Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932237AbaJUIIg (ORCPT ); Tue, 21 Oct 2014 04:08:36 -0400 Received: from g4t3426.houston.hp.com ([15.201.208.54]:35392 "EHLO g4t3426.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754637AbaJUIFH (ORCPT ); Tue, 21 Oct 2014 04:05:07 -0400 From: "Li, Zhen-Hua" To: , , , , , Cc: , , , , , , , , , , , , , "Li, Zhen-Hua" Subject: [PATCH 3/5] iommu/vt-d: data types and functions used for kdump Date: Tue, 21 Oct 2014 16:04:17 +0800 Message-Id: <1413878659-1383-4-git-send-email-zhen-hual@hp.com> X-Mailer: git-send-email 2.0.0-rc0 In-Reply-To: <1413878659-1383-1-git-send-email-zhen-hual@hp.com> References: <1413878659-1383-1-git-send-email-zhen-hual@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Populate it with support functions to copy iommu translation tables from from the panicked kernel into the kdump kernel in the event of a crash. Bill Sumner: Original version, the creation of the data types and functions. Li, Zhenhua: Minor change: update the usage of context_get_* and context_put*, use context_* and context_set_* for replacement. Signed-off-by: Bill Sumner Signed-off-by: Li, Zhen-Hua --- drivers/iommu/intel-iommu.c | 562 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 562 insertions(+) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 99fe408..73afed4 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -378,6 +378,65 @@ struct domain_values_entry { 2 == 1GiB, 3 == 512GiB, 4 == 1TiB */ }; +/* + * Lists of domain_values_entry to hold domain values found during the copy. + * One list for each iommu in g_number_of_iommus. + */ +static struct list_head *domain_values_list; + + +/* ======================================================================== + * Copy iommu translation tables from old kernel into new kernel. + * Entry to this set of functions is: intel_iommu_copy_translation_tables() + * ------------------------------------------------------------------------ + */ +#define RET_BADCOPY -1 /* Return-code: Cannot copy translate tables */ + +/* + * Struct copy_page_addr_parms is used to allow copy_page_addr() + * to accumulate values across multiple calls and returns. + */ +struct copy_page_addr_parms { + u32 first; /* flag: first-time */ + u32 last; /* flag: last-time */ + u32 bus; /* last bus number we saw */ + u32 devfn; /* last devfn we saw */ + u32 shift; /* last shift we saw */ + u64 pte; /* Page Table Entry */ + u64 next_addr; /* next-expected page_addr */ + + u64 page_addr; /* page_addr accumulating size */ + u64 page_size; /* page_size accumulated */ + + struct domain_values_entry *dve; /* to accumulate iova ranges */ +}; + +enum returns_from_copy_context_entry { +RET_CCE_NOT_PRESENT = 1, +RET_CCE_NEW_PAGE_TABLES, +RET_CCE_PASS_THROUGH_1, +RET_CCE_PASS_THROUGH_2, +RET_CCE_RESERVED_VALUE, +RET_CCE_PREVIOUS_DID +}; + +static int copy_context_entry(struct intel_iommu *iommu, u32 bus, u32 devfn, + void *ppap, struct context_entry *ce); + +static int copy_context_entry_table(struct intel_iommu *iommu, + u32 bus, void *ppap, + struct context_entry **context_new_p, + struct context_entry *context_old_phys); + +static int copy_root_entry_table(struct intel_iommu *iommu, void *ppap, + struct root_entry **root_new_virt_p, + struct root_entry *root_old_phys); + +static int intel_iommu_copy_translation_tables(struct dmar_drhd_unit *drhd, + struct root_entry **root_old_phys_p, + struct root_entry **root_new_virt_p, + int g_num_of_iommus); + #endif /* CONFIG_CRASH_DUMP */ /* @@ -4669,3 +4728,506 @@ static void __init check_tylersburg_isoch(void) printk(KERN_WARNING "DMAR: Recommended TLB entries for ISOCH unit is 16; your BIOS set %d\n", vtisochctrl); } + +#ifdef CONFIG_CRASH_DUMP + +/* + * Copy memory from a physically-addressed area into a virtually-addressed area + */ +static int oldcopy(void *to, void *from, int size) +{ + size_t ret = 0; /* Length copied */ + unsigned long pfn; /* Page Frame Number */ + char *buf = to; /* Adr(Output buffer) */ + size_t csize = (size_t)size; /* Num(bytes to copy) */ + unsigned long offset; /* Lower 12 bits of from */ + int userbuf = 0; /* to is in kernel space */ + + + pfn = ((unsigned long) from) >> VTD_PAGE_SHIFT; + offset = ((unsigned long) from) & (~VTD_PAGE_MASK); + ret = copy_oldmem_page(pfn, buf, csize, offset, userbuf); + + return (int) ret; +} + + +/* + * constant for initializing instances of copy_page_addr_parms properly. + */ +static struct copy_page_addr_parms copy_page_addr_parms_init = {1, 0}; + + + +/* + * Lowest-level function in the 'Copy Page Tables' set + * Called once for each page_addr present in an iommu page-address table. + * + * Because of the depth-first traversal of the page-tables by the + * higher-level functions that call 'copy_page_addr', all pages + * of a domain will be presented in ascending order of IO Virtual Address. + * + * This function accumulates each contiguous range of these IOVAs and + * reserves it within the proper domain in the crashdump kernel when a + * non-contiguous range is detected, as determined by any of the following: + * 1. a change in the bus or device owning the presented page + * 2. a change in the page-size of the presented page (parameter shift) + * 3. a change in the page-table entry of the presented page + * 4. a presented IOVA that does not match the expected next-page address + * 5. the 'last' flag is set, indicating that all IOVAs have been seen. + */ +static int copy_page_addr(u64 page_addr, u32 shift, u32 bus, u32 devfn, + u64 pte, struct domain_values_entry *dve, + void *parms) +{ + struct copy_page_addr_parms *ppap = parms; + + u64 page_size = ((u64)1 << shift); /* page_size */ + u64 pfn_lo; /* For reserving IOVA range */ + u64 pfn_hi; /* For reserving IOVA range */ + struct iova *iova_p; /* For reserving IOVA range */ + + if (!ppap) { + pr_err("ERROR: ppap is NULL: 0x%3.3x(%3.3d) DevFn: 0x%3.3x(%3.3d) Page: 0x%16.16llx Size: 0x%16.16llx(%lld)\n", + bus, bus, devfn, devfn, page_addr, + page_size, page_size); + return 0; + } + + /* If (only extending current addr range) */ + if (ppap->first == 0 && + ppap->last == 0 && + ppap->bus == bus && + ppap->devfn == devfn && + ppap->shift == shift && + (ppap->pte & ~VTD_PAGE_MASK) == (pte & ~VTD_PAGE_MASK) && + ppap->next_addr == page_addr) { + + /* Update page size and next-expected address */ + ppap->next_addr += page_size; + ppap->page_size += page_size; + return 0; + } + + if (!ppap->first) { + /* Close-out the accumulated IOVA address range */ + + if (!ppap->dve) { + pr_err("%s ERROR: ppap->dve is NULL -- needed to reserve range for B:D:F=%2.2x:%2.2x:%1.1x\n", + __func__, + ppap->bus, ppap->devfn >> 3, ppap->devfn & 0x7); + return RET_BADCOPY; + } + pfn_lo = IOVA_PFN(ppap->page_addr); + pfn_hi = IOVA_PFN(ppap->page_addr + ppap->page_size); + iova_p = reserve_iova(&ppap->dve->iovad, pfn_lo, pfn_hi); + } + + /* Prepare for a new IOVA address range */ + ppap->first = 0; /* Not first-time anymore */ + ppap->bus = bus; + ppap->devfn = devfn; + ppap->shift = shift; + ppap->pte = pte; + ppap->next_addr = page_addr + page_size; /* Next-expected page_addr */ + + ppap->page_addr = page_addr; /* Addr(new page) */ + ppap->page_size = page_size; /* Size(new page) */ + + ppap->dve = dve; /* adr(device_values_entry for new range) */ + + return 0; +} + +/* + * Recursive function to copy the tree of page tables (max 6 recursions) + * Parameter 'shift' controls the recursion + */ +static int copy_page_table(struct dma_pte **dma_pte_new_p, + struct dma_pte *dma_pte_phys, + u32 shift, u64 page_addr, + struct intel_iommu *iommu, + u32 bus, u32 devfn, + struct domain_values_entry *dve, void *ppap) +{ + int ret; /* Integer