence.

This created an opportunity to reorganize the second part of enable_ddw():

Without this patch enable_ddw() does, in order:
kzalloc() property & members, create_ddw(), fill ddwprop inside property,
ddw_list_add(), do tce_setrange_multi_pSeriesLP_walk in all memory,
of_add_property().

With this patch enable_ddw() does, in order:
create_ddw(), ddw_property_create(), of_add_property(), ddw_list_add(),
do tce_setrange_multi_pSeriesLP_walk in all memory.

This change requires of_remove_property() in case anything fails after
of_add_property(), but we get to do tce_setrange_multi_pSeriesLP_walk
in all memory, which looks the most expensive operation, only if
everything else succeeds.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
---
arch/powerpc/platforms/pseries/iommu.c | 97 +++++++++++++++-----------
1 file changed, 57 insertions(+), 40 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 4031127c9537..3a1ef02ad9d5 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1123,6 +1123,31 @@ static void reset_dma_window(struct pci_dev *dev, struct device_node *par_dn)
ret);
}

+static int ddw_property_create(struct property **ddw_win, const char *propname,
+ u32 liobn, u64 dma_addr, u32 page_shift, u32 window_shift)
+{
+ struct dynamic_dma_window_prop *ddwprop;
+ struct property *win64;
+
+ *ddw_win = win64 = kzalloc(sizeof(*win64), GFP_KERNEL);
+ if (!win64)
+ return -ENOMEM;
+
+ win64->name = kstrdup(propname, GFP_KERNEL);
+ ddwprop = kzalloc(sizeof(*ddwprop), GFP_KERNEL);
+ win64->value = ddwprop;
+ win64->length = sizeof(*ddwprop);
+ if (!win64->name || !win64->value)
+ return -ENOMEM;
+
+ ddwprop->liobn = cpu_to_be32(liobn);
+ ddwprop->dma_base = cpu_to_be64(dma_addr);
+ ddwprop->tce_shift = cpu_to_be32(page_shift);
+ ddwprop->window_shift = cpu_to_be32(window_shift);
+
+ return 0;
+}
+
/*
* If the PE supports dynamic dma windows, and there is space for a table
* that can map all pages in a linear offset, then setup such a table,
@@ -1140,12 +1165,11 @@ static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)
struct ddw_query_response query;
struct ddw_create_response create;
int page_shift;
- u64 max_addr;
+ u64 max_addr, win_addr;
struct device_node *dn;
u32 ddw_avail[DDW_APPLICABLE_SIZE];
struct direct_window *window;
- struct property *win64;
- struct dynamic_dma_window_prop *ddwprop;
+ struct property *win64 = NULL;
struct failed_ddw_pdn *fpdn;
bool default_win_removed = false;

@@ -1244,38 +1268,34 @@ static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)
goto out_failed;
}
len = order_base_2(max_addr);
- win64 = kzalloc(sizeof(struct property), GFP_KERNEL);
- if (!win64) {
- dev_info(&dev->dev,
- "couldn't allocate property for 64bit dma window\n");
+
+ ret = create_ddw(dev, ddw_avail, &create, page_shift, len);
+ if (ret != 0)
goto out_failed;
- }
- win64->name = kstrdup(DIRECT64_PROPNAME, GFP_KERNEL);
- win64->value = ddwprop = kmalloc(sizeof(*ddwprop), GFP_KERNEL);
- win64->length = sizeof(*ddwprop);
- if (!win64->name || !win64->value) {
+
+ dev_dbg(&dev->dev, "created tce table LIOBN 0x%x for %pOF\n",
+ create.liobn, dn);
+
+ win_addr = ((u64)create.addr_hi << 32) | create.addr_lo;
+ ret = ddw_property_create(&win64, DIRECT64_PROPNAME, create.liobn, win_addr,
+ page_shift, len);
+ if (ret) {
dev_info(&dev->dev,
- "couldn't allocate property name and value\n");
+ "couldn't allocate property, property name, or value\n");
goto out_free_prop;
}

- ret = create_ddw(dev, ddw_avail, &create, page_shift, len);
- if (ret != 0)
+ ret = of_add_property(pdn, win64);
+ if (ret) {
+ dev_err(&dev->dev, "unable to add dma window property for %pOF: %d",
+ pdn, ret);
goto out_free_prop;
-
- 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);
-
- dev_dbg(&dev->dev, "created tce table LIOBN 0x%x for %pOF\n",
- create.liobn, dn);
+ }

/* Add new window to existing DDW list */
- window = ddw_list_add(pdn, ddwprop);
+ window = ddw_list_add(pdn, win64->value);
if (!window)
- goto out_clear_window;
+ goto out_prop_del;

ret = walk_system_ram_range(0, memblock_end_of_DRAM() >> PAGE_SHIFT,
win64->value, tce_setrange_multi_pSeriesLP_walk);
@@ -1285,14 +1305,7 @@ static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)
goto out_free_window;
}

- ret = of_add_property(pdn, win64);
- if (ret) {
- dev_err(&dev->dev, "unable to add dma window property for %pOF: %d",
- pdn, ret);
- goto out_free_window;
- }
-
- dev->dev.archdata.dma_offset = be64_to_cpu(ddwprop->dma_base);
+ dev->dev.archdata.dma_offset = win_addr;
goto out_unlock;

out_free_window:
@@ -1302,14 +1315,18 @@ static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)

kfree(window);

-out_clear_window:
- remove_ddw(pdn, true);
+out_prop_del:
+ of_remove_property(pdn, win64);

out_free_prop:
- kfree(win64->name);
- kfree(win64->value);
- kfree(win64);
- win64 = NULL;
+ if (win64) {
+ kfree(win64->name);
+ kfree(win64->value);
+ kfree(win64);
+ win64 = NULL;
+ }
+
+ remove_ddw(pdn, true);

out_failed:
if (default_win_removed)
--
2.25.4