[PATCH v3 5/7] iommu/io-pgtable-arm: Support 52-bit physical address
Robin Murphy
robin.murphy at arm.com
Mon Mar 26 05:35:13 PDT 2018
Bring io-pgtable-arm in line with the ARMv8.2-LPA feature allowing
52-bit physical addresses when using the 64KB translation granule.
This will be supported by SMMUv3.1.
Tested-by: Nate Watterson <nwatters at codeaurora.org>
Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---
v3: 64K-granule-specific logic in iopte_to_paddr() makes it much more
symmetrical with paddr_to_iopte() and generates shorter code.
I haven't implemented explicit input masking in paddr_to_iopte()
since I realised that if we did ever get an out-of-range address
there, it would only make the difference between silently mapping
the wrong address and silently mapping a slightly different wrong
address.
I also went to add a comment about io_pgtable_alloc() updating the
cfg, only to find that it's been documented as such from the start.
drivers/iommu/io-pgtable-arm.c | 67 ++++++++++++++++++++++++++++++------------
1 file changed, 49 insertions(+), 18 deletions(-)
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 51e5c43caed1..a5be4c92c5c8 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -21,6 +21,7 @@
#define pr_fmt(fmt) "arm-lpae io-pgtable: " fmt
#include <linux/atomic.h>
+#include <linux/bitops.h>
#include <linux/iommu.h>
#include <linux/kernel.h>
#include <linux/sizes.h>
@@ -32,7 +33,7 @@
#include "io-pgtable.h"
-#define ARM_LPAE_MAX_ADDR_BITS 48
+#define ARM_LPAE_MAX_ADDR_BITS 52
#define ARM_LPAE_S2_MAX_CONCAT_PAGES 16
#define ARM_LPAE_MAX_LEVELS 4
@@ -86,6 +87,8 @@
#define ARM_LPAE_PTE_TYPE_TABLE 3
#define ARM_LPAE_PTE_TYPE_PAGE 3
+#define ARM_LPAE_PTE_ADDR_MASK GENMASK_ULL(47,12)
+
#define ARM_LPAE_PTE_NSTABLE (((arm_lpae_iopte)1) << 63)
#define ARM_LPAE_PTE_XN (((arm_lpae_iopte)3) << 53)
#define ARM_LPAE_PTE_AF (((arm_lpae_iopte)1) << 10)
@@ -159,6 +162,7 @@
#define ARM_LPAE_TCR_PS_42_BIT 0x3ULL
#define ARM_LPAE_TCR_PS_44_BIT 0x4ULL
#define ARM_LPAE_TCR_PS_48_BIT 0x5ULL
+#define ARM_LPAE_TCR_PS_52_BIT 0x6ULL
#define ARM_LPAE_MAIR_ATTR_SHIFT(n) ((n) << 3)
#define ARM_LPAE_MAIR_ATTR_MASK 0xff
@@ -170,9 +174,7 @@
#define ARM_LPAE_MAIR_ATTR_IDX_DEV 2
/* IOPTE accessors */
-#define iopte_deref(pte,d) \
- (__va((pte) & ((1ULL << ARM_LPAE_MAX_ADDR_BITS) - 1) \
- & ~(ARM_LPAE_GRANULE(d) - 1ULL)))
+#define iopte_deref(pte,d) __va(iopte_to_paddr(pte, d))
#define iopte_type(pte,l) \
(((pte) >> ARM_LPAE_PTE_TYPE_SHIFT) & ARM_LPAE_PTE_TYPE_MASK)
@@ -184,12 +186,6 @@
(iopte_type(pte,l) == ARM_LPAE_PTE_TYPE_PAGE) : \
(iopte_type(pte,l) == ARM_LPAE_PTE_TYPE_BLOCK))
-#define iopte_to_pfn(pte,d) \
- (((pte) & ((1ULL << ARM_LPAE_MAX_ADDR_BITS) - 1)) >> (d)->pg_shift)
-
-#define pfn_to_iopte(pfn,d) \
- (((pfn) << (d)->pg_shift) & ((1ULL << ARM_LPAE_MAX_ADDR_BITS) - 1))
-
struct arm_lpae_io_pgtable {
struct io_pgtable iop;
@@ -203,6 +199,27 @@ struct arm_lpae_io_pgtable {
typedef u64 arm_lpae_iopte;
+static arm_lpae_iopte paddr_to_iopte(phys_addr_t paddr,
+ struct arm_lpae_io_pgtable *data)
