fpga: m10bmc-sec: Add support for N6000

Add support for PMCI-based flash access path and N6000 sec update
support. Access to flash staging area is different for N6000 from that
of the SPI interfaced counterparts.

Introduce intel_m10bmc_flash_bulk_ops to allow interface specific
differentiations for the flash access path for sec update and make
m10bmc_sec_read/write() in sec update driver to use the new operations.
The .flash_mutex serializes read/read. Flash update (erase+write) must
use ->lock/unlock_write() to prevent reads during update (reads would
timeout on setting flash MUX as BMC will prevent it).

Create a type specific RSU status reg handler for N6000 because the
field has moved from doorbell to auth result register.

If a failure is detected while altering the flash MUX, it seems safer
to try to set it back and doesn't seem harmful. Likely there are enough
troubles in that case anyway so setting it back fails too (which is
harmless sans the small extra delay) or just confirms that the value
wasn't changed.

Co-developed-by: Tianfei zhang <tianfei.zhang@intel.com>
Signed-off-by: Tianfei zhang <tianfei.zhang@intel.com>
Co-developed-by: Russ Weight <russell.h.weight@intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230116100845.6153-12-ilpo.jarvinen@linux.intel.com

1 files changed, 239 insertions, 3 deletions

diff --git a/drivers/mfd/intel-m10-bmc-pmci.c b/drivers/mfd/intel-m10-bmc-pmci.c
index 975019f644b5..8821f1876dd6 100644
--- a/drivers/mfd/intel-m10-bmc-pmci.c
+++ b/drivers/mfd/intel-m10-bmc-pmci.c
@@ -6,16 +6,20 @@
  * Copyright (C) 2020-2023 Intel Corporation.
  */
 
+#include <linux/bitfield.h>
 #include <linux/device.h>
 #include <linux/dfl.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/intel-m10-bmc.h>
+#include <linux/minmax.h>
 #include <linux/module.h>
 #include <linux/regmap.h>
 
 struct m10bmc_pmci_device {
 	void __iomem *base;
 	struct intel_m10bmc m10bmc;
+	struct mutex flash_mutex;	/* protects flash_busy and serializes flash read/read */
+	bool flash_busy;
 };
 
 /*
@@ -114,6 +118,215 @@ static int indirect_reg_write(void *context, unsigned int reg, unsigned int val)
 	return ret2;
 }
 
