The current static shared memory code is using bootinfo banks when it
needs to find the number of borrower, so every time assign_shared_memory
is called, the bank is searched in the bootinfo.shmem structure.
There is nothing wrong with it, however the bank can be used also to
retrieve the start address and size and also to pass less argument to
assign_shared_memory. When retrieving the information from the bootinfo
bank, it's also possible to move the checks on alignment to
process_shm_node in the early stages.
So create a new function find_shm() which takes a 'struct shared_meminfo'
structure and the shared memory ID, to look for a bank with a matching ID,
take the physical host address and size from the bank, pass the bank to
assign_shared_memory() removing the now unnecessary arguments and finally
remove the acquire_nr_borrower_domain() function since now the information
can be extracted from the passed bank.
Move the "xen,shm-id" parsing early in process_shm to bail out quickly in
case of errors (unlikely), as said above, move the checks on alignment
to process_shm_node.
Drawback of this change is that now the bootinfo are used also when the
bank doesn't need to be allocated, however it will be convinient later
to use it as an argument for assign_shared_memory when dealing with
the use case where the Host physical address is not supplied by the user.
Signed-off-by: Luca Fancellu <luca.fance...@arm.com>
---
xen/arch/arm/static-shmem.c | 105 ++++++++++++++++++++----------------
1 file changed, 58 insertions(+), 47 deletions(-)
diff --git a/xen/arch/arm/static-shmem.c b/xen/arch/arm/static-shmem.c
index 09f474ec6050..f6cf74e58a83 100644
--- a/xen/arch/arm/static-shmem.c
+++ b/xen/arch/arm/static-shmem.c
@@ -19,29 +19,24 @@ static void __init __maybe_unused build_assertions(void)
offsetof(struct shared_meminfo, bank)));
}
-static int __init acquire_nr_borrower_domain(struct domain *d,
- paddr_t pbase, paddr_t psize,
- unsigned long *nr_borrowers)
+static const struct membank __init *find_shm(const struct membanks *shmem,
+ const char *shm_id)
{
- const struct membanks *shmem = bootinfo_get_shmem();
unsigned int bank;
- /* Iterate reserved memory to find requested shm bank. */
+ BUG_ON(!shmem || !shm_id);
+
for ( bank = 0 ; bank < shmem->nr_banks; bank++ )
{
- paddr_t bank_start = shmem->bank[bank].start;
- paddr_t bank_size = shmem->bank[bank].size;
-
- if ( (pbase == bank_start) && (psize == bank_size) )
+ if ( strncmp(shm_id, shmem->bank[bank].shmem_extra->shm_id,
+ MAX_SHM_ID_LENGTH) == 0 )
break;
}
if ( bank == shmem->nr_banks )
- return -ENOENT;
-
- *nr_borrowers = shmem->bank[bank].shmem_extra->nr_shm_borrowers;
+ return NULL;
- return 0;
+ return &shmem->bank[bank];
}
/*
@@ -103,14 +98,20 @@ static mfn_t __init acquire_shared_memory_bank(struct
domain *d,
return smfn;
}
-static int __init assign_shared_memory(struct domain *d,
- paddr_t pbase, paddr_t psize,
- paddr_t gbase)
+static int __init assign_shared_memory(struct domain *d, paddr_t gbase,
+ const struct membank *shm_bank)
{
mfn_t smfn;
int ret = 0;
unsigned long nr_pages, nr_borrowers, i;
struct page_info *page;
+ paddr_t pbase, psize;
+
+ BUG_ON(!shm_bank || !shm_bank->shmem_extra);
+
+ pbase = shm_bank->start;
+ psize = shm_bank->size;
+ nr_borrowers = shm_bank->shmem_extra->nr_shm_borrowers;
printk("%pd: allocate static shared memory BANK
%#"PRIpaddr"-%#"PRIpaddr".\n",
d, pbase, pbase + psize);
@@ -135,14 +136,6 @@ static int __init assign_shared_memory(struct domain *d,
}
}
- /*
- * Get the right amount of references per page, which is the number of
- * borrower domains.
