[RFC PATCH 14/30] iommu/arm-smmu-v3: Share process page tables

Jean-Philippe Brucker
2017-02-27T19:54:25Z

Copy the content of TCR, MAIR and TTBR of a given task into a context
descriptor.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
---
drivers/iommu/arm-smmu-v3.c | 39 +++++++++++++++++++++++++++++++++++++--
1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index ab49164bf09b..c3fa4616bd58 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -44,6 +44,7 @@
#include <linux/amba/bus.h>

#include "io-pgtable.h"
+#include "io-pgtable-arm.h"

/* MMIO registers */
#define ARM_SMMU_IDR0 0x0
@@ -2191,6 +2192,9 @@ static int arm_smmu_init_task_pgtable(struct arm_smmu_task *smmu_task)
{
int ret;
int asid;
+ unsigned long tcr;
+ unsigned long reg, par;
+ struct arm_smmu_s1_cfg *cfg = &smmu_task->s1_cfg;

/* Pin ASID on the CPU side */
asid = mm_context_get(smmu_task->mm);
@@ -2203,8 +2207,39 @@ static int arm_smmu_init_task_pgtable(struct arm_smmu_task *smmu_task)
return ret;
}

- /* TODO: Initialize the rest of s1_cfg */
- smmu_task->s1_cfg.asid = asid;
+ tcr = TCR_T0SZ(VA_BITS) | TCR_IRGN0_WBWA | TCR_ORGN0_WBWA |
+ TCR_SH0_INNER | ARM_LPAE_TCR_EPD1;
+
+ switch (PAGE_SIZE) {
+ case SZ_4K:
+ tcr |= TCR_TG0_4K;
+ break;
+ case SZ_16K:
+ tcr |= TCR_TG0_16K;
+ break;
+ case SZ_64K:
+ tcr |= TCR_TG0_64K;
+ break;
+ default:
+ WARN_ON(1);
+ return -EFAULT;
+ }
+
+ reg = read_system_reg(SYS_ID_AA64MMFR0_EL1);
+ par = cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR0_PARANGE_SHIFT);
+ tcr |= par << ARM_LPAE_TCR_IPS_SHIFT;
+
+ /* Enable this by default, it will be filtered when writing the CD */
+ tcr |= TCR_TBI0;
+
+ cfg->asid = asid;
+ cfg->ttbr = virt_to_phys(smmu_task->mm->pgd);
+ /*
+ * MAIR value is pretty much constant and global, so we can just get it
+ * from the current CPU register
+ */
+ cfg->mair = read_sysreg(mair_el1);
+ cfg->tcr = tcr;

return 0;
}
--
2.11.0