Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754351Ab3HAEq0 (ORCPT ); Thu, 1 Aug 2013 00:46:26 -0400 Received: from mail-pd0-f171.google.com ([209.85.192.171]:51427 "EHLO mail-pd0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753698Ab3HAEpf (ORCPT ); Thu, 1 Aug 2013 00:45:35 -0400 From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , Benjamin Herrenschmidt , Paul Mackerras , Alexander Graf , kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org Subject: [PATCH 08/10] powerpc/iommu: rework to support realmode Date: Thu, 1 Aug 2013 14:44:30 +1000 Message-Id: <1375332272-22176-9-git-send-email-aik@ozlabs.ru> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1375332272-22176-1-git-send-email-aik@ozlabs.ru> References: <1375332272-22176-1-git-send-email-aik@ozlabs.ru> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10173 Lines: 343 The TCE tables handling may differ for real and virtual modes so additional ppc_md.tce_build_rm/ppc_md.tce_free_rm/ppc_md.tce_flush_rm handlers were introduced earlier. So this adds the following: 1. support for the new ppc_md calls; 2. ability to iommu_tce_build to process mupltiple entries per call; 3. arch_spin_lock to protect TCE table from races in both real and virtual modes; 4. proper TCE table protection from races with the existing IOMMU code in iommu_take_ownership/iommu_release_ownership; 5. hwaddr variable renamed to hpa as it better describes what it actually represents; 6. iommu_tce_direction is static now as it is not called from anywhere else. This will be used by upcoming real mode support of VFIO on POWER. Signed-off-by: Alexey Kardashevskiy --- arch/powerpc/include/asm/iommu.h | 9 +- arch/powerpc/kernel/iommu.c | 198 ++++++++++++++++++++++++++------------- 2 files changed, 136 insertions(+), 71 deletions(-) diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h index c34656a..b01bde1 100644 --- a/arch/powerpc/include/asm/iommu.h +++ b/arch/powerpc/include/asm/iommu.h @@ -78,6 +78,7 @@ struct iommu_table { unsigned long *it_map; /* A simple allocation bitmap for now */ #ifdef CONFIG_IOMMU_API struct iommu_group *it_group; + arch_spinlock_t it_rm_lock; #endif }; @@ -152,9 +153,9 @@ extern int iommu_tce_clear_param_check(struct iommu_table *tbl, extern int iommu_tce_put_param_check(struct iommu_table *tbl, unsigned long ioba, unsigned long tce); extern int iommu_tce_build(struct iommu_table *tbl, unsigned long entry, - unsigned long hwaddr, enum dma_data_direction direction); -extern unsigned long iommu_clear_tce(struct iommu_table *tbl, - unsigned long entry); + unsigned long *hpas, unsigned long npages, bool rm); +extern int iommu_free_tces(struct iommu_table *tbl, unsigned long entry, + unsigned long npages, bool rm); extern int iommu_clear_tces_and_put_pages(struct iommu_table *tbl, unsigned long entry, unsigned long pages); extern int iommu_put_tce_user_mode(struct iommu_table *tbl, @@ -164,7 +165,5 @@ extern void iommu_flush_tce(struct iommu_table *tbl); extern int iommu_take_ownership(struct iommu_table *tbl); extern void iommu_release_ownership(struct iommu_table *tbl); -extern enum dma_data_direction iommu_tce_direction(unsigned long tce); - #endif /* __KERNEL__ */ #endif /* _ASM_IOMMU_H */ diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index b20ff17..8314c80 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -903,7 +903,7 @@ void iommu_register_group(struct iommu_table *tbl, kfree(name); } -enum dma_data_direction iommu_tce_direction(unsigned