[PATCH 2/3] misc: sgi-gru: remove obsolete atomic fault-handling state
From: Muhammad Usama Anjum
Date: Thu Jul 30 2026 - 07:21:24 EST
After interrupt faults are sent directly to user polling mode, only the
process-context call path remains. Remove the atomic flag passed through
the fault-handling interfaces and the related dead code.
No functional change.
Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxx>
---
Only build tested.
---
drivers/misc/sgi-gru/grufault.c | 68 +++++++++++++--------------------
1 file changed, 26 insertions(+), 42 deletions(-)
diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
index 5a87c12f444a3..e43fdea01cb6f 100644
--- a/drivers/misc/sgi-gru/grufault.c
+++ b/drivers/misc/sgi-gru/grufault.c
@@ -31,7 +31,6 @@
/* Return codes for vtop functions */
#define VTOP_SUCCESS 0
#define VTOP_INVALID -1
-#define VTOP_RETRY -2
/*
@@ -188,7 +187,7 @@ static int non_atomic_pte_lookup(struct vm_area_struct *vma,
}
static int gru_vtop(struct gru_thread_state *gts, unsigned long vaddr,
- int write, int atomic, unsigned long *gpa, int *pageshift)
+ int write, unsigned long *gpa, int *pageshift)
{
struct mm_struct *mm = gts->ts_mm;
struct vm_area_struct *vma;
@@ -199,9 +198,6 @@ static int gru_vtop(struct gru_thread_state *gts, unsigned long vaddr,
if (!vma)
goto inval;
- if (atomic)
- goto upm;
-
/* Order the caller's ms_range_active check before loading PTEs. */
rmb();
if (non_atomic_pte_lookup(vma, vaddr, write, &paddr, &ps))
@@ -215,8 +211,6 @@ static int gru_vtop(struct gru_thread_state *gts, unsigned long vaddr,
inval:
return VTOP_INVALID;
-upm:
- return VTOP_RETRY;
}
@@ -240,7 +234,7 @@ static void gru_flush_cache_cbe(struct gru_control_block_extended *cbe)
* the end of the bcopy tranfer, whichever is smaller.
*/
static void gru_preload_tlb(struct gru_state *gru,
- struct gru_thread_state *gts, int atomic,
+ struct gru_thread_state *gts,
unsigned long fault_vaddr, int asid, int write,
unsigned char tlb_preload_count,
struct gru_tlb_fault_handle *tfh,
@@ -262,13 +256,13 @@ static void gru_preload_tlb(struct gru_state *gru,
vaddr = min(vaddr, fault_vaddr + tlb_preload_count * PAGE_SIZE);
while (vaddr > fault_vaddr) {
- ret = gru_vtop(gts, vaddr, write, atomic, &gpa, &pageshift);
+ ret = gru_vtop(gts, vaddr, write, &gpa, &pageshift);
if (ret || tfh_write_only(tfh, gpa, GAA_RAM, vaddr, asid, write,
GRU_PAGESIZE(pageshift)))
return;
gru_dbg(grudev,
- "%s: gid %d, gts 0x%p, tfh 0x%p, vaddr 0x%lx, asid 0x%x, rw %d, ps %d, gpa 0x%lx\n",
- atomic ? "atomic" : "non-atomic", gru->gs_gid, gts, tfh,
+ "gid %d, gts 0x%p, tfh 0x%p, vaddr 0x%lx, asid 0x%x, rw %d, ps %d, gpa 0x%lx\n",
+ gru->gs_gid, gts, tfh,
vaddr, asid, write, pageshift, gpa);
vaddr -= PAGE_SIZE;
STAT(tlb_preload_page);
@@ -276,13 +270,13 @@ static void gru_preload_tlb(struct gru_state *gru,
}
/*
- * Drop a TLB entry into the GRU. The fault is described by info in an TFH.
- * Input:
- * cb Address of user CBR. Null if not running in user context
- * Return:
- * 0 = dropin, exception, or switch to UPM successful
- * 1 = range invalidate active
- * < 0 = error code
+ * Drop a TLB entry into the GRU. The fault is described by info in a TFH.
