[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [XEN v1 3/9] xen/arm: Always use 'u64' instead of 'paddr_t' for address and size in DT



Hi,

This patch is actually a good example to demonstrate the extra amount of boiler plate required to use your new boiler.

On 15/12/2022 19:32, Ayan Kumar Halder wrote:
device_tree_get_reg(), dt_next_cell() uses u64 for address and size.
Thus, the caller needs to be fixed to pass u64 values and then invoke
translate_dt_address_size() to do the translation between u64 and paddr_t.

Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>
---
  xen/arch/arm/bootfdt.c | 22 ++++++++++++++--------
  1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/xen/arch/arm/bootfdt.c b/xen/arch/arm/bootfdt.c
index 0085c28d74..835bb5feb9 100644
--- a/xen/arch/arm/bootfdt.c
+++ b/xen/arch/arm/bootfdt.c
@@ -14,6 +14,7 @@
  #include <xen/libfdt/libfdt.h>
  #include <xen/sort.h>
  #include <xsm/xsm.h>
+#include <asm/platform.h>
  #include <asm/setup.h>
static bool __init device_tree_node_matches(const void *fdt, int node,
@@ -68,7 +69,7 @@ static int __init device_tree_get_meminfo(const void *fdt, 
int node,
      unsigned int i, banks;
      const __be32 *cell;
      u32 reg_cells = address_cells + size_cells;
-    paddr_t start, size;
+    u64 start, size;
      struct meminfo *mem = data;
if ( address_cells < 1 || size_cells < 1 )
@@ -219,7 +220,7 @@ static void __init process_multiboot_node(const void *fdt, 
int node,
      const struct fdt_property *prop;
      const __be32 *cell;
      bootmodule_kind kind;
-    paddr_t start, size;
+    u64 start, size;
      int len;
      /* sizeof("/chosen/") + DT_MAX_NAME + '/' + DT_MAX_NAME + '/0' => 92 */
      char path[92];
@@ -379,7 +380,8 @@ static int __init process_shm_node(const void *fdt, int 
node,
  {
      const struct fdt_property *prop, *prop_id, *prop_role;
      const __be32 *cell;
-    paddr_t paddr, gaddr, size;
+    paddr_t paddr = 0, gaddr = 0, size = 0;

For a first 0 is a valid address. So we should not use is as initialization.

+    u64 dt_paddr, dt_gaddr, dt_size;
      struct meminfo *mem = &bootinfo.reserved_mem;
      unsigned int i;
      int len;
@@ -443,10 +445,14 @@ static int __init process_shm_node(const void *fdt, int 
node,
      }
cell = (const __be32 *)prop->data;
-    device_tree_get_reg(&cell, address_cells, address_cells, &paddr, &gaddr);
-    size = dt_next_cell(size_cells, &cell);
+    device_tree_get_reg(&cell, address_cells, address_cells, &dt_paddr,
+                        &dt_gaddr);
+    translate_dt_address_size(&dt_paddr, &dt_gaddr, &paddr, &gaddr
If we function return a value, then this should be checked. If not, then it should be explained.

In this case, it is not clear to me who is checking the conversion was successful.

Overall, I think this will increase the amount of code. So before doing the modification, I think we need to agree on whether this is worth it to check the device-tree values.

Cheers,

--
Julien Grall



 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.