From patchwork Fri Mar 22 16:41:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Niklas Cassel X-Patchwork-Id: 13600314 X-Patchwork-Delegate: kw@linux.com Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6516E5D47A for ; Fri, 22 Mar 2024 16:43:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711125788; cv=none; b=b02WUWsn1crb00dzkzztPNe27VLMtEJptsg0Q5nhsr0/jECZLbd2vhTUlzzLKquFAWA/uOtwIu6/L/TVZnsBcehN0N5QnXNV4n0hKIXFinwDcHFEOdBFmOmxWksmP5JsEh+ot83N5jwoxzw4Dpcmc6IIF08+HUs1u5S67F1/vck= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711125788; c=relaxed/simple; bh=tubpWp4wm7wrlQQQADfzZHewhjqYmvkV7y62XzK5EyU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=TdjCc9U+zVQpXnHxQuTqsT5VgVwI6t9ZvCIuWv82pJRvSFSoFIyYNxMRYIKUFdggMRAL2wCPNyHerTooWUYx7naJqG3Vt1cdc7iMLgM+X6t0ZlhxtWB899ROEcLRUDnzYIaDMgqr4F29NccbMnsK9FRziz/HLLjXzkmVGfc2yOE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UcIC9pXW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UcIC9pXW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BFCF2C433F1; Fri, 22 Mar 2024 16:43:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711125787; bh=tubpWp4wm7wrlQQQADfzZHewhjqYmvkV7y62XzK5EyU=; h=From:To:Cc:Subject:Date:From; b=UcIC9pXWgWCJYLbGeg+qh3OH4m2fgY1N3dC7AzaFkhGVYTNhOGDZTCdfE7WsC1xK9 3fctB1FCK7hEWaxHWJPWmA952CSKK1/x7ecrPOJ8kVkv94bd2Dj8pLQ23w27ky/zpd jKxmFrqepB8RqF6iLoFJyNVc+VBP0gOdfE4ktL1zxeG8LT0oywxBNgzuRtujaArQTK 2GKag65Ynu9947eSo4Cu/2zMTqYrfqHamoS0GiVUtYbYqdZ4Q0FnTFp5a2TLn/6Rc1 ST5F03+SP58equDOl67OPzdP5vvxgPadr9jd3FIgODNBEql+Wr86S0yOd5KK/f2Ahe SH/lvk9JIXaXg== From: Niklas Cassel To: Manivannan Sadhasivam , =?utf-8?q?Krzy?= =?utf-8?q?sztof_Wilczy=C5=84ski?= , Kishon Vijay Abraham I , Arnd Bergmann , Greg Kroah-Hartman Cc: Kuppuswamy Sathyanarayanan , Damien Le Moal , Niklas Cassel , linux-pci@vger.kernel.org Subject: [PATCH v4] misc: pci_endpoint_test: Use memcpy_toio()/memcpy_fromio() for BAR tests Date: Fri, 22 Mar 2024 17:41:38 +0100 Message-ID: <20240322164139.678228-1-cassel@kernel.org> X-Mailer: git-send-email 2.44.0 Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The current code uses writel()/readl(), which has an implicit memory barrier for every single readl()/writel(). Additionally, reading 4 bytes at a time over the PCI bus is not really optimal, considering that this code is running in an ioctl handler. Use memcpy_toio()/memcpy_fromio() for BAR tests. Before patch with a 4MB BAR: $ time /usr/bin/pcitest -b 1 BAR1: OKAY real 0m 1.56s After patch with a 4MB BAR: $ time /usr/bin/pcitest -b 1 BAR1: OKAY real 0m 0.54s Signed-off-by: Niklas Cassel Reviewed-by: Kuppuswamy Sathyanarayanan Reviewed-by: Manivannan Sadhasivam --- Changes since v3: -Use scope-based resource management __free attribute from cleanup.h to avoid overly verbose gotos and labels for error handling. -Added a comment related to why we allocate a buffer of max 1MB. (kmalloc() default upper limit is usually 4 MB on ARM and x86.) drivers/misc/pci_endpoint_test.c | 54 +++++++++++++++++++++++++------- 1 file changed, 42 insertions(+), 12 deletions(-) diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c index 705029ad8eb5..bf64d3aff7d8 100644 --- a/drivers/misc/pci_endpoint_test.c +++ b/drivers/misc/pci_endpoint_test.c @@ -7,6 +7,7 @@ */ #include +#include #include #include #include @@ -272,31 +273,60 @@ static const u32 bar_test_pattern[] = { 0xA5A5A5A5, }; +static int pci_endpoint_test_bar_memcmp(struct pci_endpoint_test *test, + enum pci_barno barno, int offset, + void *write_buf, void *read_buf, + int size) +{ + memset(write_buf, bar_test_pattern[barno], size); + memcpy_toio(test->bar[barno] + offset, write_buf, size); + + memcpy_fromio(read_buf, test->bar[barno] + offset, size); + + return memcmp(write_buf, read_buf, size); +} + static bool pci_endpoint_test_bar(struct pci_endpoint_test *test, enum pci_barno barno) { - int j; - u32 val; - int size; + int j, bar_size, buf_size, iters, remain; + void *write_buf __free(kfree) = NULL; + void *read_buf __free(kfree) = NULL; struct pci_dev *pdev = test->pdev; if (!test->bar[barno]) return false; - size = pci_resource_len(pdev, barno); + bar_size = pci_resource_len(pdev, barno); if (barno == test->test_reg_bar) - size = 0x4; + bar_size = 0x4; - for (j = 0; j < size; j += 4) - pci_endpoint_test_bar_writel(test, barno, j, - bar_test_pattern[barno]); + /* + * Allocate a buffer of max size 1MB, and reuse that buffer while + * iterating over the whole BAR size (which might be much larger). + */ + buf_size = min(SZ_1M, bar_size); - for (j = 0; j < size; j += 4) { - val = pci_endpoint_test_bar_readl(test, barno, j); - if (val != bar_test_pattern[barno]) + write_buf = kmalloc(buf_size, GFP_KERNEL); + if (!write_buf) + return false; + + read_buf = kmalloc(buf_size, GFP_KERNEL); + if (!read_buf) + return false; + + iters = bar_size / buf_size; + for (j = 0; j < iters; j++) + if (pci_endpoint_test_bar_memcmp(test, barno, buf_size * j, + write_buf, read_buf, buf_size)) + return false; + + remain = bar_size % buf_size; + if (remain) + if (pci_endpoint_test_bar_memcmp(test, barno, buf_size * iters, + write_buf, read_buf, remain)) return false; - } return true; }