+ * Input:
+ * cbk Address of the user CBR
+ * Return:
+ * 0 = dropin, exception, or switch to UPM successful
+ * 1 = retry required
+ * < 0 = error code
*
*/
static int gru_try_dropin(struct gru_state *gru,
@@ -292,7 +286,7 @@ static int gru_try_dropin(struct gru_state *gru,
{
struct gru_control_block_extended *cbe = NULL;
unsigned char tlb_preload_count = gts->ts_tlb_preload_count;
- int pageshift = 0, asid, write, ret, atomic = !cbk, indexway;
+ int pageshift = 0, asid, write, ret, indexway;
unsigned long gpa = 0, vaddr = 0;
/*
@@ -324,7 +318,7 @@ static int gru_try_dropin(struct gru_state *gru,
}
if (tfh->state == TFHSTATE_IDLE)
goto failidle;
- if (tfh->state == TFHSTATE_MISS_FMM && cbk)
+ if (tfh->state == TFHSTATE_MISS_FMM)
goto failfmm;
write = (tfh->cause & TFHCAUSE_TLB_MOD) != 0;
@@ -343,22 +337,20 @@ static int gru_try_dropin(struct gru_state *gru,
if (atomic_read(>s->ts_gms->ms_range_active))
goto failactive;
- ret = gru_vtop(gts, vaddr, write, atomic, &gpa, &pageshift);
+ ret = gru_vtop(gts, vaddr, write, &gpa, &pageshift);
if (ret == VTOP_INVALID)
goto failinval;
- if (ret == VTOP_RETRY)
- goto failupm;
if (!(gts->ts_sizeavail & GRU_SIZEAVAIL(pageshift))) {
gts->ts_sizeavail |= GRU_SIZEAVAIL(pageshift);
- if (atomic || !gru_update_cch(gts)) {
+ if (!gru_update_cch(gts)) {
gts->ts_force_cch_reload = 1;
goto failupm;
}
}
if (unlikely(cbe) && pageshift == PAGE_SHIFT) {
- gru_preload_tlb(gru, gts, atomic, vaddr, asid, write, tlb_preload_count, tfh, cbe);
+ gru_preload_tlb(gru, gts, vaddr, asid, write, tlb_preload_count, tfh, cbe);
gru_flush_cache_cbe(cbe);
}
@@ -367,9 +359,9 @@ static int gru_try_dropin(struct gru_state *gru,
tfh_write_restart(tfh, gpa, GAA_RAM, vaddr, asid, write,
GRU_PAGESIZE(pageshift));
gru_dbg(grudev,
- "%s: gid %d, gts 0x%p, tfh 0x%p, vaddr 0x%lx, asid 0x%x, indexway 0x%x,"
+ "gid %d, gts 0x%p, tfh 0x%p, vaddr 0x%lx, asid 0x%x, indexway 0x%x,"
" rw %d, ps %d, gpa 0x%lx\n",
- atomic ? "atomic" : "non-atomic", gru->gs_gid, gts, tfh, vaddr, asid,
+ gru->gs_gid, gts, tfh, vaddr, asid,
indexway, write, pageshift, gpa);
STAT(tlb_dropin);
return 0;
@@ -378,15 +370,12 @@ static int gru_try_dropin(struct gru_state *gru,
/* No asid (delayed unload). */
STAT(tlb_dropin_fail_no_asid);
gru_dbg(grudev, "FAILED no_asid tfh: 0x%p, vaddr 0x%lx\n", tfh, vaddr);
- if (!cbk)
- tfh_user_polling_mode(tfh);
- else
- gru_flush_cache(tfh);
+ gru_flush_cache(tfh);
gru_flush_cache_cbe(cbe);
return -EAGAIN;
failupm:
- /* Atomic failure switch CBR to UPM */
+ /* CCH update failure switches the CBR back to UPM. */
tfh_user_polling_mode(tfh);
gru_flush_cache_cbe(cbe);
STAT(tlb_dropin_fail_upm);
@@ -405,8 +394,7 @@ static int gru_try_dropin(struct gru_state *gru,
/* TFH status did not show exception pending */
gru_flush_cache(tfh);
gru_flush_cache_cbe(cbe);
- if (cbk)
- gru_flush_cache(cbk);
+ gru_flush_cache(cbk);
STAT(tlb_dropin_fail_no_exception);
gru_dbg(grudev, "FAILED non-exception tfh: 0x%p, status %d, state %d\n",
tfh, tfh->status, tfh->state);
@@ -416,14 +404,13 @@ static int gru_try_dropin(struct gru_state *gru,
/* TFH state was idle - no miss pending */
gru_flush_cache(tfh);
gru_flush_cache_cbe(cbe);
- if (cbk)
- gru_flush_cache(cbk);
+ gru_flush_cache(cbk);
STAT(tlb_dropin_fail_idle);
gru_dbg(grudev, "FAILED idle tfh: 0x%p, state %d\n", tfh, tfh->state);
return 0;
failinval:
- /* All errors (atomic & non-atomic) switch CBR to EXCEPTION state */
+ /* Invalid translations switch the CBR to EXCEPTION state. */
tfh_exception(tfh);
gru_flush_cache_cbe(cbe);
STAT(tlb_dropin_fail_invalid);
@@ -431,11 +418,8 @@ static int gru_try_dropin(struct gru_state *gru,
return -EFAULT;
failactive:
- /* Range invalidate active. Switch to UPM iff atomic */
- if (!cbk)
- tfh_user_polling_mode(tfh);
- else
- gru_flush_cache(tfh);
+ /* Retry after the active range invalidation completes. */
+ gru_flush_cache(tfh);
gru_flush_cache_cbe(cbe);
STAT(tlb_dropin_fail_range_active);
gru_dbg(grudev, "FAILED range active: tfh 0x%p, vaddr 0x%lx\n",
--
2.47.3