PCI: Add pci_irq_type() to query the allocated interrupt typegrafted

Add a helper that returns PCI_IRQ_MSIX, PCI_IRQ_MSI, or PCI_IRQ_INTX
based on the interrupt type the PCI core selected after
pci_alloc_irq_vectors().

Several drivers already open-code this check against pdev->msix_enabled
and pdev->msi_enabled, or even open code this helper [1].

A common helper avoids the duplication and keeps drivers from accessing
the bitfield directly (see also [2]).

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Link: https://elixir.bootlin.com/linux/v7.1/source/drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c#L196 [1]
Inspired-by: John Hubbard <jhubbard@nvidia.com>
Link: https://lore.kernel.org/all/DKKG2QM3YJYB.Z2H2B2UXJ75N@kernel.org/ [2]
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260813165234.620555-5-dakr@kernel.org
[ Add missing pci_irq_type() stub for CONFIG_PCI=n. ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

1 files changed, 120 insertions, 0 deletions

diff --git a/crypto/dh_helper.c b/crypto/dh_helper.c
new file mode 100644
index 000000000..2d4998793
--- /dev/null
+++ b/crypto/dh_helper.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2016, Intel Corporation
+ * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
+ */
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include <crypto/dh.h>
+#include <crypto/kpp.h>
+
+#define DH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 3 * sizeof(int))
+
+static inline u8 *dh_pack_data(u8 *dst, u8 *end, const void *src, size_t size)
+{
+	if (!dst || size > end - dst)
+		return NULL;
+	memcpy(dst, src, size);
+	return dst + size;
+}
+
+static inline const u8 *dh_unpack_data(void *dst, const void *src, size_t size)
+{
+	memcpy(dst, src, size);
+	return src + size;
+}
+
+static inline unsigned int dh_data_size(const struct dh *p)
+{
+	return p->key_size + p->p_size + p->g_size;
+}
+
+unsigned int crypto_dh_key_len(const struct dh *p)
+{
+	return DH_KPP_SECRET_MIN_SIZE + dh_data_size(p);
+}
+EXPORT_SYMBOL_GPL(crypto_dh_key_len);
+
+int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params)
+{
+	u8 *ptr = buf;
+	u8 * const end = ptr + len;
+	struct kpp_secret secret = {
+		.type = CRYPTO_KPP_SECRET_TYPE_DH,
+		.len = len
+	};
+
+	if (unlikely(!len))
+		return -EINVAL;
+
+	ptr = dh_pack_data(ptr, end, &secret, sizeof(secret));
+	ptr = dh_pack_data(ptr, end, &params->key_size,
+			   sizeof(params->key_size));
+	ptr = dh_pack_data(ptr, end, &params->p_size, sizeof(params->p_size));
+	ptr = dh_pack_data(ptr, end, &params->g_size, sizeof(params->g_size));
+	ptr = dh_pack_data(ptr, end, params->key, params->key_size);
+	ptr = dh_pack_data(ptr, end, params->p, params->p_size);
+	ptr = dh_pack_data(ptr, end, params->g, params->g_size);
+	if (ptr != end)
+		return -EINVAL;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(crypto_dh_encode_key);
+
+int __crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params)
+{
+	const u8 *ptr = buf;
+	struct kpp_secret secret;
+
+	if (unlikely(!buf || len < DH_KPP_SECRET_MIN_SIZE))
+		return -EINVAL;
+
+	ptr = dh_unpack_data(&secret, ptr, sizeof(secret));
+	if (secret.type != CRYPTO_KPP_SECRET_TYPE_DH)
+		return -EINVAL;
+
+	ptr = dh_unpack_data(&params->key_size, ptr, sizeof(params->key_size));
+	ptr = dh_unpack_data(&params->p_size, ptr, sizeof(params->p_size));
+	ptr = dh_unpack_data(&params->g_size, ptr, sizeof(params->g_size));
+	if (secret.len != crypto_dh_key_len(params))
+		return -EINVAL;
+
+	/* Don't allocate memory. Set pointers to data within
+	 * the given buffer
+	 */
+	params->key = (void *)ptr;
+	params->p = (void *)(ptr + params->key_size);
+	params->g = (void *)(ptr + params->key_size + params->p_size);
+
+	return 0;
+}
+
+int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params)
+{
+	int err;
+
+	err = __crypto_dh_decode_key(buf, len, params);
+	if (err)
+		return err;
+
+	/*
+	 * Don't permit the buffer for 'key' or 'g' to be larger than 'p', since
+	 * some drivers assume otherwise.
+	 */
+	if (params->key_size > params->p_size ||
+	    params->g_size > params->p_size)
+		return -EINVAL;
+
+	/*
+	 * Don't permit 'p' to be 0.  It's not a prime number, and it's subject
+	 * to corner cases such as 'mod 0' being undefined or
+	 * crypto_kpp_maxsize() returning 0.
+	 */
+	if (memchr_inv(params->p, 0, params->p_size) == NULL)
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(crypto_dh_decode_key);