long tce) +static enum dma_data_direction iommu_tce_direction(unsigned long tce) { if ((tce & TCE_PCI_READ) && (tce & TCE_PCI_WRITE)) return DMA_BIDIRECTIONAL; @@ -914,7 +914,6 @@ enum dma_data_direction iommu_tce_direction(unsigned long tce) else return DMA_NONE; } -EXPORT_SYMBOL_GPL(iommu_tce_direction); void iommu_flush_tce(struct iommu_table *tbl) { @@ -972,73 +971,117 @@ int iommu_tce_put_param_check(struct iommu_table *tbl, } EXPORT_SYMBOL_GPL(iommu_tce_put_param_check); -unsigned long iommu_clear_tce(struct iommu_table *tbl, unsigned long entry) -{ - unsigned long oldtce; - struct iommu_pool *pool = get_pool(tbl, entry); - - spin_lock(&(pool->lock)); - - oldtce = ppc_md.tce_get(tbl, entry); - if (oldtce & (TCE_PCI_WRITE | TCE_PCI_READ)) - ppc_md.tce_free(tbl, entry, 1); - else - oldtce = 0; - - spin_unlock(&(pool->lock)); - - return oldtce; -} -EXPORT_SYMBOL_GPL(iommu_clear_tce); - int iommu_clear_tces_and_put_pages(struct iommu_table *tbl, unsigned long entry, unsigned long pages) { - unsigned long oldtce; - struct page *page; - - for ( ; pages; --pages, ++entry) { - oldtce = iommu_clear_tce(tbl, entry); - if (!oldtce) - continue; - - page = pfn_to_page(oldtce >> PAGE_SHIFT); - WARN_ON(!page); - if (page) { - if (oldtce & TCE_PCI_WRITE) - SetPageDirty(page); - put_page(page); - } - } - - return 0; + return iommu_free_tces(tbl, entry, pages, false); } EXPORT_SYMBOL_GPL(iommu_clear_tces_and_put_pages); -/* - * hwaddr is a kernel virtual address here (0xc... bazillion), - * tce_build converts it to a physical address. - */ +int iommu_free_tces(struct iommu_table *tbl, unsigned long entry, + unsigned long npages, bool rm) +{ + int i, ret = 0, to_free = 0; + + if (rm && !ppc_md.tce_free_rm) + return -EAGAIN; + + arch_spin_lock(&tbl->it_rm_lock); + + for (i = 0; i < npages; ++i) { + unsigned long oldtce = ppc_md.tce_get(tbl, entry + i); + if (!(oldtce & (TCE_PCI_WRITE | TCE_PCI_READ))) + continue; + + if (rm) { + struct page *pg = realmode_pfn_to_page( + oldtce >> PAGE_SHIFT); + if (!pg) { + ret = -EAGAIN; + } else if (PageCompound(pg)) { + ret = -EAGAIN; + } else { + if (oldtce & TCE_PCI_WRITE) + SetPageDirty(pg); + if (!put_page_unless_one(pg)) + ret = -EAGAIN; + } + } else { + struct page *pg = pfn_to_page(oldtce >> PAGE_SHIFT); + if (!pg) { + ret = -EAGAIN; + } else { + if (oldtce & TCE_PCI_WRITE) + SetPageDirty(pg); + put_page(pg); + } + } + if (ret) + break; + to_free = i + 1; + } + + if (to_free) { + if (rm) + ppc_md.tce_free_rm(tbl, entry, to_free); + else + ppc_md.tce_free(tbl, entry, to_free); + + if (rm && ppc_md.tce_flush_rm) + ppc_md.tce_flush_rm(tbl); + else if (!rm && ppc_md.tce_flush) + ppc_md.tce_flush(tbl); + } + arch_spin_unlock(&tbl->it_rm_lock); + + /* Make sure updates are seen by hardware */ + mb(); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_free_tces); + int iommu_tce_build(struct iommu_table *tbl, unsigned long entry, - unsigned long hwaddr, enum dma_data_direction direction) + unsigned long *hpas, unsigned long npages, bool rm) { - int ret = -EBUSY; - unsigned long oldtce; - struct iommu_pool *pool = get_pool(tbl, entry); + int i, ret = 0; - spin_lock(&(pool->lock)); + if (rm && !ppc_md.tce_build_rm) + return -EAGAIN; - oldtce = ppc_md.tce_get(tbl, entry); - /* Add new entry if it is not busy */ - if (!