| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1375332272-22176-9-git-send-email-aik@ozlabs.ru>
Date: Thu, 1 Aug 2013 14:44:30 +1000
From: Alexey Kardashevskiy <aik@...abs.ru>
To: linuxppc-dev@...ts.ozlabs.org
Cc: Alexey Kardashevskiy <aik@...abs.ru>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
Alexander Graf <agraf@...e.de>, kvm@...r.kernel.org,
linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
kvm-ppc@...r.kernel.org
Subject: [PATCH 08/10] powerpc/iommu: rework to support realmode
The TCE tables handling may differ for real and virtual modes so
additional ppc_md.tce_build_rm/ppc_md.tce_free_rm/ppc_md.tce_flush_rm
handlers were introduced earlier.
So this adds the following:
1. support for the new ppc_md calls;
2. ability to iommu_tce_build to process mupltiple entries per
call;
3. arch_spin_lock to protect TCE table from races in both real and virtual
modes;
4. proper TCE table protection from races with the existing IOMMU code
in iommu_take_ownership/iommu_release_ownership;
5. hwaddr variable renamed to hpa as it better describes what it
actually represents;
6. iommu_tce_direction is static now as it is not called from anywhere else.
This will be used by upcoming real mode support of VFIO on POWER.
Signed-off-by: Alexey Kardashevskiy <aik@...abs.ru>
---
arch/powerpc/include/asm/iommu.h | 9 +-
arch/powerpc/kernel/iommu.c | 198 ++++++++++++++++++++++++++-------------
2 files changed, 136 insertions(+), 71 deletions(-)
diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index c34656a..b01bde1 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -78,6 +78,7 @@ struct iommu_table {
unsigned long *it_map; /* A simple allocation bitmap for now */
#ifdef CONFIG_IOMMU_API
struct iommu_group *it_group;
+ arch_spinlock_t it_rm_lock;
#endif
};
@@ -152,9 +153,9 @@ extern int iommu_tce_clear_param_check(struct iommu_table *tbl,
extern int iommu_tce_put_param_check(struct iommu_table *tbl,
unsigned long ioba, unsigned long tce);
extern int iommu_tce_build(struct iommu_table *tbl, unsigned long entry,
- unsigned long hwaddr, enum dma_data_direction direction);
-extern unsigned long iommu_clear_tce(struct iommu_table *tbl,
- unsigned long entry);
+ unsigned long *hpas, unsigned long npages, bool rm);
+extern int iommu_free_tces(struct iommu_table *tbl, unsigned long entry,
+ unsigned long npages, bool rm);
extern int iommu_clear_tces_and_put_pages(struct iommu_table *tbl,
unsigned long entry, unsigned long pages);
extern int iommu_put_tce_user_mode(struct iommu_table *tbl,
@@ -164,7 +165,5 @@ extern void iommu_flush_tce(struct iommu_table *tbl);
extern int iommu_take_ownership(struct iommu_table *tbl);
extern void iommu_release_ownership(struct iommu_table *tbl);
-extern enum dma_data_direction iommu_tce_direction(unsigned long tce);
-
#endif /* __KERNEL__ */
#endif /* _ASM_IOMMU_H */
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index b20ff17..8314c80 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -903,7 +903,7 @@ void iommu_register_group(struct iommu_table *tbl,
kfree(name);
}
-enum dma_data_direction iommu_tce_direction(unsigned long tce)
+static enum dma_data_direction iommu_tce_direction(unsigned long tce)
{
if ((tce & TCE_PCI_READ) && (tce & TCE_PCI_WRITE))
return DMA_BIDIRECTIONAL;
@@ -914,7 +914,6 @@ enum dma_data_direction iommu_tce_direction(unsigned long tce)
else
return DMA_NONE;
}
-EXPORT_SYMBOL_GPL(iommu_tce_direction);
void iommu_flush_tce(struct iommu_table *tbl)
{
@@ -972,73 +971,117 @@ int iommu_tce_put_param_check(struct iommu_table *tbl,
}
EXPORT_SYMBOL_GPL(iommu_tce_put_param_check);
-unsigned long iommu_clear_tce(struct iommu_table *tbl, unsigned long entry)
-{
- unsigned long oldtce;
- struct iommu_pool *pool = get_pool(tbl, entry);
-
- spin_lock(&(pool->lock));
-
- oldtce = ppc_md.tce_get(tbl, entry);
- if (oldtce & (TCE_PCI_WRITE | TCE_PCI_READ))
- ppc_md.tce_free(tbl, entry, 1);
- else
- oldtce = 0;
-
- spin_unlock(&(pool->lock));
-
- return oldtce;
-}
-EXPORT_SYMBOL_GPL(iommu_clear_tce);
-
int iommu_clear_tces_and_put_pages(struct iommu_table *tbl,
unsigned long entry, unsigned long pages)
{
- unsigned long oldtce;
- struct page *page;
-
- for ( ; pages; --pages, ++entry) {
- oldtce = iommu_clear_tce(tbl, entry);
- if (!oldtce)
- continue;
-
- page = pfn_to_page(oldtce >> PAGE_SHIFT);
- WARN_ON(!page);
- if (page) {
- if (oldtce & TCE_PCI_WRITE)
- SetPageDirty(page);
- put_page(page);
- }
- }
-
- return 0;
+ return iommu_free_tces(tbl, entry, pages, false);
}
EXPORT_SYMBOL_GPL(iommu_clear_tces_and_put_pages);
-/*
- * hwaddr is a kernel virtual address here (0xc... bazillion),
- * tce_build converts it to a physical address.