+static void pmci_write_fifo(void __iomem *base, const u32 *buf, size_t count)
+{
+	while (count--)
+		writel(*buf++, base);
+}
+
+static void pmci_read_fifo(void __iomem *base, u32 *buf, size_t count)
+{
+	while (count--)
+		*buf++ = readl(base);
+}
+
+static u32 pmci_get_write_space(struct m10bmc_pmci_device *pmci)
+{
+	u32 val;
+	int ret;
+
+	ret = read_poll_timeout(readl, val,
+				FIELD_GET(M10BMC_N6000_FLASH_FIFO_SPACE, val) ==
+				M10BMC_N6000_FIFO_MAX_WORDS,
+				M10BMC_FLASH_INT_US, M10BMC_FLASH_TIMEOUT_US,
+				false, pmci->base + M10BMC_N6000_FLASH_CTRL);
+	if (ret == -ETIMEDOUT)
+		return 0;
+
+	return FIELD_GET(M10BMC_N6000_FLASH_FIFO_SPACE, val) * M10BMC_N6000_FIFO_WORD_SIZE;
+}
+
+static int pmci_flash_bulk_write(struct intel_m10bmc *m10bmc, const u8 *buf, u32 size)
+{
+	struct m10bmc_pmci_device *pmci = container_of(m10bmc, struct m10bmc_pmci_device, m10bmc);
+	u32 blk_size, offset = 0, write_count;
+
+	while (size) {
+		blk_size = min(pmci_get_write_space(pmci), size);
+		if (blk_size == 0) {
+			dev_err(m10bmc->dev, "get FIFO available size fail\n");
+			return -EIO;
+		}
+
+		if (size < M10BMC_N6000_FIFO_WORD_SIZE)
+			break;
+
+		write_count = blk_size / M10BMC_N6000_FIFO_WORD_SIZE;
+		pmci_write_fifo(pmci->base + M10BMC_N6000_FLASH_FIFO,
+				(u32 *)(buf + offset), write_count);
+
+		size -= blk_size;
+		offset += blk_size;
+	}
+
+	/* Handle remainder (less than M10BMC_N6000_FIFO_WORD_SIZE bytes) */
+	if (size) {
+		u32 tmp = 0;
+
+		memcpy(&tmp, buf + offset, size);
+		pmci_write_fifo(pmci->base + M10BMC_N6000_FLASH_FIFO, &tmp, 1);
+	}
+
+	return 0;
+}
+
+static int pmci_flash_bulk_read(struct intel_m10bmc *m10bmc, u8 *buf, u32 addr, u32 size)
+{
+	struct m10bmc_pmci_device *pmci = container_of(m10bmc, struct m10bmc_pmci_device, m10bmc);
+	u32 blk_size, offset = 0, val, full_read_count, read_count;
+	int ret;
+
+	while (size) {
+		blk_size = min_t(u32, size, M10BMC_N6000_READ_BLOCK_SIZE);
+		full_read_count = blk_size / M10BMC_N6000_FIFO_WORD_SIZE;
+
+		read_count = full_read_count;
+		if (full_read_count * M10BMC_N6000_FIFO_WORD_SIZE < blk_size)
+			read_count++;
+
+		writel(addr + offset, pmci->base + M10BMC_N6000_FLASH_ADDR);
+		writel(FIELD_PREP(M10BMC_N6000_FLASH_READ_COUNT, read_count) |
+		       M10BMC_N6000_FLASH_RD_MODE,
+		       pmci->base + M10BMC_N6000_FLASH_CTRL);
+
+		ret = readl_poll_timeout((pmci->base + M10BMC_N6000_FLASH_CTRL), val,
+					 !(val & M10BMC_N6000_FLASH_BUSY),
+					 M10BMC_FLASH_INT_US, M10BMC_FLASH_TIMEOUT_US);
+		if (ret) {
+			dev_err(m10bmc->dev, "read timed out on reading flash 0x%xn", val);
+			return ret;
+		}
+
+		pmci_read_fifo(pmci->base + M10BMC_N6000_FLASH_FIFO,
+			       (u32 *)(buf + offset), full_read_count);
+
+		size -= blk_size;
+		offset += blk_size;
+
+		if (full_read_count < read_count)
+			break;
+
+		writel(0, pmci->base + M10BMC_N6000_FLASH_CTRL);
+	}
+
+	/* Handle remainder (less than M10BMC_N6000_FIFO_WORD_SIZE bytes) */
+	if (size) {
+		u32 tmp;
+
+		pmci_read_fifo(pmci->base + M10BMC_N6000_FLASH_FIFO, &tmp, 1);
+		memcpy(buf + offset, &tmp, size);
+
+		writel(0, pmci->base + M10BMC_N6000_FLASH_CTRL);
+	}
+
+	return 0;
+}
+
+static int m10bmc_pmci_set_flash_host_mux(struct intel_m10bmc *m10bmc, bool request)
+{
+	u32 ctrl;
+	int ret;
+
+	ret = regmap_update_bits(m10bmc->regmap, M10BMC_N6000_FLASH_MUX_CTRL,
+				 M10BMC_N6000_FLASH_HOST_REQUEST,
+				 FIELD_PREP(M10BMC_N6000_FLASH_HOST_REQUEST, request));
+	if (ret)
+		return ret;
+
+	return regmap_read_poll_timeout(m10bmc->regmap,
+					M10BMC_N6000_FLASH_MUX_CTRL, ctrl,
+					request ?
+					(get_flash_mux(ctrl) == M10BMC_N6000_FLASH_MUX_HOST) :
+					(get_flash_mux(ctrl) != M10BMC_N6000_FLASH_MUX_HOST),
+					M10BMC_FLASH_INT_US, M10BMC_FLASH_TIMEOUT_US);
+}
+
+static int m10bmc_pmci_flash_read(struct intel_m10bmc *m10bmc, u8 *buf, u32 addr, u32 size)
+{
+	struct m10bmc_pmci_device *pmci = container_of(m10bmc, struct m10bmc_pmci_device, m10bmc);
+	int ret, ret2;
+
+	mutex_lock(&pmci->flash_mutex);
+	if (pmci->flash_busy) {
+		ret = -EBUSY;
+		goto unlock;
+	}
+
+	ret = m10bmc_pmci_set_flash_host_mux(m10bmc, true);
+	if (ret)
+		goto mux_fail;
+
+	ret = pmci_flash_bulk_read(m10bmc, buf, addr, size);
+
+mux_fail:
+	ret2 = m10bmc_pmci_set_flash_host_mux(m10bmc, false);
+
+unlock:
+	mutex_unlock(&pmci->flash_mutex);
+	if (ret)
+		return ret;
+	return ret2;
+}
+
+static int m10bmc_pmci_flash_write(struct intel_m10bmc *m10bmc, const u8 *buf, u32 offset, u32 size)
+{
+	struct m10bmc_pmci_device *pmci = container_of(m10bmc, struct m10bmc_pmci_device, m10bmc);
+	int ret;
+
+	mutex_lock(&pmci->flash_mutex);
+	WARN_ON_ONCE(!pmci->flash_busy);
+	/* On write, firmware manages flash MUX */
+	ret = pmci_flash_bulk_write(m10bmc, buf + offset, size);
+	mutex_unlock(&pmci->flash_mutex);
+
+	return ret;
+}
+
+static int m10bmc_pmci_flash_lock(struct intel_m10bmc *m10bmc)
+{
+	struct m10bmc_pmci_device *pmci = container_of(m10bmc, struct m10bmc_pmci_device, m10bmc);
+	int ret = 0;
+
+	mutex_lock(&pmci->flash_mutex);
+	if (pmci->flash_busy) {
+		ret = -EBUSY;
+		goto unlock;
+	}
+
+	pmci->flash_busy = true;
+
+unlock:
+	mutex_unlock(&pmci->flash_mutex);
+	return ret;
+}
+
+static void m10bmc_pmci_flash_unlock(struct intel_m10bmc *m10bmc)
+{
+	struct m10bmc_pmci_device *pmci = container_of(m10bmc, struct m10bmc_pmci_device, m10bmc);
+
+	mutex_lock(&pmci->flash_mutex);
+	WARN_ON_ONCE(!pmci->flash_busy);
+	pmci->flash_busy = false;
+	mutex_unlock(&pmci->flash_mutex);
+}
+
+static const struct intel_m10bmc_flash_bulk_ops m10bmc_pmci_flash_bulk_ops = {
+	.read = m10bmc_pmci_flash_read,
+	.write = m10bmc_pmci_flash_write,
+	.lock_write = m10bmc_pmci_flash_lock,
+	.unlock_write = m10bmc_pmci_flash_unlock,
+};
+
 static const struct regmap_range m10bmc_pmci_regmap_range[] = {
 	regmap_reg_range(M10BMC_N6000_SYS_BASE, M10BMC_N6000_SYS_END),
 };
@@ -136,6 +349,7 @@ static struct regmap_config m10bmc_pmci_regmap_config = {
 
