--- /dev/null
+From d5430c466b3c3b5f631ee37be333a40924575b72 Mon Sep 17 00:00:00 2001
+From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+Date: Thu, 21 Nov 2019 10:26:44 +0100
+Subject: [PATCH] dma-mapping: treat dev->bus_dma_mask as a DMA limit
+
+commit a7ba70f1787f977f970cd116076c6fce4b9e01cc upstream.
+
+Using a mask to represent bus DMA constraints has a set of limitations.
+The biggest one being it can only hold a power of two (minus one). The
+DMA mapping code is already aware of this and treats dev->bus_dma_mask
+as a limit. This quirk is already used by some architectures although
+still rare.
+
+With the introduction of the Raspberry Pi 4 we've found a new contender
+for the use of bus DMA limits, as its PCIe bus can only address the
+lower 3GB of memory (of a total of 4GB). This is impossible to represent
+with a mask. To make things worse the device-tree code rounds non power
+of two bus DMA limits to the next power of two, which is unacceptable in
+this case.
+
+In the light of this, rename dev->bus_dma_mask to dev->bus_dma_limit all
+over the tree and treat it as such. Note that dev->bus_dma_limit should
+contain the higher accessible DMA address.
+
+Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+Reviewed-by: Robin Murphy <robin.murphy@arm.com>
+Signed-off-by: Christoph Hellwig <hch@lst.de>
+---
+ arch/mips/pci/fixup-sb1250.c | 16 ++++++++--------
+ arch/powerpc/sysdev/fsl_pci.c | 6 +++---
+ arch/x86/kernel/pci-dma.c | 2 +-
+ arch/x86/mm/mem_encrypt.c | 2 +-
+ arch/x86/pci/sta2x11-fixup.c | 2 +-
+ drivers/acpi/arm64/iort.c | 20 +++++++-------------
+ drivers/ata/ahci.c | 2 +-
+ drivers/iommu/dma-iommu.c | 3 +--
+ drivers/of/device.c | 9 +++++----
+ include/linux/device.h | 6 +++---
+ include/linux/dma-direct.h | 2 +-
+ include/linux/dma-mapping.h | 2 +-
+ kernel/dma/direct.c | 27 +++++++++++++--------------
+ 13 files changed, 46 insertions(+), 53 deletions(-)
+
+--- a/arch/mips/pci/fixup-sb1250.c
++++ b/arch/mips/pci/fixup-sb1250.c
+@@ -21,22 +21,22 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SI
+
+ /*
+ * The BCM1250, etc. PCI host bridge does not support DAC on its 32-bit
+- * bus, so we set the bus's DMA mask accordingly. However the HT link
++ * bus, so we set the bus's DMA limit accordingly. However the HT link
+ * down the artificial PCI-HT bridge supports 40-bit addressing and the
+ * SP1011 HT-PCI bridge downstream supports both DAC and a 64-bit bus
+ * width, so we record the PCI-HT bridge's secondary and subordinate bus
+- * numbers and do not set the mask for devices present in the inclusive
++ * numbers and do not set the limit for devices present in the inclusive
+ * range of those.
