mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-28 15:13:55 +08:00
5bef80a4b8
We are using a very simple sort routine which sorts the .iommu_table array in the order of dependencies. Specifically each structure of iommu_table_entry has a field 'depend' which contains the function pointer to the IOMMU that MUST be run before us. We sort the array of structures so that the struct iommu_table_entry with no 'depend' field are first, and then the subsequent ones are the ones for which the 'depend' function has been already invoked (in other words, precede us). Using the kernel's version 'sort', which is a mergeheap is feasible, but would require making the comparison operator scan recursivly the array to satisfy the "heapify" process: setting the levels properly. The end result would much more complex than it should be an it is just much simpler to utilize this simple sort routine. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> LKML-Reference: <1282845485-8991-4-git-send-email-konrad.wilk@oracle.com> CC: H. Peter Anvin <hpa@zytor.com> CC: Fujita Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
90 lines
2.0 KiB
C
90 lines
2.0 KiB
C
#include <linux/dma-mapping.h>
|
|
#include <asm/iommu_table.h>
|
|
#include <linux/string.h>
|
|
#include <linux/kallsyms.h>
|
|
|
|
|
|
#define DEBUG 1
|
|
|
|
static struct iommu_table_entry * __init
|
|
find_dependents_of(struct iommu_table_entry *start,
|
|
struct iommu_table_entry *finish,
|
|
struct iommu_table_entry *q)
|
|
{
|
|
struct iommu_table_entry *p;
|
|
|
|
if (!q)
|
|
return NULL;
|
|
|
|
for (p = start; p < finish; p++)
|
|
if (p->detect == q->depend)
|
|
return p;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
|
|
void __init sort_iommu_table(struct iommu_table_entry *start,
|
|
struct iommu_table_entry *finish) {
|
|
|
|
struct iommu_table_entry *p, *q, tmp;
|
|
|
|
for (p = start; p < finish; p++) {
|
|
again:
|
|
q = find_dependents_of(start, finish, p);
|
|
/* We are bit sneaky here. We use the memory address to figure
|
|
* out if the node we depend on is past our point, if so, swap.
|
|
*/
|
|
if (q > p) {
|
|
tmp = *p;
|
|
memmove(p, q, sizeof(*p));
|
|
*q = tmp;
|
|
goto again;
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
void __init check_iommu_entries(struct iommu_table_entry *start,
|
|
struct iommu_table_entry *finish)
|
|
{
|
|
struct iommu_table_entry *p, *q, *x;
|
|
char sym_p[KSYM_SYMBOL_LEN];
|
|
char sym_q[KSYM_SYMBOL_LEN];
|
|
|
|
/* Simple cyclic dependency checker. */
|
|
for (p = start; p < finish; p++) {
|
|
q = find_dependents_of(start, finish, p);
|
|
x = find_dependents_of(start, finish, q);
|
|
if (p == x) {
|
|
sprint_symbol(sym_p, (unsigned long)p->detect);
|
|
sprint_symbol(sym_q, (unsigned long)q->detect);
|
|
|
|
printk(KERN_ERR "CYCLIC DEPENDENCY FOUND! %s depends" \
|
|
" on %s and vice-versa. BREAKING IT.\n",
|
|
sym_p, sym_q);
|
|
/* Heavy handed way..*/
|
|
x->depend = 0;
|
|
}
|
|
}
|
|
|
|
for (p = start; p < finish; p++) {
|
|
q = find_dependents_of(p, finish, p);
|
|
if (q && q > p) {
|
|
sprint_symbol(sym_p, (unsigned long)p->detect);
|
|
sprint_symbol(sym_q, (unsigned long)q->detect);
|
|
|
|
printk(KERN_ERR "EXECUTION ORDER INVALID! %s "\
|
|
"should be called before %s!\n",
|
|
sym_p, sym_q);
|
|
}
|
|
}
|
|
}
|
|
#else
|
|
inline void check_iommu_entries(struct iommu_table_entry *start,
|
|
struct iommu_table_entry *finish)
|
|
{
|
|
}
|
|
#endif
|