From d2fd2311de909a7f4e99b4bd11a19e6b671d6a6b Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Thu, 18 Mar 2021 13:59:27 -0500 Subject: [PATCH 1/4] net: ipa: fix assumptions about DMA address size Some build time checks in ipa_table_validate_build() assume that a DMA address is 64 bits wide. That is more restrictive than it has to be. A route or filter table is 64 bits wide no matter what the size of a DMA address is on the AP. The code actually uses a pointer to __le64 to access table entries, and a fixed constant IPA_TABLE_ENTRY_SIZE to describe the size of those entries. Loosen up two checks so they still verify some requirements, but such that they do not assume the size of a DMA address is 64 bits. Signed-off-by: Alex Elder Signed-off-by: David S. Miller --- drivers/net/ipa/ipa_table.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/net/ipa/ipa_table.c b/drivers/net/ipa/ipa_table.c index 7450e27068f1..dd07fe9dd87a 100644 --- a/drivers/net/ipa/ipa_table.c +++ b/drivers/net/ipa/ipa_table.c @@ -126,13 +126,15 @@ static void ipa_table_validate_build(void) */ BUILD_BUG_ON(ARCH_DMA_MINALIGN % IPA_TABLE_ALIGN); - /* Filter and route tables contain DMA addresses that refer to - * filter or route rules. We use a fixed constant to represent - * the size of either type of table entry. Code in ipa_table_init() - * uses a pointer to __le64 to initialize table entriews. + /* Filter and route tables contain DMA addresses that refer + * to filter or route rules. But the size of a table entry + * is 64 bits regardless of what the size of an AP DMA address + * is. A fixed constant defines the size of an entry, and + * code in ipa_table_init() uses a pointer to __le64 to + * initialize tables. */ - BUILD_BUG_ON(IPA_TABLE_ENTRY_SIZE != sizeof(dma_addr_t)); - BUILD_BUG_ON(sizeof(dma_addr_t) != sizeof(__le64)); + BUILD_BUG_ON(sizeof(dma_addr_t) > IPA_TABLE_ENTRY_SIZE); + BUILD_BUG_ON(sizeof(__le64) != IPA_TABLE_ENTRY_SIZE); /* A "zero rule" is used to represent no filtering or no routing. * It is a 64-bit block of zeroed memory. Code in ipa_table_init() From 3c54b7be5d3677f37dfcd68afcc1d8e2b677a5b9 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Thu, 18 Mar 2021 13:59:28 -0500 Subject: [PATCH 2/4] net: ipa: use upper_32_bits() Use upper_32_bits() to extract the high-order 32 bits of a DMA address. This avoids doing a 32-position shift on a DMA address if it happens not to be 64 bits wide. Use lower_32_bits() to extract the low-order 32 bits (because that's what it's for). Suggested-by: Florian Fainelli Signed-off-by: Alex Elder Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/ipa/gsi.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c index 2119367b93ea..7f3e338ca7a7 100644 --- a/drivers/net/ipa/gsi.c +++ b/drivers/net/ipa/gsi.c @@ -351,7 +351,7 @@ void *gsi_ring_virt(struct gsi_ring *ring, u32 index) /* Return the 32-bit DMA address associated with a ring index */ static u32 gsi_ring_addr(struct gsi_ring *ring, u32 index) { - return (ring->addr & GENMASK(31, 0)) + index * GSI_RING_ELEMENT_SIZE; + return lower_32_bits(ring->addr) + index * GSI_RING_ELEMENT_SIZE; } /* Return the ring index of a 32-bit ring offset */ @@ -708,10 +708,9 @@ static void gsi_evt_ring_program(struct gsi *gsi, u32 evt_ring_id) * high-order 32 bits of the address of the event ring, * respectively. */ - val = evt_ring->ring.addr & GENMASK(31, 0); + val = lower_32_bits(evt_ring->ring.addr); iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_2_OFFSET(evt_ring_id)); - - val = evt_ring->ring.addr >> 32; + val = upper_32_bits(evt_ring->ring.addr); iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_3_OFFSET(evt_ring_id)); /* Enable interrupt moderation by setting the moderation delay */ @@ -816,10 +815,9 @@ static void gsi_channel_program(struct gsi_channel *channel, bool doorbell) * high-order 32 bits of the address of the channel ring, * respectively. */ - val = channel->tre_ring.addr & GENMASK(31, 0); + val = lower_32_bits(channel->tre_ring.addr); iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_2_OFFSET(channel_id)); - - val = channel->tre_ring.addr >> 32; + val = upper_32_bits(channel->tre_ring.addr); iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_3_OFFSET(channel_id)); /* Command channel gets low weighted round-robin priority */ @@ -1365,7 +1363,7 @@ static struct gsi_trans *gsi_event_trans(struct gsi_channel *channel, u32 tre_index; /* Event xfer_ptr records the TRE it's associated with */ - tre_offset = le64_to_cpu(event->xfer_ptr) & GENMASK(31, 0); + tre_offset = lower_32_bits(le64_to_cpu(event->xfer_ptr)); tre_index = gsi_ring_index(&channel->tre_ring, tre_offset); return gsi_channel_trans_mapped(channel, tre_index); From e5d4e96b44cf20330c970c3e30ea0a8c3a23feca Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Thu, 18 Mar 2021 13:59:29 -0500 Subject: [PATCH 3/4] net: ipa: fix table alignment requirement We currently have a build-time check to ensure that the minimum DMA allocation alignment satisfies the constraint that IPA filter and route tables must point to rules that are 128-byte aligned. But what's really important is that the actual allocated DMA memory has that alignment, even if the minimum is smaller than that. Remove the BUILD_BUG_ON() call checking against minimim DMA alignment and instead verify at rutime that the allocated memory is properly aligned. Signed-off-by: Alex Elder Signed-off-by: David S. Miller --- drivers/net/ipa/ipa_table.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/net/ipa/ipa_table.c b/drivers/net/ipa/ipa_table.c index dd07fe9dd87a..988f2c2886b9 100644 --- a/drivers/net/ipa/ipa_table.c +++ b/drivers/net/ipa/ipa_table.c @@ -118,14 +118,6 @@ /* Check things that can be validated at build time. */ static void ipa_table_validate_build(void) { - /* IPA hardware accesses memory 128 bytes at a time. Addresses - * referred to by entries in filter and route tables must be - * aligned on 128-byte byte boundaries. The only rule address - * ever use is the "zero rule", and it's aligned at the base - * of a coherent DMA allocation. - */ - BUILD_BUG_ON(ARCH_DMA_MINALIGN % IPA_TABLE_ALIGN); - /* Filter and route tables contain DMA addresses that refer * to filter or route rules. But the size of a table entry * is 64 bits regardless of what the size of an AP DMA address @@ -665,6 +657,18 @@ int ipa_table_init(struct ipa *ipa) if (!virt) return -ENOMEM; + /* We put the "zero rule" at the base of our table area. The IPA + * hardware requires rules to be aligned on a 128-byte boundary. + * Make sure the allocation satisfies this constraint. + */ + if (addr % IPA_TABLE_ALIGN) { + dev_err(dev, "table address %pad not %u-byte aligned\n", + &addr, IPA_TABLE_ALIGN); + dma_free_coherent(dev, size, virt, addr); + + return -ERANGE; + } + ipa->table_virt = virt; ipa->table_addr = addr; From 99e75a37bd0af8eb8a0560f48091672b1b6d9218 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Thu, 18 Mar 2021 13:59:30 -0500 Subject: [PATCH 4/4] net: ipa: relax 64-bit build requirement We currently assume the IPA driver is built only for a 64 bit kernel. When this constraint was put in place it eliminated some do_div() calls, replacing them with the "/" and "%" operators. We now only use these operations on u32 and size_t objects. In a 32-bit kernel build, size_t will be 32 bits wide, so there remains no reason to use do_div() for divide and modulo. A few recent commits also fix some code that assumes that DMA addresses are 64 bits wide. With that, we can get rid of the 64-bit build requirement. Signed-off-by: Alex Elder Signed-off-by: David S. Miller --- drivers/net/ipa/Kconfig | 2 +- drivers/net/ipa/ipa_main.c | 10 ++++++++-- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/net/ipa/Kconfig b/drivers/net/ipa/Kconfig index b68f1289b89e..90a90262e0d0 100644 --- a/drivers/net/ipa/Kconfig +++ b/drivers/net/ipa/Kconfig @@ -1,6 +1,6 @@ config QCOM_IPA tristate "Qualcomm IPA support" - depends on 64BIT && NET && QCOM_SMEM + depends on NET && QCOM_SMEM depends on ARCH_QCOM || COMPILE_TEST depends on QCOM_RPROC_COMMON || (QCOM_RPROC_COMMON=n && COMPILE_TEST) select QCOM_MDT_LOADER if ARCH_QCOM diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c index 97c1b55405cb..d354e3e65ec5 100644 --- a/drivers/net/ipa/ipa_main.c +++ b/drivers/net/ipa/ipa_main.c @@ -735,8 +735,14 @@ MODULE_DEVICE_TABLE(of, ipa_match); static void ipa_validate_build(void) { #ifdef IPA_VALIDATE - /* We assume we're working on 64-bit hardware */ - BUILD_BUG_ON(!IS_ENABLED(CONFIG_64BIT)); + /* At one time we assumed a 64-bit build, allowing some do_div() + * calls to be replaced by simple division or modulo operations. + * We currently only perform divide and modulo operations on u32, + * u16, or size_t objects, and of those only size_t has any chance + * of being a 64-bit value. (It should be guaranteed 32 bits wide + * on a 32-bit build, but there is no harm in verifying that.) + */ + BUILD_BUG_ON(!IS_ENABLED(CONFIG_64BIT) && sizeof(size_t) != 4); /* Code assumes the EE ID for the AP is 0 (zeroed structure field) */ BUILD_BUG_ON(GSI_EE_AP != 0);