+ */
+-struct sb1250_bus_dma_mask_exclude {
++struct sb1250_bus_dma_limit_exclude {
+ bool set;
+ unsigned char start;
+ unsigned char end;
+ };
+
+-static int sb1250_bus_dma_mask(struct pci_dev *dev, void *data)
++static int sb1250_bus_dma_limit(struct pci_dev *dev, void *data)
+ {
+- struct sb1250_bus_dma_mask_exclude *exclude = data;
++ struct sb1250_bus_dma_limit_exclude *exclude = data;
+ bool exclude_this;
+ bool ht_bridge;
+
+@@ -55,7 +55,7 @@ static int sb1250_bus_dma_mask(struct pc
+ exclude->start, exclude->end);
+ } else {
+ dev_dbg(&dev->dev, "disabling DAC for device");
+- dev->dev.bus_dma_mask = DMA_BIT_MASK(32);
++ dev->dev.bus_dma_limit = DMA_BIT_MASK(32);
+ }
+
+ return 0;
+@@ -63,9 +63,9 @@ static int sb1250_bus_dma_mask(struct pc
+
+ static void quirk_sb1250_pci_dac(struct pci_dev *dev)
+ {
+- struct sb1250_bus_dma_mask_exclude exclude = { .set = false };
++ struct sb1250_bus_dma_limit_exclude exclude = { .set = false };
+
+- pci_walk_bus(dev->bus, sb1250_bus_dma_mask, &exclude);
++ pci_walk_bus(dev->bus, sb1250_bus_dma_limit, &exclude);
+ }
+ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_SIBYTE, PCI_DEVICE_ID_BCM1250_PCI,
+ quirk_sb1250_pci_dac);
+--- a/arch/powerpc/sysdev/fsl_pci.c
++++ b/arch/powerpc/sysdev/fsl_pci.c
+@@ -115,8 +115,8 @@ static void pci_dma_dev_setup_swiotlb(st
+ {
+ struct pci_controller *hose = pci_bus_to_host(pdev->bus);
+
+- pdev->dev.bus_dma_mask =
+- hose->dma_window_base_cur + hose->dma_window_size;
++ pdev->dev.bus_dma_limit =
++ hose->dma_window_base_cur + hose->dma_window_size - 1;
+ }
+
+ static void setup_swiotlb_ops(struct pci_controller *hose)
+@@ -135,7 +135,7 @@ static void fsl_pci_dma_set_mask(struct
+ * mapping that allows addressing any RAM address from across PCI.
+ */
+ if (dev_is_pci(dev) && dma_mask >= pci64_dma_offset * 2 - 1) {
+- dev->bus_dma_mask = 0;
++ dev->bus_dma_limit = 0;
+ dev->archdata.dma_offset = pci64_dma_offset;
+ }
+ }
+--- a/arch/x86/kernel/pci-dma.c
++++ b/arch/x86/kernel/pci-dma.c
+@@ -146,7 +146,7 @@ rootfs_initcall(pci_iommu_init);
+
+ static int via_no_dac_cb(struct pci_dev *pdev, void *data)
+ {
+- pdev->dev.bus_dma_mask = DMA_BIT_MASK(32);
++ pdev->dev.bus_dma_limit = DMA_BIT_MASK(32);
+ return 0;
+ }
+
+--- a/arch/x86/mm/mem_encrypt.c
++++ b/arch/x86/mm/mem_encrypt.c
+@@ -367,7 +367,7 @@ bool force_dma_unencrypted(struct device
+ if (sme_active()) {
+ u64 dma_enc_mask = DMA_BIT_MASK(__ffs64(sme_me_mask));
+ u64 dma_dev_mask = min_not_zero(dev->coherent_dma_mask,
+- dev->bus_dma_mask);
++ dev->bus_dma_limit);
+
+ if (dma_dev_mask <= dma_enc_mask)
+ return true;
+--- a/arch/x86/pci/sta2x11-fixup.c
++++ b/arch/x86/pci/sta2x11-fixup.c
+@@ -143,7 +143,7 @@ static void sta2x11_map_ep(struct pci_de
+
+ dev->dma_pfn_offset = PFN_DOWN(-amba_base);
+
+- dev->bus_dma_mask = max_amba_addr;
++ dev->bus_dma_limit = max_amba_addr;
+ pci_set_consistent_dma_mask(pdev, max_amba_addr);
+ pci_set_dma_mask(pdev, max_amba_addr);
+
+--- a/drivers/acpi/arm64/iort.c
++++ b/drivers/acpi/arm64/iort.c
+@@ -1057,8 +1057,8 @@ static int rc_dma_get_range(struct devic
+ */
+ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
+ {
+- u64 mask, dmaaddr = 0, size = 0, offset = 0;
+- int ret, msb;
++ u64 end, mask, dmaaddr = 0, size = 0, offset = 0;
++ int ret;
+
+ /*
+ * If @dev is expected to be DMA-capable then the bus code that created
+@@ -1085,19 +1085,13 @@ void iort_dma_setup(struct device *dev,
+ }
+
+ if (!ret) {
+- msb = fls64(dmaaddr + size - 1);
+ /*
+- * Round-up to the power-of-two mask or set
+- * the mask to the whole 64-bit address space
+- * in case the DMA region covers the full
+- * memory window.
++ * Limit coherent and dma mask based on size retrieved from
++ * firmware.
+ */
+- mask = msb == 64 ? U64_MAX : (1ULL << msb) - 1;
+- /*
+- * Limit coherent and dma mask based on size
+- * retrieved from firmware.
