Re: [PATCH v5 06/11] powerpc/pseries/iommu: Add ddw_property_create() and refactor enable_ddw()

2021-08-16 Thread Leonardo Brás
Hello Fred, thanks for this feedback!

On Tue, 2021-07-20 at 19:49 +0200, Frederic Barrat wrote:
> 
> > kfree(window);
> >   
> > -out_clear_window:
> > -   remove_ddw(pdn, true);
> > +out_del_prop:
> > +   of_remove_property(pdn, win64);
> >   
> >   out_free_prop:
> > kfree(win64->name);
> > kfree(win64->value);
> > kfree(win64);
> >   
> > +out_remove_win:
> > +   remove_ddw(pdn, true);
> 
> 
> I believe there's a small problem here. We jump directly to 
> out_remove_win if allocating the property failed. Yet, the first
> thing 
> remove_ddw() does is look for the property. So it will never find it
> and 
> the window is never removed by the hypervisor.
> 
>    Fred

That makes sense, thanks for catching this one!

What I intended here was just removing the DDW, so I think it should be
ok replacing remove_ddw() by a new helper that only does the rtas-call.

I will send a v6 with this change soon.

> 
> 
> > +
> >   out_failed:
> > if (default_win_removed)
> > reset_dma_window(dev, pdn);
> > 




Re: [PATCH v5 06/11] powerpc/pseries/iommu: Add ddw_property_create() and refactor enable_ddw()

2021-07-20 Thread Frederic Barrat




On 16/07/2021 10:27, Leonardo Bras wrote:

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_new_entry(), do tce_setrange_multi_pSeriesLP_walk in all memory,
of_add_property(), and list_add().

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

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 
Reviewed-by: Alexey Kardashevskiy 
---
  arch/powerpc/platforms/pseries/iommu.c | 93 --
  1 file changed, 57 insertions(+), 36 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c 
b/arch/powerpc/platforms/pseries/iommu.c
index b34b473bbdc1..7ca79a04fa52 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1153,6 +1153,35 @@ static int iommu_get_page_shift(u32 query_page_size)
return 0;
  }
  
+static struct property *ddw_property_create(const char *propname, u32 liobn, u64 dma_addr,

+   u32 page_shift, u32 window_shift)
+{
+   struct dynamic_dma_window_prop *ddwprop;
+   struct property *win64;
+
+   win64 = kzalloc(sizeof(*win64), GFP_KERNEL);
+   if (!win64)
+   return NULL;
+
+   win64->name = kstrdup(propname, GFP_KERNEL);
+   ddwprop = kzalloc(sizeof(*ddwprop), GFP_KERNEL);
+   win64->value = ddwprop;
+   win64->length = sizeof(*ddwprop);
+   if (!win64->name || !win64->value) {
+   kfree(win64->name);
+   kfree(win64->value);
+   kfree(win64);
+   return NULL;
+   }
+
+   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 win64;
+}
+
  /*
   * 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,
@@ -1171,12 +1200,12 @@ 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 win_addr;
struct device_node *dn;
u32 ddw_avail[DDW_APPLICABLE_SIZE];
struct direct_window *window;
struct property *win64;
bool ddw_enabled = false;
-   struct dynamic_dma_window_prop *ddwprop;
struct failed_ddw_pdn *fpdn;
bool default_win_removed = false;
bool pmem_present;
@@ -1293,72 +1322,64 @@ static bool enable_ddw(struct pci_dev *dev, struct 
device_node *pdn)
1ULL << page_shift);
goto out_failed;
}
-   win64 = kzalloc(sizeof(struct property), GFP_KERNEL);
-   if (!win64) {
-   dev_info(>dev,
-   "couldn't allocate property for 64bit dma window\n");
-   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_info(>dev,
-   "couldn't allocate property name and value\n");
-   goto out_free_prop;
-   }
  
  	ret = create_ddw(dev, ddw_avail, , page_shift, len);

if (ret != 0)
-   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);
+   goto out_failed;
  
  	dev_dbg(>dev, "created tce table LIOBN 0x%x for %pOF\n",

  create.liobn, dn);
  