- */
- ret = acquire_nr_borrower_domain(d, pbase, psize, &nr_borrowers);
- if ( ret )
- return ret;
-
/*
* Instead of letting borrower domain get a page ref, we add as many
* additional reference as the number of borrowers when the owner
@@ -199,6 +192,7 @@ int __init process_shm(struct domain *d, struct kernel_info
*kinfo,
dt_for_each_child_node(node, shm_node)
{
+ const struct membank *boot_shm_bank;
const struct dt_property *prop;
const __be32 *cells;
uint32_t addr_cells, size_cells;
@@ -212,6 +206,23 @@ int __init process_shm(struct domain *d, struct
kernel_info *kinfo,
if ( !dt_device_is_compatible(shm_node, "xen,domain-shared-memory-v1")
)
continue;
+ if ( dt_property_read_string(shm_node, "xen,shm-id", &shm_id) )
+ {
+ printk("%pd: invalid \"xen,shm-id\" property", d);
+ return -EINVAL;
+ }
+ BUG_ON((strlen(shm_id) <= 0) || (strlen(shm_id) >= MAX_SHM_ID_LENGTH));
+
+ boot_shm_bank = find_shm(bootinfo_get_shmem(), shm_id);
+ if ( !boot_shm_bank )
+ {
+ printk("%pd: static shared memory bank not found: '%s'", d,
shm_id);
+ return -ENOENT;
+ }
+
+ pbase = boot_shm_bank->start;
+ psize = boot_shm_bank->size;
+
/*
* xen,shared-mem = <pbase, gbase, size>;
* TODO: pbase is optional.
@@ -221,20 +232,7 @@ int __init process_shm(struct domain *d, struct
kernel_info *kinfo,
prop = dt_find_property(shm_node, "xen,shared-mem", NULL);
BUG_ON(!prop);
cells = (const __be32 *)prop->value;
- device_tree_get_reg(&cells, addr_cells, addr_cells, &pbase, &gbase);
- psize = dt_read_paddr(cells, size_cells);
- if ( !IS_ALIGNED(pbase, PAGE_SIZE) || !IS_ALIGNED(gbase, PAGE_SIZE) )
- {
- printk("%pd: physical address 0x%"PRIpaddr", or guest address
0x%"PRIpaddr" is not suitably aligned.\n",
- d, pbase, gbase);
- return -EINVAL;
- }
- if ( !IS_ALIGNED(psize, PAGE_SIZE) )
- {
- printk("%pd: size 0x%"PRIpaddr" is not suitably aligned\n",
- d, psize);
- return -EINVAL;
- }
+ gbase = dt_read_paddr(cells + addr_cells, addr_cells);
for ( i = 0; i < PFN_DOWN(psize); i++ )
if ( !mfn_valid(mfn_add(maddr_to_mfn(pbase), i)) )
@@ -251,13 +249,6 @@ int __init process_shm(struct domain *d, struct
kernel_info *kinfo,
if ( dt_property_read_string(shm_node, "role", &role_str) == 0 )
owner_dom_io = false;
- if ( dt_property_read_string(shm_node, "xen,shm-id", &shm_id) )
- {
- printk("%pd: invalid \"xen,shm-id\" property", d);
- return -EINVAL;
- }
- BUG_ON((strlen(shm_id) <= 0) || (strlen(shm_id) >= MAX_SHM_ID_LENGTH));
-
/*
* DOMID_IO is a fake domain and is not described in the Device-Tree.
* Therefore when the owner of the shared region is DOMID_IO, we will
@@ -270,8 +261,8 @@ int __init process_shm(struct domain *d, struct kernel_info
*kinfo,
* We found the first borrower of the region, the owner was not
* specified, so they should be assigned to dom_io.
*/
- ret = assign_shared_memory(owner_dom_io ? dom_io : d,
- pbase, psize, gbase);
+ ret = assign_shared_memory(owner_dom_io ? dom_io : d, gbase,
+ boot_shm_bank);
if ( ret )
return ret;
}
@@ -440,6 +431,26 @@ int __init process_shm_node(const void *fdt, int node,
uint32_t address_cells,
device_tree_get_reg(&cell, address_cells, address_cells, &paddr, &gaddr);
size = dt_next_cell(size_cells, &cell);
+ if ( !IS_ALIGNED(paddr, PAGE_SIZE) )
+ {
+ printk("fdt: physical address 0x%"PRIpaddr" is not suitably
aligned.\n",
+ paddr);
+ return -EINVAL;
+ }
+
+ if ( !IS_ALIGNED(gaddr, PAGE_SIZE) )
+ {
+ printk("fdt: guest address 0x%"PRIpaddr" is not suitably aligned.\n",
+ gaddr);
+ return -EINVAL;
+ }
+
+ if ( !IS_ALIGNED(size, PAGE_SIZE) )
+ {
+ printk("fdt: size 0x%"PRIpaddr" is not suitably aligned\n", size);
+ return -EINVAL;
+ }
+
if ( !size )
{
printk("fdt: the size for static shared memory region can not be
zero\n");
--
2.34.1