+- */
+- dev->bus_dma_mask = mask;
++ end = dmaaddr + size - 1;
++ mask = DMA_BIT_MASK(ilog2(end) + 1);
++ dev->bus_dma_limit = end;
+ dev->coherent_dma_mask = mask;
+ *dev->dma_mask = mask;
+ }
+--- a/drivers/ata/ahci.c
++++ b/drivers/ata/ahci.c
+@@ -900,7 +900,7 @@ static int ahci_configure_dma_masks(stru
+ * value, don't extend it here. This happens on STA2X11, for example.
+ *
+ * XXX: manipulating the DMA mask from platform code is completely
+- * bogus, platform code should use dev->bus_dma_mask instead..
++ * bogus, platform code should use dev->bus_dma_limit instead..
+ */
+ if (pdev->dma_mask && pdev->dma_mask < DMA_BIT_MASK(32))
+ return 0;
+--- a/drivers/iommu/dma-iommu.c
++++ b/drivers/iommu/dma-iommu.c
+@@ -404,8 +404,7 @@ static dma_addr_t iommu_dma_alloc_iova(s
+ if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
+ iova_len = roundup_pow_of_two(iova_len);
+
+- if (dev->bus_dma_mask)
+- dma_limit &= dev->bus_dma_mask;
++ dma_limit = min_not_zero(dma_limit, dev->bus_dma_limit);
+
+ if (domain->geometry.force_aperture)
+ dma_limit = min(dma_limit, domain->geometry.aperture_end);
+--- a/drivers/of/device.c
++++ b/drivers/of/device.c
+@@ -93,7 +93,7 @@ int of_dma_configure(struct device *dev,
+ bool coherent;
+ unsigned long offset;
+ const struct iommu_ops *iommu;
+- u64 mask;
++ u64 mask, end;
+
+ ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
+ if (ret < 0) {
+@@ -148,12 +148,13 @@ int of_dma_configure(struct device *dev,
+ * Limit coherent and dma mask based on size and default mask
+ * set by the driver.
+ */
+- mask = DMA_BIT_MASK(ilog2(dma_addr + size - 1) + 1);
++ end = dma_addr + size - 1;
++ mask = DMA_BIT_MASK(ilog2(end) + 1);
+ dev->coherent_dma_mask &= mask;
+ *dev->dma_mask &= mask;
+- /* ...but only set bus mask if we found valid dma-ranges earlier */
++ /* ...but only set bus limit if we found valid dma-ranges earlier */
+ if (!ret)
+- dev->bus_dma_mask = mask;
++ dev->bus_dma_limit = end;
+
+ coherent = of_dma_is_coherent(np);
+ dev_dbg(dev, "device is%sdma coherent\n",
+--- a/include/linux/device.h
++++ b/include/linux/device.h
+@@ -1186,8 +1186,8 @@ struct dev_links_info {
+ * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
+ * hardware supports 64-bit addresses for consistent allocations
+ * such descriptors.
+- * @bus_dma_mask: Mask of an upstream bridge or bus which imposes a smaller DMA
+- * limit than the device itself supports.
++ * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
++ * DMA limit than the device itself supports.
+ * @dma_pfn_offset: offset of DMA memory range relatively of RAM
+ * @dma_parms: A low level driver may set these to teach IOMMU code about
+ * segment limitations.
