[PATCH v2 07/12] VT-d: replace find_ats_dev_drhd()

[Jan Beulich <jbeulich@xxxxxxxx>]

All callers only care about boolean outcome. For this there's no point
in allocating a duplicate of the respective DRHD structure; a simple
boolean suffices (which eventually may want to become a count, such that
the "any ATS devices assigned state" can also clear again). With that
boolean, remove respective parameters from internal helper functions
right away, as those have access to the flag through another parameter.
(While the corresponding hook can have the parameter dropped too then,
leave this for a separate change, to limit scope here.)

No functional effect intended.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
v2: Re-base over new earlier patches.

--- a/xen/drivers/passthrough/vtd/extern.h
+++ b/xen/drivers/passthrough/vtd/extern.h
@@ -65,8 +65,6 @@ struct acpi_drhd_unit *ioapic_to_drhd(un
 struct acpi_drhd_unit *hpet_to_drhd(unsigned int hpet_id);
 struct acpi_rhsa_unit *drhd_to_rhsa(const struct acpi_drhd_unit *drhd);
 
-struct acpi_drhd_unit *find_ats_dev_drhd(struct vtd_iommu *iommu);
-
 int ats_device(const struct pci_dev *, const struct acpi_drhd_unit *);
 
 int dev_invalidate_iotlb(struct vtd_iommu *iommu, u16 did,
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -624,8 +624,7 @@ int cf_check vtd_flush_iotlb_reg(
 }
 
 static int __must_check iommu_flush_iotlb_global(struct vtd_iommu *iommu,
-                                                 bool flush_non_present_entry,
-                                                 bool flush_dev_iotlb)
+                                                 bool flush_non_present_entry)
 {
     int status;
 
@@ -633,7 +632,7 @@ static int __must_check iommu_flush_iotl
     vtd_ops_preamble_quirk(iommu);
 
     status = iommu->flush.iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH,
-                                flush_non_present_entry, flush_dev_iotlb);
+                                flush_non_present_entry, 
iommu->flush_dev_iotlb);
 
     /* undo platform specific errata workarounds */
     vtd_ops_postamble_quirk(iommu);
@@ -642,8 +641,7 @@ static int __must_check iommu_flush_iotl
 }
 
 static int __must_check iommu_flush_iotlb_dsi(struct vtd_iommu *iommu, u16 did,
-                                              bool flush_non_present_entry,
-                                              bool flush_dev_iotlb)
+                                              bool flush_non_present_entry)
 {
     int status;
 
@@ -651,7 +649,7 @@ static int __must_check iommu_flush_iotl
     vtd_ops_preamble_quirk(iommu);
 
     status = iommu->flush.iotlb(iommu, did, 0, 0, DMA_TLB_DSI_FLUSH,
-                                flush_non_present_entry, flush_dev_iotlb);
+                                flush_non_present_entry, 
iommu->flush_dev_iotlb);
 
     /* undo platform specific errata workarounds */
     vtd_ops_postamble_quirk(iommu);
@@ -661,26 +659,23 @@ static int __must_check iommu_flush_iotl
 
 static int __must_check iommu_flush_iotlb_psi(struct vtd_iommu *iommu, u16 did,
                                               u64 addr, unsigned int order,
-                                              bool flush_non_present_entry,
-                                              bool flush_dev_iotlb)
+                                              bool flush_non_present_entry)
 {
     int status;
 
     /* Fallback to domain selective flush if no PSI support */
     if ( !cap_pgsel_inv(iommu->cap) )
-        return iommu_flush_iotlb_dsi(iommu, did, flush_non_present_entry,
-                                     flush_dev_iotlb);
+        return iommu_flush_iotlb_dsi(iommu, did, flush_non_present_entry);
 
     /* Fallback to domain selective flush if size is too big */
     if ( order > cap_max_amask_val(iommu->cap) )
-        return iommu_flush_iotlb_dsi(iommu, did, flush_non_present_entry,
-                                     flush_dev_iotlb);
+        return iommu_flush_iotlb_dsi(iommu, did, flush_non_present_entry);
 
     /* apply platform specific errata workarounds */
     vtd_ops_preamble_quirk(iommu);
 
     status = iommu->flush.iotlb(iommu, did, addr, order, DMA_TLB_PSI_FLUSH,
-                                flush_non_present_entry, flush_dev_iotlb);
+                                flush_non_present_entry, 
iommu->flush_dev_iotlb);
 
     /* undo platform specific errata workarounds */
     vtd_ops_postamble_quirk(iommu);
@@ -692,7 +687,6 @@ static int __must_check iommu_flush_all(
 {
     struct acpi_drhd_unit *drhd;
     struct vtd_iommu *iommu;
-    bool flush_dev_iotlb;
     int rc = 0;
 
     flush_local(FLUSH_CACHE);
@@ -703,8 +697,7 @@ static int __must_check iommu_flush_all(
 
         iommu = drhd->iommu;
         context_rc = iommu_flush_context_global(iommu, 0);
-        flush_dev_iotlb = !!find_ats_dev_drhd(iommu);
-        iotlb_rc = iommu_flush_iotlb_global(iommu, 0, flush_dev_iotlb);
+        iotlb_rc = iommu_flush_iotlb_global(iommu, 0);
 