- */
+int iommu_free_tces(struct iommu_table *tbl, unsigned long entry,
+ unsigned long npages, bool rm)
+{
+ int i, ret = 0, to_free = 0;
+
+ if (rm && !ppc_md.tce_free_rm)
+ return -EAGAIN;
+
+ arch_spin_lock(&tbl->it_rm_lock);
+
+ for (i = 0; i < npages; ++i) {
+ unsigned long oldtce = ppc_md.tce_get(tbl, entry + i);
+ if (!(oldtce & (TCE_PCI_WRITE | TCE_PCI_READ)))
+ continue;
+
+ if (rm) {
+ struct page *pg = realmode_pfn_to_page(
+ oldtce >> PAGE_SHIFT);
+ if (!pg) {
+ ret = -EAGAIN;
+ } else if (PageCompound(pg)) {
+ ret = -EAGAIN;
+ } else {
+ if (oldtce & TCE_PCI_WRITE)
+ SetPageDirty(pg);
+ if (!put_page_unless_one(pg))
+ ret = -EAGAIN;
+ }
+ } else {
+ struct page *pg = pfn_to_page(oldtce >> PAGE_SHIFT);
+ if (!pg) {
+ ret = -EAGAIN;
+ } else {
+ if (oldtce & TCE_PCI_WRITE)
+ SetPageDirty(pg);
+ put_page(pg);
+ }
+ }
+ if (ret)
+ break;
+ to_free = i + 1;
+ }
+
+ if (to_free) {
+ if (rm)
+ ppc_md.tce_free_rm(tbl, entry, to_free);
+ else
+ ppc_md.tce_free(tbl, entry, to_free);
+
+ if (rm && ppc_md.tce_flush_rm)
+ ppc_md.tce_flush_rm(tbl);
+ else if (!rm && ppc_md.tce_flush)
+ ppc_md.tce_flush(tbl);
+ }
+ arch_spin_unlock(&tbl->it_rm_lock);
+
+ /* Make sure updates are seen by hardware */
+ mb();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_free_tces);
+
int iommu_tce_build(struct iommu_table *tbl, unsigned long entry,
- unsigned long hwaddr, enum dma_data_direction direction)
+ unsigned long *hpas, unsigned long npages, bool rm)
{
- int ret = -EBUSY;
- unsigned long oldtce;
- struct iommu_pool *pool = get_pool(tbl, entry);
+ int i, ret = 0;
- spin_lock(&(pool->lock));
+ if (rm && !ppc_md.tce_build_rm)
+ return -EAGAIN;
- oldtce = ppc_md.tce_get(tbl, entry);
- /* Add new entry if it is not busy */
- if (!(oldtce & (TCE_PCI_WRITE | TCE_PCI_READ)))
- ret = ppc_md.tce_build(tbl, entry, 1, hwaddr, direction, NULL);
+ arch_spin_lock(&tbl->it_rm_lock);
- spin_unlock(&(pool->lock));
+ for (i = 0; i < npages; ++i) {
+ if (ppc_md.tce_get(tbl, entry + i) &
+ (TCE_PCI_WRITE | TCE_PCI_READ)) {
+ arch_spin_unlock(&tbl->it_rm_lock);
+ return -EBUSY;
+ }
+ }
- /* if (unlikely(ret))
- pr_err("iommu_tce: %s failed on hwaddr=%lx ioba=%lx kva=%lx ret=%d\n",
- __func__, hwaddr, entry << IOMMU_PAGE_SHIFT,
- hwaddr, ret); */
+ for (i = 0; i < npages; ++i) {
+ unsigned long volatile hva = (unsigned long) __va(hpas[i]);
+ enum dma_data_direction dir = iommu_tce_direction(hva);
+
+ if (rm)
+ ret = ppc_md.tce_build_rm(tbl, entry + i, 1,
+ hva, dir, NULL);
+ else
+ ret = ppc_md.tce_build(tbl, entry + i, 1,
+ hva, dir, NULL);
+ if (ret)
+ break;
+ }
+
+ if (rm && ppc_md.tce_flush_rm)
+ ppc_md.tce_flush_rm(tbl);
+ else if (!rm && ppc_md.tce_flush)
+ ppc_md.tce_flush(tbl);