+{
+ arm_lpae_iopte pte = paddr;
+
+ /* Of the bits which overlap, either 51:48 or 15:12 are always RES0 */
+ return (pte | (pte >> (48 - 12))) & ARM_LPAE_PTE_ADDR_MASK;
+}
+
+static phys_addr_t iopte_to_paddr(arm_lpae_iopte pte,
+ struct arm_lpae_io_pgtable *data)
+{
+ phys_addr_t paddr = pte & ARM_LPAE_PTE_ADDR_MASK;
+
+ if (data->pg_shift < 16)
+ return paddr;
+
+ /* Rotate the packed high-order bits back to the top */
+ return (paddr | (paddr << (48 - 12))) & (ARM_LPAE_PTE_ADDR_MASK << 4);
+}
+
static bool selftest_running = false;
static dma_addr_t __arm_lpae_dma_addr(void *pages)
@@ -287,7 +304,7 @@ static void __arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
pte |= ARM_LPAE_PTE_TYPE_BLOCK;
pte |= ARM_LPAE_PTE_AF | ARM_LPAE_PTE_SH_IS;
- pte |= pfn_to_iopte(paddr >> data->pg_shift, data);
+ pte |= paddr_to_iopte(paddr, data);
__arm_lpae_set_pte(ptep, pte, &data->iop.cfg);
}
@@ -528,7 +545,7 @@ static int arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
if (size == split_sz)
unmap_idx = ARM_LPAE_LVL_IDX(iova, lvl, data);
- blk_paddr = iopte_to_pfn(blk_pte, data) << data->pg_shift;
+ blk_paddr = iopte_to_paddr(blk_pte, data);
pte = iopte_prot(blk_pte);
for (i = 0; i < tablesz / sizeof(pte); i++, blk_paddr += split_sz) {
@@ -652,12 +669,13 @@ static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
found_translation:
iova &= (ARM_LPAE_BLOCK_SIZE(lvl, data) - 1);
- return ((phys_addr_t)iopte_to_pfn(pte,data) << data->pg_shift) | iova;
+ return iopte_to_paddr(pte, data) | iova;
}
static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg)
{
- unsigned long granule;
+ unsigned long granule, page_sizes;
+ unsigned int max_addr_bits = 48;
/*
* We need to restrict the supported page sizes to match the
@@ -677,17 +695,24 @@ static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg)
switch (granule) {
case SZ_4K:
- cfg->pgsize_bitmap &= (SZ_4K | SZ_2M | SZ_1G);
+ page_sizes = (SZ_4K | SZ_2M | SZ_1G);
break;
case SZ_16K:
- cfg->pgsize_bitmap &= (SZ_16K | SZ_32M);
+ page_sizes = (SZ_16K | SZ_32M);
break;
case SZ_64K:
- cfg->pgsize_bitmap &= (SZ_64K | SZ_512M);
+ max_addr_bits = 52;
+ page_sizes = (SZ_64K | SZ_512M);
+ if (cfg->oas > 48)
+ page_sizes |= 1ULL << 42; /* 4TB */
break;
default:
- cfg->pgsize_bitmap = 0;
+ page_sizes = 0;
}
+
+ cfg->pgsize_bitmap &= page_sizes;
+ cfg->ias = min(cfg->ias, max_addr_bits);
+ cfg->oas = min(cfg->oas, max_addr_bits);
}
static struct arm_lpae_io_pgtable *
@@ -784,6 +809,9 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
case 48:
reg |= (ARM_LPAE_TCR_PS_48_BIT << ARM_LPAE_TCR_IPS_SHIFT);
break;
+ case 52:
+ reg |= (ARM_LPAE_TCR_PS_52_BIT << ARM_LPAE_TCR_IPS_SHIFT);
+ break;
default:
goto out_free_data;
}
@@ -891,6 +919,9 @@ arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
case 48:
reg |= (ARM_LPAE_TCR_PS_48_BIT << ARM_LPAE_TCR_PS_SHIFT);
break;
+ case 52:
+ reg |= (ARM_LPAE_TCR_PS_52_BIT << ARM_LPAE_TCR_PS_SHIFT);
+ break;
default:
goto out_free_data;
}
--
2.16.1.dirty
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