return code */ + struct dma_pte *p; /* Physical adr(each entry) iterator */ + struct dma_pte *pgt_new_virt; /* Adr(dma_pte in new kernel) */ + struct dma_pte *dma_pte_next; /* Adr(next table down) */ + u64 u; /* index(each entry in page_table) */ + + + /* If (already done all levels -- problem) */ + if (shift < 12) { + pr_err("ERROR %s shift < 12 %p\n", __func__, dma_pte_phys); + pr_err("shift %d, page_addr %16.16llu bus %3.3u devfn %3.3u\n", + shift, page_addr, bus, devfn); + return RET_BADCOPY; + } + + /* allocate a page table in the new kernel + * copy contents from old kernel + * then update each entry in the table in the new kernel + */ + + pgt_new_virt = (struct dma_pte *)alloc_pgtable_page(iommu->node); + if (!pgt_new_virt) + return -ENOMEM; + + ret = oldcopy(pgt_new_virt, dma_pte_phys, VTD_PAGE_SIZE); + if (ret <= 0) + return ret; + + for (u = 0, p = pgt_new_virt; u < 512; u++, p++) { + + if (((p->val & DMA_PTE_READ) == 0) && + ((p->val & DMA_PTE_WRITE) == 0)) + continue; + + if (dma_pte_superpage(p) || (shift == 12)) { + + ret = copy_page_addr(page_addr | (u << shift), + shift, bus, devfn, p->val, dve, ppap); + if (ret) + return ret; + continue; + } + + ret = copy_page_table(&dma_pte_next, + (struct dma_pte *)(p->val & VTD_PAGE_MASK), + shift-9, page_addr | (u << shift), + iommu, bus, devfn, dve, ppap); + if (ret) + return ret; + + p->val &= ~VTD_PAGE_MASK; /* Clear old and set new pgd */ + p->val |= ((u64)dma_pte_next & VTD_PAGE_MASK); + } + + *dma_pte_new_p = (struct dma_pte *)virt_to_phys(pgt_new_virt); + __iommu_flush_cache(iommu, pgt_new_virt, VTD_PAGE_SIZE); + + return 0; +} + + +/* + * Called once for each context_entry found in a copied context_entry_table + * Each context_entry represents one PCIe device handled by the IOMMU. + * + * The 'domain_values_list' contains one 'domain_values_entry' for each + * unique domain-id found while copying the context entries for each iommu. + * + * The Intel-iommu spec. requires that every context_entry that contains + * the same domain-id point to the same set of page translation tables. + * The hardware uses this to improve the use of its translation cache. + * In order to insure that the copied translate tables abide by this + * requirement, this function keeps a list of domain-ids (dids) that + * have already been seen for this iommu. This function checks each entry + * already on the list for a domain-id that matches the domain-id in this + * context_entry. If found, this function places the address of the previous + * context's tree of page translation tables into this context_entry. + * If a matching previous entry is not found, a new 'domain_values_entry' + * structure is created for the domain-id in this context_entry and + * copy_page_table is called to duplicate its tree of page tables. + */ +static int copy_context_entry(struct intel_iommu *iommu, u32 bus, u32 devfn, + void *ppap, struct context_entry *ce) +{ + int ret = 0; /* Integer Return Code */ + u32 shift = 0; /* bits to shift page_addr */ + u64 page_addr = 0; /* Address of translated page */ + struct dma_pte *pgt_old_phys; /* Adr(page_table in the old kernel) */ + struct dma_pte *pgt_new_phys; /* Adr(page_table in the new kernel) */ + u8 t; /* Translation-type from context */ + u8 aw; /* Address-width from context */ + u32 aw_shift[8] = { + 12+9+9, /* [000b] 30-bit AGAW (2-level page table) */ + 12+9+9+9, /* [001b] 39-bit AGAW (3-level page table) */ + 12+9+9+9+9, /* [010b] 48-bit AGAW (4-level page table) */ + 12+9+9+9+9+9, /* [011b] 57-bit AGAW (5-level page table) */ + 12+9+9+9+9+9+9, /* [100b] 64-bit AGAW (6-level page table) */ + 0, /* [111b] Reserved */ + 0, /* [110b] Reserved */ + 0, /* [111b] Reserved */ + }; + + struct domain_values_entry *dve = NULL; + + + if (!context_present(ce)) { /* If (context not present) */ + ret = RET_CCE_NOT_PRESENT; /* Skip it */ + goto exit; + } + + t = context_translation_type(ce); + + /* If we have seen this domain-id before on this iommu, + * give this context the same page-tables and we are done. + */ + list_for_each_entry(dve, &domain_values_list[iommu->seq_id], link) { + if (dve->did == (int) context_domain_id(ce)) { + switch (t) { + case 0: /* page tables */ + case 1: /* page tables */ + context_set_address_root(ce, + virt_to_phys(dve->pgd)); + ret = RET_CCE_PREVIOUS_DID; + break; + + case 2: /* Pass through */ + if (dve->pgd == NULL) + ret = RET_CCE_PASS_THROUGH_2; + else + ret = RET_BADCOPY; + break; + + default: /* Bad value of 't'*/ + ret = RET_BADCOPY; + break; + } + goto exit; + } + } + + /* Since we now know that this is a new domain-id for this iommu, + * create a new entry, add it to the list, and handle its + * page tables. + */ + + dve = kcalloc(1, sizeof(struct domain_values_entry), GFP_KERNEL); + if (!dve) { + ret = -ENOMEM; + goto exit; + } + + dve->did = (int) context_domain_id(ce); + dve->gaw = (int) agaw_to_width(context_address_width(ce)); + dve->pgd = NULL; + init_iova_domain(&dve->iovad, DMA_32BIT_PFN); + + list_add(&dve->link, &domain_values_list[iommu->seq_id]); + + + if (t == 0 || t == 1) { /* If (context has page tables) */ + aw = context_address_width(ce); + shift = aw_shift[aw]; + + pgt_old_phys = (struct dma_pte *) + (context_address_root(ce) << VTD_PAGE_SHIFT); + + ret = copy_page_table(&pgt_new_phys, pgt_old_phys, + shift-9, page_addr, iommu, bus, devfn, dve, ppap); + + if (ret) /* if (problem) bail out */ + goto exit; + + context_set_address_root(ce, (unsigned long)(pgt_new_phys)); + dve->pgd = phys_to_virt((unsigned long)pgt_new_phys); + ret = RET_CCE_NEW_PAGE_TABLES; + goto exit; + } + + if (t == 2) { /* If (Identity mapped pass-through) */ + ret = RET_CCE_PASS_THROUGH_1; /* REVISIT: Skip for now */ + goto exit; + } + + ret = RET_CCE_RESERVED_VALUE; /* Else ce->t is a Reserved value */ + /* Note fall-through */ + +exit: /* all returns come through here to insure good clean-up */ + return ret; +} + + +/* + * Called once for each context_entry_table found in the root_entry_table + */ +static int copy_context_entry_table(struct intel_iommu *iommu, + u32 bus, void *ppap, + struct context_entry **context_new_p, + struct context_entry *context_old_phys) +{ + int ret = 0; /* Integer return code */ + struct context_entry *ce; /* Iterator */ + struct context_entry *context_new_phys; /* adr(table in new kernel) */ + struct context_entry *context_new_virt; /* adr(table in new kernel) */ + u32 devfn = 0; /* PCI Device & function */ + + /* allocate a context-entry table in the new kernel + * copy contents from old kernel + * then update each entry in the table in the new kernel + */ + context_new_virt = + (struct context_entry *)alloc_pgtable_page(iommu->node); + if (!context_new_virt) + return -ENOMEM; + + context_new_phys = + (struct context_entry *)virt_to_phys(context_new_virt); + + oldcopy(context_new_virt, context_old_phys, VTD_PAGE_SIZE); + + for (devfn = 0, ce = context_new_virt; devfn < 256; devfn++, ce++) { + + if (!context_present(ce)) /* If (context not present) */ + continue; /* Skip it */ + + ret = copy_context_entry(iommu, bus, devfn, ppap, ce); + if (ret < 0) /* if (problem) */ + return RET_BADCOPY; + + switch (ret) { + case RET_CCE_NOT_PRESENT: + continue; + case RET_CCE_NEW_PAGE_TABLES: + continue; + case RET_CCE_PASS_THROUGH_1: + continue; + case RET_CCE_PASS_THROUGH_2: + continue; + case RET_CCE_RESERVED_VALUE: + return RET_BADCOPY; + case RET_CCE_PREVIOUS_DID: + continue; + default: + return RET_BADCOPY; + }; + } + + *context_new_p = context_new_phys; + __iommu_flush_cache(iommu, context_new_virt, VTD_PAGE_SIZE); + return 0; +} + + +/* + * Highest-level function in the 'copy translation tables' set of functions + */ +static int copy_root_entry_table(struct intel_iommu *iommu, void *ppap, + struct root_entry **root_new_virt_p, + struct root_entry *root_old_phys) +{ + int ret = 0; /* Integer return code */ + u32 bus; /* Index: root-entry-table */ + struct root_entry *re; /* Virt(iterator: new table) */ + struct root_entry *root_new_virt; /* Virt(table in new kernel) */ + struct context_entry *context_old_phys; /* Phys(context table entry) */ + struct context_entry *context_new_phys; /* Phys(new context_entry) */ + + /* + * allocate a root-entry table in the new kernel + * copy contents from old kernel + * then update each entry in the table in the new kernel + */ + + root_new_virt = (struct root_entry *)alloc_pgtable_page(iommu->node); + if (!root_new_virt) + return -ENOMEM; + + oldcopy(root_new_virt, root_old_phys, VTD_PAGE_SIZE); + + for (bus = 0, re = root_new_virt; bus < 256; bus += 1, re += 1) { + + if (!root_present(re)) + continue; + + context_old_phys = get_context_phys_from_root(re); + + if (!context_old_phys) + continue; + + ret = copy_context_entry_table(iommu, bus, ppap, + &context_new_phys, + context_old_phys); + if (ret) + return ret; + + re->val &= ~VTD_PAGE_MASK; + set_root_value(re, (unsigned long)context_new_phys); + } + + *root_new_virt_p = root_new_virt; + __iommu_flush_cache(iommu, root_new_virt, VTD_PAGE_SIZE); + return 0; +} + +/* + * Interface to the "copy translation tables" set of functions + * from mainline code. + */ +static int intel_iommu_copy_translation_tables(struct dmar_drhd_unit *drhd, + struct root_entry **root_old_phys_p, + struct root_entry **root_new_virt_p, + int g_num_of_iommus) +{ + struct intel_iommu *iommu; /* Virt(iommu hardware registers) */ + unsigned long long q; /* quadword scratch */ + struct root_entry *root_phys; /* Phys(table in old kernel) */ + struct root_entry *root_new; /* Virt(table in new kernel) */ + int ret = 0; /* Integer return code */ + int i = 0; /* Loop index */ + + /* Structure so copy_page_addr() can accumulate things + * over multiple calls and returns + */ + struct copy_page_addr_parms ppa_parms = copy_page_addr_parms_init; + struct copy_page_addr_parms *ppap = &ppa_parms; + + + iommu = drhd->iommu; + q = readq(iommu->reg + DMAR_RTADDR_REG); + + if (!q) + return -1; + + *root_old_phys_p = (struct root_entry *)q; /* Returned to caller */ + + /* If (list needs initializing) do it here */ + if (!domain_values_list) { + domain_values_list = + kcalloc(g_num_of_iommus, sizeof(struct list_head), + GFP_KERNEL); + + if (!domain_values_list) { + pr_err("Allocation failed for domain_values_list array\n"); + return -ENOMEM; + } + for (i = 0; i < g_num_of_iommus; i++) + INIT_LIST_HEAD(&domain_values_list[i]); + } + + /* Copy the root-entry table from the old kernel + * foreach context_entry_table in root_entry + * foreach context_entry in context_entry_table + * foreach level-1 page_table_entry in context_entry + * foreach level-2 page_table_entry in level 1 page_table_entry + * Above pattern continues up to 6 levels of page tables + * Sanity-check the entry + * Process the bus, devfn, page_address, page_size + */ + + root_phys = (struct root_entry *)q; + ret = copy_root_entry_table(iommu, ppap, &root_new, root_phys); + if (ret) + return ret; + + + ppa_parms.last = 1; + copy_page_addr(0, 0, 0, 0, 0, NULL, ppap); + *root_new_virt_p = root_new; /* Returned to caller */ + + /* The translation tables in the new kernel should now contain + * the same translations as the tables in the old kernel. + * This will allow us to update the iommu hdw to use the new tables. + * + * NOTE: Neither the iommu hardware nor the iommu->root_entry + * struct-value is updated herein. + * These are left for the caller to do. + */ + + return 0; +} + +#endif /* CONFIG_CRASH_DUMP */ -- 2.0.0-rc0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/