PCI: add pci_request_acs
Commit ae21ee65e8
"PCI: acs p2p upsteram
forwarding enabling" doesn't actually enable ACS.
Add a function to pci core to allow an IOMMU to request that ACS
be enabled. The existing mechanism of using iommu_found() in the pci
core to know when ACS should be enabled doesn't actually work due to
initialization order; iommu has only been detected not initialized.
Have Intel and AMD IOMMUs request ACS, and Xen does as well during early
init of dom0.
Cc: Allen Kay <allen.m.kay@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This commit is contained in:
parent
b26a34aa47
commit
5d990b6275
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@ -1330,6 +1330,8 @@ void __init amd_iommu_detect(void)
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gart_iommu_aperture_disabled = 1;
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gart_iommu_aperture = 0;
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#endif
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/* Make sure ACS will be enabled */
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pci_request_acs();
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}
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}
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@ -27,6 +27,7 @@
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#include <linux/page-flags.h>
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#include <linux/highmem.h>
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#include <linux/console.h>
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#include <linux/pci.h>
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#include <xen/xen.h>
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#include <xen/interface/xen.h>
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@ -1170,8 +1171,12 @@ asmlinkage void __init xen_start_kernel(void)
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add_preferred_console("xenboot", 0, NULL);
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add_preferred_console("tty", 0, NULL);
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add_preferred_console("hvc", 0, NULL);
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} else {
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/* Make sure ACS will be enabled */
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pci_request_acs();
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}
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xen_raw_console_write("about to get started...\n");
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/* Start the world */
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@ -614,8 +614,11 @@ void __init detect_intel_iommu(void)
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#endif
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#ifdef CONFIG_DMAR
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if (ret && !no_iommu && !iommu_detected && !swiotlb &&
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!dmar_disabled)
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!dmar_disabled) {
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iommu_detected = 1;
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/* Make sure ACS will be enabled */
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pci_request_acs();
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}
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#endif
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}
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early_acpi_os_unmap_memory(dmar_tbl, dmar_tbl_size);
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@ -1550,6 +1550,16 @@ void pci_enable_ari(struct pci_dev *dev)
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bridge->ari_enabled = 1;
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}
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static int pci_acs_enable;
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/**
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* pci_request_acs - ask for ACS to be enabled if supported
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*/
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void pci_request_acs(void)
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{
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pci_acs_enable = 1;
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}
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/**
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* pci_enable_acs - enable ACS if hardware support it
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* @dev: the PCI device
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@ -1560,6 +1570,9 @@ void pci_enable_acs(struct pci_dev *dev)
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u16 cap;
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u16 ctrl;
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if (!pci_acs_enable)
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return;
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if (!pci_is_pcie(dev))
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return;
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@ -10,9 +10,7 @@
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#include <linux/module.h>
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#include <linux/cpumask.h>
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#include <linux/pci-aspm.h>
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#include <linux/iommu.h>
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#include <acpi/acpi_hest.h>
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#include <xen/xen.h>
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#include "pci.h"
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#define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */
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@ -1029,7 +1027,6 @@ static void pci_init_capabilities(struct pci_dev *dev)
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pci_iov_init(dev);
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/* Enable ACS P2P upstream forwarding */
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if (iommu_found() || xen_initial_domain())
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pci_enable_acs(dev);
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}
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@ -1328,5 +1328,7 @@ static inline bool pci_is_pcie(struct pci_dev *dev)
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return !!pci_pcie_cap(dev);
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}
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void pci_request_acs(void);
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#endif /* __KERNEL__ */
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#endif /* LINUX_PCI_H */
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