cxl: Export AFU error buffer via sysfs (e36f6fe1) · Commits · 戴 / test

Documentation/ABI/testing/sysfs-class-cxl

+11 −0

Original line number	Diff line number	Diff line
		@@ -6,6 +6,17 @@ Example: The real path of the attribute /sys/class/cxl/afu0.0s/irqs_max is

		Slave contexts (eg. /sys/class/cxl/afu0.0s):

		What: /sys/class/cxl/<afu>/afu_err_buf
		Date: September 2014
		Contact: linuxppc-dev@lists.ozlabs.org
		Description: read only
		AFU Error Buffer contents. The contents of this file are
		application specific and depends on the AFU being used.
		Applications interacting with the AFU can use this attribute
		to know about the current error condition and take appropriate
		action like logging the event etc.


		What: /sys/class/cxl/<afu>/irqs_max
		Date: September 2014
		Contact: linuxppc-dev@lists.ozlabs.org

drivers/misc/cxl/cxl.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -360,6 +360,10 @@ struct cxl_afu {
		struct mutex spa_mutex;
		spinlock_t afu_cntl_lock;

		/* AFU error buffer fields and bin attribute for sysfs */
		u64 eb_len, eb_offset;
		struct bin_attribute attr_eb;

		/*
		* Only the first part of the SPA is used for the process element
		* linked list. The only other part that software needs to worry about
		@@ -561,6 +565,9 @@ static inline void __iomem _cxl_p2n_addr(struct cxl_afu afu, cxl_p2n_reg_t reg
		u16 cxl_afu_cr_read16(struct cxl_afu *afu, int cr, u64 off);
		u8 cxl_afu_cr_read8(struct cxl_afu *afu, int cr, u64 off);

		ssize_t cxl_afu_read_err_buffer(struct cxl_afu afu, char buf,
		loff_t off, size_t count);


		struct cxl_calls {
		void (cxl_slbia)(struct mm_struct mm);

drivers/misc/cxl/pci.c

+60 −0

Original line number	Diff line number	Diff line
		@@ -593,6 +593,22 @@ static int cxl_read_afu_descriptor(struct cxl_afu *afu)
		afu->crs_len = AFUD_CR_LEN(val) * 256;
		afu->crs_offset = AFUD_READ_CR_OFF(afu);


		/* eb_len is in multiple of 4K */
		afu->eb_len = AFUD_EB_LEN(AFUD_READ_EB(afu)) * 4096;
		afu->eb_offset = AFUD_READ_EB_OFF(afu);

		/* eb_off is 4K aligned so lower 12 bits are always zero */
		if (EXTRACT_PPC_BITS(afu->eb_offset, 0, 11) != 0) {
		dev_warn(&afu->dev,
		"Invalid AFU error buffer offset %Lx\n",
		afu->eb_offset);
		dev_info(&afu->dev,
		"Ignoring AFU error buffer in the descriptor\n");
		/* indicate that no afu buffer exists */
		afu->eb_len = 0;
		}

		return 0;
		}

		@@ -672,6 +688,50 @@ static int sanitise_afu_regs(struct cxl_afu *afu)
		return 0;
		}

		#define ERR_BUFF_MAX_COPY_SIZE PAGE_SIZE
		/*
		* afu_eb_read:
		* Called from sysfs and reads the afu error info buffer. The h/w only supports
		* 4/8 bytes aligned access. So in case the requested offset/count arent 8 byte
		* aligned the function uses a bounce buffer which can be max PAGE_SIZE.
		*/
		ssize_t cxl_afu_read_err_buffer(struct cxl_afu afu, char buf,
		loff_t off, size_t count)
		{
		loff_t aligned_start, aligned_end;
		size_t aligned_length;
		void *tbuf;
		const void __iomem *ebuf = afu->afu_desc_mmio + afu->eb_offset;

		if (count == 0 \|\| off < 0 \|\| (size_t)off >= afu->eb_len)
		return 0;

		/* calculate aligned read window */
		count = min((size_t)(afu->eb_len - off), count);
		aligned_start = round_down(off, 8);
		aligned_end = round_up(off + count, 8);
		aligned_length = aligned_end - aligned_start;

		/* max we can copy in one read is PAGE_SIZE */
		if (aligned_length > ERR_BUFF_MAX_COPY_SIZE) {
		aligned_length = ERR_BUFF_MAX_COPY_SIZE;
		count = ERR_BUFF_MAX_COPY_SIZE - (off & 0x7);
		}

		/* use bounce buffer for copy */
		tbuf = (void *)__get_free_page(GFP_TEMPORARY);
		if (!tbuf)
		return -ENOMEM;

		/* perform aligned read from the mmio region */
		memcpy_fromio(tbuf, ebuf + aligned_start, aligned_length);
		memcpy(buf, tbuf + (off & 0x7), count);

		free_page((unsigned long)tbuf);

		return count;
		}

		static int cxl_init_afu(struct cxl adapter, int slice, struct pci_dev dev)
		{
		struct cxl_afu *afu;

drivers/misc/cxl/sysfs.c

+33 −0

Original line number	Diff line number	Diff line
		@@ -356,6 +356,16 @@ static ssize_t api_version_compatible_show(struct device *device,
		return scnprintf(buf, PAGE_SIZE, "%i\n", CXL_API_VERSION_COMPATIBLE);
		}

		static ssize_t afu_eb_read(struct file filp, struct kobject kobj,
		struct bin_attribute bin_attr, char buf,
		loff_t off, size_t count)
		{
		struct cxl_afu *afu = to_cxl_afu(container_of(kobj,
		struct device, kobj));

		return cxl_afu_read_err_buffer(afu, buf, off, count);
		}

		static struct device_attribute afu_attrs[] = {
		__ATTR_RO(mmio_size),
		__ATTR_RO(irqs_min),
		@@ -534,6 +544,10 @@ void cxl_sysfs_afu_remove(struct cxl_afu *afu)
		struct afu_config_record cr, tmp;
		int i;

		/* remove the err buffer bin attribute */
		if (afu->eb_len)
		device_remove_bin_file(&afu->dev, &afu->attr_eb);

		for (i = 0; i < ARRAY_SIZE(afu_attrs); i++)
		device_remove_file(&afu->dev, &afu_attrs[i]);

		@@ -555,6 +569,22 @@ int cxl_sysfs_afu_add(struct cxl_afu *afu)
		goto err;
		}

		/* conditionally create the add the binary file for error info buffer */
		if (afu->eb_len) {
		afu->attr_eb.attr.name = "afu_err_buff";
		afu->attr_eb.attr.mode = S_IRUGO;
		afu->attr_eb.size = afu->eb_len;
		afu->attr_eb.read = afu_eb_read;

		rc = device_create_bin_file(&afu->dev, &afu->attr_eb);
		if (rc) {
		dev_err(&afu->dev,
		"Unable to create eb attr for the afu. Err(%d)\n",
		rc);
		goto err;
		}
		}

		for (i = 0; i < afu->crs_num; i++) {
		cr = cxl_sysfs_afu_new_cr(afu, i);
		if (IS_ERR(cr)) {
		@@ -570,6 +600,9 @@ err1:
		cxl_sysfs_afu_remove(afu);
		return rc;
		err:
		/* reset the eb_len as we havent created the bin attr */
		afu->eb_len = 0;

		for (i--; i >= 0; i--)
		device_remove_file(&afu->dev, &afu_attrs[i]);
		return rc;

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