From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Li, Zhen-Hua" Subject: [PATCH 02/10] iommu/vt-d: Items required for kdump Date: Mon, 22 Dec 2014 17:15:21 +0800 Message-ID: <1419239729-26529-3-git-send-email-zhen-hual@hp.com> References: <1419239729-26529-1-git-send-email-zhen-hual@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1419239729-26529-1-git-send-email-zhen-hual-VXdhtT5mjnY@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, indou.takao-+CUm20s59erQFUHtdCDX3A@public.gmane.org, bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org, vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org Cc: tom.vaden-VXdhtT5mjnY@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, lisa.mitchell-VXdhtT5mjnY@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, zhen-hual-VXdhtT5mjnY@public.gmane.org, doug.hatch-VXdhtT5mjnY@public.gmane.org, ishii.hironobu-+CUm20s59erQFUHtdCDX3A@public.gmane.org, bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, billsumnerlinux-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, li.zhang6-VXdhtT5mjnY@public.gmane.org List-Id: iommu@lists.linux-foundation.org Add structure type domain_values_entry used for kdump; Add context entry functions needed for kdump. Bill Sumner: Original version; Li, Zhenhua: Changed the name of new functions, make them consistent with current context get/set functions. Signed-off-by: Bill Sumner Signed-off-by: Li, Zhen-Hua --- drivers/iommu/intel-iommu.c | 70 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 2dc6250..5ce2850 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include #include @@ -208,6 +209,12 @@ get_context_addr_from_root(struct root_entry *root) NULL); } +static inline unsigned long +get_context_phys_from_root(struct root_entry *root) +{ + return root_present(root) ? (root->val & VTD_PAGE_MASK) : 0; +} + /* * low 64 bits: * 0: present @@ -228,6 +235,32 @@ static inline bool context_present(struct context_entry *context) { return (context->lo & 1); } + +static inline int context_fault_enable(struct context_entry *c) +{ + return((c->lo >> 1) & 0x1); +} + +static inline int context_translation_type(struct context_entry *c) +{ + return((c->lo >> 2) & 0x3); +} + +static inline u64 context_address_root(struct context_entry *c) +{ + return((c->lo >> VTD_PAGE_SHIFT)); +} + +static inline int context_address_width(struct context_entry *c) +{ + return((c->hi >> 0) & 0x7); +} + +static inline int context_domain_id(struct context_entry *c) +{ + return((c->hi >> 8) & 0xffff); +} + static inline void context_set_present(struct context_entry *context) { context->lo |= 1; @@ -313,6 +346,43 @@ static inline int first_pte_in_page(struct dma_pte *pte) return !((unsigned long)pte & ~VTD_PAGE_MASK); } + +#ifdef CONFIG_CRASH_DUMP + +/* + * Fix Crashdump failure caused by leftover DMA through a hardware IOMMU + * + * Fixes the crashdump kernel to deal with an active iommu and legacy + * DMA from the (old) panicked kernel in a manner similar to how legacy + * DMA is handled when no hardware iommu was in use by the old kernel -- + * allow the legacy DMA to continue into its current buffers. + * + * In the crashdump kernel, this code: + * 1. skips disabling the IOMMU's translating of IO Virtual Addresses (IOVA). + * 2. Do not re-enable IOMMU's translating. + * 3. In kdump kernel, use the old root entry table. + * 4. Leaves the current translations in-place so that legacy DMA will + * continue to use its current buffers. + * 5. Allocates to the device drivers in the crashdump kernel + * portions of the iova address ranges that are different + * from the iova address ranges that were being used by the old kernel + * at the time of the panic. + * + */ + +struct domain_values_entry { + struct list_head link; /* link entries into a list */ + struct iova_domain iovad; /* iova's that belong to this domain */ + struct dma_pte *pgd; /* virtual address */ + int did; /* domain id */ + int gaw; /* max guest address width */ + int iommu_superpage; /* Level of superpages supported: + 0 == 4KiB (no superpages), 1 == 2MiB, + 2 == 1GiB, 3 == 512GiB, 4 == 1TiB */ +}; + +#endif /* CONFIG_CRASH_DUMP */ + /* * This domain is a statically identity mapping domain. * 1. This domain creats a static 1:1 mapping to all usable memory. -- 2.0.0-rc0