From 1f106ff0ea2782a6bc49bb927e4789681a2ec507 Mon Sep 17 00:00:00 2001 From: Parav Pandit Date: Thu, 10 Jun 2021 10:01:11 +0800 Subject: iommu/vt-d: Use bitfields for DMAR capabilities IOTLB device presence, iommu coherency and snooping are boolean capabilities. Use them as bits and keep them adjacent. Structure layout before the reorg. $ pahole -C dmar_domain drivers/iommu/intel/dmar.o struct dmar_domain { int nid; /* 0 4 */ unsigned int iommu_refcnt[128]; /* 4 512 */ /* --- cacheline 8 boundary (512 bytes) was 4 bytes ago --- */ u16 iommu_did[128]; /* 516 256 */ /* --- cacheline 12 boundary (768 bytes) was 4 bytes ago --- */ bool has_iotlb_device; /* 772 1 */ /* XXX 3 bytes hole, try to pack */ struct list_head devices; /* 776 16 */ struct list_head subdevices; /* 792 16 */ struct iova_domain iovad __attribute__((__aligned__(8))); /* 808 2320 */ /* --- cacheline 48 boundary (3072 bytes) was 56 bytes ago --- */ struct dma_pte * pgd; /* 3128 8 */ /* --- cacheline 49 boundary (3136 bytes) --- */ int gaw; /* 3136 4 */ int agaw; /* 3140 4 */ int flags; /* 3144 4 */ int iommu_coherency; /* 3148 4 */ int iommu_snooping; /* 3152 4 */ int iommu_count; /* 3156 4 */ int iommu_superpage; /* 3160 4 */ /* XXX 4 bytes hole, try to pack */ u64 max_addr; /* 3168 8 */ u32 default_pasid; /* 3176 4 */ /* XXX 4 bytes hole, try to pack */ struct iommu_domain domain; /* 3184 72 */ /* size: 3256, cachelines: 51, members: 18 */ /* sum members: 3245, holes: 3, sum holes: 11 */ /* forced alignments: 1 */ /* last cacheline: 56 bytes */ } __attribute__((__aligned__(8))); After arranging it for natural padding and to make flags as u8 bits, it saves 8 bytes for the struct. struct dmar_domain { int nid; /* 0 4 */ unsigned int iommu_refcnt[128]; /* 4 512 */ /* --- cacheline 8 boundary (512 bytes) was 4 bytes ago --- */ u16 iommu_did[128]; /* 516 256 */ /* --- cacheline 12 boundary (768 bytes) was 4 bytes ago --- */ u8 has_iotlb_device:1; /* 772: 0 1 */ u8 iommu_coherency:1; /* 772: 1 1 */ u8 iommu_snooping:1; /* 772: 2 1 */ /* XXX 5 bits hole, try to pack */ /* XXX 3 bytes hole, try to pack */ struct list_head devices; /* 776 16 */ struct list_head subdevices; /* 792 16 */ struct iova_domain iovad __attribute__((__aligned__(8))); /* 808 2320 */ /* --- cacheline 48 boundary (3072 bytes) was 56 bytes ago --- */ struct dma_pte * pgd; /* 3128 8 */ /* --- cacheline 49 boundary (3136 bytes) --- */ int gaw; /* 3136 4 */ int agaw; /* 3140 4 */ int flags; /* 3144 4 */ int iommu_count; /* 3148 4 */ int iommu_superpage; /* 3152 4 */ /* XXX 4 bytes hole, try to pack */ u64 max_addr; /* 3160 8 */ u32 default_pasid; /* 3168 4 */ /* XXX 4 bytes hole, try to pack */ struct iommu_domain domain; /* 3176 72 */ /* size: 3248, cachelines: 51, members: 18 */ /* sum members: 3236, holes: 3, sum holes: 11 */ /* sum bitfield members: 3 bits, bit holes: 1, sum bit holes: 5 bits */ /* forced alignments: 1 */ /* last cacheline: 48 bytes */ } __attribute__((__aligned__(8))); Signed-off-by: Parav Pandit Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20210530075053.264218-1-parav@nvidia.com Link: https://lore.kernel.org/r/20210610020115.1637656-20-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/intel/iommu.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 65458aee0d95..430ef2232d47 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -626,12 +626,12 @@ static void domain_update_iommu_coherency(struct dmar_domain *domain) bool found = false; int i; - domain->iommu_coherency = 1; + domain->iommu_coherency = true; for_each_domain_iommu(i, domain) { found = true; if (!iommu_paging_structure_coherency(g_iommus[i])) { - domain->iommu_coherency = 0; + domain->iommu_coherency = false; break; } } @@ -642,18 +642,18 @@ static void domain_update_iommu_coherency(struct dmar_domain *domain) rcu_read_lock(); for_each_active_iommu(iommu, drhd) { if (!iommu_paging_structure_coherency(iommu)) { - domain->iommu_coherency = 0; + domain->iommu_coherency = false; break; } } rcu_read_unlock(); } -static int domain_update_iommu_snooping(struct intel_iommu *skip) +static bool domain_update_iommu_snooping(struct intel_iommu *skip) { struct dmar_drhd_unit *drhd; struct intel_iommu *iommu; - int ret = 1; + bool ret = true; rcu_read_lock(); for_each_active_iommu(iommu, drhd) { @@ -666,7 +666,7 @@ static int domain_update_iommu_snooping(struct intel_iommu *skip) */ if (!sm_supported(iommu) && !ecap_sc_support(iommu->ecap)) { - ret = 0; + ret = false; break; } } @@ -4506,8 +4506,8 @@ static int md_domain_init(struct dmar_domain *domain, int guest_width) adjust_width = guestwidth_to_adjustwidth(guest_width); domain->agaw = width_to_agaw(adjust_width); - domain->iommu_coherency = 0; - domain->iommu_snooping = 0; + domain->iommu_coherency = false; + domain->iommu_snooping = false; domain->iommu_superpage = 0; domain->max_addr = 0; @@ -5131,7 +5131,7 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain, static bool intel_iommu_capable(enum iommu_cap cap) { if (cap == IOMMU_CAP_CACHE_COHERENCY) - return domain_update_iommu_snooping(NULL) == 1; + return domain_update_iommu_snooping(NULL); if (cap == IOMMU_CAP_INTR_REMAP) return irq_remapping_enabled == 1; -- cgit v1.2.3