-	window = ddw_list_new_entry(pdn, ddwprop);

+   win_addr = ((u64)create.addr_hi << 32) | create.addr_lo;
+   win64 = ddw_property_create(DIRECT64_PROPNAME, create.liobn, win_addr,
+   page_shift, len);
+   if (!win64) {
+   dev_info(>dev,
+"couldn't allocate property, property name, or 
value\n");
+   goto out_remove_win;
+   }
+
+   ret = 

[PATCH v5 06/11] powerpc/pseries/iommu: Add ddw_property_create() and refactor enable_ddw()

2021-07-16 Thread Leonardo Bras
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_new_entry(), do tce_setrange_multi_pSeriesLP_walk in all memory,
of_add_property(), and list_add().

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

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 
Reviewed-by: Alexey Kardashevskiy 
---
 arch/powerpc/platforms/pseries/iommu.c | 93 --
 1 file changed, 57 insertions(+), 36 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c 
b/arch/powerpc/platforms/pseries/iommu.c
index b34b473bbdc1..7ca79a04fa52 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1153,6 +1153,35 @@ static int iommu_get_page_shift(u32 query_page_size)
return 0;
 }
 
+static struct property *ddw_property_create(const char *propname, u32 liobn, 
u64 dma_addr,
+   u32 page_shift, u32 window_shift)
+{
+   struct dynamic_dma_window_prop *ddwprop;
+   struct property *win64;
+
+   win64 = kzalloc(sizeof(*win64), GFP_KERNEL);
+   if (!win64)
+   return NULL;
+
+   win64->name = kstrdup(propname, GFP_KERNEL);
+   ddwprop = kzalloc(sizeof(*ddwprop), GFP_KERNEL);
+   win64->value = ddwprop;
+   win64->length = sizeof(*ddwprop);
+   if (!win64->name || !win64->value) {
+   kfree(win64->name);
+   kfree(win64->value);
+   kfree(win64);
+   return NULL;
+   }
+
+   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 win64;
+}
+
 /*
  * 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,
@@ -1171,12 +1200,12 @@ 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 win_addr;
struct device_node *dn;
u32 ddw_avail[DDW_APPLICABLE_SIZE];
struct direct_window *window;
struct property *win64;
bool ddw_enabled = false;
-   struct dynamic_dma_window_prop *ddwprop;
struct failed_ddw_pdn *fpdn;
bool default_win_removed = false;
bool pmem_present;
@@ -1293,72 +1322,64 @@ static bool enable_ddw(struct pci_dev *dev, struct 
device_node *pdn)
1ULL << page_shift);
goto out_failed;
}
-   win64 = kzalloc(sizeof(struct property), GFP_KERNEL);
-   if (!win64) {
-   dev_info(>dev,
-   "couldn't allocate property for 64bit dma window\n");
-   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_info(>dev,
-   "couldn't allocate property name and value\n");
-   goto out_free_prop;
-   }
 
ret = create_ddw(dev, ddw_avail, , page_shift, len);
if (ret != 0)
-   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);
+   goto out_failed;
 
dev_dbg(>dev, "created tce table LIOBN 0x%x for %pOF\n",
  create.liobn, dn);
 
-   window = ddw_list_new_entry(pdn, ddwprop);
+   win_addr = ((u64)create.addr_hi << 32) | create.addr_lo;
+   win64 = ddw_property_create(DIRECT64_PROPNAME, create.liobn, win_addr,
+   page_shift, len);
+   if (!win64) {
+   dev_info(>dev,
+"couldn't allocate property, property name, or 
value\n");
+   goto out_remove_win;
+   }
+
+   ret = of_add_property(pdn, win64);
+   if (ret) {
+