+@@ -1270,7 +1270,7 @@ struct device {
+ not all hardware supports
+ 64 bit addresses for consistent
+ allocations such descriptors. */
+- u64 bus_dma_mask; /* upstream dma_mask constraint */
++ u64 bus_dma_limit; /* upstream dma constraint */
+ unsigned long dma_pfn_offset;
+
+ struct device_dma_parameters *dma_parms;
+--- a/include/linux/dma-direct.h
++++ b/include/linux/dma-direct.h
+@@ -63,7 +63,7 @@ static inline bool dma_capable(struct de
+ min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn)))
+ return false;
+
+- return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_mask);
++ return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_limit);
+ }
+
+ u64 dma_direct_get_required_mask(struct device *dev);
+--- a/include/linux/dma-mapping.h
++++ b/include/linux/dma-mapping.h
+@@ -697,7 +697,7 @@ static inline int dma_coerce_mask_and_co
+ */
+ static inline bool dma_addressing_limited(struct device *dev)
+ {
+- return min_not_zero(dma_get_mask(dev), dev->bus_dma_mask) <
++ return min_not_zero(dma_get_mask(dev), dev->bus_dma_limit) <
+ dma_get_required_mask(dev);
+ }
+
+--- a/kernel/dma/direct.c
++++ b/kernel/dma/direct.c
+@@ -26,10 +26,10 @@ static void report_addr(struct device *d
+ {
+ if (!dev->dma_mask) {
+ dev_err_once(dev, "DMA map on device without dma_mask\n");
+- } else if (*dev->dma_mask >= DMA_BIT_MASK(32) || dev->bus_dma_mask) {
++ } else if (*dev->dma_mask >= DMA_BIT_MASK(32) || dev->bus_dma_limit) {
+ dev_err_once(dev,
+- "overflow %pad+%zu of DMA mask %llx bus mask %llx\n",
+- &dma_addr, size, *dev->dma_mask, dev->bus_dma_mask);
++ "overflow %pad+%zu of DMA mask %llx bus limit %llx\n",
++ &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
+ }
+ WARN_ON_ONCE(1);
+ }
+@@ -51,15 +51,14 @@ u64 dma_direct_get_required_mask(struct
+ }
+
+ static gfp_t __dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
+- u64 *phys_mask)
++ u64 *phys_limit)
+ {
+- if (dev->bus_dma_mask && dev->bus_dma_mask < dma_mask)
+- dma_mask = dev->bus_dma_mask;
++ u64 dma_limit = min_not_zero(dma_mask, dev->bus_dma_limit);
+
+ if (force_dma_unencrypted(dev))
+- *phys_mask = __dma_to_phys(dev, dma_mask);
++ *phys_limit = __dma_to_phys(dev, dma_limit);
+ else
+- *phys_mask = dma_to_phys(dev, dma_mask);
++ *phys_limit = dma_to_phys(dev, dma_limit);
+
+ /*
+ * Optimistically try the zone that the physical address mask falls
+@@ -69,9 +68,9 @@ static gfp_t __dma_direct_optimal_gfp_ma
+ * Note that GFP_DMA32 and GFP_DMA are no ops without the corresponding
+ * zones.
+ */
+- if (*phys_mask <= DMA_BIT_MASK(zone_dma_bits))
++ if (*phys_limit <= DMA_BIT_MASK(zone_dma_bits))
+ return GFP_DMA;
+- if (*phys_mask <= DMA_BIT_MASK(32))
++ if (*phys_limit <= DMA_BIT_MASK(32))
+ return GFP_DMA32;
+ return 0;
+ }
+@@ -79,7 +78,7 @@ static gfp_t __dma_direct_optimal_gfp_ma
+ static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
+ {
+ return phys_to_dma_direct(dev, phys) + size - 1 <=
+- min_not_zero(dev->coherent_dma_mask, dev->bus_dma_mask);
++ min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);
+ }
+
+ struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
+@@ -88,7 +87,7 @@ struct page *__dma_direct_alloc_pages(st
+ size_t alloc_size = PAGE_ALIGN(size);
+ int node = dev_to_node(dev);
+ struct page *page = NULL;
+- u64 phys_mask;
++ u64 phys_limit;
+
+ if (attrs & DMA_ATTR_NO_WARN)
+ gfp |= __GFP_NOWARN;
+@@ -96,7 +95,7 @@ struct page *__dma_direct_alloc_pages(st
+ /* we always manually zero the memory once we are done: */
+ gfp &= ~__GFP_ZERO;
+ gfp |= __dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
+- &phys_mask);
++ &phys_limit);
+ page = dma_alloc_contiguous(dev, alloc_size, gfp);
+ if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
+ dma_free_contiguous(dev, page, alloc_size);
+@@ -110,7 +109,7 @@ again:
+ page = NULL;
+
+ if (IS_ENABLED(CONFIG_ZONE_DMA32) &&
+- phys_mask < DMA_BIT_MASK(64) &&
++ phys_limit < DMA_BIT_MASK(64) &&
+ !(gfp & (GFP_DMA32 | GFP_DMA))) {
+ gfp |= GFP_DMA32;
+ goto again;
projects / openwrt / staging / luka.git / blobdiff