(oldtce & (TCE_PCI_WRITE | TCE_PCI_READ))) - ret = ppc_md.tce_build(tbl, entry, 1, hwaddr, direction, NULL); + arch_spin_lock(&tbl->it_rm_lock); - spin_unlock(&(pool->lock)); + for (i = 0; i < npages; ++i) { + if (ppc_md.tce_get(tbl, entry + i) & + (TCE_PCI_WRITE | TCE_PCI_READ)) { + arch_spin_unlock(&tbl->it_rm_lock); + return -EBUSY; + } + } - /* if (unlikely(ret)) - pr_err("iommu_tce: %s failed on hwaddr=%lx ioba=%lx kva=%lx ret=%d\n", - __func__, hwaddr, entry << IOMMU_PAGE_SHIFT, - hwaddr, ret); */ + for (i = 0; i < npages; ++i) { + unsigned long volatile hva = (unsigned long) __va(hpas[i]); + enum dma_data_direction dir = iommu_tce_direction(hva); + + if (rm) + ret = ppc_md.tce_build_rm(tbl, entry + i, 1, + hva, dir, NULL); + else + ret = ppc_md.tce_build(tbl, entry + i, 1, + hva, dir, NULL); + if (ret) + break; + } + + if (rm && ppc_md.tce_flush_rm) + ppc_md.tce_flush_rm(tbl); + else if (!rm && ppc_md.tce_flush) + ppc_md.tce_flush(tbl); + + arch_spin_unlock(&tbl->it_rm_lock); + + /* Make sure updates are seen by hardware */ + mb(); return ret; } @@ -1049,7 +1092,7 @@ int iommu_put_tce_user_mode(struct iommu_table *tbl, unsigned long entry, { int ret; struct page *page = NULL; - unsigned long hwaddr, offset = tce & IOMMU_PAGE_MASK & ~PAGE_MASK; + unsigned long hpa, offset = tce & IOMMU_PAGE_MASK & ~PAGE_MASK; enum dma_data_direction direction = iommu_tce_direction(tce); ret = get_user_pages_fast(tce & PAGE_MASK, 1, @@ -1059,9 +1102,9 @@ int iommu_put_tce_user_mode(struct iommu_table *tbl, unsigned long entry, tce, entry << IOMMU_PAGE_SHIFT, ret); */ return -EFAULT; } - hwaddr = (unsigned long) page_address(page) + offset; + hpa = __pa((unsigned long) page_address(page)) + offset; - ret = iommu_tce_build(tbl, entry, hwaddr, direction); + ret = iommu_tce_build(tbl, entry, &hpa, 1, false); if (ret) put_page(page); @@ -1075,18 +1118,32 @@ EXPORT_SYMBOL_GPL(iommu_put_tce_user_mode); int iommu_take_ownership(struct iommu_table *tbl) { - unsigned long sz = (tbl->it_size + 7) >> 3; + unsigned long flags, i, sz = (tbl->it_size + 7) >> 3; + int ret = 0; + + spin_lock_irqsave(&tbl->large_pool.lock, flags); + for (i = 0; i < tbl->nr_pools; i++) + spin_lock(&tbl->pools[i].lock); if (tbl->it_offset == 0) clear_bit(0, tbl->it_map); if (!bitmap_empty(tbl->it_map, tbl->it_size)) { pr_err("iommu_tce: it_map is not empty"); - return -EBUSY; + ret = -EBUSY; + if (tbl->it_offset == 0) + clear_bit(1, tbl->it_map); + + } else { + memset(tbl->it_map, 0xff, sz); } - memset(tbl->it_map, 0xff, sz); - iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size); + for (i = 0; i < tbl->nr_pools; i++) + spin_unlock(&tbl->pools[i].lock); + spin_unlock_irqrestore(&tbl->large_pool.lock, flags); + + if (!ret) + iommu_free_tces(tbl, tbl->it_offset, tbl->it_size, false); return 0; } @@ -1094,14 +1151,23 @@ EXPORT_SYMBOL_GPL(iommu_take_ownership); void iommu_release_ownership(struct iommu_table *tbl) { - unsigned long sz = (tbl->it_size + 7) >> 3; + unsigned long flags, i, sz = (tbl->it_size + 7) >> 3; + + iommu_free_tces(tbl, tbl->it_offset, tbl->it_size, false); + + spin_lock_irqsave(&tbl->large_pool.lock, flags); + for (i = 0; i < tbl->nr_pools; i++) + spin_lock(&tbl->pools[i].lock); - iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size); memset(tbl->it_map, 0, sz); /* Restore bit#0 set by iommu_init_table() */ if (tbl->it_offset == 0) set_bit(0, tbl->it_map); + + for (i = 0; i < tbl->nr_pools; i++) + spin_unlock(&tbl->pools[i].lock); + spin_unlock_irqrestore(&tbl->large_pool.lock, flags); } EXPORT_SYMBOL_GPL(iommu_release_ownership); -- 1.8.3.2 -- 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/