 static struct mfd_cell m10bmc_pmci_n6000_bmc_subdevs[] = {
 	{ .name = "n6000bmc-hwmon" },
+	{ .name = "n6000bmc-sec-update" },
 };
 
 static const struct m10bmc_csr_map m10bmc_n6000_csr_map = {
@@ -169,11 +383,13 @@ static int m10bmc_pmci_probe(struct dfl_device *ddev)
 	struct device *dev = &ddev->dev;
 	struct m10bmc_pmci_device *pmci;
 	struct indirect_ctx *ctx;
+	int ret;
 
 	pmci = devm_kzalloc(dev, sizeof(*pmci), GFP_KERNEL);
 	if (!pmci)
 		return -ENOMEM;
 
+	pmci->m10bmc.flash_bulk_ops = &m10bmc_pmci_flash_bulk_ops;
 	pmci->m10bmc.dev = dev;
 
 	pmci->base = devm_ioremap_resource(dev, &ddev->mmio_res);
@@ -184,15 +400,34 @@ static int m10bmc_pmci_probe(struct dfl_device *ddev)
 	if (!ctx)
 		return -ENOMEM;
 
+	mutex_init(&pmci->flash_mutex);
+
 	ctx->base = pmci->base + M10BMC_N6000_INDIRECT_BASE;
 	ctx->dev = dev;
 	indirect_clear_cmd(ctx);
 	pmci->m10bmc.regmap = devm_regmap_init(dev, NULL, ctx, &m10bmc_pmci_regmap_config);
 
-	if (IS_ERR(pmci->m10bmc.regmap))
-		return PTR_ERR(pmci->m10bmc.regmap);
+	if (IS_ERR(pmci->m10bmc.regmap)) {
+		ret = PTR_ERR(pmci->m10bmc.regmap);
+		goto destroy_mutex;
+	}
+
+	ret = m10bmc_dev_init(&pmci->m10bmc, &m10bmc_pmci_n6000);
+	if (ret)
+		goto destroy_mutex;
+	return 0;
+
+destroy_mutex:
+	mutex_destroy(&pmci->flash_mutex);
+	return ret;
+}
+
+static void m10bmc_pmci_remove(struct dfl_device *ddev)
+{
+	struct intel_m10bmc *m10bmc = dev_get_drvdata(&ddev->dev);
+	struct m10bmc_pmci_device *pmci = container_of(m10bmc, struct m10bmc_pmci_device, m10bmc);
 
-	return m10bmc_dev_init(&pmci->m10bmc, &m10bmc_pmci_n6000);
+	mutex_destroy(&pmci->flash_mutex);
 }
 
 #define FME_FEATURE_ID_M10BMC_PMCI	0x12
@@ -210,6 +445,7 @@ static struct dfl_driver m10bmc_pmci_driver = {
 	},
 	.id_table = m10bmc_pmci_ids,
 	.probe    = m10bmc_pmci_probe,
+	.remove   = m10bmc_pmci_remove,
 };
 
 module_dfl_driver(m10bmc_pmci_driver);