         /*
          * The current logic for returns:
@@ -734,7 +727,6 @@ static int __must_check cf_check iommu_f
     struct domain_iommu *hd = dom_iommu(d);
     struct acpi_drhd_unit *drhd;
     struct vtd_iommu *iommu;
-    bool flush_dev_iotlb;
     int iommu_domid;
     int ret = 0;
 
@@ -762,21 +754,18 @@ static int __must_check cf_check iommu_f
         if ( !test_bit(iommu->index, hd->arch.vtd.iommu_bitmap) )
             continue;
 
-        flush_dev_iotlb = !!find_ats_dev_drhd(iommu);
         iommu_domid = get_iommu_did(d->domain_id, iommu, !d->is_dying);
         if ( iommu_domid == -1 )
             continue;
 
         if ( !page_count || (page_count & (page_count - 1)) ||
              dfn_eq(dfn, INVALID_DFN) || !IS_ALIGNED(dfn_x(dfn), page_count) )
-            rc = iommu_flush_iotlb_dsi(iommu, iommu_domid,
-                                       0, flush_dev_iotlb);
+            rc = iommu_flush_iotlb_dsi(iommu, iommu_domid, 0);
         else
             rc = iommu_flush_iotlb_psi(iommu, iommu_domid,
                                        dfn_to_daddr(dfn),
                                        get_order_from_pages(page_count),
-                                       !(flush_flags & IOMMU_FLUSHF_modified),
-                                       flush_dev_iotlb);
+                                       !(flush_flags & IOMMU_FLUSHF_modified));
 
         if ( rc > 0 )
             iommu_flush_write_buffer(iommu);
@@ -1488,7 +1477,6 @@ int domain_context_mapping_one(
     uint16_t seg = iommu->drhd->segment, prev_did = 0;
     struct domain *prev_dom = NULL;
     int rc, ret;
-    bool flush_dev_iotlb;
 
     if ( QUARANTINE_SKIP(domain, pgd_maddr) )
         return 0;
@@ -1637,8 +1625,7 @@ int domain_context_mapping_one(
 
     rc = iommu_flush_context_device(iommu, prev_did, PCI_BDF(bus, devfn),
                                     DMA_CCMD_MASK_NOBIT, !prev_dom);
-    flush_dev_iotlb = !!find_ats_dev_drhd(iommu);
-    ret = iommu_flush_iotlb_dsi(iommu, prev_did, !prev_dom, flush_dev_iotlb);
+    ret = iommu_flush_iotlb_dsi(iommu, prev_did, !prev_dom);
 
     /*
      * The current logic for returns:
@@ -1882,7 +1869,6 @@ int domain_context_unmap_one(
     struct context_entry *context, *context_entries;
     u64 maddr;
     int iommu_domid, rc, ret;
-    bool flush_dev_iotlb;
 
     ASSERT(pcidevs_locked());
     spin_lock(&iommu->lock);
@@ -1908,8 +1894,7 @@ int domain_context_unmap_one(
                                     PCI_BDF(bus, devfn),
                                     DMA_CCMD_MASK_NOBIT, 0);
 
-    flush_dev_iotlb = !!find_ats_dev_drhd(iommu);
-    ret = iommu_flush_iotlb_dsi(iommu, iommu_domid, 0, flush_dev_iotlb);
+    ret = iommu_flush_iotlb_dsi(iommu, iommu_domid, 0);
 
     /*
      * The current logic for returns:
--- a/xen/drivers/passthrough/vtd/iommu.h
+++ b/xen/drivers/passthrough/vtd/iommu.h
@@ -484,6 +484,7 @@ struct vtd_iommu {
     spinlock_t register_lock; /* protect iommu register handling */
     u64 root_maddr; /* root entry machine address */
     nodeid_t node;
+    bool flush_dev_iotlb;
     struct msi_desc msi;
     struct acpi_drhd_unit *drhd;
 
--- a/xen/drivers/passthrough/vtd/x86/ats.c
+++ b/xen/drivers/passthrough/vtd/x86/ats.c
@@ -28,22 +28,8 @@
 #include "../extern.h"
 #include "../../ats.h"
 
-static LIST_HEAD(ats_dev_drhd_units);
-
-struct acpi_drhd_unit *find_ats_dev_drhd(struct vtd_iommu *iommu)
-{
-    struct acpi_drhd_unit *drhd;
-    list_for_each_entry ( drhd, &ats_dev_drhd_units, list )
-    {
-        if ( drhd->iommu == iommu )
-            return drhd;
-    }
-    return NULL;
-}
-
 int ats_device(const struct pci_dev *pdev, const struct acpi_drhd_unit *drhd)
 {
-    struct acpi_drhd_unit *ats_drhd;
     unsigned int pos, expfl = 0;
     const struct acpi_satc_unit *satc;
 
@@ -66,17 +52,10 @@ int ats_device(const struct pci_dev *pde
     if ( opt_ats < 0 && (!satc || !satc->atc_required) )
         return 0;
 
-    ats_drhd = find_ats_dev_drhd(drhd->iommu);
     pos = pci_find_ext_capability(pdev->sbdf, PCI_EXT_CAP_ID_ATS);
+    if ( pos )
+        drhd->iommu->flush_dev_iotlb = true;
 
-    if ( pos && (ats_drhd == NULL) )
-    {
-        ats_drhd = xmalloc(struct acpi_drhd_unit);
-        if ( !ats_drhd )
-            return -ENOMEM;
-        *ats_drhd = *drhd;
-        list_add_tail(&ats_drhd->list, &ats_dev_drhd_units);
-    }
     return pos;
 }