+
+ arch_spin_unlock(&tbl->it_rm_lock);
+
+ /* Make sure updates are seen by hardware */
+ mb();
return ret;
}
@@ -1049,7 +1092,7 @@ int iommu_put_tce_user_mode(struct iommu_table *tbl, unsigned long entry,
{
int ret;
struct page *page = NULL;
- unsigned long hwaddr, offset = tce & IOMMU_PAGE_MASK & ~PAGE_MASK;
+ unsigned long hpa, offset = tce & IOMMU_PAGE_MASK & ~PAGE_MASK;
enum dma_data_direction direction = iommu_tce_direction(tce);
ret = get_user_pages_fast(tce & PAGE_MASK, 1,
@@ -1059,9 +1102,9 @@ int iommu_put_tce_user_mode(struct iommu_table *tbl, unsigned long entry,
tce, entry << IOMMU_PAGE_SHIFT, ret); */
return -EFAULT;
}
- hwaddr = (unsigned long) page_address(page) + offset;
+ hpa = __pa((unsigned long) page_address(page)) + offset;
- ret = iommu_tce_build(tbl, entry, hwaddr, direction);
+ ret = iommu_tce_build(tbl, entry, &hpa, 1, false);
if (ret)
put_page(page);
@@ -1075,18 +1118,32 @@ EXPORT_SYMBOL_GPL(iommu_put_tce_user_mode);
int iommu_take_ownership(struct iommu_table *tbl)
{
- unsigned long sz = (tbl->it_size + 7) >> 3;
+ unsigned long flags, i, sz = (tbl->it_size + 7) >> 3;
+ int ret = 0;
+
+ spin_lock_irqsave(&tbl->large_pool.lock, flags);
+ for (i = 0; i < tbl->nr_pools; i++)
+ spin_lock(&tbl->pools[i].lock);
if (tbl->it_offset == 0)
clear_bit(0, tbl->it_map);
if (!bitmap_empty(tbl->it_map, tbl->it_size)) {
pr_err("iommu_tce: it_map is not empty");
- return -EBUSY;
+ ret = -EBUSY;
+ if (tbl->it_offset == 0)
+ clear_bit(1, tbl->it_map);
+
+ } else {
+ memset(tbl->it_map, 0xff, sz);
}
- memset(tbl->it_map, 0xff, sz);
- iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size);
+ for (i = 0; i < tbl->nr_pools; i++)
+ spin_unlock(&tbl->pools[i].lock);
+ spin_unlock_irqrestore(&tbl->large_pool.lock, flags);
+
+ if (!ret)
+ iommu_free_tces(tbl, tbl->it_offset, tbl->it_size, false);
return 0;
}
@@ -1094,14 +1151,23 @@ EXPORT_SYMBOL_GPL(iommu_take_ownership);
void iommu_release_ownership(struct iommu_table *tbl)
{
- unsigned long sz = (tbl->it_size + 7) >> 3;
+ unsigned long flags, i, sz = (tbl->it_size + 7) >> 3;
+
+ iommu_free_tces(tbl, tbl->it_offset, tbl->it_size, false);
+
+ spin_lock_irqsave(&tbl->large_pool.lock, flags);
+ for (i = 0; i < tbl->nr_pools; i++)
+ spin_lock(&tbl->pools[i].lock);
- iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size);
memset(tbl->it_map, 0, sz);
/* Restore bit#0 set by iommu_init_table() */
if (tbl->it_offset == 0)
set_bit(0, tbl->it_map);
+
+ for (i = 0; i < tbl->nr_pools; i++)
+ spin_unlock(&tbl->pools[i].lock);
+ spin_unlock_irqrestore(&tbl->large_pool.lock, flags);
}
EXPORT_SYMBOL_GPL(iommu_release_ownership);
--
1.8.3.2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists