Author: jhibbits
Date: Wed May 8 16:15:28 2019
New Revision: 347354
URL: https://svnweb.freebsd.org/changeset/base/347354
Log:
powerpc/booke: Rewrite pmap_sync_icache() a bit
* Make mmu_booke_sync_icache() use the DMAP on 64-bit prcoesses, no need to
map the page into the user's address space. This removes the
pvh_global_lock from the equation on 64-bit.
* Don't map the page with user-readability on 32-bit. I don't know what the
chance of a given user process being able to access the NULL page when
another process's page is added there, but it doesn't seem like a good
idea to map it to NULL with user read permissions.
* Only sync as much as we need to. There are only two significant places
where pmap_sync_icache is used: proc_rwmem(), and the SIGILL second-chance
for powerpc. The SIGILL second chance is likely the most common, and only
syncs 4 bytes, so avoid the other 127 loop iterations (4096 / 32 byte
cacheline) in __syncicache().
Modified:
head/sys/powerpc/booke/pmap.c
Modified: head/sys/powerpc/booke/pmap.c
==============================================================================
--- head/sys/powerpc/booke/pmap.c Wed May 8 16:07:43 2019
(r347353)
+++ head/sys/powerpc/booke/pmap.c Wed May 8 16:15:28 2019
(r347354)
@@ -2871,18 +2871,20 @@ static void
mmu_booke_sync_icache(mmu_t mmu, pmap_t pm, vm_offset_t va, vm_size_t sz)
{
pte_t *pte;
+ vm_paddr_t pa = 0;
+ int sync_sz, valid;
+#ifndef __powerpc64__
pmap_t pmap;
vm_page_t m;
vm_offset_t addr;
- vm_paddr_t pa = 0;
- int active, valid;
+ int active;
+#endif
- va = trunc_page(va);
- sz = round_page(sz);
-
+#ifndef __powerpc64__
rw_wlock(&pvh_global_lock);
pmap = PCPU_GET(curpmap);
active = (pm == kernel_pmap || pm == pmap) ? 1 : 0;
+#endif
while (sz > 0) {
PMAP_LOCK(pm);
pte = pte_find(mmu, pm, va);
@@ -2890,24 +2892,34 @@ mmu_booke_sync_icache(mmu_t mmu, pmap_t pm, vm_offset_
if (valid)
pa = PTE_PA(pte);
PMAP_UNLOCK(pm);
+ sync_sz = PAGE_SIZE - (va & PAGE_MASK);
+ sync_sz = min(sync_sz, sz);
if (valid) {
+#ifdef __powerpc64__
+ pa += (va & PAGE_MASK);
+ __syncicache((void *)PHYS_TO_DMAP(pa), sync_sz);
+#else
if (!active) {
/* Create a mapping in the active pmap. */
addr = 0;
m = PHYS_TO_VM_PAGE(pa);
PMAP_LOCK(pmap);
pte_enter(mmu, pmap, m, addr,
- PTE_SR | PTE_VALID | PTE_UR, FALSE);
- __syncicache((void *)addr, PAGE_SIZE);
+ PTE_SR | PTE_VALID, FALSE);
+ addr += (va & PAGE_MASK);
+ __syncicache((void *)addr, sync_sz);
pte_remove(mmu, pmap, addr, PTBL_UNHOLD);
PMAP_UNLOCK(pmap);
} else
- __syncicache((void *)va, PAGE_SIZE);
+ __syncicache((void *)va, sync_sz);
+#endif
}
- va += PAGE_SIZE;
- sz -= PAGE_SIZE;
+ va += sync_sz;
+ sz -= sync_sz;
}
+#ifndef __powerpc64__
rw_wunlock(&pvh_global_lock);
+#endif
}
/*
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