Merge branch 'ipa-32bit'

Alex Elder says:

====================
net: ipa: support 32-bit targets

There is currently a configuration dependency that restricts IPA to
be supported only on 64-bit machines.  There are only a few things
that really require that, and those are fixed in this series.  The
last patch in the series removes the CONFIG_64BIT build dependency
for IPA.

Version 2 of this series uses upper_32_bits() rather than creating
a new function to extract bits out of a DMA address.  Version 3 of
uses lower_32_bits() as well.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

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

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);

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);

drivers/net/ipa/ipa_table.c

@@ -118,21 +118,15 @@
 /* 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.
+	/* 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(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.
-	 */
-	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()
@@ -663,6 +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;